Semiconductor brittle material processing medium and method of making same
By combining polyether lubricant with extreme pressure anti-wear agent and other additives, the problems of insufficient lubrication film load-bearing capacity and limited chip dispersion ability in semiconductor cutting are solved, achieving efficient and stable processing results and improving processing efficiency and surface quality.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- TALENT BIOLOGICAL ENGINEERING CO LTD
- Filing Date
- 2026-04-03
- Publication Date
- 2026-07-03
AI Technical Summary
In existing semiconductor cutting processes, insufficient lubrication film bearing capacity leads to rapid tool wear, excessively high local temperature rise, and limited chip dispersion ability, affecting processing stability and surface quality.
A compound system of polyether lubricant and extreme pressure anti-wear agent is adopted, combined with the synergistic effect of amphoteric polymer dispersant, low foaming wetting agent, chelating agent and pH adjuster, to form a stable lubricating film and an efficient chip removal mechanism, control foam generation, and remove metal ions through precision filtration.
It achieves stable lubrication and efficient chip removal under high contact pressure, improves processing efficiency, reduces wafer chipping rate and surface roughness, ensures the stability of processing fluid foam, avoids overflow, and improves cooling effect.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of semiconductor material processing technology, and in particular to a semiconductor brittle material processing medium and its preparation method. Background Technology
[0002] In the semiconductor device manufacturing process, various cutting operations are required on wafers or ingots, such as dicing, grooving, back-side thinning, and slicing. These processes are typically performed using tools such as electroplated diamond wire saws, resin-bonded diamond wheels, or metal-bonded diamond blades.
[0003] However, semiconductor materials (such as silicon, silicon carbide, and gallium nitride) have typical mechanical characteristics of high hardness, high brittleness, and low fracture toughness. During the cutting process, the mechanical impact and frictional heat effect between the tool and the workpiece can easily generate high stress concentration and thermal stress coupling in the machining area, leading to defects such as chipping, microcracks, and surface scratches on the workpiece edges. At the same time, it can also aggravate tool wear and cause excessive local temperature rise.
[0004] Water-based cutting fluids are commonly used as machining media in existing technologies, but they are mostly developed for metal cutting applications, and their lubrication and dispersion systems are difficult to adapt to the machining requirements of brittle semiconductor materials. Specifically, this manifests in several ways: insufficient lubrication film load-bearing capacity, making it difficult to effectively reduce the coefficient of friction and thermal stress in the cutting zone; limited chip dispersion ability, easily leading to chip accumulation and secondary scratches; poor foam control, affecting machining stability and cooling effect; and some components pose a risk of metal ion contamination, which may adversely affect the electrical performance of semiconductor devices. Summary of the Invention
[0005] In view of this, the purpose of this invention is to provide a processing medium for brittle semiconductor materials and its preparation method, solving the problems of insufficient lubrication film bearing capacity leading to rapid tool wear and excessive local temperature rise causing thermal crack propagation during existing semiconductor cutting processes. This processing medium can achieve stable lubrication and efficient chip removal under high contact pressure, improving processing efficiency while ensuring low chipping rate and high flatness of the wafer surface, and maintaining stable working fluid foam during processing without overflowing the tank.
[0006] The present invention solves the above-mentioned technical problems through the following technical means:
[0007] In a first aspect, the present invention provides a machining medium for semiconductor brittle materials, comprising the following raw materials by weight percentage:
[0008] 1.0–6.0% polyether lubricant, 0.05–0.5% extreme pressure anti-wear agent, 0.1–1.0% amphoteric polymer dispersant, 0.02–0.2% low-foaming wetting agent, 0.01–0.1% chelating agent, 0.01–0.08% defoamer, 0.01–0.1% preservative and antibacterial agent, 0.1–0.4% pH adjuster, and the balance being deionized water.
[0009] Preferably, the polyether lubricant is one or more combinations of polyethylene glycol, polypropylene glycol, and ethylene oxide / propylene oxide block copolymer.
[0010] More preferably, the polyether lubricant is a combination of polyethylene glycol, polypropylene glycol, and ethylene oxide / propylene oxide block copolymer, wherein the mass ratio of polyethylene glycol:polypropylene glycol:ethylene oxide / propylene oxide block copolymer is (4-6):(2-3):1.
[0011] Further preferred, by mass ratio, the ratio of polyethylene glycol:polypropylene glycol:ethylene oxide / propylene oxide block copolymer is 5:3:1.
[0012] Based on the aforementioned technical methods, polyether polymers possess excellent water solubility and shear stability, enabling them to form an interfacial lubrication film at the friction interface between the cutting tool and semiconductor materials, primarily based on physical adsorption and fluid lubrication, providing basic lubrication and reducing initial friction. Polyethylene glycol (PEG) exhibits excellent water solubility and strong interfacial wetting ability, rapidly spreading on the hydrophilic surface of the semiconductor substrate to form a basic adsorption layer; polypropylene glycol (PPG) possesses certain hydrophobicity and strong boundary lubrication ability, enhancing the load-bearing capacity of the lubrication film. By controlling the ratio of PEG to PPG within the range of (4-6):(2-3), the complementarity of their hydrophobic / hydrophilic segments is utilized to construct a composite lubrication film with high flexibility and stability. Furthermore, an EO / PO block copolymer is specifically introduced to regulate the interface and enhance compatibility, possessing both the hydrophilic segments of PEG and the hydrophobic segments of PPG. At a specific ratio of 5:3:1, the block copolymer exhibits excellent compatibilization and directional arrangement, resulting in a more stable and continuous lubrication film structure formed by PEG and PPG at the microscopic level. This compound system not only significantly reduces the dynamic surface tension of the cutting fluid, ensuring that the machining fluid can penetrate into the micron-level gaps where the diamond tool contacts the hard and brittle substrate, but also greatly improves the shear stability of the film. Finally, this ternary compound system can effectively cope with local film rupture caused by instantaneous high temperatures during cutting. When local temperature rise leads to a decrease in the viscosity of the low molecular weight component, it helps to improve the stability of the lubricating film under high shear and local temperature rise conditions, thereby effectively suppressing wafer "edge chipping" caused by thermal stress and tool adhesive wear, solving the technical pain point of lubrication failure of a single lubricating component under high-load cutting.
[0013] Preferably, the extreme pressure anti-wear agent is one or more combinations of organophosphates, phosphonates, and borates.
[0014] Further preferably, the extreme pressure anti-wear agent is a mixture of organic phosphate ester and phosphonate, with a mass ratio of organic phosphate ester:phosphonate = (2-8):1.
[0015] Further preferred, by mass ratio, the ratio of organophosphate to phosphonate is 4:1.
[0016] The organophosphate ester is preferably one or a combination of fatty alcohol polyoxyethylene ether phosphate ester, monoalkyl phosphate ester, or dialkyl phosphate ester.
[0017] The phosphonate is preferably one or a combination of hydroxyethylidene diphosphonic acid, aminotrimethylphosphonic acid, or diethylenetriaminepentamethylidene phosphonic acid.
[0018] More preferably, the organophosphate is a fatty alcohol polyoxyethylene ether phosphate, and the phosphonate is hydroxyethylidene diphosphonic acid.
[0019] Based on the aforementioned technical methods, polyether lubricants mainly form interfacial lubrication films through physical adsorption and fluid lubrication under high temperature and high pressure conditions, but their load-bearing capacity is limited. By introducing extreme pressure anti-wear agents, a composite lubrication structure composed of an adsorption film and a tribochemical reaction film can be formed at the friction interface, thereby significantly improving the ultimate load-bearing capacity of the lubrication film.
[0020] Organophosphates exhibit good interfacial activity; their polar groups can rapidly adsorb onto the tool bond surface and machining interface, forming a flexible boundary lubricating film under normal and medium temperature conditions, thereby reducing frictional resistance in the initial stages of cutting. Phosphonates, on the other hand, possess high thermal stability and, under frictional heat and high contact pressure, may participate in interfacial tribochemical reactions, thus forming a stable protective layer at the machining interface and improving the shear resistance of the lubricating film.
[0021] By controlling the mass ratio of organophosphate to phosphonate within the range of (2-8):1, preferably 4:1, a synergistic effect of adsorption film formation and interfacial reaction protection can be achieved. Organophosphate provides stable basic lubrication isolation, while phosphonate forms a new interfacial protective layer in micro-regions of the lubricating film that are locally shear-damaged, thereby significantly improving the extreme pressure carrying capacity and anti-wear performance of the lubrication system. This compound system can effectively reduce the friction coefficient and local temperature rise at the machining interface, thereby reducing wafer edge chipping caused by thermal stress concentration, while also reducing tool adhesive wear, achieving a synergistic effect of improved tool life and machining quality.
[0022] Preferably, the amphoteric polymer dispersant is one or more combinations of polyaspartate, amphoteric polyacrylic acid, and carboxyl quaternary ammonium salt copolymer.
[0023] Further preferably, the amphoteric polymer dispersant is sodium polyaspartate glutamate.
[0024] Based on the aforementioned technical means, amphoteric polymer dispersants, through their anionic and cationic groups on their molecular chains, can sensitively capture and adsorb onto the surface of charged semiconductor chips (such as silicon powder and silicon carbide particles). Utilizing charge repulsion and steric hindrance effects, the chips are stably suspended in the medium, preventing them from agglomerating in the cutting area or causing "secondary grinding" that would result in fine scratches on the wafer surface (LPC control).
[0025] Preferably, the low-foaming wetting agent is one or more combinations of fatty alcohol polyoxyethylene ether, polyoxyethylene polyoxypropylene pentaerythritol ether, and block nonionic surfactant.
[0026] Further preferably, the low-foaming wetting agent is a combination of fatty alcohol polyoxyethylene ether and polyoxyethylene polyoxypropylene pentaerythritol ether, with a mass ratio of fatty alcohol polyoxyethylene ether: polyoxyethylene polyoxypropylene pentaerythritol ether = (1-6):(1-4).
[0027] Further optimization is achieved by a mass ratio of 3:1 for fatty alcohol polyoxyethylene ether to polyoxyethylene polyoxypropylene pentaerythritol ether.
[0028] First, fatty alcohol polyoxyethylene ether, as a high-performance wetting agent, possesses extremely high surface activity, significantly reducing the static and dynamic surface tension of the machining medium. This ensures that during high-speed cutting, the machining fluid can rapidly wet the semiconductor material surface and, through its strong penetration, enter the micro-gap and micro-cracks in the tool-wafer contact area, forming a continuous liquid film covering and cooling heat transfer interface, thereby improving interface lubrication and heat removal efficiency.
[0029] Secondly, polyoxyethylene polyoxypropylene pentaerythritol ether possesses a unique multi-branched star-shaped structure. Compared to traditional linear surfactants, it exhibits lower foam stability at the gas-liquid interface and is less prone to forming persistent foam. By controlling the mass ratio of fatty alcohol polyoxyethylene ether to polyoxyethylene polyoxypropylene pentaerythritol ether to (1-6):(1-4), especially when the ratio reaches 3:1, the synergistic distribution and mutual regulation of the two at the interface can help suppress foam formation and promote the breakage of existing foam while ensuring excellent wetting and spreading capabilities. This synergistic effect not only suppresses foam generated by high-pressure spray circulation but also accelerates the breakage of existing foam.
[0030] Finally, this specific ratio helps mitigate localized bubble buildup or film isolation around high-speed rotating tools. At a 3:1 ratio, the machining fluid does not form an insulating bubble layer around the high-speed rotating tool, improving the effective contact between the cooling medium and the machining area. This not only enhances heat dissipation efficiency but also prevents microcrack propagation caused by excessive local thermal gradients.
[0031] Preferably, the chelating agent is one or a combination of methylglycine diacetic acid, glutamic acid diacetic acid, and ethylenediamine disuccinic acid.
[0032] Further preferably, the chelating agent is a combination of methylglycine diacetic acid and glutamic acid diacetic acid, with a mass ratio of methylglycine diacetic acid: glutamic acid diacetic acid = (1-6):(1-4).
[0033] Further optimization is achieved by a mass ratio of 3:1 for methylglycine diacetic acid to glutamic acid diacetic acid.
[0034] Methylglycine diacetic acid (MGDA), as a small-molecule polycarboxylic acid chelating agent, possesses good complexing ability and high water solubility. It can form stable complexes with hard water ions such as calcium and magnesium, as well as some transition metal ions, present in the processing medium and on the workpiece surface, thereby reducing the deposition or recombination of these metal ions at the processing interface. Glutamic acid diacetic acid (GLDA), on the other hand, has a wide pH range and excellent solubility, maintaining stable complexing ability even under weakly alkaline conditions, thus continuously playing a role in controlling metal ions in the processing system. By controlling the mass ratio of MGDA to GLDA within the range of (1-6):(1-4), preferably 3:1, a complementary relationship can be formed in terms of complexing rate and complexing stability, thus exhibiting a synergistic complexing effect. MGDA is mainly responsible for rapidly complexing metal ions in the system, while GLDA helps maintain the stability of the complexed state. This synergistic effect can weaken the bridging effect that metal ions may generate between semiconductor debris particles and the wafer surface, making it easier for fine particles to be carried away by the processing fluid, thereby reducing the probability of particle redeposition. At this formulation, even at low addition levels, the chelating agent system effectively controls the metal ion content in the processing medium, thereby reducing the risk of surface deposition or adhesion caused by metal impurities and helping to improve the cleanliness and stability of semiconductor material processing surfaces. Furthermore, since both MGDA and GLDA have good biodegradability, this system achieves efficient metal ion control while also being environmentally friendly.
[0035] Preferably, the defoaming agent is polyether-modified silicone.
[0036] Further preferably, the polyether-modified silicone is a polysiloxane-type defoamer containing EO / PO block polyether side chains.
[0037] More preferably, the molar ratio of EO to PO in the polyether segment is 1:1 to 4:1.
[0038] Based on the above technical means, the defoaming agent inhibits foam generation in the circulating spray system, thereby avoiding local dry friction points.
[0039] Preferably, the preservative and antibacterial agent is one or more of isothiazolinone compounds and phenoxyethanol compounds.
[0040] More preferably, the preservative and antibacterial agent is a combination of 1,2-benzisothiazolin-3-one and phenoxyethanol, wherein the mass ratio of 1,2-benzisothiazolin-3-one to phenoxyethanol is (1–5):(1–3).
[0041] More preferably, the mass ratio of 1,2-benzisothiazolin-3-one to phenoxyethanol is 3:1.
[0042] Isothiazolinones can disrupt the active sites of key enzymes in microbial cells, thereby inhibiting microbial metabolism, while phenoxyethanol can disrupt the structure of microbial cell membranes. The synergistic effect of the two can significantly improve antibacterial efficiency and extend the recycling cycle of processing media.
[0043] Preferably, the pH adjuster is one or a combination of organic amines and alkali metal salts. It is used to adjust the pH of the processing medium to 7.5–9.5.
[0044] More preferably, the pH adjuster is an organic amine.
[0045] More preferably, the organic amine is an alcohol amine.
[0046] More preferably, the alkanolamine is a combination of monoethanolamine and 2-amino-2-methyl-1-propanol, and the mass ratio of monoethanolamine to 2-amino-2-methyl-1-propanol is (1-6):(1-4).
[0047] More preferably, the mass ratio of monoethanolamine to 2-amino-2-methyl-1-propanol is 3:1.
[0048] Based on the above technical means, locking the system in a weakly alkaline range can, on the one hand, soften the micro-regions on the semiconductor surface through chemical action and improve cutting efficiency; on the other hand, organic amine components can form an anti-corrosion layer on the silicon wafer surface, which, together with chelating agents, controls the penetration and contamination of the wafer by metal ions.
[0049] In a second aspect, the present invention provides a method for preparing a semiconductor brittle material processing medium, for preparing the aforementioned semiconductor brittle material processing medium, the preparation method comprising:
[0050] S1. Add the amphoteric polymer dispersant to deionized water, stir until homogeneous, add the low-foaming wetting agent, mix until homogeneous, and form a mixed system;
[0051] S2. Premix the extreme pressure anti-wear agent with a portion of the polyether lubricant to form a mother liquor, and then slowly add the mother liquor to the system of step S1;
[0052] S3. Add the remaining polyether lubricant, stir well, add chelating agent and pH adjuster to adjust pH to 7.5–9.5, add antifoaming agent and preservative and antibacterial agent, stir well to obtain a mixture;
[0053] S4. Filter the mixture to obtain the semiconductor brittle material cutting medium.
[0054] Preferably, the mass ratio of extreme pressure anti-wear agent to part of polyether lubricant in the premixed mother liquor of step S2 is 1:(2-5).
[0055] More preferably, the mass ratio of extreme pressure anti-wear agent to a portion of polyether lubricant in the premixed mother liquor of step S2 is 1:3.
[0056] Preferably, the filtration process in step S4 employs precision filtration with a filter membrane pore size of 25μm-50μm.
[0057] The beneficial effects of this invention are:
[0058] (1) This invention employs a compound system of polyether lubricant and extreme pressure anti-wear agent. Polyether molecules form a continuous adsorption film on the tool surface through hydrogen bonds and van der Waals forces, providing basic friction reduction; while under the instantaneous high temperature and high pressure in the micro-area of cutting, extreme pressure agents such as organophosphates rapidly undergo tribochemical reactions to generate an inorganic protective film with high shear strength. This dual mechanism effectively prevents direct contact between the diamond tool and the hard and brittle semiconductor substrate, solving the common adhesive wear problem when machining superhard materials such as silicon carbide.
[0059] (2) The amphoteric polymer dispersant introduced in this invention has a cationic center on its molecular chain that can quickly capture negatively charged semiconductor debris, while the anionic and long-chain structure forms a strong steric hindrance, ensuring that submicron-sized debris (such as silicon powder) is stably suspended in the processing fluid without agglomeration. Combined with the extremely low surface tension of the low-foaming wetting agent, the processing fluid can quickly penetrate into the micron-sized kerf, rapidly carrying the detached debris away from the processing area, completely eliminating "secondary grinding" scratches caused by debris accumulation, and significantly reducing the chipping rate of the wafer edge.
[0060] (3) This invention precisely locks the pH value within the weakly alkaline range of 7.5 to 9.5, using pH adjusters to stabilize and neutralize acidic byproducts generated during processing, maintaining the optimal activity of the additives; simultaneously, organic amine components can form a monomolecular passivation film on the semiconductor surface, inhibiting the corrosion of sensitive materials (such as gallium nitride and lead-containing components) by alkaline components. This "chemical softening-surface protection" balance mechanism, without damaging the substrate, utilizes chemical action to assist physical cutting, achieving a simultaneous improvement in processing efficiency and surface smoothness.
[0061] (4) In the preparation process, this invention specifically introduces a precision filtration and premixing degassing process with a particle size of 25μm to 50μm, strictly controlling the metal ion content (≤10 ppm) and initial particle size (>1μm particles ≤100 / mL) of the processing medium itself. This not only avoids secondary pollution introduced by the medium, but also eliminates the influence of microbubbles on cooling heat exchange efficiency. In addition, the addition of a low-foaming wetting agent ensures that no foam overflow is generated in the high-flow, high-pressure spray circulation system, greatly improving the stability of industrial continuous production.
[0062] (5) The present invention can achieve stable lubrication and efficient chip removal under high contact pressure, while improving processing efficiency and ensuring low chipping rate and high flatness of wafer surface. The working fluid foam is kept stable during the processing and there is no overflow of the tank. Detailed Implementation
[0063] The technical solutions of the present invention will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.
[0064] A semiconductor brittle material processing medium in this application embodiment includes the following raw materials:
[0065] The mass ratio of polyether lubricant: polyethylene glycol: polypropylene glycol: ethylene oxide / propylene oxide block copolymer is 5:3:1;
[0066] Extreme pressure anti-wear agent: fatty alcohol polyoxyethylene ether phosphate: hydroxyethylidene diphosphonic acid in a mass ratio of 4:1;
[0067] Amphoteric polymer dispersant: Sodium polyaspartate glutamate;
[0068] Low-foaming wetting agent: The mass ratio of fatty alcohol polyoxyethylene ether to polyoxyethylene polyoxypropylene pentaerythritol ether is 3:1;
[0069] Chelating agent: The mass ratio of methylglycine diacetic acid to glutamic acid diacetic acid is 3:1;
[0070] Defoaming agent: Polysiloxane type defoaming agent containing EO / PO block polyether side chains, wherein the molar ratio of EO to PO in the polyether segments is 1:1-4:1.
[0071] Preservative and antibacterial agent: The mass ratio of 1,2-benzisothiazolin-3-one to phenoxyethanol is 3:1.
[0072] pH adjuster: The mass ratio of monoethanolamine to 2-amino-2-methyl-1-propanol is 3:1;
[0073] And the remaining amount of deionized water.
[0074] Example 1
[0075] This embodiment provides a semiconductor brittle material processing medium and its preparation method. The semiconductor brittle material processing medium, by mass percentage, comprises: 1.0% polyether lubricant (polyethylene glycol:polypropylene glycol:ethylene oxide / propylene oxide block copolymer in a mass ratio of 5:3:1), 0.05% extreme pressure anti-wear agent (fatty alcohol polyoxyethylene ether phosphate:hydroxyethylidene diphosphonic acid in a mass ratio of 4:1), 0.1% sodium polyaspartate glutamate, 0.02% low-foaming wetting agent (fatty alcohol polyoxyethylene ether:polyoxyethylene polyoxypropylene pentaerythritol ether in a mass ratio of 3:1), 0.01% chelating agent (methylglycine diacetic acid:glutamic acid diacetic acid in a mass ratio of 3:1), 0.01% defoaming agent, 0.01% preservative and antibacterial agent (polysiloxane-type defoaming agent containing EO / PO block polyether side chains, where the molar ratio of EO to PO in the polyether segments is 1:1-4:1), and 0.1%... pH adjuster (mass ratio of monoethanolamine to 2-amino-2-methyl-1-propanol is 3:1), and the balance is deionized water.
[0076] Preparation methods include:
[0077] S1. Add the amphoteric polymer dispersant to deionized water, stir until homogeneous, add the low-foaming wetting agent, mix until homogeneous, and form a mixed system;
[0078] S2. The extreme pressure anti-wear agent and a portion of the polyether lubricant are premixed to form a mother liquor, and then the mother liquor is slowly added to the system of step S1; the mass ratio of extreme pressure anti-wear agent to a portion of polyether lubricant in the premixed mother liquor of step S2 is 1:2.
[0079] S3. Add the remaining polyether lubricant, stir well, add chelating agent and pH adjuster to adjust pH to 7.5–9.5, add antifoaming agent and preservative and antibacterial agent, stir well to obtain a mixture;
[0080] S4. The mixture is filtered using a precision filter with a membrane pore size of 25 μm. This yields a cutting medium for brittle semiconductor materials.
[0081] Example 2
[0082] This embodiment provides a semiconductor brittle material processing medium and its preparation method. The semiconductor brittle material processing medium, by mass percentage, comprises: 3.50% polyether lubricant (polyethylene glycol:polypropylene glycol:ethylene oxide / propylene oxide block copolymer in a mass ratio of 5:3:1), 0.275% extreme pressure anti-wear agent (fatty alcohol polyoxyethylene ether phosphate:hydroxyethylidene diphosphonic acid in a mass ratio of 4:1), 0.55% sodium polyaspartate glutamate, 0.11% low-foaming wetting agent (fatty alcohol polyoxyethylene ether:polyoxyethylene polyoxypropylene pentaerythritol ether in a mass ratio of 3:1), 0.055% chelating agent (methylglycine diacetic acid:glutamic acid diacetic acid in a mass ratio of 3:1), 0.03% defoaming agent, 0.055% preservative and antibacterial agent (polysiloxane-type defoaming agent containing EO / PO block polyether side chains, with a molar ratio of EO to PO of 1:1-4:1 in the polyether segments), and 0.25%... pH adjuster (mass ratio of monoethanolamine to 2-amino-2-methyl-1-propanol is 3:1), and the balance is deionized water.
[0083] Preparation methods include:
[0084] S1. Add the amphoteric polymer dispersant to deionized water, stir until homogeneous, add the low-foaming wetting agent, mix until homogeneous, and form a mixed system;
[0085] S2. The extreme pressure anti-wear agent and a portion of the polyether lubricant are premixed to form a mother liquor, and then the mother liquor is slowly added to the system of step S1; the mass ratio of extreme pressure anti-wear agent to a portion of polyether lubricant in the premixed mother liquor of step S2 is 1:3.
[0086] S3. Add the remaining polyether lubricant, stir well, add chelating agent and pH adjuster to adjust pH to 7.5–9.5, add antifoaming agent and preservative and antibacterial agent, stir well to obtain a mixture;
[0087] S4. The mixture is filtered using a precision filter with a membrane pore size of 25 μm. This yields a cutting medium for brittle semiconductor materials.
[0088] Example 3
[0089] This embodiment provides a semiconductor brittle material processing medium and its preparation method. The semiconductor brittle material processing medium, by mass percentage, comprises: 6.0% polyether lubricant (polyethylene glycol:polypropylene glycol:ethylene oxide / propylene oxide block copolymer in a mass ratio of 5:3:1), 0.5% extreme pressure anti-wear agent (fatty alcohol polyoxyethylene ether phosphate:hydroxyethylidene diphosphonic acid in a mass ratio of 4:1), 1.0% sodium polyaspartate glutamate, 0.2% low-foaming wetting agent (fatty alcohol polyoxyethylene ether:polyoxyethylene polyoxypropylene pentaerythritol ether in a mass ratio of 3:1), 0.1% chelating agent (methylglycine diacetic acid:glutamic acid diacetic acid in a mass ratio of 3:1), 0.08% defoaming agent, 0.1% preservative and antibacterial agent (polysiloxane-type defoaming agent containing EO / PO block polyether side chains, where the molar ratio of EO to PO in the polyether segments is 1:1-4:1), and 0.4%... pH adjuster (mass ratio of monoethanolamine to 2-amino-2-methyl-1-propanol is 3:1), and the balance is deionized water.
[0090] Preparation methods include:
[0091] S1. Add the amphoteric polymer dispersant to deionized water, stir until homogeneous, add the low-foaming wetting agent, mix until homogeneous, and form a mixed system;
[0092] S2. The extreme pressure anti-wear agent and a portion of the polyether lubricant are premixed to form a mother liquor, and then the mother liquor is slowly added to the system of step S1; the mass ratio of extreme pressure anti-wear agent to a portion of polyether lubricant in the premixed mother liquor of step S2 is 1:5.
[0093] S3. Add the remaining polyether lubricant, stir well, add chelating agent and pH adjuster to adjust pH to 7.5–9.5, add antifoaming agent and preservative and antibacterial agent, stir well to obtain a mixture;
[0094] S4. The mixture is filtered using a precision filter with a pore size of 50 μm. This yields a cutting medium for brittle semiconductor materials.
[0095] Comparative Example 1
[0096] The difference from Example 2 is that the total amount of polyether lubricant is maintained at 3.50%, but only PEG is used, without the addition of PPG and EO / PO block copolymer.
[0097] Comparative Example 2
[0098] The difference from Example 2 is that the extreme pressure anti-wear agent is removed and replaced with deionized water.
[0099] Comparative Example 3
[0100] The difference from Example 2 is that the total amount of extreme pressure anti-wear agent is maintained at 0.275%, but HEDP is not added, and only fatty alcohol polyoxyethylene ether phosphate is used.
[0101] Comparative Example 4
[0102] The difference from Example 2 is that the total amount of low-foaming wetting agent is kept at 0.11%, but the ratio of fatty alcohol polyoxyethylene ether to polyoxyethylene polyoxypropylene pentaerythritol ether is changed from 3:1 to 1:3.
[0103] Comparative Example 5
[0104] The difference from Example 2 is that the chelating agent was removed and replaced with deionized water.
[0105] Comparative Example 6
[0106] The difference from Example 2 is that the pH adjuster was removed and replaced with deionized water.
[0107] Comparative Example 7
[0108] The difference from Example 2 is that the formulation is the same as in Example 2, but the pH is adjusted to:
[0109] Comparative Example 7A: pH 6.8
[0110] Comparative Example 7B: pH 10.2.
[0111] Comparative Example 8
[0112] The difference from Example 2 is that in step S2, the "extreme pressure anti-wear agent + part of the polyether lubricant" are not premixed, but added directly all at once.
[0113] Four-inch 4H-SiC wafers and sapphire wafers were selected as test objects. Using the same type of diamond cutting tool, and under the same spindle speed, feed rate, spray flow rate, and ambient temperature conditions, the machining media for each embodiment and comparative example were first diluted 1:20 before cutting tests. Test parameters included friction coefficient, peak temperature rise in the cutting zone, tool life, kerf surface roughness, average chipping width, surface scratch density, 24-hour settling rate, dynamic surface tension, spray foam height, total metal ions in the machining media, and the number of residual particles on the wafer surface.
[0114] Performance testing methods:
[0115] 1. Cutting performance test
[0116] Equipment: Diamond scribing machine
[0117] Conditions: Spindle speed: 30,000 rpm; Feed rate: 3 mm / s; Cooling flow rate: 1.2 L / min
[0118] Tests: coefficient of friction, tool life, chipping width, surface roughness
[0119] 2. Chip Dispersion Test
[0120] Method: SiC powder was added to the processing fluid to simulate debris. After 2 hours of circulating spraying, the following parameters were measured: 24-hour sedimentation rate, D90 particle size, and zeta potential.
[0121] 3. Wetting performance test
[0122] Tests: Dynamic surface tension, contact angle, foam height
[0123] 4. Cleanliness test
[0124] Testing of the processing medium and the surface of the processed wafer after 24 hours of cycling:
[0125] ICP-MS measurement of Na, K, Ca, Mg, Fe, Cu
[0126] Number of particles on the wafer surface
[0127] The experimental data are shown in Table 1-4.
[0128] Table 1 Cutting performance
[0129]
[0130] Table 2 Chip Dispersion Performance
[0131]
[0132] Table 3 Wetting properties
[0133]
[0134] Table 4
[0135]
[0136] Example 2 outperforms the comparative examples in terms of friction coefficient, temperature rise, tool life, chipping width, and surface roughness; it also shows significant advantages in particle dispersion stability, wetting performance, metal ion control, and foam control. The results indicate that there is a significant synergistic effect among the polyether lubrication system, extreme pressure anti-wear system, dispersion system, wetting system, and chelation system in the processing medium of this invention, thereby significantly improving the surface quality of brittle semiconductor materials while increasing processing efficiency.
[0137] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications and substitutions should be covered within the scope of the claims of the present invention. Technical aspects, shapes, and structures not described in detail in this invention are all well-known technologies.
Claims
1. A semiconductor brittle material processing medium, characterized in that, It includes the following raw materials by weight percentage: 1.0–6.0% polyether lubricant, 0.05–0.5% extreme pressure anti-wear agent, 0.1–1.0% amphoteric polymer dispersant, 0.02–0.2% low-foaming wetting agent, 0.01–0.1% chelating agent, 0.01–0.08% defoamer, 0.01–0.1% preservative and antibacterial agent, 0.1–0.4% pH adjuster, and the balance being deionized water.
2. The semiconductor brittle material processing medium according to claim 1, characterized in that: The polyether lubricant is one or more of polyethylene glycol, polypropylene glycol, and ethylene oxide / propylene oxide block copolymer.
3. The semiconductor brittle material processing medium according to claim 2, characterized in that: The extreme pressure anti-wear agent is one or more combinations of organic phosphate esters, phosphonates, and borate esters.
4. The semiconductor brittle material processing medium according to claim 3, characterized in that: The amphoteric polymer dispersant is one or more combinations of polyaspartate, amphoteric polyacrylic acid, and carboxyl quaternary ammonium salt copolymer.
5. The semiconductor brittle material processing medium according to claim 4, characterized in that: The low-foaming wetting agent is one or more combinations of fatty alcohol polyoxyethylene ether, polyoxyethylene polyoxypropylene pentaerythritol ether, and block nonionic surfactant.
6. The semiconductor brittle material processing medium according to claim 5, characterized in that: The chelating agent is one or more combinations of methylglycine diacetic acid, glutamic acid diacetic acid, and ethylenediamine disuccinic acid.
7. The semiconductor brittle material processing medium according to claim 1, characterized in that: The pH adjuster is one or more combinations of organic amines and alkali metal salts.
8. The semiconductor brittle material processing medium according to claim 1, characterized in that: The defoaming agent is polyether-modified silicone.
9. A method for preparing a semiconductor brittle material processing medium, used to prepare the semiconductor brittle material processing medium according to any one of claims 1-8, characterized in that: The preparation method includes: S1. Add the amphoteric polymer dispersant to deionized water, stir until homogeneous, add the low-foaming wetting agent, mix until homogeneous, and form a mixed system; S2. Premix the extreme pressure anti-wear agent with a portion of the polyether lubricant to form a mother liquor, and then slowly add the mother liquor to the system of step S1; S3. Add the remaining polyether lubricant, stir well, add chelating agent and pH adjuster to adjust pH to 7.5–9.5, add antifoaming agent and preservative and antibacterial agent, stir well to obtain a mixture; S4. Filter the mixture to obtain the semiconductor brittle material cutting medium.
10. The method for preparing a semiconductor brittle material processing medium according to claim 8, characterized in that: In step S2, the mass ratio of extreme pressure anti-wear agent to part of polyether lubricant in the premixed mother liquor is 1:(2-5), and the filtration treatment in step S4 adopts precision filtration with a filter membrane pore size of 25μm-50μm.