A surfactant composition, a silicon carbide wafer cleaning agent, a silicon carbide wafer and a cleaning method, a device and an apparatus thereof

Abstract

The application discloses a surfactant composition, a silicon carbide wafer cleaning agent, a silicon carbide wafer and a cleaning method, a device and equipment thereof, and belongs to the field of silicon carbide wafers, wherein the surfactant composition comprises: a) an alcohol amine compound; b) a polyethylene imine; and c) at least one fatty alcohol polyoxyethylene ether surfactant with a general formula of CH3(CH2)nO(CH2CH2O)mH. The alcohol amine compound, the polyethylene imine and the fatty alcohol polyoxyethylene ether surfactant are selected and used in combination, so that the critical micelle concentration value of the surfactant is significantly reduced, and the wetting performance of the surfactant on the surface of the silicon carbide wafer is enhanced. On this basis, the application further provides a silicon carbide wafer cleaning agent, which has the characteristics of high removal rate of pollutants such as surface particles and metal ions on the silicon carbide wafer, short cleaning time and high yield, etc.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of silicon carbide wafers, and particularly relates to a surfactant composition, a silicon carbide wafer cleaning agent, a silicon carbide wafer and a cleaning method, a device and an apparatus thereof. BACKGROUND

[0002] With the rapid development of semiconductor technology, silicon carbide (SiC) has shown great application potential in many fields such as power electronics, radio frequency communication, new energy vehicles, etc. due to its excellent physical and chemical properties such as high breakdown electric field, high thermal conductivity, high electron saturation drift speed, etc. The surface quality of a silicon carbide wafer, as a basic material for manufacturing silicon carbide devices, is directly related to the performance and reliability of subsequent devices. Therefore, high-quality cleaning of the silicon carbide wafer is a crucial link in the semiconductor manufacturing process.

[0003] The surfactant is an important component in the silicon carbide wafer cleaning agent. However, the existing surfactant has problems such as too large critical micelle concentration value and poor wetting performance on the surface of the silicon carbide wafer, which reduces the cleaning effect of the silicon carbide wafer cleaning agent and makes it difficult to meet the stringent requirements for cleaning the silicon carbide wafer. SUMMARY

[0004] The present application aims to at least partially solve one of the technical problems in the related art. To this end, the present application proposes a surfactant composition, a silicon carbide wafer cleaning agent, a silicon carbide wafer and a cleaning method, a device and an apparatus thereof. By selecting an alcohol amine compound, polyethylene imine and a fatty alcohol polyoxyethylene ether surfactant for use, the present application not only significantly reduces the critical micelle concentration value of the surfactant, but also enhances the wetting performance of the surfactant on the surface of the silicon carbide wafer. On this basis, the present application further provides a silicon carbide wafer cleaning agent, which has high removal rate of contaminants such as surface particles and metal ions on the silicon carbide wafer, and has the characteristics of short cleaning time and high yield.

[0005] The present application proposes a surfactant composition in the first aspect. According to an embodiment of the present application, the surfactant composition comprises:

[0006] a) an alcohol amine compound; and

[0007] b) polyethylene imine; and

[0008] c) at least one fatty alcohol polyoxyethylene ether surfactant with a general formula of ; wherein R is an alkyl group, and n is any natural number selected from 7-10.

[0009] The surfactant composition of the above embodiments of the present application, by innovatively selecting alcohol amine compounds, polyethyleneimine and fatty alcohol polyoxyethylene ether surfactants (n is 7-10) for use, not only significantly reduces the critical micelle concentration value of the surfactant, but also enhances the wetting performance of the surfactant on the silicon carbide wafer surface.

[0010] In addition, the surfactant composition according to the above embodiments of the present application can also have the following additional technical features:

[0011] In some embodiments of the present application, in the surfactant composition, the weight percentage of the alcohol amine compound is 4%-84%;

[0012] And / or, the weight percentage of the polyethyleneimine is 8-48%;

[0013] And / or, the weight percentage of the fatty alcohol polyoxyethylene ether is 8-48%.

[0014] In some embodiments of the present application, in the surfactant composition, the weight percentage of the alcohol amine compound is 27-43%;

[0015] And / or, the weight percentage of the polyethyleneimine is 16-34%;

[0016] And / or, the weight percentage of the fatty alcohol polyoxyethylene ether is 33-46%.

[0017] In some embodiments of the present application, the number average molecular weight of the polyethyleneimine is 600g / mol-5000g / mol;

[0018] And / or, the amino content in the polyethyleneimine is ≥30% by mass fraction;

[0019] And / or, the alkyl group is an alkyl group with 7-9 carbon atoms or an alkyl group with 12-18 carbon atoms.

[0020] In some embodiments of the present application, the alcohol amine compound includes at least one of monoethanolamine, diethanolamine, triethanolamine, n-propyl alcohol amine, dipropyl alcohol amine and diisopropyl alcohol amine;

[0021] And / or, the fatty alcohol polyoxyethylene ether surfactant includes at least one of fatty alcohol polyoxyethylene ether-7, fatty alcohol polyoxyethylene ether-8, fatty alcohol polyoxyethylene ether-9 and fatty alcohol polyoxyethylene ether-10.

[0022] In some embodiments of the present application, the critical micelle concentration value of the surfactant composition is 0.009 g / L-0.048 g / L;

[0023] And / or, the contact angle of the aqueous solution of the surfactant composition on the surface of the silicon carbide wafer is ≤20°, and the mass fraction of the surfactant composition in the aqueous solution is 10%-20%.

[0024] The second aspect of the present application provides a silicon carbide wafer cleaning agent. According to an embodiment of the present application, the silicon carbide wafer cleaning agent comprises the surfactant composition described in the first aspect.

[0025] The silicon carbide wafer cleaning agent of the above-mentioned embodiments of the present application comprises the surfactant composition described in the first aspect. Thus, the silicon carbide wafer cleaning agent has good wetting effect on the surface of the silicon carbide wafer, which is conducive to improving the cleaning effect of the silicon carbide wafer cleaning agent.

[0026] In addition, the silicon carbide wafer cleaning agent according to the above-mentioned embodiments of the present application can also have the following additional technical features:

[0027] In some embodiments of the present application, the silicon carbide wafer cleaning agent comprises, in parts by weight:

[0028] The surfactant composition is 4-20 parts, the chelating agent is 1-5 parts, the organic base is 1-5 parts, and the solvent is 70-90 parts.

[0029] In some embodiments of the present application, the silicon carbide wafer cleaning agent comprises, in parts by weight:

[0030] The surfactant composition is 9-15 parts, the chelating agent is 1-5 parts, the organic base is 1-5 parts, the stabilizer is 0.2-2 parts, the dispersing scale inhibitor is 0.2-2 parts, and the solvent is 70-90 parts.

[0031] In some embodiments of the present application, the silicon carbide wafer cleaning agent comprises, in parts by weight:

[0032] The surfactant composition is 9-15 parts, the chelating agent is 1-2 parts, the organic base is 2-4 parts, the stabilizer is 0.5-1 part, the dispersing scale inhibitor is 0.5-1 part, and the solvent is 70-83 parts.

[0033] In some embodiments of the present application, the chelating agent comprises at least one of ethylenediaminetetraacetic acid, hydroxyethyl ethylenediaminetetraacetic acid, and hydroxyethyl ethylenediaminetetraacetic acid ammonium;

[0034] And / or, the organic base comprises at least one of ethylenediamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, trimethylethylammonium hydroxide, dimethyldiethylammonium hydroxide, and (2-hydroxyethyl) trimethylammonium hydroxide;

[0035] And / or, the stabilizer comprises at least one of polyvinyl alcohol and polyethylene glycol;

[0036] and / or the dispersant scale inhibitor comprises hydroxyethyl cellulose;

[0037] and / or the solvent comprises water.

[0038] In some embodiments of the present application, the removal rate of the silicon carbide wafer cleaning agent on the surface particle contaminants of the silicon carbide wafer is ≥80%.

[0039] A third aspect of the present application provides a cleaning method of a silicon carbide wafer. According to embodiments of the present application, the cleaning agent used in the cleaning method comprises the silicon carbide wafer cleaning agent described in the second aspect.

[0040] The cleaning method of the silicon carbide wafer of the above-mentioned embodiments of the present application. This method uses the silicon carbide wafer cleaning agent described in the second aspect as a cleaning agent. Therefore, the cleaning method has a high removal rate on the contaminants such as surface particles, metal ions, etc. of the silicon carbide wafer, and has the characteristics of short cleaning time and high yield.

[0041] In addition, the cleaning method of the silicon carbide wafer according to the above-mentioned embodiments of the present application can also have the following additional technical features:

[0042] In some embodiments of the present application, the cleaning method comprises the following steps:

[0043] The silicon carbide wafer to be cleaned is added to a solution containing the silicon carbide wafer cleaning agent for ultrasonic cleaning to obtain a cleaned silicon carbide wafer.

[0044] In some embodiments of the present application, the temperature of the ultrasonic cleaning is 50-70°C;

[0045] and / or the ultrasonic cleaning time is 10-30 minutes;

[0046] and / or the ultrasonic cleaning ultrasonic frequency is 40-120 kHz.

[0047] In some embodiments of the present application, the cleaning method further comprises diluting the silicon carbide wafer cleaning agent by 5-20 times to obtain the solution containing the silicon carbide wafer cleaning agent.

[0048] In some embodiments of the present application, the silicon carbide wafer to be cleaned is added to a solution containing the silicon carbide wafer cleaning agent for ultrasonic cleaning to obtain a first treated silicon carbide wafer, and the cleaning method further comprises rinsing and drying the first treated silicon carbide wafer.

[0049] In some embodiments of the present application, the first treated silicon carbide wafer is subjected to a rinsing process to obtain a second treated silicon carbide wafer, and the rinsing process comprises at least one of pure water rinsing and megasonic rinsing.

[0050] In some embodiments of the present application, the drying process comprises the following steps:

[0051] In a first protective gas atmosphere, the second treated silicon carbide wafer is subjected to spin-drying to obtain a third treated silicon carbide wafer;

[0052] In a second protective gas atmosphere, the third treated silicon carbide wafer is subjected to drying to obtain the cleaned silicon carbide wafer.

[0053] A fourth aspect of the present application provides a silicon carbide wafer. According to embodiments of the present application, the silicon carbide wafer is cleaned by the cleaning method of the third aspect. Thus, the silicon carbide wafer has a low content of surface particles, metal ions, etc., and can meet the stringent requirements of device manufacturing such as semiconductors.

[0054] In addition, the silicon carbide wafer according to the above embodiments of the present application can have the following additional technical features:

[0055] In some embodiments of the present application, the number of particles on the surface of the silicon carbide wafer is <10 / cm 2 , the particle size of the particles is ≤0.2 μm;

[0056] and / or, the number of metal sodium ions on the surface of the silicon carbide wafer is ≤8.66E+10 / cm 2 ;

[0057] and / or, the number of metal potassium ions on the surface of the silicon carbide wafer is ≤9.67E+10 / cm 2 ;

[0058] and / or, the number of metal aluminum ions on the surface of the silicon carbide wafer is ≤1.19E+10 / cm 2 .

[0059] A fifth aspect of the present application provides a device comprising the silicon carbide wafer of the fourth aspect. Thus, the device of the above embodiments of the present application has a significant performance improvement in response speed, service life, etc.

[0060] In addition, the device according to the above embodiments of the present application can have the following additional technical features:

[0061] In some embodiments of the present application, the device comprises at least one of a semiconductor device and a heating device.

[0062] The sixth aspect of the present application provides a device. According to embodiments of the present application, the device comprises the silicon carbide wafer of the fourth aspect or the device of the fifth aspect. Thus, the features and advantages described above for the device also apply to the device, which will not be repeated here.

[0063] In addition, the device according to the above-mentioned embodiments of the present application can also have the following additional technical features:

[0064] In some embodiments of the present application, the device comprises at least one of an electronic device, a communication device, an energy device and a medical device.

[0065] Additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0066] The above-mentioned and / or additional aspects and advantages of the present application will become apparent and be readily appreciated from the following description, including the appended drawings, wherein:

[0067] Figure 1 The macroscopic appearance of the silicon carbide wafer after cleaning for Example 16 is shown in the figure.

[0068] Figure 2 The macroscopic appearance of the silicon carbide wafer after cleaning for Comparative Example 5 is shown in the figure. DETAILED DESCRIPTION

[0069] The embodiments of the present application are described in detail below with reference to the accompanying drawings, wherein the same or similar components are denoted by the same or similar reference numerals throughout. The embodiments described below are exemplary and are intended to explain the present application, and should not be understood as limiting the present application.

[0070] The first aspect of the present application provides a surfactant composition. According to embodiments of the present application, the surfactant composition comprises:

[0071] a) an alcohol amine compound; and

[0072] b) a polyethyleneimine; and

[0073] c) at least one fatty alcohol polyoxyethylene ether surfactant of the general formula: wherein R is an alkyl group, and n is any natural number selected from 7-10.

[0074] The surfactant composition of the above embodiments of the present application is prepared by innovatively selecting alcohol amine compounds, polyethylene imine and fatty alcohol polyoxyethylene ether surfactants (n is 7-10) for use in combination, which not only significantly reduces the critical micelle concentration value of the surfactant, but also enhances the wetting performance of the surfactant on the surface of silicon carbide wafers. Specifically:

[0075] The alcohol amine compounds contain hydroxyl groups and the like which interact with solvent molecules through hydrogen bonds. Such hydrogen bond interaction not only enhances the water solubility of the alcohol amine compounds, but also further enables the fatty alcohol polyoxyethylene ether surfactants to be more easily dispersed in the solution by forming hydrogen bonds, thereby reducing the concentration required for micelle formation. In addition, the weak alkalinity of the alcohol amine compounds can maintain the pH value of the system stable to a certain extent, thereby maintaining the stability of the micelles. The primary amine, secondary amine and tertiary amine groups in the molecular chain of the polyethylene imine are suitable for being combined with the fatty alcohol polyoxyethylene ether and ethanol amine molecules through hydrogen bonds and electrostatic interactions, which can promote the adsorption of the surfactant on the hydrophobic surface, reduce the Gibbs adsorption energy, and be conducive to promoting the formation of mixed micelles and enhancing the wetting performance of the system on the surface of silicon carbide wafers. The fatty alcohol polyoxyethylene ether includes a hydrophobic fatty alcohol chain and a hydrophilic polyoxyethylene chain. Such amphiphilic structure enables it to form a directional arrangement on the liquid surface (the hydrophobic part faces the air, and the hydrophilic part faces the water), reduces the contact area between water molecules and air and the interaction force between water molecules, thereby enhancing the wetting effect of the system on the dirt on the surface of silicon carbide wafers.

[0076] In the embodiments of the present application, the above-mentioned alcohol amine compounds are compounds containing at least one hydroxyl group and at least one amine group (such as primary amine, secondary amine and tertiary amine), such as monoethanolamine (MEA), diethanolamine (DEA), triethanolamine (TEA), N-methyldiethanolamine (MDEA) and the like.

[0077] In the embodiments of the present application, the above-mentioned polyethylene imine is a water-soluble polymer formed by ring-opening polymerization of ethylene imine units, and contains a large number of primary amine, secondary amine and tertiary amine in the molecular chain.

[0078] In the embodiments of the present application, the above-mentioned fatty alcohol polyoxyethylene ether surfactant is a non-ionic surfactant formed by addition polymerization of fatty alcohol (R-OH, R can be C8-C18 alkyl) and ethylene oxide (EO), and the molecular structure can be represented as wherein R is an alkyl group, such as an alkyl group with a carbon atom number of 7-9 or an alkyl group with a carbon atom number of 12-18, etc.; n is a polyoxyethylene chain The number of repeating units of the alcohol amine compound, for example, can be 7, 8, 9, 10, and n is preferably 6-9; meanwhile, if n is too small (for example, n is 3), the polyoxyethylene chain is too short, which will also significantly reduce the effect of the surfactant composition.

[0079] According to some specific embodiments of the present application, the weight percentage of the alcohol amine compound in the surfactant composition is 4%-84%, for example, can be 4%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 84%, etc., and is preferably 27-43%;

[0080] And / or, the weight percentage of the polyethyleneimine is 8-48%, for example, can be 10%, 20%, 30%, 40%, 48%, etc., and is preferably 16-34%;

[0081] And / or, the weight percentage of the fatty alcohol polyoxyethylene ether is 8-48% by weight, for example, can be 10%, 20%, 30%, 40%, 48%, etc., and is preferably 33-46%.

[0082] The inventors have found that by limiting the use amount of the alcohol amine compound, the polyethyleneimine, and the fatty alcohol polyoxyethylene ether surfactant within the above ranges, the obtained surfactant composition not only has a lower critical micelle concentration value but also has better wetting performance on the surface of the silicon carbide wafer.

[0083] According to still some specific embodiments of the present application, the number average molecular weight of the polyethyleneimine is 600-5000 g / mol, for example, can be 800 g / mol, 900 g / mol, 1000 g / mol, 1500 g / mol, 1800 g / mol, 2000 g / mol, 3000 g / mol, 4000 g / mol, 5000 g / mol, etc.; and / or, the amino content in the polyethyleneimine is ≥30% by mass fraction, for example, can be 30%, 40%, 50%, 60%, 70%, etc.; and / or, the alkyl group is an alkyl group with 7-9 carbon atoms or an alkyl group with 12-18 carbon atoms. The inventors have found that by selecting a polyethyleneimine with a suitable number average molecular weight and amino content, the cleaning effect of the cleaning agent can be enhanced. In addition, the number average molecular weight of the polyethyleneimine can be determined by using existing detection methods such as gel permeation chromatography (separation by molecular size, combined with standard curve to calculate molecular weight); meanwhile, the amino content in the polyethyleneimine can be determined by using existing detection methods such as chemical titration method (utilizing the alkalinity of the amino group, determining its content by acid-base neutralization reaction), ultraviolet spectrophotometry (utilizing the characteristic absorption peak of the amino group in the polyethyleneimine at a specific wavelength (such as 235 nm), comparing the absorbance with the standard curve for quantitative determination).

[0084] According to still some embodiments of the present application, the alcohol amine compound includes at least one of monoethanolamine, diethanolamine, triethanolamine, n-propanolamine, dipropanolamine and diisopropanolamine, preferably diethanolamine or monoethanolamine;

[0085] And / or, the fatty alcohol polyoxyethylene ether surfactant includes at least one of fatty alcohol polyoxyethylene ether-7, fatty alcohol polyoxyethylene ether-8, fatty alcohol polyoxyethylene ether-9 and fatty alcohol polyoxyethylene ether-10, preferably fatty alcohol polyoxyethylene ether-9.

[0086] According to still some embodiments of the present application, the critical micelle concentration of the surfactant composition is 0.009 g / L-0.048 g / L, for example, can be 0.009 g / L, 0.012 g / L, 0.016 g / L, etc.; and / or, the contact angle of the aqueous solution of the surfactant composition on the surface of the silicon carbide wafer is ≤20°, for example, can be 10°, 12°, 15°, etc.; the mass fraction of the surfactant composition in the aqueous solution is 10%-20%, such as 11%, 12%, 15%, etc. It can be seen that the surfactant composition provided by the present application has the characteristics of low critical micelle concentration and good wetting performance on the surface of the silicon carbide wafer.

[0087] It should be noted that the critical micelle concentration (Critical Micelle Concentration, abbreviated as CMC) refers to the minimum concentration required for the surfactant composition to form micelles in the solution. Below CMC, the surfactant composition molecules are dispersed in the solution in monomer form; when the concentration reaches the critical micelle concentration, the surfactant composition molecules will spontaneously aggregate to form micelles (for example, the hydrophilic head faces outward, and the hydrophobic tail faces inward), thereby significantly changing the physical and chemical properties of the solution (such as reducing the surface tension, increasing the solubility, etc.). In addition, the test method of the critical micelle concentration is: the surface tension γ of a series of solutions with different concentrations is determined, the γ-lgc curve is drawn, the straight line part of the turning point of the curve is extrapolated, and the intersection point is the critical micelle concentration of the surfactant in this system. The contact angle of the surfactant composition on the surface of the silicon carbide wafer can be determined by using existing detection methods such as sessile drop method (dropping liquid on the solid surface, capturing the liquid drop profile by optical system (such as microscope or camera), and calculating the contact angle by using Young's equation), pendant drop method (suspension of liquid on the solid surface, analysis of contact angle by liquid drop shape), etc.

[0088] The second aspect of the present application provides a silicon carbide wafer cleaning agent. According to embodiments of the present application, the silicon carbide wafer cleaning agent includes the surfactant composition described in the first aspect.

[0089] The silicon carbide wafer cleaning agent of the above-mentioned embodiments of the present application comprises the surfactant composition described in the first aspect. Thus, the silicon carbide wafer cleaning agent has good wetting effect on the surface of the silicon carbide wafer, which is conducive to improving the cleaning effect of the silicon carbide wafer cleaning agent.

[0090] According to still some specific embodiments of the present application, the silicon carbide wafer cleaning agent comprises, in parts by weight:

[0091] The surfactant composition is 4-20 parts, the chelating agent is 1-5 parts, the organic base is 1-5 parts, and the solvent is 70-90 parts.

[0092] On the basis of the surfactant provided in the above-mentioned first aspect, the inventors have further found that the existing silicon carbide wafer cleaning agent also has problems such as metal ion contamination risk, too long cleaning time (such as more than 2 hours), and low yield rate in the cleaning of silicon carbide wafer. Based on this, the present application further introduces a chelating agent and an organic base. The chelating agent such as ethylenediaminetetraacetic acid (EDTA) can form a stable complex with metal ions and keep the metal ions in a dissolved state in the solution, preventing these ions from re-depositing on the surface of the silicon carbide wafer during the cleaning process, thereby improving the thoroughness of cleaning. The organic base such as tetramethylammonium hydroxide has strong alkalinity, good solubility, and certain surface activity, mainly providing sufficient alkaline environment for the system to improve the ability to remove the oxide layer on the surface of the silicon carbide wafer. At the same time, the strong alkaline environment can inhibit the protonation of polyethyleneimine (PEI), and the deprotonated polyethyleneimine molecules have higher hydrophilicity, enhanced surface activity, and reduced electrostatic interference between polyethyleneimine and other charged substances in the solution, thereby achieving simultaneous improvement of the cleaning effect of silicon carbide, significant reduction of the cleaning time, and improvement of the cleaning efficiency.

[0093] According to still some specific embodiments of the present application, the silicon carbide wafer cleaning agent comprises, in parts by weight:

[0094] The surfactant composition is 9-15 parts, the chelating agent is 1-5 parts, the organic base is 1-5 parts, the stabilizer is 0.2-2 parts, the dispersant scale inhibitor is 0.2-2 parts, and the solvent is 70-90 parts.

[0095] On the basis of the above-mentioned silicon carbide wafer cleaning agent system (i.e. the surfactant composition, the organic base, and the chelating agent complex system), the inventors have further found that further adding a small amount of stabilizer and dispersant scale inhibitor can improve the overall stability of the cleaning agent and avoid re-contaminating the surface of the cleaned silicon carbide wafer, which can further improve the cleaning effect of the silicon carbide wafer cleaning agent on the silicon carbide wafer.

[0096] In the embodiments of the present application, the parts by weight of the above-mentioned surfactant composition can be 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, etc.

[0097] In the embodiments of the present application, the weight fraction of the chelating agent can be 1 part, 2 parts, 3 parts, 4 parts, 5 parts, etc.

[0098] In the embodiments of the present application, the weight fraction of the organic base can be 1 part, 2 parts, 3 parts, 4 parts, 5 parts, etc.

[0099] In the embodiments of the present application, the weight fraction of the stabilizer can be 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1.0 parts, 1.1 parts, 1.2 parts, 1.3 parts, 1.4 parts, 1.5 parts, 1.6 parts, 1.7 parts, 1.8 parts, 1.9 parts, 2.0 parts, etc.

[0100] In the embodiments of the present application, the weight fraction of the dispersant antifouling agent can be 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1.0 parts, 1.1 parts, 1.2 parts, 1.3 parts, 1.4 parts, 1.5 parts, 1.6 parts, 1.7 parts, 1.8 parts, 1.9 parts, 2.0 parts, etc.

[0101] In the embodiments of the present application, the weight fraction of the solvent can be 70 parts, 71 parts, 72 parts, 73 parts, 74 parts, 75 parts, 76 parts, 77 parts, 78 parts, 79 parts, 80 parts, 81 parts, 82 parts, 83 parts, 84 parts, 85 parts, 86 parts, 87 parts, 88 parts, 89 parts, 90 parts, etc.

[0102] According to some specific embodiments of the present application, the silicon carbide wafer cleaning agent includes, in terms of weight fraction, 9-15 parts of the surfactant composition, 1-2 parts of the chelating agent, 2-4 parts of the organic base, 0.5-1 part of the stabilizer, 0.5-1 part of the dispersant antifouling agent, and 70-83 parts of the solvent. The inventors have found through further screening of the amount that the cleaning effect is better when the components in the silicon carbide wafer cleaning agent are limited to the above ranges.

[0103] According to some specific embodiments of the present application, the chelating agent includes at least one of ethylenediaminetetraacetic acid, hydroxyethylethylenediaminetetraacetic acid, and hydroxyethylethylenediaminetetraacetic acid ammonium;

[0104] And / or, the organic base includes at least one of ethylenediamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, trimethylethylammonium hydroxide, dimethyldiethylammonium hydroxide, and (2-hydroxyethyl)trimethylammonium hydroxide;

[0105] And / or, the stabilizer includes at least one of polyvinyl alcohol and polyethylene glycol, preferably polyvinyl alcohol, which is advantageous to improve the uniform stability of the entire material system of the silicon carbide wafer cleaning agent;

[0106] and / or, the dispersing scale inhibitor comprises hydroxyethyl cellulose; the above hydroxyethyl cellulose (HEC) enhances the dispersion capacity of the system and improves the cleaning effect mainly through hydroxyl-hydroxyl, hydroxyl-metal ion hydrogen bond and steric hindrance;

[0107] and / or, the solvent comprises water.

[0108] In the embodiments of the present application, the components in the above-mentioned silicon carbide wafer cleaning agent synergize with each other, so that the entire cleaning agent system has excellent wetting, spreading, wetting, emulsifying and solubilizing effects on the dirt on the surface of the silicon carbide wafer material. Specifically:

[0109] Ethylene diamine tetraacetic acid and the like are used as chelating agents, aiming to complex the metal ions in the solution to achieve the purpose of removing the metal ions adsorbed on the surface of the silicon carbide wafer. The addition of organic bases such as tetramethylammonium hydroxide can adjust the pH of the cleaning agent system, enhance the solubility and complexing ability of the chelating agent such as ethylene diamine tetraacetic acid, and at the same time, the alkaline environment can inhibit the protonation of polyethyleneimine (PEI) in the surfactant composition. The deprotonated PEI molecules have higher hydrophilicity, the surface activity is enhanced, and the electrostatic interference between PEI and other charged substances in the solution is reduced, thereby improving the overall stability of the cleaning agent. The addition of the surfactant composition composed of alcohol amine compounds, polyethyleneimine and fatty alcohol polyoxyethylene ether can synergistically achieve sufficient wetting and wrapping of the surface of the silicon carbide wafer. Among them, polyethyleneimine has high adsorbability and reactivity, and performs well in removing organic dirt; at the same time, polyethyleneimine in the cleaning agent can promote the adsorption of the surfactant on the hydrophobic surface, reduce the Gibbs adsorption energy, thereby reducing the amount of other ingredients to achieve the same cleaning effect, reducing the viscosity of the surfactant preparation, thereby improving the flowability of the detergent, facilitating subsequent rinsing and drying, and avoiding the formation of water droplets on the surface due to insufficient drying; fatty alcohol polyoxyethylene ether has significant emulsifying, wetting, dispersing and wrapping properties, and has strong removal ability for particulate contaminants; alcohol amine compounds such as diethanolamine have good wetting properties for hydrophobic materials, and can effectively penetrate and clean the hydrophobic surface of the silicon carbide wafer, thereby enhancing the cleaning effect. The addition of stabilizers such as polyvinyl alcohol can increase the uniformity of the cleaning agent, so that the chelating agent combines with most metal ions, and together with the organic dirt or particles wrapped by the surfactant, enters the cleaning solution and disperses in the system; at the same time, the addition of dispersing scale inhibitors such as hydroxyethyl cellulose can disperse the peeled dirt in the system, so as not to pollute the cleaned surface again, and the components synergize with each other to complete the cleaning process.

[0110] According to still some specific embodiments of the present application, the removal rate of the silicon carbide wafer cleaning agent to the surface particle contamination of the silicon carbide wafer is ≥80%, for example, the removal rate of the surface particle contamination can reach 98%. It can be seen that the silicon carbide wafer cleaning agent provided by the present application has good removal effect to the surface particle contamination of the silicon carbide wafer. In addition, the removal rate of the above-mentioned surface particle contamination of the silicon carbide wafer can be determined by the conventional calculation method in the art, such as the ratio of the number of surface particle contaminations after the silicon carbide wafer is cleaned by the silicon carbide wafer cleaning agent to the number of surface particle contaminations before the silicon carbide wafer is cleaned by the silicon carbide wafer cleaning agent.

[0111] It should be noted that the preparation method of the above-mentioned silicon carbide wafer cleaning agent of the embodiments of the present application is not particularly limited, and each component can be uniformly mixed according to the conventional method of the cleaning agent in the art.

[0112] The third aspect of the present application provides a cleaning method of a silicon carbide wafer. According to the embodiments of the present application, the cleaning agent used in the cleaning method comprises the silicon carbide wafer cleaning agent described in the second aspect.

[0113] The cleaning method of the silicon carbide wafer of the above-mentioned embodiments of the present application. The method uses the silicon carbide wafer cleaning agent described in the second aspect as a cleaning agent. Therefore, the cleaning method has high removal rate to the contaminants such as surface particles and metal ions of the silicon carbide wafer, and has the characteristics of short cleaning time and high yield. Specifically:

[0114] Compared with the existing cleaning method of the silicon carbide wafer (mainly including processes such as cleaning with a mixture of sulfuric acid and hydrogen peroxide-pure water rinsing-diluted hydrogen fluoride cleaning-pure water rinsing-hydrochloric acid-hydrogen peroxide-water mixture cleaning-pure water rinsing-drying), the cleaning method of the silicon carbide wafer provided by the embodiments of the present application only needs to use the above-mentioned silicon carbide wafer cleaning agent for cleaning and drying, which not only achieves excellent cleaning effect, but also greatly simplifies the cleaning process of the silicon carbide wafer and shortens the cleaning time.

[0115] According to still some specific embodiments of the present application, the cleaning method comprises the following steps:

[0116] The silicon carbide wafer to be cleaned is added to the solution containing the silicon carbide wafer cleaning agent for ultrasonic cleaning to obtain the cleaned silicon carbide wafer.

[0117] In the embodiments of the present application, the above-mentioned solution containing the silicon carbide wafer cleaning agent refers to the solution obtained by diluting the silicon carbide wafer cleaning agent with water, and the preparation method thereof is not particularly limited and can use the conventional mechanical stirring in the art.

[0118] According to still some specific embodiments of the present application, the temperature of the ultrasonic cleaning is 50-70℃, for example, can be 50℃, 51℃, 52℃, 53℃, 54℃, 55℃, 56℃, 57℃, 58℃, 59℃, 60℃, 61℃, 62℃, 63℃, 64℃, 65℃, 66℃, 67℃, 68℃, 69℃, 70℃, etc.

[0119] And / or, the time of the ultrasonic cleaning is 10-30min, for example, can be 10min, 11min, 12min, 13min, 14min, 15min, 16min, 17min, 18min, 19min, 20min, 21min, 22min, 23min, 24min, 25min, 26min, 27min, 28min, 29min, 30min, etc.

[0120] And / or, the ultrasonic frequency of the ultrasonic cleaning is 40-120KHz, for example, can be 40KHz, 50KHz, 60KHz, 70KHz, 80KHz, 90KHz, 100KHz, 110KHz, 120KHz, etc.

[0121] According to still some specific embodiments of the present application, the cleaning method further comprises: diluting the silicon carbide wafer cleaning agent by 5-20 times to obtain the solution containing the silicon carbide wafer cleaning agent, for example, can be 5 times, 6 times, 7 times, 8 times, 9 times, 10 times, 15 times, etc.

[0122] According to still some specific embodiments of the present application, after the silicon carbide wafer to be cleaned is added to the solution containing the silicon carbide wafer cleaning agent for ultrasonic cleaning to obtain a first treated silicon carbide wafer, the cleaning method further comprises rinsing and drying the first treated silicon carbide wafer.

[0123] According to still some specific embodiments of the present application, after the first treated silicon carbide wafer is rinsed to obtain a second treated silicon carbide wafer, the rinsing comprises at least one of pure water rinsing and megasonic rinsing.

[0124] In the embodiments of the present application, the above pure water rinsing is not particularly limited. Specifically, the pure water rinsing can comprise the following processes:

[0125] Spraying stage: full coverage spraying is performed through an up-down double nozzle system, and the spraying time is set to 80-200 seconds (for example, can be 80 seconds, 90 seconds, 100 seconds, 110 seconds, 120 seconds, 130 seconds, 140 seconds, 150 seconds, 160 seconds, 170 seconds, 180 seconds, 190 seconds, 200 seconds, etc.), to ensure that the workpiece surface is fully infiltrated and the residues are preliminarily stripped.

[0126] Bubbling disturbance stage: start the bubbling device at the bottom of the tank, and clean the workpiece again by the turbulence generated by the rising bubbles. The disturbance time is set to 50-100 seconds (for example, 50 seconds, 60 seconds, 70 seconds, 80 seconds, 90 seconds, 100 seconds, etc.), which can effectively loosen the attached particles.

[0127] Overflow drainage stage: open the overflow device for 20-100 seconds (for example, 20 seconds, 30 seconds, 40 seconds, 50 seconds, 60 seconds, 70 seconds, 80 seconds, 90 seconds, 100 seconds, etc.), and set a 5-10 degree inclination at the bottom of the tank. The slight inclination of the tank bottom facilitates the discharge of dirt.

[0128] In addition, hot water at 40-70°C (for example, 40°C, 50°C, 60°C, 70°C, etc.) can be used for rinsing to improve cleaning effect and efficiency.

[0129] In the embodiments of the present application, the above megasonic rinsing is not particularly limited. Specifically, the megasonic rinsing can include the following process: rinsing for 100-300 seconds (for example, 100 seconds, 120 seconds, 140 seconds, 160 seconds, 180 seconds, 200 seconds, 220 seconds, 240 seconds, 260 seconds, 280 seconds, 300 seconds, etc.) under the condition of megasonic frequency of 750-1200 KHz (for example, 750 KHz, 760 KHz, 770 KHz, 780 KHz, 790 KHz, 800 KHz, 810 KHz, 820 KHz, 830 KHz, 840 KHz, 850 KHz, 860 KHz, 870 KHz, 880 KHz, 890 KHz, 900 KHz, 910 KHz, 920 KHz, 930 KHz, 940 KHz, 950 KHz, 960 KHz, 970 KHz, 980 KHz, 990 KHz, 1000 KHz, 1010 KHz, 1020 KHz, 1030 KHz, 1040 KHz, 1050 KHz, 1060 KHz, 1070 KHz, 1080 KHz, 1090 KHz, 1100 KHz, 1110 KHz, 1120 KHz, 1130 KHz, 1140 KHz, 1150 KHz, 1160 KHz, 1170 KHz, 1180 KHz, 1190 KHz, 1200 KHz, etc.), and then overflow after water injection at the bottom for 50-100 seconds (for example, 50 seconds, 60 seconds, 70 seconds, 80 seconds, 90 seconds, 100 seconds, etc.), which can effectively remove tiny particles with a particle size of 0.1-0.3 µm and improve rinsing effect.

[0130] According to some specific embodiments of the present application, the drying step comprises the following processes:

[0131] In the first protective gas atmosphere, the second treated silicon carbide wafer is subjected to spin-drying to obtain a third treated silicon carbide wafer;

[0132] In the second protective gas atmosphere, the third treated silicon carbide wafer is subjected to drying to obtain the cleaned silicon carbide wafer.

[0133] In the embodiments of the present application, by adopting the drying process of spin-drying combined with drying, the drying efficiency and drying effect of the silicon carbide wafer are improved. The specific process of the above drying can comprise:

[0134] 1. High-speed spin-drying stage: a first nitrogen blowing atmosphere is formed by a double-row nitrogen gas nozzle (e.g. nozzle spacing 10-20 mm, aperture 0.2-0.5 mm), the first nitrogen blowing is switched with the high-low pressure mode (pressure range 0.2-0.6 MPa) synchronously with the rotation of the cleaning basket loaded with the silicon carbide wafer, the nitrogen flow is 70-90 L / min, the rotation speed of the cleaning basket is 600-1400 r / min, and the spin-drying time is 120-300 s.

[0135] 2. Low-speed hot nitrogen drying stage: the nitrogen flow is switched to a low flow mode (20-40 L / min) and the nitrogen gas temperature is 50-70℃ to form a second nitrogen blowing atmosphere, and the drying is performed at a rotation speed of 200-800 r / min for 100-200 s.

[0136] The fourth aspect of the present application proposes a silicon carbide wafer. According to the embodiments of the present application, the silicon carbide wafer is obtained by cleaning using the cleaning method described in the third aspect. Therefore, the content of surface particles such as particulate contaminants, metal ions, etc. of the silicon carbide wafer is low, which can meet the stringent requirements of device manufacturing such as semiconductors.

[0137] In some embodiments of the present application, the number of particulate contaminants on the surface of the silicon carbide wafer is <10 / cm 2 , the particle size r of the particulate contaminants is ≤0.2 μm;

[0138] and / or, the number of metal sodium ions on the surface of the silicon carbide wafer is ≤8.66E+10 / cm 2 ;

[0139] and / or, the number of metal potassium ions on the surface of the silicon carbide wafer is ≤9.67E+10 / cm 2 ;

[0140] and / or, the number of metal aluminum ions on the surface of the silicon carbide wafer is ≤1.19E+10 / cm 2 .

[0141] The number of particulate pollutants mentioned above in this application is <10 particles / cm². 2 This indicates that the number of particles with a diameter r ≤ 0.2 μm per square centimeter on the silicon carbide wafer surface does not exceed 10; similarly, the number of sodium ions is ≤ 8.66E+10 ions / cm². 2 The number of potassium ions is ≤9.67E+10 / cm 2 The number of aluminum ions is ≤1.19E+10 / cm 2 This indicates that the number of sodium ions per square centimeter on the surface of the silicon carbide wafer does not exceed 8.66 × 10⁻⁶. 10 The number of potassium ions does not exceed 9.67 × 10⁻⁶. 10 The number of aluminum ions does not exceed 1.19 × 10⁻⁶. 10 The low number of particulate contaminants and metal ions on the silicon carbide wafer surface described in this application is beneficial to the stability of subsequent silicon carbide wafer processing and the final yield of processed products. Furthermore, the number of particulate contaminants can be determined using existing methods such as laser scattering (using a laser beam to irradiate the wafer surface and statistically analyze the number and size of particles by detecting the intensity and distribution of scattered light) or scanning electron microscopy (using a high-energy electron beam to scan the surface and observe particle morphology through secondary electron imaging). Simultaneously, the number of sodium / potassium / aluminum ions can be determined using existing methods such as secondary ion mass spectrometry (using a high-energy ion beam to sputter the wafer surface and analyze the types and content of secondary ions generated by sputtering) or X-ray photoelectron spectroscopy (using X-rays to irradiate the sample surface, exciting photoelectrons, and measuring their kinetic energy through an energy analyzer to determine the element types and contents).

[0142] The fifth aspect of this application provides a device comprising the silicon carbide wafer described in the fourth aspect. Therefore, the devices of the above embodiments of this application offer significant performance improvements in response speed, lifespan, and other aspects.

[0143] In some embodiments of this application, the device includes at least one of a semiconductor device and a heating device.

[0144] A sixth aspect of this application provides for an apparatus. According to embodiments of this application, the apparatus includes a silicon carbide wafer as described in the fourth aspect or a device as described in the fifth aspect. Therefore, the features and advantages described above for the device also apply to this apparatus, and will not be repeated here.

[0145] In some embodiments of this application, the device includes at least one of electronic devices, communication devices, energy devices, and medical devices.

[0146] The embodiments of the present application are described below in detail, it should be noted that the embodiments described below are exemplary, only for explaining the present application, and can not be understood as limiting the present application. In addition, if not specifically stated, all reagents used in the following examples are commercially available, or can be synthesized according to the methods described herein or known methods, and the reaction conditions not listed are also easily obtained by those skilled in the art.

[0147] Example 1

[0148] The present embodiment provides a surfactant composition, the surfactant composition comprises, in weight percentage:

[0149] Fatty alcohol polyoxyethylene ether-9 (AEO-9) 38.46%, diethanolamine (DEA) 38.46%, and polyethyleneimine (PEI, purchased from Shanghai Yinn Chemical Technology Co., Ltd., the number average molecular weight is 1800 g / mol, and the amino mass fraction is 30%-42%) 23.08%.

[0150] Example 2

[0151] The present embodiment provides a surfactant composition, the surfactant composition comprises, in weight percentage:

[0152] Fatty alcohol polyoxyethylene ether-9 (AEO-9) 33.33%, diethanolamine (DEA) 41.67%, and polyethyleneimine (PEI, purchased from Shanghai Yinn Chemical Technology Co., Ltd., the number average molecular weight is 1800 g / mol, and the amino mass fraction is 30%-42%) 25.00%.

[0153] Example 3

[0154] The present embodiment provides a surfactant composition, the surfactant composition comprises, in weight percentage:

[0155] Fatty alcohol polyoxyethylene ether-9 (AEO-9) 42.86%, diethanolamine (DEA) 35.71%, and polyethyleneimine (PEI, purchased from Shanghai Yinn Chemical Technology Co., Ltd., the number average molecular weight is 1800 g / mol, and the amino mass fraction is 30%-42%) 21.43%.

[0156] Example 4

[0157] The present embodiment provides a surfactant composition, the surfactant composition comprises, in weight percentage:

[0158] Fatty alcohol polyoxyethylene ether-9 (AEO-9) 45.46%, diethanolamine (DEA) 27.27%, and polyethyleneimine (PEI, purchased from Shanghai Yinn Chemical Technology Co., Ltd., with a number average molecular weight of 1800 g / mol and an amino mass fraction of 30-42%) 27.27%.

[0159] Example 5

[0160] This example provides a surfactant composition, which includes, in weight percent:

[0161] Fatty alcohol polyoxyethylene ether-9 (AEO-9) 35.71%, diethanolamine (DEA) 42.86%, and polyethyleneimine (PEI, purchased from Shanghai Yinn Chemical Technology Co., Ltd., with a number average molecular weight of 1800 g / mol and an amino mass fraction of 30-42%) 21.43%.

[0162] Example 6

[0163] This example provides a surfactant composition, which includes, in weight percent:

[0164] Fatty alcohol polyoxyethylene ether-9 (AEO-9) 41.67%, diethanolamine (DEA) 41.67%, and polyethyleneimine (PEI, purchased from Shanghai Yinn Chemical Technology Co., Ltd., with a number average molecular weight of 1800 g / mol and an amino mass fraction of 30-42%) 16.66%.

[0165] Example 7

[0166] This example provides a surfactant composition, which includes, in weight percent:

[0167] Fatty alcohol polyoxyethylene ether-9 (AEO-9) 33.33%, diethanolamine (DEA) 33.33%, and polyethyleneimine (PEI, purchased from Shanghai Yinn Chemical Technology Co., Ltd., with a number average molecular weight of 1800 g / mol and an amino mass fraction of 30-42%) 33.34%.

[0168] Example 8

[0169] This example provides a surfactant composition, which includes, in weight percent:

[0170] Fatty alcohol polyoxyethylene ether-9 (AEO-9) 8.33%, diethanolamine (DEA) 83.34%, and polyethyleneimine (PEI, purchased from Shanghai Yinn Chemical Technology Co., Ltd., with a number average molecular weight of 1800 g / mol and an amino mass fraction of 30-42%) 8.33%.

[0171] Example 9

[0172] This example provides a surfactant composition, which includes, in weight percentage:

[0173] Fatty alcohol polyoxyethylene ether-9 (AEO-9) 8.33%, diethanolamine (DEA) 83.34%, and polyethyleneimine (PEI, purchased from Shanghai Yinn Chemical Technology Co., Ltd., with a number average molecular weight of 1800 g / mol and an amino mass fraction of 30-42%) 8.33%.

[0174] Example 10

[0175] This example provides a surfactant composition, which includes, in weight percentage:

[0176] Fatty alcohol polyoxyethylene ether-10 (AEO-10) 38.46%, diisopropanolamine 38.46%, and polyethyleneimine (PEI, purchased from Shanghai Yinn Chemical Technology Co., Ltd., with a number average molecular weight of 1800 g / mol and an amino mass fraction of 30-42%) 23.08%.

[0177] Example 11

[0178] This example provides a surfactant composition, which includes, in weight percentage:

[0179] Fatty alcohol polyoxyethylene ether-7 (AEO-7) 38.46%, diethanolamine 38.46%, and polyethyleneimine (PEI, purchased from Shanghai Yinn Chemical Technology Co., Ltd., with a number average molecular weight of 1800 g / mol and an amino mass fraction of 30-42%) 23.08%.

[0180] Example 12

[0181] This example provides a surfactant composition, which includes, in weight percentage:

[0182] Fatty alcohol polyoxyethylene ether-9 (AEO-9) 8.33%, diethanolamine (DEA) 83.34%, and polyethyleneimine (PEI, purchased from Shanghai Yinn Chemical Technology Co., Ltd., with a number average molecular weight of 1800 g / mol and an amino mass fraction of 30-42%) 8.33%.

[0183] Example 13

[0184] This example provides a surfactant composition, which is only different from Example 1 in that:

[0185] (1) The polyethyleneimine (PEI) is purchased from Shanghai McLean Biological Reagent Co., Ltd., and has a number average molecular weight of 10000 g / mol.

[0186] Example 14

[0187] This example provides a surfactant composition, which is only different from Example 1 in that:

[0188] The polyethyleneimine (PEI) has a number average molecular weight of 600 g / mol.

[0189] Example 15

[0190] This example provides a surfactant composition, which is only different from Example 1 in that:

[0191] The polyethyleneimine (PEI) has a number average molecular weight of 5000 g / mol.

[0192] Example 16

[0193] This example provides a silicon carbide wafer cleaning agent, which comprises the surfactant composition provided in Example 1; the silicon carbide wafer cleaning agent comprises, in parts by weight:

[0194] ultrapure water 81 parts, the surfactant composition provided in Example 1 13 parts, organic base tetramethylammonium hydroxide (TMAH) 3 parts, chelating agent ethylenediaminetetraacetic acid (EDTA) 1 part, stabilizer polyvinyl alcohol (PVA, purchased from Shanghai Yinn Chemical Technology Co., Ltd., number average molecular weight 170 g / mol) 1 part, and dispersion antifouling agent hydroxyethyl cellulose (HEC, purchased from Ino Kai Chemical Reagent Co., Ltd.) 1 part.

[0195] The silicon carbide wafer cleaning agent obtained in this example is denoted as BFY-s.

[0196] Example 17

[0197] This example provides a silicon carbide wafer cleaning agent, which comprises the surfactant composition provided in Example 2; the silicon carbide wafer cleaning agent comprises, in parts by weight:

[0198] ultrapure water 82 parts, the surfactant composition provided in Example 2 12 parts, tetramethylammonium hydroxide (TMAH) 3 parts, ethylenediaminetetraacetic acid (EDTA) 1 part, polyvinyl alcohol (PVA, purchased from Shanghai Yinn Chemical Technology Co., Ltd., number average molecular weight 170 g / mol) 1 part, and hydroxyethyl cellulose (HEC, purchased from Inoke Chemical Reagent Co., Ltd.) 1 part.

[0199] The silicon carbide wafer cleaning agent obtained in this example is recorded as BFY1-1.

[0200] Example 18

[0201] This example provides a silicon carbide wafer cleaning agent, which comprises the surfactant composition provided in Example 3; in terms of parts by weight, the silicon carbide wafer cleaning agent comprises:

[0202] ultrapure water 80 parts, the surfactant composition provided in Example 3 14 parts, tetramethylammonium hydroxide (TMAH) 3 parts, ethylenediaminetetraacetic acid (EDTA) 1 part, polyvinyl alcohol (PVA, purchased from Shanghai Yinn Chemical Technology Co., Ltd., number average molecular weight 170 g / mol) 1 part, and hydroxyethyl cellulose (HEC, purchased from Inoke Chemical Reagent Co., Ltd.) 1 part.

[0203] The silicon carbide wafer cleaning agent obtained in this example is recorded as BFY1-2.

[0204] Example 19

[0205] This example provides a silicon carbide wafer cleaning agent, which comprises the surfactant composition provided in Example 4; in terms of parts by weight, the silicon carbide wafer cleaning agent comprises:

[0206] ultrapure water 83 parts, the surfactant composition provided in Example 4 11 parts, tetramethylammonium hydroxide (TMAH) 3 parts, ethylenediaminetetraacetic acid (EDTA) 1 part, polyvinyl alcohol (PVA, purchased from Shanghai Yinn Chemical Technology Co., Ltd., number average molecular weight 170 g / mol) 1 part, and hydroxyethyl cellulose (HEC, purchased from Inoke Chemical Reagent Co., Ltd.) 1 part.

[0207] The silicon carbide wafer cleaning agent obtained in this example is recorded as BFY2-1.

[0208] Example 20

[0209] This example provides a silicon carbide wafer cleaning agent, which comprises the surfactant composition provided in Example 5; in terms of parts by weight, the silicon carbide wafer cleaning agent comprises:

[0210] ultrapure water 80 parts, the surfactant composition 14 parts provided in Example 5, tetramethylammonium hydroxide (TMAH) 3 parts, ethylenediaminetetraacetic acid (EDTA) 1 part, polyvinyl alcohol (PVA, purchased from Shanghai Yinn Chemical Technology Co., Ltd., number average molecular weight 170 g / mol) 1 part, and hydroxyethyl cellulose (HEC, purchased from Inoke Chemical Reagent Co., Ltd.) 1 part.

[0211] The carbonized silicon wafer cleaning agent obtained in this example is recorded as BFY2-2.

[0212] Example 21

[0213] This example provides a carbonized silicon wafer cleaning agent, which comprises the surfactant composition provided in Example 6; in terms of parts by weight, the carbonized silicon wafer cleaning agent comprises:

[0214] ultrapure water 82 parts, the surfactant composition 12 parts provided in Example 6, tetramethylammonium hydroxide (TMAH) 3 parts, ethylenediaminetetraacetic acid (EDTA) 1 part, polyvinyl alcohol (PVA, purchased from Shanghai Yinn Chemical Technology Co., Ltd., number average molecular weight 170 g / mol) 1 part, and hydroxyethyl cellulose (HEC, purchased from Inoke Chemical Reagent Co., Ltd.) 1 part.

[0215] The carbonized silicon wafer cleaning agent obtained in this example is recorded as BFY3-1.

[0216] Example 22

[0217] This example provides a carbonized silicon wafer cleaning agent, which comprises the surfactant composition provided in Example 7; in terms of parts by weight, the carbonized silicon wafer cleaning agent comprises:

[0218] ultrapure water 70 parts, the surfactant composition 15 parts provided in Example 7, tetramethylammonium hydroxide (TMAH) 3 parts, ethylenediaminetetraacetic acid (EDTA) 1 part, polyvinyl alcohol (PVA, purchased from Shanghai Yinn Chemical Technology Co., Ltd., number average molecular weight 170 g / mol) 1 part, and hydroxyethyl cellulose (HEC, purchased from Inoke Chemical Reagent Co., Ltd.) 1 part.

[0219] The carbonized silicon wafer cleaning agent obtained in this example is recorded as BFY3-2.

[0220] Example 23

[0221] This example provides a carbonized silicon wafer cleaning agent, which is only different from Example 16 in that:

[0222] (1) The ultrapure water is adjusted to 82 parts;

[0223] (2) Tetramethylammonium hydroxide (TMAH) is adjusted to 2 parts.

[0224] The silicon carbide wafer cleaning agent obtained in this example is recorded as BFY4-1.

[0225] Example 24

[0226] This example provides a silicon carbide wafer cleaning agent, which is only different from Example 16 in that:

[0227] (1) The ultrapure water is adjusted to 80 parts;

[0228] (2) The tetramethylammonium hydroxide (TMAH) is adjusted to 4 parts.

[0229] The silicon carbide wafer cleaning agent obtained in this example is recorded as BFY4-2.

[0230] Example 25

[0231] This example provides a silicon carbide wafer cleaning agent, which is only different from Example 16 in that:

[0232] (1) The ultrapure water is adjusted to 80 parts;

[0233] (2) The ethylenediaminetetraacetic acid (EDTA) is adjusted to 2 parts.

[0234] The silicon carbide wafer cleaning agent obtained in this example is recorded as BFY5-1.

[0235] Example 26

[0236] This example provides a silicon carbide wafer cleaning agent, which is only different from Example 16 in that:

[0237] (1) The ultrapure water is adjusted to 81.5 parts;

[0238] (2) The polyvinyl alcohol (PVA) is adjusted to 0.5 parts.

[0239] The silicon carbide wafer cleaning agent obtained in this example is recorded as BFY6-1.

[0240] Example 27

[0241] This example provides a silicon carbide wafer cleaning agent, which is only different from Example 16 in that:

[0242] (1) The ultrapure water is adjusted to 81.5 parts;

[0243] (2) The hydroxyethyl cellulose (HEC) is adjusted to 0.5 parts.

[0244] The silicon carbide wafer cleaning agent obtained in this example is recorded as BFY7-1.

[0245] Example 28

[0246] This example provides a cleaning agent for silicon carbide wafers, which differs from example 16 only in that:

[0247] (1) The surfactant composition is adjusted to that provided in example 11.

[0248] The resulting cleaning agent for silicon carbide wafers from this example is designated BFY-r1.

[0249] Example 29

[0250] This example provides a cleaning agent for silicon carbide wafers, which differs from example 16 only in that:

[0251] (1) Tetramethylammonium hydroxide (TMAH) is adjusted to tetraethylammonium hydroxide (TEAH).

[0252] The resulting cleaning agent for silicon carbide wafers from this example is designated BFY-r2.

[0253] Example 30

[0254] This example provides a cleaning agent for silicon carbide wafers, which differs from example 16 only in that:

[0255] (1) Polyvinyl alcohol (PVA) is adjusted to polyethylene glycol (PEG, number average molecular weight of 575 g / mol).

[0256] The resulting cleaning agent for silicon carbide wafers from this example is designated BFY-r3.

[0257] Example 31

[0258] This example provides a cleaning agent for silicon carbide wafers, which differs from example 16 only in that:

[0259] (1) The surfactant composition is adjusted to that provided in example 12.

[0260] The resulting cleaning agent for silicon carbide wafers from this example is designated BFY-r4.

[0261] Example 32

[0262] This example provides a cleaning agent for silicon carbide wafers, which differs from example 16 only in that:

[0263] (1) The surfactant composition is adjusted to that provided in example 8.

[0264] The resulting cleaning agent for silicon carbide wafers from this example is designated BFY-r5.

[0265] Example 33

[0266] The present example provides a cleaning agent for silicon carbide wafer, which is different from example 16 only in that:

[0267] (1) The surfactant composition is adjusted to the surfactant composition provided in example 10.

[0268] The cleaning agent for silicon carbide wafer obtained in the present example is recorded as BFY-r8.

[0269] Example 34

[0270] The present example provides a cleaning agent for silicon carbide wafer, which comprises the surfactant composition provided in example 1; the cleaning agent for silicon carbide wafer comprises, in terms of parts by weight:

[0271] 70 parts of ultrapure water, 19.6 parts of the surfactant composition provided in example 1, 5 parts of (2-hydroxyethyl)trimethylamine hydroxide, 5 parts of ethylenediaminetetraacetic acid (EDTA), 0.2 parts of polyvinyl alcohol (PVA, purchased from Shanghai Yinn Chemical Technology Co., Ltd., with a number average molecular weight of 170 g / mol), and 0.2 parts of hydroxyethyl cellulose (HEC, purchased from Inoke Chemical Reagent Co., Ltd.).

[0272] The cleaning agent for silicon carbide wafer obtained in the present example is recorded as BFY-r9.

[0273] Example 35

[0274] The present example provides a cleaning agent for silicon carbide wafer, which comprises the surfactant composition provided in example 1; the cleaning agent for silicon carbide wafer comprises, in terms of parts by weight:

[0275] 90 parts of ultrapure water, 4 parts of the surfactant composition provided in example 1, 1 part of ethylenediamine, 1 part of hydroxyethyl ethylenediamine tetraacetic acid ammonium, 2 parts of polyvinyl alcohol (PVA, purchased from Shanghai Yinn Chemical Technology Co., Ltd., with a number average molecular weight of 170 g / mol), and 2 parts of hydroxyethyl cellulose (HEC, purchased from Inoke Chemical Reagent Co., Ltd.).

[0276] The cleaning agent for silicon carbide wafer obtained in the present example is recorded as BFY-r10.

[0277] Example 36

[0278] The present example provides a cleaning agent for silicon carbide wafer, which is different from example 16 only in that:

[0279] (1) The surfactant composition is adjusted to the surfactant composition provided in example 13.

[0280] The cleaning agent for silicon carbide wafer obtained in the present example is recorded as BFY-r13.

[0281] Example 37

[0282] This example provides a silicon carbide wafer cleaning agent, which differs from example 16 only in that:

[0283] (1) The weight fraction of hydroxyethyl cellulose (HEC) is adjusted to 0 parts (i.e. no dispersant antifouling agent is added).

[0284] The silicon carbide wafer cleaning agent obtained in this example is denoted as BFY-r11.

[0285] Example 38

[0286] This example provides a silicon carbide wafer cleaning agent, which differs from example 16 only in that:

[0287] (1) The weight fraction of polyvinyl alcohol (PVA) is adjusted to 0 parts (i.e. no stabilizer is added).

[0288] The silicon carbide wafer cleaning agent obtained in this example is denoted as BFY-r12.

[0289] Example 39

[0290] This example provides a silicon carbide wafer cleaning agent, which differs from example 16 only in that:

[0291] (1) Tetramethylammonium hydroxide (TMAH) is adjusted to potassium hydroxide.

[0292] The silicon carbide wafer cleaning agent obtained in this example is denoted as BFY-r14.

[0293] Comparative Example 1

[0294] This comparative example provides a surfactant composition, which differs from example 1 only in that:

[0295] (1) No fatty alcohol polyoxyethylene ether-9 is added.

[0296] Comparative Example 2

[0297] This comparative example provides a surfactant composition, which differs from example 1 only in that:

[0298] (1) No polyethyleneimine is added.

[0299] Comparative Example 3

[0300] This comparative example provides a surfactant composition, which differs from example 1 only in that:

[0301] (1) No diethanolamine is added.

[0302] Comparative Example 4

[0303] This comparative example provides a surfactant composition, which is only different from Example 1 in that:

[0304] (1) The fatty alcohol polyoxyethylene ether-9 (AEO-9) is replaced by fatty alcohol polyoxyethylene ether-3 (AEO-3, i.e. n is 3 in the fatty alcohol polyoxyethylene ether).

[0305] Comparative Example 5

[0306] This comparative example provides a silicon carbide wafer cleaning agent, which is only different from Example 16 in that:

[0307] (1) The surfactant composition is adjusted to the surfactant composition provided in Comparative Example 1.

[0308] The silicon carbide wafer cleaning agent obtained in this example is denoted as AFY-1.

[0309] Comparative Example 6

[0310] This comparative example provides a silicon carbide wafer cleaning agent, which is only different from Example 16 in that:

[0311] (1) The surfactant composition is adjusted to the surfactant composition provided in Comparative Example 2.

[0312] The silicon carbide wafer cleaning agent obtained in this example is denoted as AFY-2.

[0313] Comparative Example 7

[0314] This comparative example provides a silicon carbide wafer cleaning agent, which is only different from Example 16 in that:

[0315] (1) The surfactant composition is adjusted to the surfactant composition provided in Comparative Example 3.

[0316] The silicon carbide wafer cleaning agent obtained in this example is denoted as AFY-3.

[0317] Test Example 1

[0318] This test example tests the critical micelle concentration of the surfactant compositions obtained in Examples 1-15 and Comparative Examples 1-4 above. The critical micelle concentration is tested by the surface tension method, and the test steps are as follows:

[0319] 1. Precisely weigh the surfactant to be tested and prepare surfactant solutions with different concentrations. The concentration gradient should cover the expected CMC range as much as possible, and the concentration gradient should be as uniform and detailed as possible (concentration gradient: 0 g / L, 0.2 g / L, 0.4 g / L, 0.6 g / L, 0.8 g / L, 1.0 g / L, 1.2 g / L, 1.4 g / L, 1.6 g / L, 1.8 g / L, 2.0 g / L, 2.2 g / L, 2.4 g / L, 2.6 g / L, 2.8 g / L, 3.0 g / L, 3.2 g / L, 3.4 g / L, 3.6 g / L, 3.8 g / L, 4.0 g / L, 4.2 g / L, 4.4 g / L, 4.6 g / L, 4.8 g / L, 5.0 g / L, 5.2 g / L, 5.4 g / L, 5.6 g / L, 5.8 g / L, 6.0 g / L).

[0320] 2. Place the prepared solution in a constant temperature water bath for more than one hour to ensure uniform temperature.

[0321] 3. Preheat and calibrate the surface tension tester (OCA-20 from Dataphysics, Germany).

[0322] 4. Measure the surface tension γ of each solution using the surface tension tester. The test sequence is from low concentration to high concentration, and each concentration is repeated three times to take the average value.

[0323] 5. Record the surface tension (γ) and the logarithm value (lgC) of the concentration (C) in real time.

[0324] 6. Make a γ-lgc curve with surface tension (γ) as the vertical coordinate and lgC as the horizontal coordinate. Extrapolate the straight line parts on both sides of the turning point of the curve, and the concentration of the intersection point is the critical micelle concentration of the surfactant in this system.

[0325] The test results are shown in Table 1.

[0326] Table 1

[0327]

[0328] As shown in Table 1, compared with Comparative Example 1 (without adding fatty alcohol polyoxyethylene ether-9), Comparative Example 2 (without adding polyethyleneimine), Comparative Example 3 (without adding diethanolamine), and Comparative Example 4 (n is 3 in the fatty alcohol polyoxyethylene ether), the critical micelle concentration of the surfactant composition provided by Examples 1-15 of the present application is significantly reduced.

[0329] Test Example 2

[0330] The test example tests the wetting performance of the surface active agent compositions obtained in the above examples 1-15 and comparative examples 1-4 on the surface of silicon carbide wafers. The surface active agent compositions are added to an aqueous solvent to prepare an aqueous solution with a mass fraction of 13%, and the contact angle of the aqueous solution droplets on the wafer surface is measured to characterize the wetting performance of the cleaning agent on the wafer surface. The test method is as follows:

[0331] 1. Maintain the laboratory temperature at 23 ± 2 ℃ and the relative humidity at 40-60 %.

[0332] 2. Preheat and calibrate the surface tension tester (OCA-20 from Dataphysics, Germany).

[0333] 3. Fill the test liquid into the syringe, and exhaust all air bubbles in the barrel and needle. Repeat the fast push and fast pull of the piston, and observe no air bubbles remaining.

[0334] 4. Load the sample and adjust the focal length.

[0335] 5. The software automatically generates a green contour line. After checking the actual boundary of the droplet, read the average value of the θ angles on the left and right sides.

[0336] 6. Repeat the test at the same point for ≥5 times, test at different positions for ≥3 points, and calculate the average value and standard deviation.

[0337] The test results are shown in Table 2.

[0338] Table 2

[0339]

[0340] From Table 2, it can be seen that:

[0341] 1) Compared with comparative example 1 (without adding fatty alcohol polyoxyethylene ether-9), comparative example 2 (without adding polyethyleneimine), comparative example 3 (without adding diethanolamine), and comparative example 4 (n is 3 in the fatty alcohol polyoxyethylene ether), the surface active agent composition provided in the examples 1-15 has a lower contact angle on the surface of the silicon carbide wafer, indicating that it has better wetting performance on the surface of the silicon carbide wafer.

[0342] 2) By comparing the test results of examples 1-7 and examples 8-9, it is shown that when the types of the components in the surface active agent composition are the same, the use amount ratio of the components in the surface active agent composition of the present application is maintained within the range shown in examples 1-7, and the improvement effect on the wetting performance of the silicon carbide wafer surface is better.

[0343] 3) By comparing the test results of Comparative Example 1 and Examples 10-12, it is shown that in the case of the same proportion of the use amount of each component in the surfactant composition, the wetting effect on the surface of the silicon carbide wafer is better when the types of each component in the surfactant composition of the application are limited to the categories in Example 1 or Example 12 (i.e., the alcohol amine compound is preferably diethanolamine or monoethanolamine, and the fatty alcohol polyoxyethylene ether is preferably fatty alcohol polyoxyethylene ether-9).

[0344] 4) By comparing the test results of Example 1, Example 14, Example 15, and Example 13, it is shown that in the case of the same types and proportions of the use amount of each component in the surfactant composition, the wetting effect on the surface of the silicon carbide wafer is better when the number average molecular weight of the polyethyleneimine is controlled to be 600 g / mol-5000 g / mol.

[0345] Test Example 3

[0346] In this test example, the silicon carbide wafer cleaning agents obtained in Examples 16-39 and Comparative Examples 5-7 described above are used to clean the surface of the silicon carbide wafer, and the cleaning method includes the following processes:

[0347] 1) Loading: The silicon carbide wafers to be cleaned are randomly grouped, with 10 pieces in each group, and then the silicon carbide wafers to be cleaned are transferred into a PFA (dissolvable polytetrafluoroethylene) cleaning basket.

[0348] 2) Ultrasonic cleaning: Each group in the above 1) is cleaned with the silicon carbide wafer cleaning agent obtained in Examples 16-39 and Comparative Examples 5-7 described above, the dilution multiple of the silicon carbide wafer cleaning agent is 8 times, the temperature is 60°C, the cleaning time is 20 minutes, and the ultrasonic frequency is 80KHz.

[0349] 3) Pure water rinsing: Full coverage spraying is performed through an up-and-down double nozzle system, the water temperature is 50°C, the spraying time is set to 100 seconds, then the bottom bubbling device is started, the bubbling disturbance time is set to 60 seconds, and the overflow device is turned on for continuous overflow for 60 seconds.

[0350] 4) Megasonic rinsing: Rinsing is performed at a megasonic frequency of 900KHz for 200s, and after the megasonic rinsing is completed, the bottom is injected with water and overflowed for 60s.

[0351] 5) drying: a first nitrogen blowing atmosphere was formed by upper and lower double-row nitrogen nozzles (nozzle spacing 15 mm, aperture 0.3 mm), the first nitrogen blowing was switched between high and low pressure modes (pressure range 0.2-0.6 MPa) synchronously with the rotation of the cleaning basket loaded with the silicon carbide wafer, the nitrogen flow was 80 L / min, the cleaning basket rotation speed was 1000 r / min, and the spin-drying dehydration time was 180 s; after spin-drying, the nitrogen flow was switched to a low flow mode (30 L / min) and the nitrogen gas temperature was 60°C to form a second nitrogen blowing atmosphere, and the wafer was dried at a speed of 500 r / min for 150 s to obtain the cleaned silicon carbide wafer sample.

[0352] The above cleaned silicon carbide wafer sample was detected, and the detection method included:

[0353] 1) white point-like contamination detection: each example was used to clean 10 wafers as a group, and the wafers were isolated in a dust-free workshop after cleaning. After two days of standing, the wafer surface was observed under a strong light lamp.

[0354] 2) surface particle contamination detection: each example was used to clean 10 wafers as a group, and the wafer surface was scanned before and after cleaning using Candela8520, the number of particles with a particle size of r≤0.2 μm was counted, the number of particles on the surface of the wafer before cleaning was denoted as N1 (pieces / cm 2 ), and the number of particles on the surface of the wafer after cleaning was denoted as N2 (pieces / cm 2 ); and the removal rate η of the silicon carbide wafer cleaning agent for the particle contamination on the surface of the silicon carbide wafer was calculated according to the formula: removal rate η = (N1-N2) / N1 x 100%.

[0355] The test results of the detection are shown in Table 3; in addition, Figure 1 is a standard appearance performance diagram of the silicon carbide wafer cleaned according to Example 16, Figure 2 is a macroscopic performance diagram of the time fog of the silicon carbide wafer cleaned according to Comparative Example 5.

[0356] Table 3

[0357]

[0358] From Table 3, it can be seen that:

[0359] 1) Compared with Comparative Examples 5-7, the cleaning effect of the silicon carbide wafer cleaning agent provided by Examples 16-36 is better, and the removal rate of the surface particle contamination is maintained at more than 85%.

[0360] 2) Compared with Examples 16-36, the effect of the silicon carbide wafer cleaning agent provided by Examples 37-39 is slightly worse, but is still significantly better than that of Comparative Examples 5-7. ​

[0361] Based on the above test results, the test example further detects the metal ions on the surface of the silicon carbide wafer cleaned by the above examples 16-39 and comparative examples 5-7: each example is used to clean 10 wafers as a group, and after cleaning, the wafer surface is analyzed for metal elements using ICP-MS 7900 sample preparation, and the test results are shown in Table 4.

[0362] Table 4

[0363]

[0364] As can be seen from Table 4: whether for sodium ions, potassium ions or aluminum ions, the content of metal ions on the surface of the silicon carbide wafer cleaned by the silicon carbide wafer cleaner provided by the examples 16-39 of the present application is lower than that of the comparative examples 5-7, which indicates that the silicon carbide wafer cleaner provided by the present application has better removal ability for the metal ions on the surface of the silicon carbide wafer.

[0365] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example" or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, different embodiments or examples described in the present specification and the features of different embodiments or examples can be combined and combined by those skilled in the art without contradiction.

[0366] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. A cleaning agent for silicon carbide wafers, characterized by comprising: The silicon carbide wafer cleaning agent comprises a surfactant composition 9-15 parts by weight, the critical micelle concentration value of the surfactant composition is 0.009 g / L-0.048 g / L; the contact angle of the aqueous solution of the surfactant composition on the surface of the silicon carbide wafer is ≤20°, the mass fraction of the surfactant composition in the aqueous solution is 10%-20%, and the surfactant composition comprises: a) an alcohol amine compound, the weight percentage of which is 27-43%; and b) polyethyleneimine, the weight percentage of which is 16-34%; and c) 33-46% by weight of at least one fatty alcohol polyoxyethylene ether of the general formula R-(OCH2-CH2)n-OH; wherein R is an alkyl group and n is any natural number selected from 7-10; In the surfactant composition, the number average molecular weight of the polyethyleneimine is 600 g / mol-5000 g / mol; the amino content in the polyethyleneimine is 30%-42% by mass fraction; The silicon carbide wafer cleaning agent further comprises ethylenediaminetetraacetic acid 1-2 parts, tetramethylammonium hydroxide 2-4 parts, polyvinyl alcohol 0.5-1 part, hydroxyethyl cellulose 0.5-1 part, and water 70-83 parts, The removal rate of the silicon carbide wafer cleaning agent for the surface particle contaminants of the silicon carbide wafer is ≥80%.

2. The silicon carbide wafer cleaning agent of claim 1, wherein The alkyl group is an alkyl group with 7-9 carbon atoms or an alkyl group with 12-18 carbon atoms.

3. The silicon carbide wafer cleaning agent of claim 1, wherein In the surfactant composition, The alcohol amine compound comprises at least one of monoethanolamine, diethanolamine, triethanolamine, n-propyl alcohol amine, dipropyl alcohol amine, and diisopropyl alcohol amine; And / or, the fatty alcohol polyoxyethylene ether comprises at least one of fatty alcohol polyoxyethylene ether-7, fatty alcohol polyoxyethylene ether-8, fatty alcohol polyoxyethylene ether-9, and fatty alcohol polyoxyethylene ether-10.

4. A method of cleaning a silicon carbide wafer, comprising: The cleaning agent used in the cleaning method comprises the silicon carbide wafer cleaning agent according to any one of claims 1-3.

5. The method of claim 4, wherein the cleaning is performed by using a cleaning solution containing at least one of hydrogen peroxide, ozone, and hydrogen fluoride. The cleaning method comprises the following steps: The silicon carbide wafer to be cleaned is added to a solution containing the silicon carbide wafer cleaning agent for ultrasonic cleaning, to obtain a cleaned silicon carbide wafer.

6. The method of cleaning a silicon carbide wafer of claim 5, wherein, The temperature of the ultrasonic cleaning is 50°C-70°C; And / or, the time of the ultrasonic cleaning is 10 min-30 min; And / or, the ultrasonic frequency of the ultrasonic cleaning is 40 KHz-120 KHz.

7. The method of claim 5, wherein the cleaning is performed by using a cleaning solution containing at least one of hydrogen peroxide, ozone, and hydrogen fluoride. The cleaning method further comprises diluting the silicon carbide wafer cleaning agent by 5-20 times to obtain the solution containing the silicon carbide wafer cleaning agent.

8. The method of claim 5, 6, or 7, wherein the silicon carbide wafer is cleaned by the method of claim 1, 2, 3, 4, or 5. The silicon carbide wafer to be cleaned is added to a solution containing the silicon carbide wafer cleaning agent for ultrasonic cleaning, to obtain a cleaned silicon carbide wafer.

9. The method of claim 8, wherein the cleaning is performed by using a cleaning solution containing at least one of hydrogen peroxide, ozone, and hydrogen fluoride. The silicon carbide wafer to be cleaned is added to a solution containing the silicon carbide wafer cleaning agent for ultrasonic cleaning, to obtain a cleaned silicon carbide wafer.

10. The method of claim 9, wherein The rinsing of the first treated silicon carbide wafer comprises at least one of pure water rinsing and megasonic rinsing. The drying step comprises the following processes: The second treated silicon carbide wafer is subjected to spin-drying under a first protective gas atmosphere to obtain a third treated silicon carbide wafer; The third treated silicon carbide wafer is subjected to drying under a second protective gas atmosphere to obtain the cleaned silicon carbide wafer.

11. A silicon carbide wafer, characterized by, The silicon carbide wafer is cleaned by the cleaning method of any one of claims 4-10.

12. The silicon carbide wafer of Claim 11 wherein, The number of particle contaminants on the surface of the silicon carbide wafer is < 10 / cm 2 The particle contaminants have a particle size r < 0.2 μm. and / or the number of metallic sodium ions on the surface of the silicon carbide wafer is < 8.66E+10 ions / cm2 2 ; and / or the number of metallic potassium ions on the surface of the silicon carbide wafer is < 9.67E+10 / cm2 2 ; and / or the number of metallic aluminum ions on the surface of the silicon carbide wafer is < 1.19E+10 / cm2 2 .

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