High-efficiency environment-friendly chemical polishing solution and preparation method thereof

Abstract

The present application relates to the technical field of polishing liquid, in particular to a kind of high-efficiency environmental protection chemical polishing liquid and preparation method thereof.The chemical polishing liquid includes the following raw materials by weight percentage: 5-8% nanometer metal abrasive, 2-4% silicon oxide abrasive, 2-10% oxidizing agent, 1-5% complexing agent, 0.05-0.5% corrosion inhibitor, the rest is deionized water;It also includes pH regulator, and the pH of the chemical polishing liquid is adjusted to 7.5-8.5 by using pH regulator.The chemical polishing liquid of the present application uses environmental protection raw materials, and shows good polishing effect for the precision machining of monocrystalline silicon wafer, the material removal efficiency is high, and the surface of polished silicon wafer is smooth and undamaged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of polishing liquid, in particular to a kind of high-efficiency environmental protection chemical polishing liquid and preparation method thereof. BACKGROUND

[0002] As a widely used surface planarization technology, chemical mechanical polishing has become one of the important processes for precision polishing of alloy surfaces in the fields of precision metal parts, electronic components and semiconductor device manufacturing. Chemical mechanical polishing is a processing method that combines the chemical action of additives in the polishing liquid with the mechanical action of abrasive particles. The polishing liquid is the key to the polishing effect. However, most of the current polishing liquids use single abrasive particles or traditional abrasive particles as polishing abrasives. However, due to the shape, size and dispersibility of single abrasive particles, they have a great impact on the polishing effect, so it is often necessary to add more chemical reagents to improve the polishing effect. On the other hand, most of the current polishing liquids use strong acid, BTA, potassium nitrate and other chemical reagents that pose potential risks to the environment and human body. The components of the polishing liquid are complex, the cost is high, the pollution is large, and it needs to match a high polishing pressure, which is easy to cause damage to the surface of the material. Therefore, how to effectively control the interface contact state between the abrasive and the sample under lower operating pressure conditions, and thus reduce the scratching of the alloy surface, while giving the polishing liquid high-efficiency environmental protection characteristics, is one of the key problems to be solved in the production of polishing liquid. SUMMARY

[0003] The present application aims to provide a high-efficiency environmental protection chemical polishing liquid and preparation method thereof to solve the problems of the prior art.

[0004] The present application achieves the above-mentioned purpose by the following technical solution: a high-efficiency environmental protection chemical polishing liquid, comprising the following raw materials by weight percentage: 5%-8% nanometer metal abrasive, 2%-4% silicon oxide abrasive, 2%-10% oxidizing agent, 1%-5% complexing agent, 0.05%-0.5% corrosion inhibitor, 0.01%-0.3% surfactant, and the rest is deionized water; further comprising a pH adjuster, which is used to adjust the pH of the chemical polishing liquid to 7.5-8.5.

[0005] Further, the nanometer metal abrasive includes at least one of nanometer cerium oxide, nanometer aluminum oxide and nanometer zinc oxide.

[0006] Further, the nanometer metal abrasive is composed of nanometer cerium oxide and nanometer aluminum oxide in a mass ratio of 1:0.5-0.7.

[0007] Further, the preparation method of the nano cerium oxide comprises the following steps: taking cerium nitrate to be fully dissolved in deionized water to obtain a cerium nitrate solution, then adding acetic acid and ethylene glycol solution into the cerium nitrate solution in sequence and stirring uniformly, then transferring into a reaction kettle, reacting at 175-190℃ for 2-3h, after the reaction, naturally cooling, centrifuging, washing, drying, and then calcining at 400-500℃ for 3-4h, to obtain the nano cerium oxide.

[0008] Further, the concentration of the cerium nitrate solution is 0.8-1.2g / mL. The particle size of the nano cerium oxide prepared by the above preparation steps is 130-160nm.

[0009] Further, the nano cerium oxide is a cerium oxide doped with rare earth metal ions, and the rare earth metal ions are preferably La, Pr or Sm. By doping the rare earth metal particles into the cerium oxide, the oxygen vacancy concentration on the surface of the cerium oxide is adjusted, and the chemical reaction ability of the cerium oxide with the surface of the silicon wafer is enhanced, that is, the Ce of the cerium oxide abrasive can be improved, and the polishing efficiency of the cerium oxide abrasive can be improved. In the present application, the preparation method of the cerium oxide doped with rare earth metal ions comprises the following steps: taking cerium nitrate to be fully dissolved in deionized water to obtain a cerium nitrate solution, then adding acetic acid and ethylene glycol solution into the cerium nitrate solution in sequence and stirring uniformly, then adding a rare earth metal nitrate solution dropwise, then transferring into a reaction kettle, reacting at 175-190℃ for 2-3h, after the reaction, naturally cooling, centrifuging, washing, drying, and then calcining at 400-500℃ for 3-4h, to obtain the nano cerium oxide doped with rare earth metal particles.

[0010] Further, the nano cerium oxide is a cerium oxide doped with rare earth metal ions, and the rare earth metal ions are preferably La, Pr or Sm. By doping the rare earth metal particles into the cerium oxide, the oxygen vacancy concentration on the surface of the cerium oxide is adjusted, and the chemical reaction ability of the cerium oxide with the surface of the silicon wafer is enhanced, that is, the Ce of the cerium oxide abrasive can be improved, and the polishing efficiency of the cerium oxide abrasive can be improved. In the present application, the preparation method of the cerium oxide doped with rare earth metal ions comprises the following steps: taking cerium nitrate to be fully dissolved in deionized water to obtain a cerium nitrate solution, then adding acetic acid and ethylene glycol solution into the cerium nitrate solution in sequence and stirring uniformly, then adding a rare earth metal nitrate solution dropwise, then transferring into a reaction kettle, reacting at 175-190℃ for 2-3h, after the reaction, naturally cooling, centrifuging, washing, drying, and then calcining at 400-500℃ for 3-4h, to obtain the nano cerium oxide doped with rare earth metal particles.

[0011] Further, the particle size of the nano cerium oxide is 5-20nm, and the thickness of the silicon oxide coating layer is 9-13nm.

[0012] In the present application, by coating the surface of the nano cerium oxide with silicon oxide, the damage risk of the nano cerium oxide to the polishing interface due to its high hardness is reduced, the polishing surface quality is improved, and the dispersibility and stability of the cerium oxide are significantly improved.

[0013] Further, the particle size of the silicon oxide abrasive is 30-60 nm. In the present application, the preparation method of the silicon oxide abrasive comprises the following steps: adding an ammonia chloride buffer solution into a container containing deionized water, uniformly stirring to obtain a buffer solution; then adding a small amount of tetraethyl orthosilicate into the buffer solution in multiple times, stirring and heating to 75-85℃, and reacting for 12-16 h to obtain a silica sol, and then performing rotary evaporation on the silica sol to obtain the silicon oxide abrasive.

[0014] In the present application, the silicon oxide abrasive prepared by the above preparation method has uniform particle size, good dispersibility and is not easy to agglomerate, so that it can be uniformly dispersed in the polishing liquid system and has good stability. The small-sized silicon oxide abrasive is beneficial to further reducing the surface roughness and improving the polishing surface quality when combined with the nano metal abrasive, so that the chemical polishing liquid is suitable for precision polishing processing.

[0015] Further, the oxidizing agent is any one of hydrogen peroxide, NaClO and K2S2O8.

[0016] Further, the complexing agent is at least one of glycine, potassium hydrogen phthalate and sorbitol. As preferred in the present application, the complexing agent is a combination of glycine and potassium hydrogen phthalate in a mass ratio of 1.5-2:1. The present application can complex the copper and iron metal impurities by the green and environmentally friendly glycine, and simultaneously has a strong complexation effect between the high-valence metal particles by the potassium hydrogen phthalate, so as to meet the use under a variety of polishing conditions in a wide temperature and pH range, effectively ensure the polishing effect, reduce the impact on the environment, and reduce the production cost of the polishing liquid.

[0017] Further, the corrosion inhibitor is at least one of 1,2,4-triazole, polyvinylpyrrolidone, disodium hydrogen phosphate and sodium benzoate. As preferred in the present application, the corrosion inhibitor is a combination of 1,2,4-triazole and polyvinylpyrrolidone in a mass ratio of 2-3:1. The present application can have a good release effect on the metal by the combination of 1,2,4-triazole and polyvinylpyrrolidone, form a protective film on the surface of the silicon wafer, reduce the direct contact between the abrasive and the surface of the silicon wafer in the polishing liquid, and play a release effect while being beneficial to the dispersion and stability of the abrasive.

[0018] Further, the surface active agent is at least one of octylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, cetyltrimethylammonium bromide, and sodium dodecyl benzene sulfonate. As preferred in the present application, the surface active agent is a combination of cetyltrimethylammonium bromide and fatty alcohol polyoxyethylene ether in a mass ratio of 1:1-1.2. By using cetyltrimethylammonium bromide and fatty alcohol polyoxyethylene ether together, the present application can reduce the interfacial tension between the polishing liquid and the silicon wafer, improve the polishing efficiency and uniformity, and facilitate the dispersion of the abrasive and prevent its agglomeration.

[0019] Further, the pH regulator is at least one of dihydrogen phosphate-hydrogen phosphate buffer, amino propanol, polyamine organic base, oxalic acid, and L-malic acid.

[0020] The present application also provides a preparation method of the high-efficiency and environmentally friendly polishing liquid, which comprises the following steps: mixing the nano metal abrasive, the silicon oxide abrasive, and the deionized water into a suspension for ultrasonic dispersion, then adding the oxidizing agent, the corrosion inhibitor, the complexing agent, and the surface active agent into the suspension for stirring, and finally adding the pH regulator to adjust the pH of the solution to 7.5-8.5.

[0021] The present application has the following advantages: the chemical polishing liquid prepared by using green and environmentally friendly raw materials has good dispersibility and stability, and exhibits good polishing effect in the finishing of silicon wafers, with high material removal efficiency and smooth and non-damaged surface of the polished silicon wafer. The accurate proportioning of the nano cerium oxide, the nano aluminum oxide, and the silicon oxide to form the abrasive plays an important role in improving the polishing efficiency and surface effect of the polishing liquid. The addition of the complexing agent can expand the use conditions and range of the polishing liquid while ensuring the polishing effect, the addition of the specific corrosion inhibitor can achieve good slow-release effect, and the combination of cetyltrimethylammonium bromide and fatty alcohol polyoxyethylene ether can reduce the interfacial tension between the polishing liquid and the silicon wafer, improve the polishing efficiency and uniformity, and facilitate the dispersion and stability of the abrasive. DETAILED DESCRIPTION

[0022] For the convenience of understanding of those skilled in the art, the present application is further described below in combination with examples, and the content mentioned in the embodiments is not a limitation on the present application.

[0023] Example 1

[0024] The embodiment provides a high-efficiency and environment-friendly chemical polishing solution, which comprises the following raw materials in percentage by weight: 6% of nano metal abrasive, 2% of silica abrasive, 3% of oxidant, 1.2% of complexing agent, 0.08% of corrosion inhibitor, 0.03% of surfactant, and the rest of deionized water; and further comprises a pH regulator, and the pH of the chemical polishing solution is adjusted to 7.5 by using the pH regulator.

[0025] Further, the nano metal abrasive is combined by nano cerium oxide and nano aluminum oxide with a mass ratio of 1:0.5.

[0026] Further, the preparation method of the nano cerium oxide comprises the following steps: 1g of cerium nitrate is fully dissolved in deionized water to obtain a cerium nitrate solution, 1ml of acetic acid and 30ml of ethylene glycol solution are sequentially added into the cerium nitrate solution and stirred uniformly, then the solution is transferred into a reaction kettle, and the reaction is carried out at 180℃ for 2.5h, after the reaction is completed, the supernatant is removed by centrifugation, and the obtained product is washed repeatedly with water and ethanol, and then dried in a 60℃ oven overnight, and finally calcined at 450℃ for 3.5h to obtain the nano cerium oxide.

[0027] Further, the concentration of the cerium nitrate solution is 0.9g / mL, and the average particle size of the nano cerium oxide prepared by the above preparation steps is 150nm.

[0028] Further, the nano aluminum oxide is nano aluminum oxide with a silica coating layer on the surface, and the preparation method comprises the following steps: 1g of nano aluminum oxide is taken into a reactor, 80ml of ethanol and 20ml of deionized water are sequentially added into the reactor, and then ultrasonic mixing is carried out, then 5g of hexadecyl trimethyl ammonium bromide and sodium hydroxide are added into the reactor and mixed uniformly, and then TEOS is added drop by drop, and the stirring reaction is carried out at room temperature for 6h, and finally the product is obtained by centrifugation, washing and drying.

[0029] Further, the nano aluminum oxide is spherical and has a particle size of 20nm, and the thickness of the silica coating layer is 10nm.

[0030] Further, the particle size of the silica abrasive is 30nm, and the preparation method of the silica abrasive comprises the following steps: an ammonia chloride buffer solution is added into a container containing deionized water, and the buffer solution with a pH of 10.5 is obtained after fully stirring; then a small amount of tetraethyl orthosilicate (deionized water and tetraethyl orthosilicate with a mass ratio of 1.2:1) is added into the buffer solution in multiple times, and the temperature is increased to 75℃ while stirring, and the silica sol is obtained by reacting for 12h, and then the silica sol is rotary evaporated at 50℃, and the silica abrasive is obtained after vacuum drying.

[0031] Further, the oxidant is K2S2O8.

[0032] Further, the complexing agent is a combination of glycine and potassium biphthalate in a mass ratio of 1.5:1.

[0033] Further, the corrosion inhibitor is a combination of 1,2,4-triazole and polyvinylpyrrolidone in a mass ratio of 2:1.

[0034] Further, the surfactant is a combination of dodecyl trimethyl ammonium bromide and fatty alcohol polyoxyethylene ether in a mass ratio of 1:1.05.

[0035] Further, the pH regulator is aminopropanol.

[0036] The preparation method of the high-efficiency and environmentally friendly polishing liquid in the embodiment includes the following steps: mixing nano metal abrasive, silica abrasive and deionized water into a suspension for ultrasonic dispersion, then adding an oxidizing agent, a corrosion inhibitor, a complexing agent and a surfactant into the suspension for stirring, and then adding a pH regulator to adjust the pH of the solution to 7.5.

[0037] Embodiment 2

[0038] The embodiment provides a high-efficiency and environmentally friendly chemical polishing liquid, which includes the following raw materials in percentage by weight: 7% of nano metal abrasive, 3% of silica abrasive, 5% of an oxidizing agent, 3% of a complexing agent, 0.2% of a corrosion inhibitor, 0.15% of a surfactant, and the rest being deionized water; and a pH regulator is further included, which is used to adjust the pH of the chemical polishing liquid to 8.0.

[0039] Further, the nano metal abrasive is a combination of Pr-doped nano cerium oxide and nano aluminum oxide in a mass ratio of 1:0.6.

[0040] Further, the preparation method of the Pr-doped nano cerium oxide includes the following steps: 1g of cerium nitrate is fully dissolved in deionized water to obtain a cerium nitrate solution, 1ml of acetic acid and 30ml of ethylene glycol solution are then added into the cerium nitrate solution for stirring, a praseodymium nitrate solution is then added dropwise into the solution, and then the solution is transferred into a reaction kettle for reaction at 180℃ for 2.5h, after which the solution is naturally cooled, the supernatant is removed by centrifugation, and the residue is washed repeatedly with water and ethanol and then dried in a 60℃ oven overnight, and finally the residue is calcined at 450℃ for 3.5h to obtain the Pr-doped nano cerium oxide.

[0041] Further, the concentration of the cerium nitrate solution is 1.0g / mL, and the concentration of the praseodymium nitrate solution is 0.5g / mL. The average particle size of the nano cerium oxide prepared by the above preparation steps is 140nm, and the atomic percentage of Pr doped in the cerium oxide is 2%.

[0042] Further, the nano-alumina is nano-alumina with a silica coating layer on the surface, and the preparation method comprises the following steps: 1g of nano-alumina is taken in a reactor, 80mL of ethanol and 20mL of deionized water are sequentially added, and then ultrasonic mixing is performed, then 5g of hexadecyl trimethyl ammonium bromide and sodium hydroxide are uniformly mixed and added dropwise, then TEOS is added dropwise, stirring is performed at room temperature for 10h, and then centrifugation, washing and drying are performed to obtain the nano-alumina with the silica coating layer on the surface.

[0043] Further, the nano-alumina is spherical, and the particle size is 10nm; and the thickness of the silica coating layer is 11nm.

[0044] Further, the particle size of the silica abrasive is 40nm. The preparation method of the silica abrasive comprises the following steps: an ammonia-ammonium chloride buffer solution is added to a container containing deionized water, the buffer solution with a pH of 10.5 is obtained after sufficient stirring; then a small amount of tetraethyl orthosilicate (deionized water and tetraethyl orthosilicate are mixed at a mass ratio of 1.2:1) is added dropwise to the buffer solution, the temperature is increased to 80℃ while stirring, and then the reaction is performed for 12h to obtain a silica sol, and then the silica sol is subjected to rotary evaporation at 50℃, and then vacuum drying is performed to obtain the silica abrasive.

[0045] Further, the oxidizing agent is hydrogen peroxide.

[0046] Further, the complexing agent is a combination of glycine and potassium hydrogen phthalate at a mass ratio of 1.5:1.

[0047] Further, the corrosion inhibitor is a combination of 1,2,4-triazole and polyvinylpyrrolidone at a mass ratio of 2.5:1.

[0048] Further, the surfactant is a combination of dodecyl trimethyl ammonium bromide and fatty alcohol polyoxyethylene ether at a mass ratio of 1:1.1.

[0049] Further, the pH regulator is a potassium dihydrogen phosphate-potassium hydrogen phosphate buffer.

[0050] The preparation method of the high-efficiency and environmentally friendly polishing liquid comprises the following steps: nano-metal abrasive and silica abrasive are mixed with deionized water to form a suspension for ultrasonic dispersion, then an oxidizing agent, a corrosion inhibitor, a complexing agent and a surfactant are added and stirred uniformly, and then a pH regulator is added to adjust the pH of the solution to 8.0.

[0051] Example 3

[0052] The embodiment provides a high-efficiency and environment-friendly chemical polishing solution, which comprises the following raw materials in percentage by weight: 7% of nano metal abrasive, 3% of silica abrasive, 6% of oxidant, 3% of complexing agent, 0.3% of corrosion inhibitor, 0.2% of surfactant, and the rest is deionized water; and further comprises a pH regulator, and the pH of the chemical polishing solution is adjusted to 8.0 by using the pH regulator.

[0053] Further, the nano metal abrasive is combined by nano cerium oxide doped with La and nano aluminum oxide with a mass ratio of 1:0.6.

[0054] Further, the preparation method of the nano cerium oxide doped with La comprises the following steps: 1g of cerium nitrate is fully dissolved in deionized water to obtain a cerium nitrate solution, 1ml of acetic acid and 30ml of ethylene glycol solution are sequentially added into the cerium nitrate solution and stirred uniformly, then lanthanum nitrate solution is added dropwise, and then the mixture is transferred into a reaction kettle, and reacted at 180℃ for 2.5h, and after the reaction is completed, the supernatant is removed by centrifugation, and the obtained product is washed repeatedly with water and ethanol, and then dried in a 60℃ oven overnight, and finally calcined at 450℃ for 4h to obtain the nano cerium oxide doped with La.

[0055] Further, the concentration of the cerium nitrate solution is 1.0g / mL, and the concentration of the lanthanum nitrate solution is 0.5g / mL. The average particle size of the nano cerium oxide prepared by the above preparation steps is 150nm, and the atomic percentage of La doped in the cerium oxide is 2%.

[0056] Further, the nano aluminum oxide is nano aluminum oxide with a silica coating layer on the surface, and the preparation method comprises the following steps: 1g of nano aluminum oxide is taken into a reactor, 80ml of ethanol and 20ml of deionized water are sequentially added into the reactor, and then ultrasonic mixing is performed, then 5g of cetyltrimethylammonium bromide and sodium hydroxide are added into the reactor and mixed uniformly, and then TEOS is added dropwise, and the mixture is stirred at room temperature for 12h, and then the product is obtained by centrifugation, washing and drying.

[0057] Further, the particle size of the nano aluminum oxide is 10nm, and the thickness of the silica coating layer is 12nm.

[0058] Further, the particle size of the silica abrasive is 40nm. The preparation method of the silica abrasive comprises the following steps: an ammonia chloride buffer solution is added into a container containing deionized water, and the buffer solution with a pH of 10.5 is obtained after fully stirring; then a small amount of tetraethyl orthosilicate (deionized water and tetraethyl orthosilicate with a mass ratio of 1.2:1) is added dropwise into the buffer solution for several times, and the temperature is increased to 80℃ while stirring, and the silica sol is obtained by reacting for 12h, and then the silica sol is rotary evaporated at 50℃, and the silica abrasive is obtained after vacuum drying.

[0059] Further, the oxidizing agent is hydrogen peroxide.

[0060] Further, the complexing agent is a combination of glycine and potassium biphthalate in a mass ratio of 2:1.

[0061] Further, the corrosion inhibitor is a combination of 1,2,4-triazole and polyvinylpyrrolidone in a mass ratio of 2.5:1.

[0062] Further, the surfactant is a combination of dodecyl trimethyl ammonium bromide and fatty alcohol polyoxyethylene ether in a mass ratio of 1:1.1.

[0063] Further, the pH regulator is potassium dihydrogen phosphate-potassium hydrogen phosphate buffer.

[0064] The preparation method of the high-efficiency and environmentally friendly polishing solution provided in the embodiment includes the following steps: mixing nano metal abrasive, silica abrasive and deionized water into a suspension for ultrasonic dispersion, then adding an oxidizing agent, a corrosion inhibitor, a complexing agent and a surfactant into the suspension for stirring, and then adding a pH regulator to adjust the pH of the solution to 8.0.

[0065] Embodiment 4

[0066] The embodiment provides a high-efficiency and environmentally friendly chemical polishing solution, which includes the following raw materials in percentage by weight: 8% of nano metal abrasive, 3% of silica abrasive, 8% of an oxidizing agent, 4% of a complexing agent, 0.4% of a corrosion inhibitor, 0.25% of a surfactant, and the rest being deionized water; and a pH regulator is further included, which is used to adjust the pH of the chemical polishing solution to 8.5.

[0067] Further, the nano metal abrasive is a combination of Sm-doped nano cerium oxide and nano aluminum oxide in a mass ratio of 1:0.7.

[0068] Further, the preparation method of the Sm-doped nano cerium oxide includes the following steps: 1g of cerium nitrate is fully dissolved in deionized water to obtain a cerium nitrate solution, 1ml of acetic acid and 30ml of ethylene glycol solution are then added into the cerium nitrate solution for stirring, a samarium nitrate solution is then added dropwise into the solution, and then the solution is transferred into a reaction kettle for reaction at 180℃ for 3h, after which the solution is naturally cooled, the supernatant is removed by centrifugation, and the obtained product is washed repeatedly with water and ethanol, and then dried in a 60℃ oven overnight, and finally calcined at 500℃ for 4h to obtain the Sm-doped nano cerium oxide.

[0069] Further, the concentration of the cerium nitrate solution is 1.2 g / mL, and the concentration of the samarium nitrate solution is 0.5 g / mL. The average particle size of the Sm-doped nano ceria prepared by the above preparation steps is 130 nm, and the atomic percentage of Sm doped in the ceria is 2%.

[0070] Further, the nano alumina is nano alumina with a silica coating layer on the surface, and the preparation method comprises the following steps: taking 1 g of nano alumina in a reactor, sequentially adding 80 mL of ethanol and 20 mL of deionized water, ultrasonic mixing, then adding 5 g of cetyltrimethylammonium bromide and sodium hydroxide uniformly, and then adding TEOS drop by drop, stirring at room temperature for 12 h, and then obtaining the nano alumina with a silica coating layer on the surface by centrifugation, washing and drying.

[0071] Further, the particle size of the nano alumina is 10 nm, and the thickness of the silica coating layer is 12 nm.

[0072] Further, the particle size of the silica abrasive is 40 nm. The preparation method of the silica abrasive comprises the following steps: adding an ammonia-ammonium chloride buffer solution into a container containing deionized water, stirring uniformly to obtain a buffer solution with a pH of 10.5; then adding tetraethyl orthosilicate (deionized water and tetraethyl orthosilicate in a mass ratio of 1.2:1) dropwise into the buffer solution in small amounts and multiple times, stirring while heating to 75°C, and reacting for 12 h to obtain a silica sol, and then performing rotary evaporation on the silica sol at 50°C, and vacuum drying to obtain the silica abrasive.

[0073] Further, the oxidizing agent is hydrogen peroxide.

[0074] Further, the complexing agent is a combination of glycine and potassium hydrogen phthalate in a mass ratio of 2:1.

[0075] Further, the corrosion inhibitor is a combination of 1,2,4-triazole and polyvinylpyrrolidone in a mass ratio of 3:1.

[0076] Further, the surfactant is a combination of dodecyltrimethylammonium bromide and fatty alcohol polyoxyethylene ether in a mass ratio of 1:1.2.

[0077] Further, the pH regulator is a polyhydroxy diamine.

[0078] The preparation method of the high-efficiency and environmentally friendly polishing liquid described in the embodiment comprises the following steps: mixing nano metal abrasive and silica abrasive with deionized water to form a suspension for ultrasonic dispersion, then adding an oxidizing agent, a corrosion inhibitor, a complexing agent and a surfactant to stir uniformly, and then adding a pH regulator to adjust the pH of the solution to 8.5.

[0079] Comparative Example 1

[0080] The difference between the present comparative example and Example 1 is that the commercially available silicon oxide (Hangzhou Jiupeng New Material Co., Ltd., particle size of 30 nm) is used to replace the silicon oxide abrasive in Example 2.

[0081] Comparative Example 2

[0082] The difference between the present comparative example and Example 3 is that the commercially available cerium oxide (HN-CeO3, Hangzhou Hengna New Material Co., Ltd.) and commercially available aluminum oxide (ALuna-2032, Hubei HuiFu Nanometer Material Co., Ltd.) are used to replace the nano cerium oxide and nano aluminum oxide in Example 2, and the mass ratio is unchanged.

[0083] Comparative Example 3

[0084] The difference between the present comparative example and Example 3 is that the undoped nano cerium oxide is used to replace the nano metal abrasive in Example 3.

[0085] Comparative Example 4

[0086] The difference between the present comparative example and Example 3 is that the nano aluminum oxide (ALuna-2032, Hubei HuiFu Nanometer Material Co., Ltd.) is used to replace the nano metal abrasive in Example 3.

[0087] Comparative Example 5

[0088] The difference between the present comparative example and Example 3 is that the present comparative example uses an equal amount of silicon oxide abrasive to replace the nano metal abrasive in Example 3.

[0089] In order to verify the polishing effect of the chemical polishing solution described in the present application, the polishing solutions prepared in Examples 1-4 and Comparative Examples 1-5 are used for fine polishing of single crystal silicon wafers. The polishing process parameters are as follows: the polishing disc rotation speed is 80 rpm, the carrier disc rotation speed is 60 rpm, the polishing solution flow rate is 12 ml / min, the polishing pressure is 36 kPa, the polishing time is 1 h, and the polishing pad is a sanding leather polishing pad. The test results are shown in the following table:

[0090]

[0091] From the above results, compared with Comparative Examples 1-5, the chemical polishing solution prepared in Examples 1-4 has good polishing effect on the surface processing of single crystal silicon wafers, high material removal efficiency, and low surface roughness of the polished silicon wafers, and shows good polishing effect for the precision processing of single crystal silicon wafers. At the same time, the raw materials of such chemical polishing solution are environmentally friendly and harmless to the environment and human body.

[0092] On the other hand, the chemical polishing solution prepared in Examples 1-4 was left to stand at room temperature for 7 days, and the results showed that the four groups of polishing solutions still had a large amount of suspended abrasive after 7 days, and the sedimentation was less, thus indicating that the polishing solution prepared in the present application has good dispersibility and high stability of the abrasive. The chemical polishing solution prepared in Comparative Examples 1-5 all had different degrees of sedimentation, and the degree of sedimentation from light to heavy was in the order of Comparative Example 1, Comparative Example 3, Comparative Example 2, Comparative Example 5 and Comparative Example 4.

[0093] The above specific examples are further illustrations of the technical solutions and beneficial effects of the present application, and are not limitations on the embodiments. Any obvious substitutions for those skilled in the art without departing from the concept of the present application are within the protection scope of the present application.

Claims

1. A high-efficiency environmentally friendly chemical polishing solution, characterized in that: The raw materials include the following weight percentages: 5%-8% nanometer metal abrasive, 2%-4% silicon oxide abrasive, 2%-10% oxidant, 1%-5% complexing agent, 0.05%-0.5% corrosion inhibitor, 0.01%-0.3% surfactant, and the rest is deionized water; further comprising a pH adjusting agent, and the pH of the chemical polishing solution is adjusted to 7.5-8.5 by using the pH adjusting agent; ​ The nanometer metal abrasive is composed of nanometer cerium oxide and nanometer aluminum oxide in a mass ratio of 1:0.5-0.7; The nanometer cerium oxide is cerium oxide doped with rare earth metal ions, and the rare earth metal ions are La, Pr or Sm; The nanometer aluminum oxide is nanometer aluminum oxide with a silicon oxide coating layer on the surface; The complexing agent is composed of glycine and potassium hydrogen phthalate in a mass ratio of 1.5-2:1; The corrosion inhibitor is composed of 1,2,4-triazole and polyvinylpyrrolidone in a mass ratio of 2-3:1; The surfactant is composed of dodecyltrimethylammonium bromide and fatty alcohol polyoxyethylene ether in a mass ratio of 1:1-1.

2.

2. The high-efficiency environmentally friendly chemical polishing solution according to claim 1, characterized in that: The particle size of the silicon oxide abrasive is 30-60 nm.

3. The high-efficiency environmentally friendly chemical polishing solution according to claim 1, characterized in that: The oxidant is any one of hydrogen peroxide, NaClO, and K2S2O8.

4. The high-efficiency environmentally friendly chemical polishing solution according to claim 1, characterized in that: The pH adjusting agent is at least one of dihydrogen phosphate-hydrogen phosphate buffer, aminopropanol, polyamine organic base, oxalic acid, and L-malic acid.

5. The preparation method of the high-efficiency environmentally friendly chemical polishing solution according to any one of claims 1-4, characterized by comprising the following steps: mixing nanometer metal abrasive, silicon oxide abrasive, and deionized water into a suspension for ultrasonic dispersion, then adding an oxidant, a corrosion inhibitor, a complexing agent, and a surfactant to stir uniformly, and then adding a pH adjusting agent to adjust the pH of the solution to 7.5-8.

5. ​

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