Semiconductor total synthesis suspension grinding fluid and preparation method thereof

Abstract

The invention belongs to the technical field of lubricating materials, and discloses a semiconductor total synthesis suspension grinding fluid and a preparation method thereof. The semiconductor total synthesis suspension grinding fluid comprises the following components in percentage by mass: 50-80% of deionized water, 5-10% of a pH regulator, 2-10% of a suspension dispersant, 5-10% of an antirust agent, 3-8% of a lubricant, 4-6% of a humectant and 5-10% of a surfactant, wherein the sum of the percentages of the components is 100%. The lubricating material is suitable for grinding semiconductor substrates. According to the grinding fluid, all the optimized additives are optimally combined, the prepared grinding fluid is high in comprehensive performance, protection and lubrication are provided for the grinding process, corrosion is prevented, carborundum powder can suspend in the grinding fluid, the settling speed is low, foam is few, and the carborundum powder is easy to clean and free of residues. The excellent lubricity and cooling performance can improve the product yield, prolong the service life of the die and improve the production efficiency.

Description

Technical Field

[0001] This invention relates to the field of lubricating materials, and in particular to a semiconductor fully synthetic suspension grinding fluid and its preparation method. Background Technology

[0002] Semiconductors have wide applications in consumer electronics, communication systems, photovoltaics, medical equipment, and home appliances. Supported by national policies and continuous technological innovation, China's semiconductor industry is progressing steadily, with breakthroughs in core technologies and gradual self-sufficiency. In existing markets such as mobile phones and servers, the value of semiconductors continues to increase; emerging markets such as artificial intelligence, 5G, 6G, and smart cars are becoming the main drivers of semiconductor market demand growth.

[0003] Ultra-precision grinding is a core technology for planarization and back-side thinning of semiconductor substrates, significantly impacting the processing efficiency and quality of semiconductor devices. Currently available semiconductor grinding products suffer from poor process compatibility, insufficient suspending capacity leading to abrasive agglomeration and settling, excessive foaming during grinding, and difficulty in cleaning and residue buildup, severely impacting work efficiency and wasting materials. To achieve high-efficiency, high-quality grinding of semiconductor substrates, a fully synthetic semiconductor suspension grinding fluid with strong process compatibility and wide operational adaptability is urgently needed. Summary of the Invention

[0004] The purpose of this invention is to provide a semiconductor fully synthetic suspension grinding fluid that is suitable for high-efficiency, high-quality grinding of semiconductor substrates.

[0005] The objective of this invention is achieved through the following solution:

[0006] A semiconductor fully synthetic suspension grinding fluid comprises the following components by mass percentage: pH adjuster 5-10%, suspending and dispersing agent 2-10%, rust inhibitor 5-10%, lubricant 3-8%, humectant 4-6%, surfactant 5-10%, and is replenished to 100% with deionized water.

[0007] The pH adjuster is at least one of KOH, monoethanolamine, diethanolamine, and triethanolamine, with triethanolamine being the preferred pH adjuster.

[0008] The suspending dispersant is a self-prepared polyacrylate emulsion. The preparation process is as follows: methyl methacrylate, styrene, and butyl acrylate are weighed in a certain proportion and added to an aqueous solution containing Tween 80 and sodium dodecylbenzene sulfate. The mixture is rapidly stirred at 40°C for 30 minutes to obtain a pre-emulsion. Two-fifths of the pre-emulsion is placed in a four-necked flask, rapidly stirred, and heated to 75°C. Simultaneously, sodium bisulfite and ammonium persulfate initiators, as well as the crosslinking monomer acrylamide and the remaining three-fifths of the pre-emulsion, are added dropwise to the flask. The dropwise addition time is controlled at 1.5 hours. After the addition is complete, the water bath temperature is raised to 85°C, and the reaction is maintained at this temperature for 0.5 hours. After the emulsion cools, a small amount of ammonia is added dropwise to adjust the pH of the emulsion to 7, thus obtaining the polyacrylate emulsion. The preferred ratio of the anionic emulsifier sodium dodecylbenzene sulfate and the nonionic emulsifier Tween 80 is 1:1. This ratio results in less coagulation, smaller particle size, and better emulsion stability. The preferred mass ratio of the added monomers methyl methacrylate, styrene, and butyl acrylate is 10:4:5. The preferred mass fraction of the added emulsifier is 4.0%, which results in less foaming due to thorough emulsification. The added initiator is a mixture of ammonium sulfate and sodium bisulfite, preferably in a mass ratio of 1:1, which minimizes the amount of coagulated material and increases the solids content of the emulsion. The polyacrylate emulsion synthesized under these conditions is a milky white liquid with a faint bluish tint, a solids content of 26.15%, and a viscosity of 6.35 mPa·s. This emulsion is stable, meets the requirements for suspension and dispersion, and does not form sedimentary flocs.

[0009] The rust inhibitor is a compound of at least one of sebacic acid and ternary polycarboxylic acid and borate, and the preferred rust inhibitor is a compound of sebacic acid and borate in a mass ratio of 1:1.

[0010] The lubricant is one or a mixture of two or more of polyethylene glycol, polypropylene glycol, trans-block polyether, water-soluble polymeric ester, polyether ester, and borate ester. The preferred lubricant is a mixture of polyethylene glycol and trans-block polyether in a mass ratio of 2:1.

[0011] The moisturizer is at least one of sorbitol, glycerin, 1,2-propanediol, and PEG-8, with the preferred moisturizer being a mixture of glycerin and PEG-8 in a 1:1 mass ratio.

[0012] The surfactant is at least one of fatty alcohol polyoxyethylene ether, castor oil polyoxyethylene ether, and alkylphenol polyoxyethylene ether, with fatty alcohol polyoxyethylene ether being the preferred surfactant.

[0013] The aforementioned semiconductor fully synthetic suspension grinding fluid can be prepared using conventional stirring and blending methods in the art:

[0014] 1. Add deionized water and suspending dispersant to the reactor, heat to about 50℃~70℃ and stir for 30 minutes;

[0015] 2. After stirring until clear and transparent, cool to room temperature, then add pH adjuster, rust inhibitor, lubricant, humectant and surfactant to the reaction vessel in sequence, and stir until evenly mixed to form a whitish clear and transparent liquid, thus obtaining semiconductor fully synthetic suspension grinding fluid.

[0016] The above-mentioned grinding fluid is used in semiconductor substrate grinding production lines.

[0017] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0018] To obtain a grinding fluid with good suspension properties, dispersants and surfactants need to be added to improve slurry stability by enhancing steric hindrance and supramolecular anchoring mechanisms. The preferred additives of this invention, through optimized combination, result in a grinding fluid with excellent comprehensive performance. The formulation system of this invention provides suitable lubrication for semiconductor grinding processes, excellent rust prevention, and simultaneously suspends diamond powder in the grinding fluid with slow settling speed, low foaming, easy cleaning without residue, and is environmentally friendly, while significantly improving grinding efficiency and yield. Detailed Implementation

[0019] The present invention will be further described in detail below with reference to embodiments, but the implementation of the present invention is not limited thereto.

[0020] Example 1: Preparation of a Semiconductor Fully Synthetic Suspension Grinding Fluid

[0021] A semiconductor fully synthetic suspension grinding fluid comprises the following raw materials by weight percentage: 6% pH adjuster, 5% suspending dispersant, 5% rust inhibitor, 7% lubricant, 6% humectant, 7% surfactant, and 64% deionized water.

[0022] Preparation method:

[0023] 1. Add deionized water and suspending dispersant to the reaction vessel, heat to about 50℃~70℃ and stir;

[0024] 2. After stirring until clear and transparent, cool to room temperature, then add pH adjuster, rust inhibitor, lubricant, humectant and surfactant to the reaction vessel in sequence, and stir until evenly mixed to form a whitish clear and transparent liquid, thus obtaining semiconductor fully synthetic suspension grinding fluid.

[0025] Performance testing:

[0026] The semiconductor fully synthetic suspension grinding fluid prepared in Example 1 was tested:

[0027]

[0028]

[0029] Note: Test methods

[0030] Example 2: Preparation of a Semiconductor Fully Synthetic Suspension Grinding Fluid

[0031] A semiconductor fully synthetic suspension grinding fluid comprises the following raw materials in weight percentage: 5% pH adjuster, 2% suspending dispersant, 5% rust inhibitor, 6% lubricant, 5% humectant, 5% surfactant, and 72% deionized water.

[0032] Preparation method:

[0033] 1. Add deionized water and suspending dispersant to the reaction vessel, heat to about 50℃~70℃ and stir;

[0034] 2. After stirring until clear and transparent, cool to room temperature, then add pH adjuster, rust inhibitor, lubricant, humectant and surfactant to the reaction vessel in sequence, and stir until evenly mixed to form a whitish clear and transparent liquid, thus obtaining semiconductor fully synthetic suspension grinding fluid.

[0035] Performance testing:

[0036] The semiconductor fully synthetic suspension grinding fluid prepared in Example 2 was tested:

[0037]

[0038]

[0039] Remark:

[0040] Example 3: Preparation of a Semiconductor Fully Synthetic Suspension Grinding Fluid

[0041] A semiconductor fully synthetic suspension grinding fluid comprises the following raw materials by weight percentage: 5% pH adjuster, 3% suspending and dispersing agent, 5% rust inhibitor, 7% lubricant, 6% humectant, 8% surfactant, and 66% deionized water.

[0042] Preparation method:

[0043] 1. Add deionized water and suspending dispersant to the reaction vessel, heat to about 50℃~70℃ and stir;

[0044] 2. After stirring until clear and transparent, cool to room temperature, then add pH adjuster, rust inhibitor, lubricant, humectant and surfactant to the reaction vessel in sequence, and stir until evenly mixed to form a whitish clear and transparent liquid, thus obtaining semiconductor fully synthetic suspension grinding fluid.

[0045] Performance testing:

[0046] The semiconductor fully synthetic suspension grinding fluid prepared in the examples was tested:

[0047]

[0048]

[0049] Example 4: Preparation of a Semiconductor Fully Synthetic Suspension Grinding Fluid

[0050] A semiconductor fully synthetic suspension grinding fluid comprises the following raw materials by weight percentage: 5% pH adjuster, 9% suspending and dispersing agent, 5% rust inhibitor, 7% lubricant, 6% humectant, 5% surfactant, and 63% deionized water.

[0051] Preparation method:

[0052] 1. Add deionized water and suspending dispersant to the reaction vessel, heat to about 50℃~70℃ and stir;

[0053] 2. After stirring until clear and transparent, cool to room temperature, then add pH adjuster, rust inhibitor, lubricant, humectant and surfactant to the reaction vessel in sequence, and stir until evenly mixed to form a whitish clear and transparent liquid, thus obtaining semiconductor fully synthetic suspension grinding fluid.

[0054] Performance testing:

[0055] The semiconductor fully synthetic suspension grinding fluid prepared in the examples was tested:

[0056]

[0057]

[0058] As can be seen from the performance tests of Examples 1 to 4 above, the semiconductor fully synthetic suspension grinding fluid of the present invention has good suspension and dispersion properties, while providing suitable lubrication and cooling effects, which can meet the requirements of semiconductor substrate processing technology and realize high-efficiency and high-quality grinding processing of semiconductor substrates.

[0059] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A semiconductor fully synthetic suspension grinding fluid, characterized in that... It contains the following components by mass percentage: 50-80% deionized water, 5-10% pH adjuster, 2-10% suspending and dispersing agent, 5-10% rust inhibitor, 3-8% lubricant, 4-6% humectant, and 5-10% surfactant. The sum of the percentages of the above components is 100%.

2. The semiconductor fully synthetic suspension grinding fluid according to claim 1, characterized in that: The pH adjuster is at least one of KOH, monoethanolamine, diethanolamine, and triethanolamine, with triethanolamine being the preferred pH adjuster.

3. The semiconductor fully synthetic suspension grinding fluid according to claim 1, characterized in that: The suspending dispersant is a self-prepared polyacrylate emulsion. The preparation process is as follows: methyl methacrylate, styrene, and butyl acrylate are weighed in a certain proportion and added to an aqueous solution containing Tween 80 and sodium dodecylbenzene sulfate. The mixture is rapidly stirred at 40°C for 30 minutes to obtain a pre-emulsion. Two-fifths of the pre-emulsion is placed in a four-necked flask, rapidly stirred, and heated to 75°C. Simultaneously, sodium bisulfite and ammonium persulfate initiators, as well as the crosslinking monomer acrylamide and the remaining three-fifths of the pre-emulsion, are added dropwise to the flask. The dropwise addition time is controlled at 1.5 hours. After the addition is complete, the water bath temperature is raised to 85°C, and the reaction is maintained at this temperature for 0.5 hours. After the emulsion cools, a small amount of ammonia is added dropwise to adjust the pH of the emulsion to 7, thus obtaining the polyacrylate emulsion. The preferred ratio of the anionic emulsifier sodium dodecylbenzene sulfate and the nonionic emulsifier Tween 80 is 1:

1. This ratio results in less coagulation, smaller particle size, and better emulsion stability. The preferred mass ratio of the added monomers methyl methacrylate, styrene, and butyl acrylate is 10:4:

5. The preferred mass fraction of the added emulsifier is 4.0%, which results in less foaming due to thorough emulsification. The added initiator is a mixture of ammonium sulfate and sodium bisulfite, preferably in a mass ratio of 1:1, which minimizes the amount of coagulated material and increases the solids content of the emulsion. The polyacrylate emulsion synthesized under these conditions is a milky white liquid with a faint bluish tint, a solids content of 26.15%, and a viscosity of 6.35 mPa·s. This emulsion is stable, meets the requirements for suspension and dispersion, and does not form sedimentary flocs.

4. The semiconductor fully synthetic suspension grinding fluid according to claim 1, characterized in that: The rust inhibitor is a compound of at least one of sebacic acid and ternary polycarboxylic acid and borate, and the preferred rust inhibitor is a compound of sebacic acid and borate in a mass ratio of 1:

1.

5. The semiconductor fully synthetic suspension grinding fluid according to claim 1, characterized in that: The lubricant is one or a mixture of two or more of polyethylene glycol, polypropylene glycol, trans-block polyether, water-soluble polymeric ester, polyether ester, and borate ester. The preferred lubricant is a mixture of polyethylene glycol and trans-block polyether in a mass ratio of 2:

1.

6. The semiconductor fully synthetic suspension grinding fluid according to claim 1, characterized in that: The moisturizer is at least one of sorbitol, glycerin, 1,2-propanediol, and PEG-8, with the preferred moisturizer being a mixture of glycerin and PEG-8 in a 1:1 mass ratio.

7. The semiconductor fully synthetic suspension grinding fluid according to claim 1, characterized in that: The surfactant is at least one of fatty alcohol polyoxyethylene ether, castor oil polyoxyethylene ether, and alkylphenol polyoxyethylene ether, with fatty alcohol polyoxyethylene ether being the preferred surfactant.

8. A method for preparing a semiconductor fully synthetic suspension grinding fluid according to any one of claims 1 to 7, characterized in that... The specific steps include: (1) Add deionized water and suspending dispersant to the reactor, heat to about 50℃~70℃ and stir; (2) Stir until clear and transparent, then cool to room temperature, and add pH adjuster, rust inhibitor, lubricant, humectant and surfactant to the reactor in sequence to form a white clear and transparent liquid, and obtain semiconductor fully synthetic suspension grinding fluid.

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