Phosphorus-containing organic matter, preparation method thereof and silicon wafer cleaning agent

Abstract

The invention belongs to the technical field of silicon wafer processing, and provides a phosphorus-containing organic matter, a preparation method thereof and a silicon wafer cleaning agent. The phosphorus-containing organic matter has a structure as shown in a formula 1, and R is alkyl with the carbon atom number of 6-18. The phosphorus-containing organic matter serving as a surfactant is applied to a silicon wafer cleaning agent, particles and organic pollutants on the surface of a silicon wafer can be effectively removed, metal ion impurities can also be removed, and the comprehensive cleaning effect on the silicon wafer is remarkably improved. Formula 1

Description

Technical Field

[0001] This invention belongs to the field of silicon wafer processing technology, specifically relating to a phosphorus-containing organic compound, its preparation method, and a silicon wafer cleaning agent. Background Technology

[0002] As the core substrate for integrated circuit manufacturing, the surface cleanliness of semiconductor silicon wafers directly affects device performance and yield. In nanoscale processes, after slicing, grinding, polishing, and multiple manufacturing cycles, silicon wafers retain residual particulate matter (such as silicon chips and environmental dust), organic contaminants (photoresist and grease), and critical contaminants such as metal ions. These contaminants, especially metal ions that are firmly bound through chemical adsorption, can cause lattice defects and increase leakage current during subsequent heat treatment, leading to a significant decrease in device reliability.

[0003] Wet cleaning is a critical process for ensuring the cleanliness of silicon wafers. The traditional RCA standard cleaning method uses alkaline hydrogen peroxide (SC-1) and acidic hydrogen peroxide (SC-2) in steps, but this system has inherent defects: although the SC-1 solution can remove particles through oxidative etching, it can cause some metal ions to redeposit on the surface, and its continuous etching effect increases the surface roughness; the SC-2 solution has limited removal effect on some metals and is insufficient in cleaning particles and organic contaminants.

[0004] To improve cleaning effectiveness, some technologies suggest introducing surfactants into the cleaning solution. However, traditional surfactants primarily rely on physical adsorption and steric hindrance to disperse contaminants, offering limited removal capabilities for critical metal impurities. More seriously, these surfactants are difficult to completely remove during the cleaning process, and their residues can become new sources of contamination, easily causing dirt deposition and affecting subsequent processes. Furthermore, to enhance the removal of metal ions, some technologies mention adding traditional chelating agents such as ethylenediaminetetraacetic acid (EDTA) and citric acid to the cleaning system. However, the synergistic effect of these chelating agents with surfactants is limited, and they may lead to the formation of difficult-to-remove metal chelate residues on the silicon wafer surface.

[0005] In summary, existing cleaning agents are insufficient for the synergistic removal of multiple contaminants, including particles, organic matter, and metal ions, and thus cannot meet the cleanliness requirements of advanced manufacturing processes for silicon wafers. Therefore, there is an urgent need to develop a novel cleaning agent capable of simultaneously removing multiple contaminants without introducing secondary pollution. Summary of the Invention

[0006] The purpose of this invention is to provide a novel phosphorus-containing organic compound and its preparation method, as well as a silicon wafer cleaning agent containing the phosphorus-containing organic compound. When the phosphorus-containing organic compound is applied to the silicon wafer cleaning agent, it can not only effectively remove particles and organic contaminants from the surface of the silicon wafer, but also remove metal ion impurities, significantly improving the overall cleaning effect on the silicon wafer.

[0007] In a first aspect, the present invention provides a phosphorus-containing organic compound having the structure shown in Formula 1: Formula 1 Wherein, R is an alkyl group having 6 to 18 carbon atoms.

[0008] The phosphorus-containing organic compound of this invention belongs to a chelating surfactant. As shown in Formula 1, the multiple phosphonic acid groups in the structure of the phosphorus-containing organic compound endow it with excellent metal ion coordination ability, enabling it to form stable chelates with metal ions; at the same time, the hydrophobic aliphatic chain (-NHR) in the molecule can form a hydrophobic-hydrophilic amphiphilic structure with the hydrophilic phosphonic acid groups, which can not only significantly reduce the surface tension of the cleaning agent and enhance its wetting performance on the silicon wafer surface, but also generate effective steric hindrance and charge repulsion effects through the adsorption of phosphonic acid groups on the particle surface, thereby preventing the redeposition of particulate contaminants and achieving excellent particle removal effect.

[0009] In a second aspect, the present invention provides a method for preparing the phosphorus-containing organic compound described in the first aspect of the present invention, comprising the following steps: 1) In an organic solvent, cyanuric chloride is reacted with an aliphatic amine with the structure shown in formula a at a temperature of -5°C to 30°C to generate intermediate I with the structure shown in formula b. Formula a, Formula b; 2) In an aqueous solvent, intermediate I is subjected to a second nucleophilic substitution reaction with a portion of aminodi(methylene phosphate) at 50-60°C; 3) The reaction system obtained in step (2) is heated to 80~90℃, and the remaining amino di(methylene phosphate) is added to carry out the third nucleophilic substitution reaction to form a phosphorus-containing organic compound with the structure shown in Formula 1.

[0010] Thirdly, the present invention provides a silicon wafer cleaning agent comprising a surfactant, wherein the surfactant is a phosphorus-containing organic compound as described in the first aspect of the present invention.

[0011] In some embodiments of the present invention, the silicon wafer cleaning agent further includes water, hydrogen peroxide, and alcohol compounds.

[0012] Furthermore, based on the total mass of the silicon wafer cleaning agent, the mass content of the alcohol compound is 1%~10%, the mass content of hydrogen peroxide is 2%~12%, and the mass content of the surfactant is 0.01%~0.1%.

[0013] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Detailed Implementation

[0014] The embodiments of the present invention are described in detail below. The embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0015] The "scope" disclosed in this invention is defined in the form of a lower limit and / or an upper limit, whereby a given scope is defined by selecting a lower limit and / or an upper limit. This scope may or may not include endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form an undefined scope, and any lower limit can be combined with other lower limits to form an undefined scope, similarly, any upper limit can be combined with any other upper limit to form an undefined scope. Furthermore, each individually disclosed point or single value can itself serve as a lower or upper limit and can be combined with any other point or single value, or with other lower or upper limits, to form an undefined scope.

[0016] Unless otherwise specified, all embodiments and optional embodiments of the present invention may be combined with each other to form new technical solutions, and such technical solutions should be considered to be included in the disclosure of the present invention.

[0017] A first aspect of the present invention provides a phosphorus-containing organic compound having the structure shown in Formula 1: Formula 1 Wherein, R is an alkyl group having 6 to 18 carbon atoms.

[0018] In this invention, R can be a straight-chain alkyl group with 6 to 18 carbon atoms, or a branched-chain alkyl group with 6 to 18 carbon atoms. The molecular formula of R can be represented as -C n H 2n+1 n is any integer from 6 to 18, specifically 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 or 18.

[0019] In some embodiments, R is a straight-chain alkyl group having 8 to 18 carbon atoms, such as octyl, dodecyl, tetradecyl, hexadecyl, octadecyl, etc.

[0020] As some specific examples, the phosphorus-containing organic compound is selected from at least one of the following compounds A1 to A8:

[0021] In a second aspect, the present invention provides a method for preparing the phosphorus-containing organic compound described in the first aspect of the present invention, comprising the following steps: 1) In an organic solvent, cyanuric chloride undergoes a first nucleophilic substitution reaction with the aliphatic amine shown in formula a to generate intermediate I shown in formula b: Formula a, Formula b; Wherein, R is defined as described in the first aspect of the present invention; 2) In an aqueous solvent, intermediate I undergoes a second nucleophilic substitution reaction with a portion of aminodi(methylene phosphate); 3) The reaction system obtained in step 2) is heated, and the remaining amino di(methylene phosphate) is added to carry out a third nucleophilic substitution reaction to obtain a phosphorus-containing organic compound with the structure shown in Formula 1.

[0022] According to the present invention, in step 1), the temperature of the first nucleophilic substitution reaction is -5°C to 30°C, for example -5°C, 0°C, 2°C, 5°C, 10°C, 12°C, 15°C, 20°C, 25°C, 28°C, 30°C, etc., or any temperature within the range defined by any two of the above values, for example -5°C to 0°C, 0~5°C, 10~20°C, 20~25°C, 25~30°C, etc.

[0023] In some embodiments, the time for the first nucleophilic substitution reaction can be 1 to 4 hours, such as 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, etc.

[0024] In some embodiments, the organic solvent is at least one selected from acetone, tetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide, methanol, ethanol, and isopropanol.

[0025] In step 1), the amount of organic solvent used relative to 1g of cyanuric chloride can be 10~50mL, for example 10mL, 20mL, 25mL, 30mL, 40mL, 43mL, 45mL, 48mL, 50mL, etc.

[0026] In step 1), specific examples of the fatty amine include, but are not limited to, octylamine, dodecylamine, tetradecylamine, hexadecylamine, or octadecylamine.

[0027] In step 1), the preferred molar ratio of cyanuric chloride to the fatty amine is 1:(0.8~1.2), for example, 1:0.8, 1:0.9, 1:1, 1:1.1, 1:1.2, etc.

[0028] As a preferred example, step 1) includes the following process: 1-1) Under stirring conditions, a solution of fatty amines was slowly added dropwise to a solution of cyanuric chloride to carry out a low-temperature reaction. The addition time was controlled to be 20-30 min, and the temperature of the reaction system was maintained between -5℃ and 5℃. 1-2) After the addition is complete, raise the temperature to 20~30℃ (e.g., room temperature) and continue stirring the reaction for 1~3 hours.

[0029] Optionally, step 1) further includes: after the reaction is completed, the reaction solution is quenched with ice water, followed by solid-liquid separation, the obtained solid is washed with water until the washing solution is neutral, and then dried under vacuum at 30~50℃ to obtain solid intermediate I.

[0030] According to the present invention, in step 2), the temperature of the second nucleophilic substitution reaction is 50~60°C, for example 50°C, 52°C, 55°C, 57°C, 58°C, 60°C, etc., or any temperature within the range defined by any two of the above values, for example 50~53°C, 52~55°C, 50~56°C, 52~60°C, etc.

[0031] In some embodiments, the second nucleophilic substitution reaction can take 8 to 13 hours, for example, 8 hours, 9 hours, 9.5 hours, 10 hours, 11 hours, 12 hours, 13 hours, etc.

[0032] In step 2), the second nucleophilic substitution reaction is preferably carried out under alkaline conditions at pH 8 to 10.

[0033] In step 2), the aqueous solvent can be a mixed solvent composed of water and a polar solvent. Preferably, the polar solvent is selected from at least one of acetonitrile, tetrahydrofuran, and N,N-dimethylformamide. According to some embodiments, the volume ratio of water to the polar solvent in the aqueous solvent can be (5~12):10, for example 8:10, 10:10, 10:11, 10:12, etc.

[0034] In step 2), the amount of the aqueous solvent used relative to each 1g of intermediate I can be 10~30mL, for example 10mL, 14mL, 15mL, 18mL, 20mL, 22mL, 25mL, 28mL, 30mL, etc.

[0035] In step 2), the molar ratio of intermediate I to aminodi(methylenephosphoric acid) is preferably 1:(0.8~1.2), for example 0.8:1, 0.9:1, 1:1, 1.2:1, etc.

[0036] As a preferred example, step 2) includes: adding an alkaline solution to a solution containing intermediate I under stirring at a temperature of 50-60°C to maintain the pH of the system at 8-9; then adding an aqueous solution of aminodi(methylene phosphate) dropwise, controlling the dropwise addition time to 20-30 min; and continuing the reaction for 8-12 h after the dropwise addition is completed.

[0037] According to the present invention, in step 3), the temperature of the third nucleophilic substitution reaction is 80~90℃, for example 80℃, 83℃, 85℃, 88℃, 90℃, etc., or any temperature within the range defined by any two of the above values, such as 80~83℃, 82~85℃, 80~55℃, 80~90℃, etc.

[0038] In some embodiments, the third nucleophilic substitution reaction can take 18 to 24 hours, for example, 18 hours, 19 hours, 20 hours, 21 hours, 22 hours, 23 hours, 24 hours, etc.

[0039] In step 3), the third nucleophilic substitution reaction is preferably carried out under alkaline conditions at pH 8 to 10.

[0040] The preferred molar ratio of aminodi(methylenephosphoric acid) in step 3) to aminodi(methylenephosphoric acid) in step 2) is 1:(0.8~1.2), for example, 1:0.8, 1:0.9, 1:1, 1:1.1, 1:1.2, etc.

[0041] As a preferred example, step 3) includes: adding an alkaline solution at a temperature of 80-90°C under stirring to maintain the pH of the system at 8-9, then adding an aqueous solution of aminodi(methylene phosphate) dropwise, controlling the dropwise addition time to 20-30 min, and continuing the reaction for 18-23 h after the dropwise addition is completed.

[0042] Optionally, step 3) further includes: after the reaction is completed, the solid is separated into solid and liquid, the solid is washed with water until the washing liquid is neutral, and then dried under vacuum at 30~50°C to obtain the solid phosphorus-containing organic compound.

[0043] According to the present invention, in steps 2) and 3), the mass concentration of the aqueous solution of aminodi(methylenephosphoric acid) can be 50% to 65%, for example, 55%, 60%, 65%, etc. The concentration of the alkaline solution can be 1 to 3 mol / L, for example, 1 mol / L, 2 mol / L, 3 mol / L, etc. The alkali in the alkaline solution can be one or more of NaOH, KOH, Na2CO3, and K2CO3.

[0044] Thirdly, the present invention provides a silicon wafer cleaning agent, wherein the silicon wafer cleaning agent comprises a surfactant, wherein the surfactant is a phosphorus-containing organic compound as described in the first aspect of the present invention.

[0045] In some embodiments, the surfactant content is 0.01% to 0.1% by mass, for example, 0.01%, 0.02%, 0.03%, 0.05%, 0.07%, 0.08%, etc., based on the total mass of the silicon wafer cleaning agent.

[0046] In some embodiments, the silicon wafer cleaning agent may also contain water, hydrogen peroxide (H2O2), and alcohol compounds.

[0047] In the silicon wafer cleaning agent, water can serve as a base solvent, dissolving other components. Based on the total mass of the silicon wafer cleaning agent, the water content can be 85% to 97%, for example, 88%, 89%, 90%, 93%, 96%, etc.

[0048] In the silicon wafer cleaning agent, hydrogen peroxide effectively removes contaminants through oxidative stripping: it undergoes a controlled oxidation reaction with the silicon wafer surface, decomposing organic contaminants while inducing the formation of a hydrophilic oxide layer, and dissociating adsorbed metallic contaminants from the surface. Based on the total mass of the silicon wafer cleaning agent, the hydrogen peroxide content can be 2% to 12%, for example, 2%, 3%, 5%, 8%, 10%, 12%, etc.

[0049] In the silicon wafer cleaning agent, the alcohol compound can adjust the solubility and wetting properties of the system. Based on the total mass of the silicon wafer cleaning agent, the mass content of the alcohol compound can be 1% to 10%, for example, 1%, 3%, 5%, 8%, 10%, etc.

[0050] In some embodiments, the alcohol compound is a monohydric alcohol or polyhydric alcohol having 1 to 6 carbon atoms. Preferably, the alcohol compound is selected from at least one of methanol, ethanol, isopropanol, n-butanol, ethylene glycol, propylene glycol, glycerol, and 1,4-butanediol.

[0051] The present invention does not particularly limit the preparation method of the silicon wafer cleaning agent; any method well known in the art can be used to dissolve and mix the components to form a homogeneous solution. In particular, the silicon wafer cleaning agent can achieve efficient cleaning of silicon wafers under relatively mild process conditions. As some preferred examples, the method of cleaning silicon wafers using the silicon wafer cleaning agent includes: immersing the silicon wafer to be cleaned in the silicon wafer cleaning agent and cleaning it at a temperature of 40-50°C for 120-240 seconds.

[0052] The following describes embodiments of the present invention. These embodiments are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0053] The following synthetic examples illustrate the phosphorus-containing organic compounds and their preparation methods of the present invention.

[0054] The aqueous solution of aminodi(methylenephosphoric acid) used was 60% by mass, and the alkaline solution was 2 mol / L NaOH aqueous solution.

[0055] Synthesis example 1 (1) Synthesis of intermediate IM-2 Add cyanuric chloride (5 g, 27.1 mmol) and 80 mL of acetone to a round-bottom flask and stir until dissolved. Place the flask in an ice-water bath and cool to 0°C. Under stirring, slowly add a solution of octylamine (2.84 g, 22.0 mmol) in 20 mL of acetone over a period of 20 min, maintaining the temperature of the reaction system between 0 and 5°C. After the addition is complete, allow the mixture to warm naturally to room temperature (25°C) and continue stirring for 2 h. After the reaction is complete, quench the reaction mixture in ice water, precipitating a white solid. Collect the solid by filtration, wash with water, and then dry under vacuum at 40°C to obtain 4,6-dichloro-N-octyl-1,3,5-triazine-2-amine, i.e., intermediate IM-2 (5.18 g, yield 85.0%).

[0056]

[0057] (2) Synthesize compound A2 Add intermediate IM-2 (2.88 g, 10.4 mmol), 20 mL of water, and 20 mL of acetonitrile to a round-bottom flask and stir until dissolved. Heat the system to 50 °C, and while stirring, add alkali solution dropwise to maintain the pH of the reaction system at 8-9. Then add 3.42 g of an aqueous solution of aminodi(methylenephosphonic acid) (containing 10.0 mmol of aminodi(methylenephosphonic acid)) dropwise over 20 min. After the addition is complete, continue stirring the reaction for 10 h, maintaining the temperature at 50-55 °C throughout the reaction.

[0058] Subsequently, the reaction system was heated to 80°C, and an alkaline solution was added dropwise under stirring to maintain the pH between 8 and 9. Then, 3.76 g of an aqueous solution of aminodi(methylenephosphonic acid) (containing 11.0 mmol of aminodi(methylenephosphonic acid)) was added dropwise over a period of 20 min. After the addition was complete, the reaction was stirred for another 20 h, with the temperature maintained at 80–85°C throughout the reaction. After the reaction was completed, the mixture was cooled to room temperature, the resulting reaction system was filtered, the solid was collected, washed with water, and then dried under vacuum at 40°C to obtain the target product, compound A2 (5.31 g, yield 83%).

[0059]

[0060] NMR characterization of compound A2 1 H-NMR(400MHz, CDCl3) δ(ppm): 4.80(8H, s), 7.01(1H,s), 3.45(8H, m), 3.35(2H, m), 1.63(2H, m), 1.36(2H, m), 1.27(2H, m), 1.26(6H,m), 0.88(3H, t).

[0061] Mass spectrometric characterization of compound A2, LCMS (ESI) m / z [M+H] + : 615.3678.

[0062] Synthesis example 2 (1) Synthesis of intermediate IM-3 Add cyanuric chloride (5 g, 27.1 mmol) and 80 mL of acetone to a round-bottom flask and stir to dissolve. Place the reaction flask in an ice-water bath to cool and maintain the temperature at 0°C. Under stirring, slowly add a solution of dodecylamine (4.17 g, 22.5 mmol) in 30 mL of acetone over a period of 20 min, maintaining the temperature of the reaction system between 0 and 5°C. After the addition is complete, allow the mixture to warm naturally to room temperature and continue stirring for 3 h. After the reaction is complete, quench the reaction mixture in ice water to precipitate a white solid. Collect the solid by filtration, wash with water, and then dry under vacuum at 40°C to obtain intermediate IM-3 (6.30 g, 84% yield).

[0063]

[0064] (2) Synthesize compound A3 Add intermediate IM-3 (3.53 g, 10.6 mmol), 25 mL of water, and 25 mL of acetonitrile to a round-bottom flask and stir until dissolved. While stirring, add alkali solution dropwise to maintain the pH of the reaction system at 8–9. Heat the system to 50 °C and add 3.56 g of an aqueous solution of aminodi(methylenephosphonic acid) (containing 10.4 mmol of aminodi(methylenephosphonic acid)) dropwise over 20 min. After the addition is complete, continue stirring the reaction for 10 h, maintaining the temperature at 50–55 °C throughout the reaction.

[0065] Subsequently, the reaction system was heated to 85°C, and an alkaline solution was added dropwise under stirring to maintain the pH between 8 and 9. Then, 3.76 g of an aqueous solution of aminodi(methylenephosphoric acid) (containing 11.0 mmol of aminodi(methylenephosphoric acid)) was added dropwise over a period of 20 min. After the addition was complete, the reaction was stirred for another 18 h, with the temperature maintained between 85 and 90°C throughout the reaction. After the reaction was completed, the mixture was cooled to room temperature, the resulting reaction system was filtered, the solid was collected, washed with water, and dried under vacuum at 40°C to obtain the target product, compound A3 (5.69 g, 80% yield).

[0066]

[0067] NMR characterization of compound A3 1H-NMR(400MHz, CDCl3) δ(ppm): 4.80(8H, s), 7.01(1H,s), 3.45(8H, m), 3.35(2H, m), 1.63(2H, m), 1.36(2H, m), 1.24(2H, m), 1.27(2H,m), 1.26(12H, m), 0.88(3H, t).

[0068] Mass spectrometric characterization of compound A3, LCMS (ESI) m / z [M+H] + : 671.4778.

[0069] Synthesis example 3 (1) Synthesis of intermediate IM-4 Add cyanuric chloride (5 g, 27.1 mmol) and 80 mL of acetone to a round-bottom flask and stir to dissolve. Place the reaction flask in an ice-water bath and cool to 0°C. Under stirring, slowly add a solution of tetradecylamine (4.9 g, 23.0 mmol) in 40 mL of acetone over a period of 20 min, maintaining the temperature of the reaction system between 0 and 5°C. After the addition is complete, allow the mixture to warm naturally to room temperature and continue stirring for 2.5 h. After the reaction is complete, quench the reaction mixture in ice water to precipitate a white solid. Collect the solid by filtration, wash with water, and then dry under vacuum at 40°C to obtain intermediate IM-4 (6.82 g, 82% yield).

[0070]

[0071] (2) Synthesize compound A4 Add intermediate IM-4 (3.76 g, 10.4 mmol), 25 mL of water, and 25 mL of acetonitrile to a round-bottom flask and stir until dissolved. While stirring, add alkali solution dropwise to maintain the pH of the reaction system at 8–9. Heat the system to 50 °C and add 3.56 g of an aqueous solution of aminodi(methylenephosphonic acid) (containing 10.4 mmol of aminodi(methylenephosphonic acid)) dropwise over 20 min. After the addition is complete, continue stirring the reaction for 8 h, maintaining the temperature at 50–55 °C throughout the reaction.

[0072] Subsequently, the reaction system was heated to 85°C, and an alkaline solution was added dropwise under stirring to maintain the pH between 8 and 9. Then, 3.76 g of an aqueous solution of aminodi(methylenephosphonic acid) (containing 11.0 mmol of aminodi(methylenephosphonic acid)) was added dropwise over a period of 20 min. After the addition was complete, the reaction was stirred for another 18 h, with the temperature maintained between 85 and 90°C throughout the process. After the reaction was completed, the mixture was cooled to room temperature, the resulting reaction system was filtered, the solid was collected, washed with water, and then dried under vacuum at 40°C to obtain the target product, compound A4 (5.66 g, yield 78%).

[0073]

[0074] NMR characterization of compound A4: 1 H-NMR(400MHz, CDCl3) δ(ppm): 4.80(8H, s), 7.01(1H,s), 3.45(8H, m), 3.35(2H, m), 1.63(2H, m), 1.36(2H, m), 1.24(2H, m), 1.27(2H,m), 1.26(16H, m), 0.88(3H, t).

[0075] Mass spectrometric characterization of compound A4, LCMS (ESI) m / z [M+H] + : 699.5278.

[0076] Synthesis example 4 (1) Synthesis of intermediate IM-6 Add cyanuric chloride (5 g, 27.1 mmol) and 80 mL of acetone to a round-bottom flask and stir to dissolve. Place the reaction flask in an ice-water bath to cool and maintain the temperature at 0°C. Under stirring, slowly add a solution of hexadecylamine (5.4 g, 22.4 mmol) in 40 mL of acetone over a period of 20 min, maintaining the temperature of the reaction system between 0 and 5°C. After the addition is complete, allow the mixture to warm naturally to room temperature and continue stirring for 2 h. After the reaction is complete, quench the reaction mixture in ice water to precipitate a white solid. Collect the solid by filtration, wash with water, and then dry under vacuum at 40°C to obtain intermediate IM-6 (7.41 g, 85% yield).

[0077]

[0078] (2) Synthesis of compound A6 Add intermediate IM-6 (4.05 g, 10.4 mmol), 25 mL of water, and 25 mL of acetonitrile to a round-bottom flask and stir until dissolved. Heat the system to 50 °C, and while stirring, add alkali solution to maintain the pH of the reaction system at 8-9. Then, add 3.56 g of an aqueous solution of aminodi(methylenephosphonic acid) (containing 10.4 mmol of aminodi(methylenephosphonic acid)) dropwise over a period of 20 min. After the addition is complete, continue stirring the reaction for 10 h, maintaining the temperature at 55-60 °C throughout the reaction.

[0079] Subsequently, the reaction system was heated to 80°C, and an alkaline solution was added dropwise to maintain the pH between 8 and 9. Then, 3.76 g of an aqueous solution of aminodi(methylenephosphoric acid) (containing 11.0 mmol of aminodi(methylenephosphoric acid)) was added dropwise over a period of 20 min. After the addition was complete, the reaction was stirred for another 22 h, with the temperature maintained at 80–85°C throughout the reaction. After the reaction was completed, the mixture was cooled to room temperature, the resulting reaction system was filtered, the solid was collected, washed with water, and then dried under vacuum at 40°C to obtain the target product, compound A6 (6.35 g, yield 84%).

[0080]

[0081] NMR characterization of compound A6: 1 H-NMR(400MHz, CDCl3) δ(ppm): 4.80(8H, s), 7.01(1H,s), 3.45(8H, m), 3.35(2H, m), 1.63(2H, m), 1.36(2H, m), 1.24(2H, m), 1.27(2H,m), 1.26(20H, m), 0.88(3H, t).

[0082] Mass spectrometric characterization of compound A6, LCMS (ESI) m / z [M+H] + : 727.5878.

[0083] Synthesis example 5 (1) Synthesis of intermediate IM-7 Add cyanuric chloride (5 g, 27.1 mmol) and 80 mL of acetone to a round-bottom flask and stir to dissolve. Place the reaction flask in an ice-water bath and cool to 0°C. Under stirring, slowly add a solution of octadecylamine (6.1 g, 22.5 mmol) in 45 mL of acetone over a period of 20 min, maintaining the temperature of the reaction system between 0 and 5°C. After the addition is complete, allow the mixture to warm naturally to room temperature and continue stirring for 2 h. After the reaction is complete, quench the reaction solution in ice water to precipitate a white solid. Collect the solid by filtration, wash with water, and then dry under vacuum at 40°C to obtain intermediate IM-7 (7.51 g, 80% yield).

[0084]

[0085] (2) Synthesis of compound A7 Add intermediate IM-7 (4.34 g, 10.4 mmol), 28 mL of water, and 30 mL of acetonitrile to a round-bottom flask and stir until dissolved. Heat the system to 50 °C, and while stirring, add alkali solution dropwise to maintain the pH of the reaction system at 8-9. Add 3.56 g of an aqueous solution of aminodi(methylenephosphonic acid) (containing 10.4 mmol of aminodi(methylenephosphonic acid)) dropwise over a period of 20 min. After the addition is complete, continue stirring the reaction for 10 h, maintaining the temperature at 50-60 °C throughout the reaction.

[0086] Subsequently, the reaction system was heated to 80°C, and an alkaline solution was added dropwise under stirring to maintain the pH between 8 and 9. Then, 3.76 g of an aqueous solution of aminodi(methylenephosphoric acid) (containing 11.0 mmol of aminodi(methylenephosphoric acid)) was added dropwise over a period of 20 min. After the addition was complete, the reaction was stirred for another 20 h, with the temperature maintained at 80–85°C throughout the reaction. After the reaction was completed, the mixture was cooled to room temperature, the resulting reaction system was filtered, the solid was collected, washed with water, and dried under vacuum at 40°C to obtain the target product, compound A7 (6.12 g, yield 78%).

[0087]

[0088] NMR characterization of compound A7: 1 H-NMR(400MHz, CDCl3) δ(ppm): 4.8(8H, s), 7.01(1H,s), 3.45(8H, m), 3.35(2H, m), 1.63(2H, m), 1.36(2H, m), 1.24(2H,m) 1.27(2H,m), 1.26(22H, m), 0.88(3H, t).

[0089] Mass spectrometric characterization of compound A7, LCMS (ESI) m / z [M+H] + : 755.6378.

[0090] The following examples illustrate the silicon wafer cleaning agent and its preparation method of the present invention.

[0091] Hydrogen peroxide is used in its aqueous solution form at a concentration of 30%.

[0092] Example 1 According to the proportions shown in Table 1, water, ethanol, hydrogen peroxide aqueous solution and surfactant (compound A2) were added to the stirred tank in sequence and stirred at room temperature for 10 min to obtain a homogeneous solution, which is the silicon wafer cleaning agent. The prepared cleaning agent is denoted as C1.

[0093] Examples 2-8 Silicon wafer cleaning agents were prepared according to the method of Example 1, except that the formula was adjusted according to Table 1, and the prepared silicon wafer cleaning agents were denoted as C2 to C8.

[0094] Comparative Example 1 The silicon wafer cleaning agent was prepared according to the method of Example 1, except that no surfactant was added and the amount of water was adjusted accordingly. The prepared silicon wafer cleaning agent is denoted as D1.

[0095] Comparative Example 2 The silicon wafer cleaning agent was prepared according to the method of Example 1, except that the surfactant (compound A2) was replaced with trilauryl citrate. The prepared silicon wafer cleaning agent was denoted as D2.

[0096] Table 1

[0097] Note: All percentage contents in Table 1 refer to mass percentage contents.

[0098] Test case The test examples are used to illustrate the performance of the silicon wafer cleaning agents prepared in the above embodiments and comparative examples.

[0099] 1. Provide test samples Unused n-type (100) silicon wafers were used as blank wafers. The wafers were immersed in the cleaning agents mentioned above and cleaned at 40°C for 2 minutes. They were then rinsed thoroughly with deionized water and dried with high-purity nitrogen to obtain the test samples.

[0100] 2. Contact Angle Test The contact angle (θ) of the silicon wafer surface to water after cleaning was measured using a contact angle tester to evaluate the hydrophilicity / hydrophobicity and cleanliness of the silicon wafer surface. Five points were randomly tested in each group, and the average value of the results was taken. The test results are shown in Table 2.

[0101] Table 2

[0102] As shown in Table 2, the contact angles of the silicon wafers cleaned by cleaning agents C1 to C8 in Examples 1-8 were all <8°, exhibiting excellent hydrophilicity. In contrast, the contact angles of the silicon wafers cleaned by the comparative cleaning agent D1 were >45°, indicating the presence of hydrophobic contaminants on the silicon wafer surface after cleaning. The contact angle of the comparative cleaning agent D2 was <10°, indicating that it was basically clean. It is evident that, compared to Comparative Examples 1-2, the cleaning agents in Examples 1-8 are more effective at removing contaminants and forming hydrophilic terminals on the silicon wafer surface.

[0103] 3. Metal content analysis The metal content of the cleaned silicon wafers was tested using inductively coupled plasma mass spectrometry (ICP-MS), and the test results are shown in Table 3.

[0104] Table 3

[0105] Note: The unit for the content of metallic elements is ppb.

[0106] As shown in Table 3, the total metal element content of silicon wafers cleaned with cleaning agents D1 and D2 reached as high as 18.94 ppb and 12.38 ppb, respectively, both significantly higher than that of silicon wafers cleaned with cleaning agents C1-C8. This demonstrates that compounds A2-A4 and A6, A7, used in the cleaning agent formulations of Examples 1-8, as chelating surfactants, can efficiently strip and complex metal impurities through both surfactant micellar solubilization and chelating agent coordination, preventing their redeposition.

[0107] 4. Particle Adsorption Stability Test One hundred blank silicon wafers were cleaned using cleaning agents C1, C5, and C7, and comparative cleaning agents D1 and D2, respectively, according to the method described in item 1.

[0108] A surface particle analyzer was used to test the number of particles on the surface of silicon wafers after storage for different periods to assess the long-term stability of their cleanliness. The specific method is as follows: immediately after cleaning (recorded as 0h), particle testing was performed on the silicon wafers; subsequently, all silicon wafers were stored in a controlled clean environment (ISO Class 5, 22±1℃, 45±5% RH), and the tests were repeated at 12h, 24h, 48h, and 70h.

[0109] According to SEMI standards, a compliance benchmark is defined as having fewer than 10 particles with a diameter > 0.5 μm on a single silicon wafer. The total number of compliant silicon wafers at each time point was recorded, and the percentage of compliant silicon wafers to the total number of wafers was calculated (compliance percentage). The results are recorded in Table 4.

[0110] Table 4

[0111] As shown in Table 4, cleaning agents C1, C5, and C7 all achieved a 100% particle compliance rate after cleaning (0h), significantly higher than the comparative cleaning agents D1 (43%) and D2 (62%), demonstrating that the cleaning agents in this example have a higher initial particle removal capability. Furthermore, during the 70h storage period, the compliance rate of silicon wafers treated with cleaning agents C1, C5, and C7 consistently remained above 96%, indicating that the cleaning agents not only removed particles during the cleaning process but also formed a stable passivation layer on the silicon wafer surface, greatly inhibiting secondary particle adsorption. In contrast, the compliance rate of silicon wafers treated with cleaning agents D1 and D2 decreased sharply with storage time, indicating that their cleaning effect was incomplete and the surface state was unstable, allowing particles to be quickly re-adsorbed during storage, failing to meet the stability requirements of actual production.

[0112] In summary, the silicon wafer cleaning agent of this invention, using the aforementioned phosphorus-containing organic compound as a surfactant, exhibits comprehensive cleaning performance. It can form superhydrophilic terminals (contact angle <8°) on the silicon wafer surface, providing favorable conditions for achieving high-quality photolithography, thin film deposition, and other key processes. Simultaneously, this cleaning agent can stably control the total residual amount of various metal impurities at extremely low levels, effectively avoiding device performance degradation caused by metal contamination. Furthermore, the silicon wafer cleaning agent not only possesses highly efficient initial particle removal capabilities but also endows the silicon surface with excellent anti-secondary adsorption properties after cleaning, ensuring that it maintains ultra-high cleanliness during storage, thereby improving the process stability and product yield of high-end semiconductor manufacturing.

[0113] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still 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. 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, and they should all be covered within the scope of the claims and specification of the present invention. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A phosphorus-containing organic compound, characterized in that, It has the structure shown in Equation 1: Formula 1 Wherein, R is an alkyl group having 6 to 18 carbon atoms.

2. The phosphorus-containing organic compound according to claim 1, characterized in that, R is a straight-chain alkyl group with 8 to 18 carbon atoms.

3. The phosphorus-containing organic compound according to claim 1, characterized in that, The phosphorus-containing organic compound is selected from at least one of the following compounds A1 to A8: 。 4. A method for preparing the phosphorus-containing organic compound according to any one of claims 1-3, characterized in that, Includes the following steps: 1) In an organic solvent, cyanuric chloride is reacted with an aliphatic amine with the structure shown in formula a at a temperature of -5°C to 30°C to generate intermediate I with the structure shown in formula b. Formula a, Formula b; 2) In an aqueous solvent, intermediate I is subjected to a second nucleophilic substitution reaction with a portion of aminodi(methylene phosphate) at 50-60°C; 3) Heat the reaction system obtained in step 2) to 80~90℃, and then add the remaining amino di(methylene phosphate) to carry out the third nucleophilic substitution reaction to form a phosphorus-containing organic compound with the structure shown in Formula 1.

5. The method according to claim 4, characterized in that, In step 1), the molar ratio of cyanuric chloride to the fatty amine is 1:(0.8~1.2); Preferably, the first nucleophilic substitution reaction takes 1 to 4 hours; Preferably, the organic solvent is at least one selected from acetone, tetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide, methanol, ethanol, and isopropanol.

6. The method according to claim 4 or 5, characterized in that, In step 2), the molar ratio of intermediate I to aminodi(methylenephosphoric acid) is 1:(0.8~1.2), and the time for the second nucleophilic substitution reaction is 8~13h; Preferably, the second nucleophilic substitution reaction is carried out under alkaline conditions at a pH of 8-10; Preferably, the aqueous solvent is composed of water and a polar solvent, and the polar solvent is selected from at least one of acetonitrile, tetrahydrofuran, and N,N-dimethylformamide; Preferably, in the aqueous solvent, the volume ratio of water to the polar solvent is (5~12):

10.

7. The method according to any one of claims 4-6, characterized in that, The molar ratio of aminodi(methylenephosphonic acid) in step 3) to that in step 2) is (0.8~1.2):1, and the time for the third nucleophilic substitution reaction is 18~24h; Preferably, the third nucleophilic substitution reaction is carried out under alkaline conditions at a pH of 8-10.

8. A silicon wafer cleaning agent, characterized in that, The silicon wafer cleaning agent contains a surfactant, wherein the surfactant is a phosphorus-containing organic compound as described in any one of claims 1-3.

9. The silicon wafer cleaning agent according to claim 8, characterized in that, The silicon wafer cleaning agent also contains water, hydrogen peroxide, and alcohol compounds; Preferably, based on the total mass of the silicon wafer cleaning agent, the mass content of the alcohol compound is 1% to 10%, the mass content of hydrogen peroxide is 2% to 12%, and the mass content of the surfactant is 0.01% to 0.1%.

10. The silicon wafer cleaning agent according to claim 9, characterized in that, The alcohol compounds are monohydric or polyhydric alcohols having 1 to 6 carbon atoms; Preferably, the alcohol compound is selected from at least one of methanol, ethanol, isopropanol, n-butanol, ethylene glycol, propylene glycol, glycerol, and 1,4-butanediol.

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