Wafer cutting cleaning fluid and preparation method thereof

Abstract

The invention relates to the field of semiconductor wafer processing, in particular to wafer cutting cleaning fluid and a preparation method thereof. Comprising the following raw materials in parts by weight: 1-3 parts of phase change microcapsules, 4-8 parts of a chelating agent, 4-8 parts of a microemulsion matrix, 1-3 parts of an amphiphilic polymer, 1-5 parts of a fluorine-containing surfactant, 0.1-0.3 part of 3-mercaptopropyltrimethoxysilane, 0.3-0.6 part of a pH buffer agent and 40-70 parts of deionized water. The phase change microcapsule, the chelating agent, the microemulsion matrix, the amphiphilic polymer, the fluorine-containing surfactant, the 3-mercaptopropyltrimethoxysilane, the pH buffering agent and other active ingredients are organically combined, synchronous and efficient removal of organic / inorganic / metal ions is achieved, the removal rate can reach 99.3% or above, the cleaning effect is remarkably improved, and the cleaning agent is suitable for industrial production. The method is suitable for cleaning the cut advanced packaging wafer.

Description

Technical Field

[0001] This invention relates to the field of semiconductor wafer processing, and more specifically to a wafer dicing and cleaning fluid and its preparation method. Background Technology

[0002] Wafer dicing and cleaning technology is a crucial step in semiconductor manufacturing, significantly impacting product quality and performance. However, existing wafer dicing and cleaning technologies suffer from several problems, such as low simultaneous removal rates of multiple organic / inorganic / metal ion residues, easy re-oxidation of the die surface during the rinsing-drying stage after cleaning, high COD in wastewater due to the use of high-concentration strong alkalis / strong oxidants, and high treatment costs. These issues severely restrict the application and development of wafer dicing and cleaning technology.

[0003] Currently, commonly used wafer dicing and cleaning methods mainly include high-temperature, high-pressure water jets, chemical etching, and mechanical wiping. However, these methods often struggle to simultaneously achieve the goals of efficient decontamination, in-situ oxidation resistance, and reversible protection. For example, using high-temperature, high-pressure water jets may damage the microstructure of the wafer surface, while chemical etching may introduce new contaminants. Furthermore, these methods typically require large quantities of chemical reagents, generating significant amounts of wastewater, increasing treatment costs and environmental burden.

[0004] Therefore, developing a wafer dicing cleaning fluid that can simultaneously achieve efficient decontamination, in-situ oxidation resistance, and reversible protection, while also possessing good environmental performance and economic benefits, has become a key research focus and challenge. This requires not only innovation in formulation design but also optimization in preparation processes and application methods to address the problems existing in current technologies and meet practical production needs. Summary of the Invention

[0005] Existing technologies suffer from problems such as low residual rates of organic / inorganic / metal ions during wafer dicing and cleaning, easy re-oxidation of the grain surface after cleaning, high COD in wastewater, and high treatment costs. Therefore, to address these issues, this invention provides a wafer dicing cleaning solution and its preparation method. This cleaning solution features highly efficient decontamination, in-situ oxidation resistance, and reversible protection.

[0006] The objective of this invention is achieved through the following technical solution: a wafer dicing cleaning solution, comprising the following raw materials in parts by weight: 1-3 parts of phase change microcapsules, 4-8 parts of chelating agent, 4-8 parts of microemulsion matrix, 1-3 parts of amphiphilic polymer, 1-5 parts of fluorinated surfactant, 0.1-0.3 parts of 3-mercaptopropyltrimethoxysilane (R-SAM precursor), 0.3-0.6 parts of pH buffer, and 40-70 parts of deionized water; wherein the pH buffer is citric acid-sodium citrate.

[0007] This invention achieves simultaneous and efficient removal of organic, inorganic, and metal ions by organically combining multiple active ingredients such as phase change microcapsules, chelating agents, microemulsion matrices, amphiphilic polymers, fluorinated surfactants, 3-mercaptopropyltrimethoxysilane, and pH buffers. Simultaneously, the cleaning solution simultaneously constructs pH-responsive phase change microcapsules, microemulsion micelle channels, and a reversibly self-assembled monolayer (3-mercaptopropyltrimethoxysilane) precursor within the same aqueous system, achieving one-step decontamination, chelation, anti-oxidation, and protection. The cleaning solution can be cycled 5 times while maintaining a removal rate of >92%. Furthermore, the 3-mercaptopropyltrimethoxysilane used as a precursor can form a 2-4 nm reversible hydrophobic protective layer on the wafer surface, effectively preventing re-oxidation of the wafer surface while ensuring the wafer's hydrophilicity, providing a good foundation for subsequent processes.

[0008] Preferably, the chelating agent is composed of citric acid and sodium gluconate in a mass ratio of 3.0-4.0:1.0-2.0.

[0009] Preferably, the phase change microcapsule includes a core and a shell encapsulating the outer surface of the core. The shell is a polyacrylate-methyl methacrylate copolymer, and the core is composed of a nonionic surfactant and an antioxidant in a mass ratio of 1.5-2.5:0.8-1.2.

[0010] Preferably, the nonionic surfactant is at least one of fatty alcohol polyoxyethylene ether, alkylphenol polyoxyethylene ether, and fatty acid polyoxyethylene ester.

[0011] Preferably, the antioxidant is at least one of ascorbyl palmitate, propyl gallate, and butylated hydroxytoluene.

[0012] Preferably, the phase change microcapsules are prepared by the following method: first, a nonionic surfactant and an antioxidant are dissolved in ethyl acetate as the oil phase, and a 0.5 wt% polyacrylate emulsion is used as the aqueous phase; then, the oil phase and the aqueous phase are mixed and emulsified at a rate of 12000-13000 rpm for 15-20 min, and the solvent is evaporated under reduced pressure to obtain phase change microcapsules with an average particle size of 1.2 µm and an encapsulation efficiency of 88-90%; wherein, the ratio of the oil phase to the aqueous phase is 0.4-0.6:2.0-2.2, and the weight ratio of the nonionic surfactant and antioxidant to ethyl acetate is 1.5-2.5:0.8-1.2:3.0-3.5.

[0013] This invention employs a specially designed phase change microcapsule structure. The design of the core encapsulating the outer shell allows the wafer surface to self-seal after cleaning, effectively preventing re-oxidation of the wafer surface during the rinsing-drying stage. The oxygen content can be controlled within 0.42 within 24 hours, effectively solving the problem of increased oxygen content on the wafer surface in the prior art.

[0014] Preferably, the microemulsion matrix is ​​composed of Tween-80, vegetable oil, and water in a mass ratio of 0.5-1.0:2.0-3.0:1.0-1.5; the microemulsion matrix is ​​an O / W microemulsion with an average particle size of 30-80 nm formed by mixing Tween-80, vegetable oil, and water, heating to 35-40°C, and stirring at a rate of 8000-9000 rpm for 10-20 min.

[0015] The present invention utilizes a microemulsion matrix design to ensure that active ingredients are uniformly dispersed in a water-based system, avoiding environmental pollution caused by the use of high-concentration strong alkalis / strong oxidants, significantly reducing wastewater COD, and lowering treatment costs.

[0016] Preferably, the amphiphilic polymer is poly(2-acrylamide-2-methylpropanesulfonic acid-co-dimethylaminopropylmethacrylamide).

[0017] Preferably, the fluorinated surfactant is at least one of sodium perfluorohexyl ethyl sulfonate, fluorinated polyol polyoxyethylene ether, and short-chain anionic fluoroalkyl sulfonate.

[0018] This invention also provides a method for preparing a wafer dicing cleaning solution, comprising the following steps: S1. Disperse the chelating agent in deionized water according to the weight parts, and then slowly add the microemulsion matrix at a stirring rate of 300-350 rpm for 5-10 min to form a "chelation-microemulsion" composite phase for later use. S2. According to the weight proportions, add the phase change microcapsules to the composite phase. After the addition is complete, increase the rotation speed to 400-500 rpm and maintain it for 10-20 minutes to allow the three phases to be initially dispersed. Then add the amphiphilic polymer, fluorinated surfactant, 3-mercaptopropyltrimethoxysilane, and pH buffer to the reaction system and continue stirring at a speed of 500-600 rpm for 5-10 minutes. Finally, filter to obtain the cleaning solution.

[0019] This invention also provides a method for using a wafer dicing cleaning fluid, comprising the following steps: A1. Place the diced wafer in a cleaning solution at 40±2℃ and apply ultrasonic waves at 40-42kHz and 300-350W, while simultaneously applying a pulsed electric field at 5-10V / cm, frequency 1-1.1kHz, and duty cycle 50-55%, for 5-8 minutes. A2. Stop the electric field and continue ultrasound for 1-2 minutes to desorb the bubbles; A3. Rinse with deionized water for 30 seconds, then dry with nitrogen in a rotating manner. The pH of the cleaning solution is increased from 5.0 to 8.0-8.2, which triggers the rupture of phase change microcapsules and releases antioxidants. The precursor 3-mercaptopropyltrimethoxysilane forms a 2-4 nm reversible hydrophobic protective layer on the wafer surface.

[0020] The beneficial effects of this invention are as follows: 1. This invention organically combines multiple active ingredients such as phase change microcapsules, chelating agents, microemulsion matrix, amphiphilic polymers, fluorinated surfactants, 3-mercaptopropyltrimethoxysilane, and pH buffers to achieve simultaneous and efficient removal of organic / inorganic / metal ions, with a removal rate of over 99.3%, significantly improving the cleaning effect. 2. This invention employs a specially designed phase change microcapsule structure. The design of the core encapsulating the outer shell enables the wafer surface to self-seal after cleaning, effectively preventing re-oxidation of the wafer surface during the rinsing-drying stage. The oxygen content can be controlled at 0.42 within 24 hours, effectively solving the problem of increased oxygen content on the wafer surface in the prior art. 3. This invention, through the design of a microemulsion matrix, enables the active ingredients to be uniformly dispersed in the water-based system, avoiding environmental pollution caused by the use of high-concentration strong alkalis / strong oxidants, significantly reducing wastewater COD, and reducing treatment costs; 4. This invention uses 3-mercaptopropyltrimethoxysilane as a precursor to form a 2-4 nm reversible hydrophobic protective layer on the wafer surface, which can effectively prevent the wafer surface from being re-oxidized and ensure the hydrophilicity of the wafer, providing a good foundation for subsequent processes. 5. By optimizing the formula design and preparation process, this invention enables the cleaning solution to have good stability and recyclability, significantly reducing production costs and improving production efficiency. Detailed Implementation

[0021] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments. The content mentioned in the embodiments is not intended to limit the present invention. Example 1

[0022] A wafer dicing cleaning solution comprises the following raw materials in parts by weight: 1 part phase change microcapsule, 4 parts chelating agent, 4 parts microemulsion matrix, 1 part amphiphilic polymer, 1 part fluorinated surfactant, 0.1 part 3-mercaptopropyltrimethoxysilane, 0.3 parts pH buffer, and 40 parts deionized water; wherein the pH buffer is citric acid-sodium citrate.

[0023] The chelating agent is composed of citric acid and sodium gluconate in a mass ratio of 3.0:1.0.

[0024] The phase change microcapsule includes a core and a shell encapsulating the outer surface of the core. The shell is a copolymer of polyacrylate and methyl methacrylate. The core is composed of a nonionic surfactant and an antioxidant in a mass ratio of 1.5:0.8.

[0025] The nonionic surfactant is a fatty alcohol polyoxyethylene ether. The antioxidant is ascorbate palmitate.

[0026] The phase change microcapsules were prepared by the following method: First, a nonionic surfactant and an antioxidant were dissolved in ethyl acetate as the oil phase, and a 0.5 wt% polyacrylate emulsion was used as the aqueous phase; then, the oil phase and the aqueous phase were mixed and emulsified at a rate of 12000 rpm for 20 min, and the solvent was evaporated under reduced pressure to obtain phase change microcapsules with an average particle size of 1.2 µm and an encapsulation efficiency of 88-90%; wherein, the ratio of the oil phase to the aqueous phase was 0.4:2.0, and the weight ratio of the nonionic surfactant and antioxidant to ethyl acetate was 1.5:0.8:3.0.

[0027] The microemulsion matrix is ​​composed of Tween-80, vegetable oil and water in a mass ratio of 0.5:2.0:1.0; the microemulsion matrix is ​​an O / W microemulsion with an average particle size of 30-80nm formed by mixing Tween-80, vegetable oil and water, heating to 35°C and stirring at a rate of 9000rpm for 20min.

[0028] The amphiphilic polymer is poly(2-acrylamide-2-methylpropanesulfonic acid-co-dimethylaminopropylmethacrylamide), preferably Poly(AMPS-co-DMAPMA) from Xi'an Qiyue Biotechnology Co., Ltd., with a specification of Mw 100 kDa (actually measured 95-110 kDa) and an AMPS:DMAPMA molar ratio of 7:3.

[0029] The fluorinated surfactant is sodium perfluorohexyl ethyl sulfonate.

[0030] A method for preparing a wafer dicing cleaning fluid includes the following steps: S1. Disperse the chelating agent in deionized water according to the weight parts, and then slowly add the microemulsion matrix at a stirring rate of 300 rpm for 10 min to form a "chelation-microemulsion" composite phase for later use. S2. According to the weight proportions, add the phase change microcapsules to the composite phase. After the addition is complete, increase the rotation speed to 400 rpm and maintain it for 20 min to allow the three phases to be initially dispersed. Then add the amphiphilic polymer, fluorinated surfactant, 3-mercaptopropyltrimethoxysilane, and pH buffer to the reaction system and continue stirring at 500 rpm for 10 min. Finally, filter to obtain the cleaning solution. Example 2

[0031] A wafer dicing cleaning solution comprises the following raw materials in parts by weight: 2 parts phase change microcapsules, 6 parts chelating agent, 6 parts microemulsion matrix, 2 parts amphiphilic polymer, 3 parts fluorinated surfactant, 0.2 parts 3-mercaptopropyltrimethoxysilane, 0.5 parts pH buffer, and 50 parts deionized water; wherein the pH buffer is citric acid-sodium citrate.

[0032] The chelating agent is composed of citric acid and sodium gluconate in a mass ratio of 3.5:1.5.

[0033] The phase change microcapsule includes a core and a shell encapsulating the outer surface of the core. The shell is a copolymer of polyacrylate and methyl methacrylate. The core is composed of a nonionic surfactant and an antioxidant in a mass ratio of 2.0:1.0.

[0034] The nonionic surfactant is a fatty alcohol polyoxyethylene ether. The antioxidant is ascorbate palmitate.

[0035] The phase change microcapsules were prepared by the following method: First, a nonionic surfactant and an antioxidant were dissolved in ethyl acetate as the oil phase, and a 0.5 wt% polyacrylate emulsion was used as the aqueous phase; then, the oil phase and the aqueous phase were mixed and emulsified at a rate of 13000 rpm for 15 min, and the solvent was evaporated under reduced pressure to obtain phase change microcapsules with an average particle size of 1.2 µm and an encapsulation efficiency of 88-90%; wherein, the ratio of the oil phase to the aqueous phase was 0.5:2.1, and the weight ratio of the nonionic surfactant and antioxidant to ethyl acetate was 2.0:1.0:3.3.

[0036] The microemulsion matrix is ​​composed of Tween-80, vegetable oil and water in a mass ratio of 0.8:2.5:1.3; the microemulsion matrix is ​​an O / W microemulsion with an average particle size of 30-80nm formed by mixing Tween-80, vegetable oil and water, heating to 38°C and stirring at a rate of 9000rpm for 10min.

[0037] The amphiphilic polymer is poly(2-acrylamide-2-methylpropanesulfonic acid-co-dimethylaminopropylmethacrylamide), preferably Poly(AMPS-co-DMAPMA) from Xi'an Qiyue Biotechnology Co., Ltd., with a specification of Mw 100 kDa (actually measured 95-110 kDa) and an AMPS:DMAPMA molar ratio of 7:3.

[0038] The fluorinated surfactant is sodium perfluorohexyl ethyl sulfonate.

[0039] A method for preparing a wafer dicing cleaning fluid includes the following steps: S1. Disperse the chelating agent in deionized water according to the weight parts, and then slowly add the microemulsion matrix at a stirring speed of 300 rpm for 10 min to form a "chelation-microemulsion" composite phase for later use. S2. According to the weight proportions, add the phase change microcapsules to the composite phase. After the addition is complete, increase the rotation speed to 450 rpm and maintain it for 15 minutes to allow the three phases to be initially dispersed. Then add the amphiphilic polymer, fluorinated surfactant, 3-mercaptopropyltrimethoxysilane, and pH buffer to the reaction system and continue stirring at 550 rpm for 8 minutes. Finally, filter to obtain the cleaning solution. Example 3

[0040] A wafer dicing cleaning solution comprises the following raw materials in parts by weight: 3 parts phase change microcapsules, 8 parts chelating agent, 8 parts microemulsion matrix, 3 parts amphiphilic polymer, 5 parts fluorinated surfactant, 0.3 parts 3-mercaptopropyltrimethoxysilane, 0.6 parts pH buffer, and 70 parts deionized water; wherein the pH buffer is citric acid-sodium citrate.

[0041] The chelating agent is composed of citric acid and sodium gluconate in a mass ratio of 4.0:2.0.

[0042] The phase change microcapsule includes a core and a shell encapsulating the outer surface of the core. The shell is a copolymer of polyacrylate and methyl methacrylate. The core is composed of a nonionic surfactant and an antioxidant in a mass ratio of 2.5:1.2.

[0043] The nonionic surfactant is alkylphenol polyoxyethylene ether. The antioxidant is butylated hydroxytoluene.

[0044] The phase change microcapsules were prepared by the following method: First, a nonionic surfactant and an antioxidant were dissolved in ethyl acetate as the oil phase, and a 0.5 wt% polyacrylate emulsion was used as the aqueous phase; then, the oil phase and the aqueous phase were mixed and emulsified at a rate of 13000 rpm for 15 min, and the solvent was evaporated under reduced pressure to obtain phase change microcapsules with an average particle size of 1.2 µm and an encapsulation efficiency of 88-90%; wherein, the ratio of the oil phase to the aqueous phase was 0.6:2.2, and the weight ratio of the nonionic surfactant and antioxidant to ethyl acetate was 2.5:1.2:3.5.

[0045] The microemulsion matrix is ​​composed of Tween-80, vegetable oil and water in a mass ratio of 1.0:3.0:1.5; the microemulsion matrix is ​​an O / W microemulsion with an average particle size of 30-80nm formed by mixing Tween-80, vegetable oil and water, heating to 40°C and stirring at a rate of 8000rpm for 20min.

[0046] The amphiphilic polymer is poly(2-acrylamide-2-methylpropanesulfonic acid-co-dimethylaminopropylmethacrylamide), preferably Poly(AMPS-co-DMAPMA) from Xi'an Qiyue Biotechnology Co., Ltd., with a specification of Mw 100 kDa (actually measured 95-110 kDa) and an AMPS:DMAPMA molar ratio of 7:3.

[0047] The fluorinated surfactant is a fluorinated polyol polyoxyethylene ether.

[0048] A method for preparing a wafer dicing cleaning fluid includes the following steps: S1. Disperse the chelating agent in deionized water according to the weight parts, and then slowly add the microemulsion matrix at a stirring speed of 350 rpm for 5 minutes to form a "chelation-microemulsion" composite phase for later use. S2. According to the weight proportions, add the phase change microcapsules to the composite phase. After the addition is complete, increase the rotation speed to 500 rpm and maintain it for 10 minutes to allow the three phases to be initially dispersed. Then add the amphiphilic polymer, fluorinated surfactant, 3-mercaptopropyltrimethoxysilane, and pH buffer to the reaction system and continue stirring at 600 rpm for 5 minutes. Finally, filter to obtain the cleaning solution. Example 4

[0049] A wafer dicing cleaning solution comprises the following raw materials in parts by weight: 2 parts phase change microcapsules, 6 parts chelating agent, 6 parts microemulsion matrix, 2 parts amphiphilic polymer, 3 parts fluorinated surfactant, 0.2 parts 3-mercaptopropyltrimethoxysilane, 0.5 parts pH buffer, and 50 parts deionized water; wherein the pH buffer is citric acid-sodium citrate.

[0050] The chelating agent is composed of citric acid and sodium gluconate in a mass ratio of 4.0:2.0.

[0051] The phase change microcapsule includes a core and a shell encapsulating the outer surface of the core. The shell is a copolymer of polyacrylate and methyl methacrylate. The core is composed of a nonionic surfactant and an antioxidant in a mass ratio of 2.5:1.2.

[0052] The nonionic surfactant is alkylphenol polyoxyethylene ether. The antioxidant is butylated hydroxytoluene.

[0053] The phase change microcapsules were prepared by the following method: First, a nonionic surfactant and an antioxidant were dissolved in ethyl acetate as the oil phase, and a 0.5 wt% polyacrylate emulsion was used as the aqueous phase; then, the oil phase and the aqueous phase were mixed and emulsified at a rate of 13000 rpm for 15 min, and the solvent was evaporated under reduced pressure to obtain phase change microcapsules with an average particle size of 1.2 µm and an encapsulation efficiency of 88-90%; wherein, the ratio of the oil phase to the aqueous phase was 0.6:2.2, and the weight ratio of the nonionic surfactant and antioxidant to ethyl acetate was 2.5:1.2:3.5.

[0054] The microemulsion matrix is ​​composed of Tween-80, vegetable oil and water in a mass ratio of 1.0:3.0:1.5; the microemulsion matrix is ​​an O / W microemulsion with an average particle size of 30-80nm formed by mixing Tween-80, vegetable oil and water, heating to 40°C and stirring at a rate of 8000rpm for 20min.

[0055] The amphiphilic polymer is poly(2-acrylamide-2-methylpropanesulfonic acid-co-dimethylaminopropylmethacrylamide), preferably Poly(AMPS-co-DMAPMA) from Xi'an Qiyue Biotechnology Co., Ltd., with a specification of Mw 100 kDa (actually measured 95-110 kDa) and an AMPS:DMAPMA molar ratio of 7:3.

[0056] The fluorinated surfactant is a fluorinated polyol polyoxyethylene ether.

[0057] A method for preparing a wafer dicing cleaning fluid includes the following steps: S1. Disperse the chelating agent in deionized water according to the weight parts, and then slowly add the microemulsion matrix at a stirring speed of 350 rpm for 5 minutes to form a "chelation-microemulsion" composite phase for later use. S2. According to the weight proportions, add the phase change microcapsules to the composite phase. After the addition is complete, increase the rotation speed to 500 rpm and maintain it for 10 minutes to allow the three phases to be initially dispersed. Then add the amphiphilic polymer, fluorinated surfactant, 3-mercaptopropyltrimethoxysilane, and pH buffer to the reaction system and continue stirring at 600 rpm for 5 minutes. Finally, filter to obtain the cleaning solution. Example 5

[0058] A method for using a wafer dicing cleaning fluid includes the following steps: A1. Place the diced wafer in a cleaning solution at 40±2℃, apply 40kHz, 300W ultrasound, and simultaneously apply a pulsed electric field of 5-10V / cm, frequency 1-1.1kHz, and duty cycle 50% for 5-8 minutes. A2. Stop the electric field and continue ultrasound for 1-2 minutes to desorb the bubbles; A3. Rinse with deionized water for 30 seconds, then dry with nitrogen in a rotating manner. The pH of the cleaning solution is increased from 5.0 to 8.0-8.2, which triggers the rupture of phase change microcapsules and releases antioxidants. The precursor 3-mercaptopropyltrimethoxysilane forms a 2-4 nm reversible hydrophobic protective layer on the wafer surface.

[0059] A 4-inch silicon wafer was cut to a thickness of 50µm, with blade wear resulting in 1.8×10⁻⁶ Fe contamination of the metal. 13 (atoms / cm²). Using the cleaning solution prepared in Example 2, and following the usage method in Example 5, the cleaning was performed, followed by performance testing. Organic residues: According to GB / T 33203-2016 "Test Method for Contaminants on Silicon Wafer Surface - Secondary Ion Mass Spectrometry", the CH fragment count decreased by 96.2%. Metal ion-ICP-MS: According to GB / T 32646-2016 "Determination of Metal Contamination on Silicon Wafer Surface by Inductively Coupled Plasma Mass Spectrometry", the Fe residue was 2.3 × 10⁻⁶. 11 atoms / cm², removal rate 99.7%; Surface oxygen content - XPS: According to GB / T 30704-2014 "Surface chemical analysis - quantitative determination of surface elements of silicon wafers by X-ray photoelectron spectroscopy", the O / Si atomic ratio decreased from 0.68 to 0.42, and there was no increase in re-oxidation within 24 h; Contact angle: Tested according to GB / T 30693-2014 "Determination of contact angle between plastic film and water". After cleaning, the contact angle was 52° → after R-SAM formation, it was 108°. After rinsing with 1 wt% KOH (pH=11) for 10s, the contact angle dropped to 12°, proving that the removal was reversible. Cleaning solution circulation test: The test was conducted in accordance with the SEMI S2 / S8 environmental circulation assessment principle. After adding 1.5 wt% of phase change microcapsules to 5 consecutive batches of 25 tablets each, the removal rate of the 5th batch was still 99.3%.

[0060] Comparative Example 1

[0061] The difference between this comparative example and Example 2 above is that the raw materials of the cleaning solution in this comparative example do not contain phase change microcapsules. The rest of the contents of this comparative example are the same as those of Example 2, and will not be repeated here.

[0062] A 4-inch silicon wafer was cut to a thickness of 50 µm, with blade wear resulting in 1.8 × 10⁻⁶ Fe contamination of the metal. 13(atoms / cm²). Using the cleaning solution prepared in Comparative Example 1, the cleaning was performed according to the method described in Example 5. After cleaning, the performance was tested according to the aforementioned test method: the organic residue reduction rate was 82.4%; the Fe removal rate was 85.1%; the XPS (O / Si atomic ratio) increased from 0.42 to 0.57; the water contact angle was 52° (no protective film was formed); and the Fe removal rate was 72% after 5 cycles.

[0063] Comparative Example 2

[0064] This comparative example used only 2 wt% KOH + 1 wt% H2O2 for conventional cleaning. After cleaning, the organic residue decreased by 82%, the Fe removal rate was 85%, the oxygen content increased by 6 at.% after 24 hours, and the wastewater COD was 5800 mg / L.

[0065] The above embodiments are preferred implementations of the present invention. In addition, the present invention can be implemented in other ways. Any obvious substitutions without departing from the concept of the present invention are within the protection scope of the present invention.

Claims

1. A wafer dicing cleaning fluid, characterized in that: The raw materials include the following parts by weight: 1-3 parts phase change microcapsules, 4-8 parts chelating agent, 4-8 parts microemulsion matrix, 1-3 parts amphiphilic polymer, 1-5 parts fluorinated surfactant, 0.1-0.3 parts 3-mercaptopropyltrimethoxysilane, 0.3-0.6 parts pH buffer, and 40-70 parts deionized water.

2. The wafer dicing cleaning fluid according to claim 1, characterized in that: The chelating agent is composed of citric acid and sodium gluconate in a mass ratio of 3.0-4.0:1.0-2.

0.

3. The wafer dicing cleaning fluid according to claim 1, characterized in that: The phase change microcapsule includes a core and a shell encapsulating the outer surface of the core. The shell is a copolymer of polyacrylate and methyl methacrylate. The core is composed of a nonionic surfactant and an antioxidant in a mass ratio of 1.5-2.5:0.8-1.

2.

4. The wafer dicing cleaning fluid according to claim 3, characterized in that: The nonionic surfactant is at least one of fatty alcohol polyoxyethylene ether, alkylphenol polyoxyethylene ether, and fatty acid polyoxyethylene ester.

5. The wafer dicing cleaning fluid according to claim 3, characterized in that: The antioxidant is at least one of ascorbyl palmitate, propyl gallate, and butylated hydroxytoluene.

6. The wafer dicing cleaning fluid according to claim 3, characterized in that: The phase change microcapsules were prepared by the following method: First, a nonionic surfactant and an antioxidant were dissolved in ethyl acetate as the oil phase, and a 0.5 wt% polyacrylate emulsion was used as the aqueous phase; then, the oil phase and the aqueous phase were mixed and emulsified at a rate of 12000-13000 rpm for 15-20 min, and the solvent was evaporated under reduced pressure to obtain phase change microcapsules with an average particle size of 1.2 µm and an encapsulation efficiency of 88-90%; wherein, the ratio of the oil phase to the aqueous phase was 0.4-0.6:2.0-2.2, and the weight ratio of the nonionic surfactant and antioxidant to ethyl acetate was 1.5-2.5:0.8-1.2:3.0-3.

5.

7. The wafer dicing cleaning fluid according to claim 1, characterized in that: The microemulsion matrix is ​​composed of Tween-80, vegetable oil, and water in a mass ratio of 0.5-1.0:2.0-3.0:1.0-1.5; the microemulsion matrix is ​​an O / W microemulsion with an average particle size of 30-80nm formed by mixing Tween-80, vegetable oil, and water, heating to 35-40℃, and stirring at a rate of 8000-9000rpm for 10-20min.

8. The wafer dicing cleaning fluid according to claim 1, characterized in that: The amphiphilic polymer is poly(2-acrylamide-2-methylpropanesulfonic acid-co-dimethylaminopropylmethacrylamide).

9. The wafer dicing cleaning fluid according to claim 1, characterized in that: The fluorinated surfactant is at least one of sodium perfluorohexyl ethyl sulfonate, fluorinated polyol polyoxyethylene ether, and short-chain anionic fluoroalkyl sulfonate.

10. A method for preparing a wafer dicing cleaning fluid as described in any one of claims 1-9, characterized in that: Includes the following steps: S1. Disperse the chelating agent in deionized water according to the weight parts, and then slowly add the microemulsion matrix at a stirring rate of 300-350 rpm for 5-10 min to form a composite phase for later use. S2. According to the weight proportions, add the phase change microcapsules to the composite phase. After the addition is complete, increase the rotation speed to 400-500 rpm and maintain it for 10-20 minutes to allow the three phases to be initially dispersed. Then add the amphiphilic polymer, fluorinated surfactant, 3-mercaptopropyltrimethoxysilane, and pH buffer to the reaction system and continue stirring at a speed of 500-600 rpm for 5-10 minutes. Finally, filter to obtain the cleaning solution.