Low-temperature-resistant silicon polishing composition and application thereof

Abstract

The application provides a low-temperature-resistant silicon polishing composition and application thereof, and the low-temperature-resistant silicon polishing composition takes nanosilica colloid as a main polishing component, and antifreeze and amino acid type surfactant are added. The low-temperature-resistant silicon polishing composition of the application simultaneously adds the antifreeze and the amino acid type surfactant as low-temperature-resistant assistants, can effectively inhibit freezing gel and the problem that the average particle size and the number of large particles significantly increase which are prone to occur in the composition under a low-temperature environment, can prevent the composition from deteriorating and failing under a low temperature, and has obvious advantages compared with the prior art.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of chemical mechanical polishing, in particular to a low-temperature-resistant silicon polishing composition and application thereof. BACKGROUND

[0002] The development of integrated circuits greatly promotes the speed of human society moving towards informationization and intelligentization, and in this process, semiconductor silicon materials play an irreplaceable role. High-purity single crystal silicon material is the main substrate material in the IC manufacturing process, and polycrystalline silicon is the main material for manufacturing gates. In the processing of silicon materials, chemical mechanical polishing (CMP) is one of the key technologies.

[0003] In the process of chemical mechanical polishing of silicon materials, the polishing liquid and the polishing pad are key consumables. The polishing liquid not only plays a chemical role, but also plays a mechanical role, and has an important influence on the polishing surface quality. Since the hardness of silicon oxide and silicon is close, and the nano-silicon oxide has fine particle size, the wafer surface after polishing has few defects, which can meet the manufacturing requirements of large-scale integrated circuits. Therefore, the polishing liquid for silicon materials on the market mainly uses nano-silica sol as abrasive, and also adds rate accelerators, pH regulators, complexing agents and other components.

[0004] The polishing liquid composed of nano-silicon oxide abrasive and chemical additives belongs to a typical metastable liquid sol system, and its stability is easily affected by external conditions such as high temperature and low temperature. Moreover, the agglomeration of nano-silicon oxide abrasive is irreversible, so once the nano-silica sol abrasive in the polishing liquid loses stability, it will cause economic losses and material waste. At present, downstream Fab factories need a continuous supply of polishing liquid. During the transportation and storage in winter, the polishing liquid is easily subjected to a certain degree of low-temperature environment. Under low-temperature conditions (such as below 0℃), the nano-silica sol in the polishing liquid is prone to agglomeration, forming large particles, and even freezing gel phenomenon may occur in severe cases. Therefore, this problem needs to be solved urgently.

[0005] In the field of low-temperature resistant polishing liquid, some solutions are proposed in some published patents. For example, the domestic published patent CN101096577A proposes a kind of anti-freezing polishing liquid and its preparation method, wherein the antifreeze agent is methanol, ethanol, ethylene glycol, glycerol, polyethylene glycol, and a polyoxyethylene nonionic surfactant is also added to reduce the freezing point of the polishing liquid and prevent freezing gel. The anti-freezing polishing composition proposed in patent CN108531087A contains 50-60% ethylene glycol as an antifreeze agent, and a nonionic surfactant Tween is also added. The anti-freezing nano-ceramic polishing liquid proposed in the published patent CN105400435A uses ethylene glycol, propylene glycol, and glycerol as antifreeze agents, and also adds amine and ether nonionic surfactants and some silane coupling agents. However, with the rapid development of IC manufacturing, the performance indicators of the polishing composition, such as average particle size and large particle count, are constantly improving. The compositions mentioned in the above-mentioned patents basically use ethylene glycol and propylene glycol as antifreeze agents, the main purpose of which is to reduce the freezing point of the polishing liquid and prevent it from freezing gel. However, under low temperature conditions, the silica sol abrasive is prone to micro-agglomeration, even if there is no frozen gel, but a large number of large particles (>0.56 μm) have already been generated, and the average particle size has also increased significantly, which reduces the performance of the polishing composition (such as scratch and polishing rate consistency). The existing technology still cannot solve this problem.

[0006] According to the above analysis, in order to solve the problem of the increase of average particle size and large particle count caused by frozen gel and micro-agglomeration under low temperature during the transportation and storage of the polishing composition, it is still necessary to improve the composition of the polishing liquid from the perspective of chemical formula to prevent the frozen gel of the composition under low temperature conditions, and further inhibit the increase of the average particle size and large particle count of the composition to overcome the shortcomings of the above-mentioned existing technology. SUMMARY

[0007] To solve the above technical problems, the present application provides a kind of low-temperature resistant silicon polishing composition, by adding antifreeze agent and amino acid surfactant to the polishing composition, the frozen gel of the polishing composition under low temperature conditions and the increase of average particle size and large particle count can be effectively prevented.

[0008] Another object of the present application is to provide the application of the low-temperature resistant silicon polishing composition in silicon chemical mechanical polishing, wherein the silicon material is not limited to single crystal silicon and polycrystalline silicon.

[0009] To achieve the above-mentioned object, the technical scheme adopted by the present application is as follows:

[0010] A kind of low-temperature resistant silicon polishing composition, using nanometer silica colloid as abrasive, wherein, including antifreeze agent and amino acid surfactant.

[0011] In a preferred embodiment, the low temperature resistant silicon polishing composition further comprises nanosilica colloids, rate accelerators, pH adjusters, complexing agents, and the balance deionized water.

[0012] In a preferred embodiment, the low temperature resistant silicon polishing composition comprises nanosilica colloids 5-40 wt%, antifreeze 0.5-8 wt%, amino acid surfactant 0.005-6 wt%, rate accelerators 0.1-8 wt%, pH adjusters 0.01-1 wt%, complexing agents 0.001-0.1 wt%, and the balance deionized water; wherein, preferably, the amino acid surfactant comprises 0.1-15% by weight of the nanosilica colloids in the low temperature resistant polishing composition, and the nanosilica colloids in the polishing composition have a negative charge on the surface with a Zeta potential of 10-45 mV.

[0013] In a more preferred embodiment, the low temperature resistant silicon polishing composition comprises nanosilica colloids 10-25 wt%, antifreeze 1-5 wt%, amino acid surfactant 0.2-2.5 wt%, rate accelerators 0.5-6 wt%, pH adjusters 0.05-0.5 wt%, complexing agents 0.01-0.05 wt%, and the balance deionized water; wherein, further preferably, the amino acid surfactant comprises 2-10% by weight of the nanosilica colloids in the low temperature resistant polishing composition, and the nanosilica colloids in the polishing composition have a negative charge on the surface with a Zeta potential of 15-35 mV.

[0014] In a specific embodiment, the nanosilica colloids have an average particle size of 10-100 nm and a mass concentration of 30-50 wt%.

[0015] In a specific embodiment, the antifreeze is selected from at least one of alcohols, alcohol ethers, alkenyl alcohols, or amides, preferably at least one of ethylene glycol, propylene glycol, diethylene glycol, isopropyl alcohol, ethylene glycol butyl ether, ethylene glycol butyl ether acetate, propylene glycol butyl ether, diethylene glycol butyl ether, ethylene glycol, propylene glycol, dimethyl sulfoxide, formamide, dimethyl formamide, thiourea, urea, preferably at least one of diethylene glycol, ethylene glycol butyl ether, propylene glycol butyl ether, diethylene glycol butyl ether, dimethyl formamide, and urea.

[0016] In one specific embodiment, the amino acid type surfactant is at least one of sodium cocoyl glutamate, disodium cocoyl glutamate, cocoyl glutamic acid triethanolamine, sodium cocoyl sarcosinate, cocoyl alanine triethanolamine, sodium cocoyl aminopropionate, sodium cocoyl methyl taurate, aminosulfonic betaine, potassium cocoyl glycinate, sodium cocoyl glycinate, sodium cocoyl isethionate, sodium lauroyl glutamate, disodium lauroyl glutamate, sodium lauroyl aspartate, disodium lauroyl aspartate, sodium lauroyl sarcosinate, lauroyl lysine, sodium lauroyl glycinate, potassium lauroyl glycinate, sodium myristoyl glutamate, sodium myristoyl sarcosinate, potassium myristoyl glycinate, sodium myristoyl isethionate, N-myristoyl-β-aminopropionic acid, sodium methyl lauroyl taurate, formyl lauroyl lysine triethanolamine, sodium dodecyl aminopropionate, sodium dodecyl dimethylene aminodiacetate, dodecyl aminoethyl glycine, octadecanoyl formyl lysine triethanolamine, preferably at least one of sodium cocoyl glutamate, potassium cocoyl glycinate, sodium lauroyl glutamate, sodium lauroyl glycinate, sodium myristoyl glutamate, sodium methyl lauroyl taurate, sodium dodecyl aminopropionate.

[0017] In one specific embodiment, the rate accelerator is at least one of potassium hydroxide, potassium carbonate, potassium bicarbonate, ammonium hydroxide, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, (2-hydroxyethyl)trimethylammonium hydroxide, diethyldimethylammonium hydroxide, methyltriethylammonium hydroxide, benzyltrimethylammonium hydroxide, benzyltriethylammonium hydroxide, guanidine carbonate, guanidine hydrochloride, metformin, tetramethylguanidine, imidazole, methylimidazole, ethylenediamine, hydroxyethylethylenediamine, tetrahydroxypropylethylenediamine, piperazine, N-aminoethylpiperazine, 1-methylpiperazine, 2-methylpiperazine, homopiperazine, pyrazine, pyridazine, monoethanolamine, preferably at least one of potassium hydroxide, tetramethylammonium hydroxide, guanidine carbonate, imidazole.

[0018] In one specific embodiment, the pH adjusting agent is at least one of nitric acid, phosphoric acid, acetic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, malic acid, citric acid, tartaric acid, lactic acid, maleic acid, preferably malonic acid, tartaric acid; preferably, the pH of the low temperature resistant type silicon polishing composition is adjusted to 9 to 12.5.

[0019] In one specific embodiment, the complexing agent is at least one of ethylenediaminetetraacetic acid, ethylenediaminetetramethylene phosphonic acid, aminotrimethylene phosphonic acid, hydroxyethylenediphosphonic acid, ethylene glycol-bis-(2-aminoethyl) tetraacetic acid, diethylenetriamine pentaacetic acid, diethylenetriamine pentaacetic acid pentapotassium, potassium pyrophosphate, preferably ethylenediaminetetraacetic acid.

[0020] Another aspect, the aforementioned low-temperature-resistant silicon polishing composition is used in silicon chemical mechanical polishing.

[0021] Compared with the prior art, the present application has the following advantages:

[0022] The present application uses nanometer silica colloidal as the basic abrasive, has the advantages of fast polishing rate, clean polished surface and less scratches on the polished material surface. In addition, the present application adds antifreeze agent in the polishing composition, which reduces the freezing point of the polishing composition and prevents it from freezing gel at low temperature. On this basis, amino acid surfactant is also added. In low temperature environment, the amino acid surfactant can effectively inhibit the micro-agglomeration of the abrasive in the polishing composition, reduce the generation of large particles and the rise of the average particle size in the polishing composition, avoid the waste and economic loss of the polishing composition, and save the cost in transportation and storage process. Compared with the prior art, the present application has obvious advantages. DETAILED DESCRIPTION

[0023] In order to better understand the technical solutions of the present application, the following examples will further illustrate the method provided by the present application, but the present application is not limited to the listed examples, and any other known changes within the scope of the claims of the present application should also be included.

[0024] A low-temperature-resistant silicon polishing composition, which uses nanometer silica colloidal as the main polishing component and adds antifreeze agent and amino acid surfactant as additives. That is, on the basis of the existing silicon chemical mechanical polishing liquid using nanometer silica colloidal as abrasive, antifreeze agent and amino acid surfactant are added as low-temperature-resistant additives to obtain the low-temperature-resistant silicon polishing composition of the present application.

[0025] The antifreeze agent used includes alcohol, alcohol ether, enol and amide, etc., which has a lower melting point and does not contain strong corrosive Cl - When these antifreeze agents are added to the polishing composition, the freezing point is reduced, and under low temperature conditions, such as-10℃ to 0℃, the polishing composition still maintains good fluidity without crystallization gel, thereby effectively avoiding the irreversible deterioration of the polishing composition.

[0026] The amino acid surfactant used is a kind of amphoteric surfactant, which behaves as a cationic surfactant in acidic condition and as an anionic surfactant in alkaline condition. The amino acid surfactant includes carboxylic acid type and sulfonic acid type, among which the carboxylic acid type is more common, and generally contains hydrophilic groups such as amino and carboxyl from amino acids (such as glycine, glutamic acid, alanine, etc.) and hydrophobic groups such as coconut acyl, lauryl, myristoyl and other long-chain alkyl groups. When the amino acid surfactant is added to the alkaline polishing composition, it behaves as an anionic surfactant, and is easily adsorbed on the surface of the nanometer silica particles by the hydrophilic-hydrophobic interaction and the hydrogen bond between the amino and carboxyl groups and the Si-OH on the surface of the silica sol, so that the negative charge on the surface of the nanometer silica particles is enhanced, the absolute value of the Zeta potential is increased, the electrostatic repulsion between the particles is increased, and thus the tendency of micro-agglomeration between the nanometer silica particles is weakened, and the formation of large particles is more difficult, so that the increase of the average particle size and the number of large particles in the composition can be prevented.

[0027] It is found in the research process that the Zeta potential of the nanometer silica colloids in the composition is related to the amount of the amino acid surfactant added to the polishing composition. Within a certain range, the absolute value of the Zeta potential of the composition is generally increased with the increasing amount of the amino acid surfactant (the surface of the nanometer silica sol in the composition is negatively charged), and the tendency of micro-agglomeration is weakened under low temperature condition, but the hydrophilic-hydrophobic molecular chains of the excessive amino acid surfactant and the micelles formed therefrom are easily bridged and entangled between the nanometer silica sol particles, causing micro-agglomeration of the silica sol abrasive. In addition, from the perspective of controlling the polishing rate of the silicon material, the electrostatic repulsion between the silica sol abrasive in the composition and the surface of the silicon material should not be too strong, otherwise the removal rate will be significantly inhibited, and thus the ratio between the amino acid surfactant and the nanometer silica colloids needs to be properly adjusted. In the present application, the weight fraction of the amino acid surfactant in the nanometer silica colloids in the low-temperature-resistant polishing composition is preferably 0.1-15%, for example, including but not limited to 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 12%, 15%, and the Zeta potential of the polishing composition is adjusted to -10 to -45 mV; further, the weight fraction of the amino acid surfactant in the nanometer silica sol abrasive in the low-temperature-resistant polishing composition is preferably 2-10%, and the Zeta potential of the polishing composition is adjusted to -15 to -35 mV.

[0028] The antifreeze agent and the amino acid surfactant improve the low-temperature resistance of the polishing composition through the above-mentioned mechanism, inhibit the problems of frozen gel and micellar aggregation of the polishing composition at low temperature, maintain the use performance of the polishing composition after the low-temperature environment, and thus reduce the loss of the polishing composition during the transportation and storage in winter.

[0029] The average particle size of the nanosilica colloid is 10-100 nm, for example, including but not limited to 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 95 nm, 100 nm, and preferably 40 nm-60 nm; and the mass concentration of the nanosilica colloid is 30-50 wt%, for example, 30%, 35%, 40%, 45%, 50%, and preferably 40%.

[0030] As the antifreeze agent, for example, any one, any two combinations or more of ethylene glycol, propylene glycol, diethylene glycol, isopropyl alcohol, ethylene glycol butyl ether, ethylene glycol butyl ether acetate, propylene glycol butyl ether, diethylene glycol butyl ether, ethylene glycol, propylene glycol, dimethyl sulfoxide, formamide, dimethyl formamide, thiourea, urea are selected, and preferably any one of diethylene glycol, ethylene glycol butyl ether, propylene glycol butyl ether, diethylene glycol butyl ether, dimethyl formamide, and urea is selected.

[0031] As the amino acid surfactant, for example, any one, any two combinations or more of sodium cocoyl glutamate, disodium cocoyl glutamate, cocoyl glutamate triethanolamine, sodium cocoyl sarcosinate, cocoyl alanine triethanolamine, sodium cocoyl aminopropionate, sodium cocoyl methyl taurate, sulfamic acid betaine, potassium cocoyl glycinate, sodium cocoyl glycinate, sodium cocoyl isethionate, sodium lauroyl glutamate, disodium lauroyl glutamate, sodium lauroyl aspartate, disodium lauroyl aspartate, sodium lauroyl sarcosinate, lauroyl lysine, sodium lauroyl glycinate, potassium lauroyl glycinate, sodium myristoyl glutamate, sodium myristoyl sarcosinate, potassium myristoyl glycinate, sodium myristoyl isethionate, N-myristoyl-β-aminopropionic acid, sodium methyl lauroyl taurate, formyl lauroyl lysine triethanolamine, sodium dodecyl aminopropionate, sodium dodecyl dimethylene aminodimethylate, dodecyl aminoethyl glycine, and octadecanoyl formyl lysine triethanolamine are selected, and preferably any one of sodium cocoyl glutamate, potassium cocoyl glycinate, sodium lauroyl glutamate, sodium lauroyl glycinate, sodium myristoyl glutamate, sodium methyl lauroyl taurate, and sodium dodecyl aminopropionate is selected.

[0032] In addition to the above-mentioned nano-silica colloidal as abrasive, and the addition of antifreeze and amino acid surfactant these two main components, the present application does not limit any other additives in the low temperature resistant polishing composition, can be applied to the conventional various silicon chemical mechanical polishing liquid system, also can according to the demand of improving the quality of silicon polishing surface and improve the removal rate, the skilled person can choose one or more kinds of rate accelerator, pH regulator, complexing agent to add to the polishing composition.

[0033] Among them, the main rate accelerator is alkaline compound, including inorganic base and organic base, which ionizes or hydrolyzes in the dispersion system, so that the low temperature resistant polishing composition in the process of use, the concentration of OH - - remains at a certain level, to facilitate the formation of soft layer on the silicon surface. As the rate accelerator, for example, is selected from at least one of potassium hydroxide, potassium carbonate, potassium bicarbonate, ammonium hydroxide, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, (2-hydroxyethyl) trimethylammonium hydroxide, diethyl dimethylammonium hydroxide, methyl triethylammonium hydroxide, benzyl trimethylammonium hydroxide, benzyl triethylammonium hydroxide, guanidine carbonate, guanidine hydrochloride, metformin, tetramethylguanidine, imidazole, methyl imidazole, ethylenediamine, hydroxyethyl ethylenediamine, tetrahydroxypropyl ethylenediamine, piperazine, N-aminoethyl piperazine, 1-methyl piperazine, 2-methyl piperazine, homopiperazine, pyrazine, pyridazine, monoethanolamine, for example, any of the above rate accelerators, any two combinations or more, preferably potassium hydroxide, tetramethylammonium hydroxide, guanidine carbonate, imidazole.

[0034] As the pH regulator, for example, is selected from at least one of nitric acid, phosphoric acid, acetic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, malic acid, citric acid, tartaric acid, lactic acid, maleic acid, for example, any of the above pH regulators, any two combinations or more, preferably malonic acid, tartaric acid. The pH regulator is used to adjust the pH value of the concentrated solution, to prevent the concentrated solution from being too alkaline to cause the dissolution of nano-silica sol particles.

[0035] As the complexing agent, for example, is selected from at least one of ethylenediaminetetraacetic acid, ethylenediaminetetramethylene phosphonic acid, aminotri-methylene phosphonic acid, hydroxyethylidene diphosphonic acid, ethylene glycol-bis-(2-aminoethyl) tetraacetic acid, diethylene triamine pentaacetic acid, diethylene triamine pentaacetic acid pentapotassium, potassium pyrophosphate, for example, any of the above complexing agents, any two combinations or more, preferably ethylenediaminetetraacetic acid. The complexing agent is used to complex the metal ions present in the composition, such as Fe 2+ , Al 3+ , etc., to weaken the adsorption of these metal ions on nano-silica sol, and improve its stability. In addition, the complexing agent also has a certain effect on the adsorption of SiO3 2-complexes the reaction products, thereby reducing the accumulation of reaction products in the circulation, inhibiting the discoloration of the polishing composition and the polishing pad.

[0036] In one specific embodiment, the low-temperature resistant silicon polishing composition is made of the following components in the following proportions:

[0037]

[0038] The weight fraction of the amino acid surfactant in the nano-silica colloid in the low-temperature resistant polishing composition is 0.1-15%, for example, including but not limited to 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 12%, 15%, adjusting the Zeta potential of the polishing composition to -10 to -45 mV; further, preferably the weight fraction between 2-10%, adjusting the Zeta potential of the polishing composition to -15 to -35 mV.

[0039] The pH value of the low-temperature resistant silicon polishing composition is 9-12.5, for example, including but not limited to 9, 9.5, 10, 10.5, 11, 11.5, 12, 12.5, preferably 10.5-12.

[0040] The preparation method of the low-temperature resistant silicon polishing composition of the present application, for example, according to the prior art, the components are mixed, specifically, for example, a preparation method of a low-temperature resistant silicon polishing composition, comprising the steps of mixing the antifreeze agent, the amino acid surfactant, the nano-silica colloid and other additives.

[0041] In a preferred embodiment, the rate accelerator, the pH adjuster, the complexing agent, the antifreeze agent, the amino acid surfactant of the present application are added to deionized water in this order and mixed and dispersed sufficiently to form chemical additives of the composition.

[0042] Then, the above-mentioned chemical additives are added to the nano-silica colloid, and after being stirred and dispersed sufficiently, the low-temperature resistant silicon polishing composition of the present application is formed. The dispersion means in this process include but are not limited to any one or more of mechanical stirring, ultrasonic dispersion, magnetic stirring.

[0043] The present application is further explained and illustrated by more specific examples below, but does not constitute any limitation.

[0044] The following examples, the evaluation method is as follows:

[0045] 1) Low-temperature resistant composition low-temperature crystallization gel test: set the temperature to 0°C, -5°C, -10°C respectively, the time is 24h, observe whether the composition appears frozen gel under this condition, and record.

[0046] 2) Average particle size test of low temperature resistant composition: The average particle size of the polishing composition after preparation and after being placed at -5°C for 24 h was tested by using a Malvern Zetasizer laser particle size analyzer.

[0047] 3) Large particle number test of low temperature resistant composition: The large particle number (>0.56 μm) of the polishing composition after preparation and after being placed at -5°C for 24 h was tested by using an AccuSizer A9000FX-nano large particle counter.

[0048] Unless otherwise specified, the raw materials and reagents used in the examples and comparative examples of the present application can be obtained commercially.

[0049] Example 1

[0050] 2 g of imidazole, 0.2 g of malonic acid, 0.02 g of ethylenediaminetetraacetic acid, 10 g of propylene glycol butyl ether, and 0.1 g of methyl lauroyl sodium taurate were added to 300 g of deionized water, stirred until uniform, and then the solution was added to 250 g of 40 wt% nano-silica colloid (average particle size 10 nm) while stirring, and deionized water was added until the total mass of the dispersion was 2 kg, and then the mixture was stirred magnetically for 30 min, packaged, and the pH of the dispersion was 9 and the Zeta potential was -10 mV.

[0051] Examples 2-10 and Comparative Examples 1-3 were prepared according to the above method, and the components, specific contents, pH, and Zeta potential of the examples and comparative examples are shown in Table 1 below.

[0052] Table 1 Components, contents, pH, and Zeta potential of examples and comparative examples

[0053]

[0054]

[0055] The compositions of the examples and comparative examples were first tested for average particle size and large particle number, and then three 0.5 kg samples of each example and comparative example were placed in constant-temperature freezers at 0°C, -5°C, and -10°C for 24 h, and the frozen gel conditions were observed, and the average particle size and large particle number of all samples placed at -5°C for 24 h were tested, and the results of the evaluation of the examples and comparative examples are shown in Tables 2 and 3 below.

[0056] Table 2 Frozen gel conditions of compositions at low temperature

[0057]

[0058] Table 3 Changes in average particle size and large particle number of compositions at low temperature

[0059]

[0060]

[0061] Comparing the above Table 2, the comparative example 1 and the example 6, it can be found that the example composition does not appear frozen gel phenomenon under the condition of 0℃, -5℃, -10℃ for 24h, while the comparative example composition has begun to appear partial frozen gel phenomenon under the condition of 0℃*24h, and completely frozen gel under the condition of -5℃*24h. By comparison, it shows that the anti-frozen gel performance of the composition added with the anti-freezing agent and the amino acid surfactant is obviously improved. Comparing the above Table 2, the comparative example 2 and the example 6, it can be found that the comparative example composition added with only the amino acid surfactant begins to appear partial frozen gel under the condition of -5℃*24h, which shows that the low temperature resistance of the composition added with only the amino acid surfactant is insufficient. Comparing the above Table 2, the comparative example 3 and the example 6, it can be found that the comparative example composition added with only the anti-freezing agent begins to appear partial frozen gel under the condition of -10℃*24h, while the example does not, so it can be said that the anti-frozen gel performance of the comparative example is slightly worse than that of the example. Through the above comparison of the comparative example and the example, it can be shown that the anti-freezing agent plays a major role in improving the anti-frozen gel performance of the composition, and the amino acid surfactant can enhance this effect. The anti-freezing agent reduces the freezing point of the composition, and the amino acid surfactant increases the absolute value of the Zeta potential of the nano-silica sol in the composition, and enhances the electrostatic repulsion between the nano-silica colloidal particles. The two additives can play a synergistic effect in inhibiting the frozen gel of the composition at low temperature.

[0062] Comparing the above Table 3, the comparative example 1, the comparative example 2 and the example 6, it can be found that the comparative example composition appears different degrees of condensation under the condition of -5℃*24h, and the particle size and the large particle number change greatly, which cannot be directly measured, so it can be seen that the anti-freezing performance of the anti-freezing agent is obvious. From the above Table 3, the comparative example 3 and the example 6, it can be found that when the comparative example composition is added with only the anti-freezing agent, although it does not appear condensation frozen gel under the condition of -5℃*24h, the average particle size and the large particle number are greatly increased, and the composition actually also deteriorates, which shows that the amino acid surfactant in the composition is also indispensable, and it has obvious effect in inhibiting the increase of the average particle size and the large particle number of the composition at low temperature, which is consistent with the anti-freezing agent to make the composition maintain good stability at low temperature environment.

[0063] Although the present application has been described in detail through the preferred embodiments, it should be appreciated that the above description is not to be construed as limiting the present application. Those skilled in the art can understand that some modifications or adjustments can be made to the present application under the teaching of the present specification. These modifications or adjustments should also be within the scope defined by the claims of the present application.

Claims

1. A low temperature resistant silicon polishing composition using nanosilica colloids as abrasives, characterized in that, The product comprises the following components in the indicated weight percentages: 5-40 wt% nano-silica gel, 0.5-8 wt% antifreeze, 0.005-6 wt% amino acid surfactant, 0.1-8 wt% rate accelerator, 0.01-1 wt% pH adjuster, 0.001-0.1 wt% complexing agent, with the balance being deionized water; the amount of the amino acid surfactant added is 0.1-15% of the mass of the nano-silica gel. The amino acid-type surfactant is selected from sodium cocoyl glutamate, disodium cocoyl glutamate, triethanolamine cocoyl glutamate, sodium cocoyl sarcosinate, triethanolamine cocoyl alanine, sodium cocoyl aminopropionate, sodium cocoyl methyl taurate, potassium cocoyl glycinate, sodium cocoyl glycinate, sodium cocoyl hydroxyethyl sulfonate, sodium lauroyl glutamate, disodium lauroyl glutamate, sodium lauroyl aspartate, disodium lauroyl aspartate, sodium lauroyl sarcosinate, and other similar surfactants. At least one of the following: lysine, sodium lauroyl glycinate, potassium lauroyl glycinate, sodium myristoyl glutamate, sodium myristoyl sarcosine, potassium myristoyl glycinate, sodium myristoyl hydroxyethanesulfonate, N-myristoyl-β-aminopropionic acid, sodium methyl lauroyl taurate, formyl lauroyl lysine triethanolamine, sodium dodecyl aminopropionate, sodium dodecyl dimethylene aminodicarboxylate, dodecyl aminoethyl glycine, and octadecyl formyl lysine triethanolamine; The complexing agent is selected from at least one of ethylenediaminetetraacetic acid, ethylenediaminetetramethylenephosphonic acid, aminotrimethylenephosphonic acid, hydroxyethylidene diphosphonic acid, ethylene glycol-bis-(2-aminoethyl)tetraacetic acid, diethylenetriaminepentaacetic acid, diethylenetriaminepentaacetic acid pentapotassium, and potassium pyrophosphate. The pH adjuster is selected from at least one of nitric acid, phosphoric acid, acetic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, malic acid, citric acid, tartaric acid, lactic acid, and maleic acid. The nano-silica gel in the composition has a negative charge on its surface, and the absolute value of the Zeta potential is between 10 and 45 mV.

2. The low temperature resistant type silicon polishing composition according to claim 1, characterized by, The product comprises the following components in the indicated weight percentages: 10–25 wt% nano-silica gel, 1–5 wt% antifreeze, 0.2–2.5 wt% amino acid surfactant, 0.5–6 wt% rate accelerator, 0.05–0.5 wt% pH adjuster, 0.01–0.05 wt% complexing agent, with the balance being deionized water.

3. The low temperature resistant type silicon polishing composition according to claim 1 or 2, characterized by, The amount of the amino acid-type surfactant added is 2 to 10% of the mass of the nano silica gel.

4. The low temperature resistant type silicon polishing composition according to claim 1, wherein The absolute value of the zeta potential is between 15 and 35 mV.

5. The low temperature resistant type silicon polishing composition according to claim 1, wherein The average particle size of the nano-silica gel is 10-100 nm, and the mass concentration is 30-50 wt%.

6. The low temperature resistant type silicon polishing composition according to claim 1 or 2, wherein The antifreeze is selected from at least one of alcohols, alcohol ethers, or amides.

7. The low temperature resistant type silicon polishing composition according to claim 6, wherein The antifreeze is selected from at least one of ethylene glycol, propylene glycol, diethylene glycol, isopropanol, ethylene glycol butyl ether, ethylene glycol butyl ether acetate, propylene glycol butyl ether, diethylene glycol butyl ether, dimethyl sulfoxide, formamide, dimethylformamide, thiourea, and urea.

8. The low temperature resistant type silicon polishing composition according to claim 7, wherein The antifreeze agent is at least one of diethylene glycol, ethylene glycol butyl ether, propylene glycol butyl ether, diethylene glycol butyl ether, dimethylformamide, urea.

9. The low temperature resistant type silicon polishing composition according to claim 1, wherein The amino acid surfactant is at least one of sodium cocoyl glutamate, potassium cocoyl glycinate, sodium lauroyl glutamate, sodium lauroyl glycinate, sodium myristoyl glutamate, sodium methyl lauroyl taurate, sodium dodecyl aminopropionate.

10. The low temperature resistant type silicon polishing composition according to claim 1 or 2, wherein The rate accelerator is at least one of potassium hydroxide, potassium carbonate, potassium bicarbonate, ammonium hydroxide, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, (2-hydroxyethyl)trimethylammonium hydroxide, diethyldimethylammonium hydroxide, methyltriethylammonium hydroxide, benzyltrimethylammonium hydroxide, benzyltriethylammonium hydroxide, guanidine carbonate, guanidine hydrochloride, metformin, tetramethylguanidine, imidazole, methylimidazole, ethylenediamine, hydroxyethylethylenediamine, tetrahydroxypropylethylenediamine, piperazine, N-aminoethylpiperazine, 1-methylpiperazine, 2-methylpiperazine, homopiperazine, pyrazine, pyridazine, monoethanolamine.

11. The low temperature resistant type silicon polishing composition according to claim 10, wherein The rate accelerator is at least one of potassium hydroxide, tetramethylammonium hydroxide, guanidine carbonate, imidazole.

12. The low temperature resistant type silicon polishing composition according to claim 1, wherein The pH adjuster is malonic acid, tartaric acid.

13. The low temperature resistant type silicon polishing composition according to claim 1, wherein The pH of the low-temperature resistant silicon polishing composition is adjusted to 9-12.

5.

14. The low temperature resistant type silicon polishing composition according to claim 1, wherein The complexing agent is ethylenediaminetetraacetic acid.

15. Use of the low-temperature resistant silicon polishing composition according to any one of claims 1-14 in silicon chemical mechanical polishing.

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