Alumina material as well as preparation method and application thereof

Abstract

The invention provides an alumina material and a preparation method and application thereof, the alumina material comprises alumina particles, the aggregation index of the alumina particles is less than or equal to 10%, and the hydration particle size of the alumina particles is 135-165 nm. The aluminum oxide material can be used for manufacturing a leveling material, and is beneficial to improving the stability and the leveling efficiency of the leveling material.

Description

Technical Field

[0001] The present application relates to the field of materials, and in particular to an aluminum oxide material and a preparation method and application thereof. Background Art

[0002] Aluminum oxide can be used as an abrasive in planarization materials. For example, α-Al2O3 abrasives can provide extremely low silicon oxide removal rates and high planarization efficiency. Nanoscale α-Al2O3 has been used in the prior art to prepare planarization materials for metal gate planarization.

[0003] Existing methods for synthesizing aluminum oxide (Al2O3) include calcining, grinding, and pulverizing a precursor. However, the resulting aluminum oxide (Al2O3) has a wide particle size distribution, resulting in a relatively high PDI. The quality of planarization materials prepared using aluminum oxide with an excessively wide particle size distribution is difficult to control, and the planarization efficiency can be unstable. Furthermore, the hydrated particle size of aluminum oxide can significantly impact its application in planarization materials.

[0004] Therefore, an alumina material with a smaller aggregation index (PDI) and a smaller hydrated particle size is urgently needed in the field. Summary of the Invention

[0005] The present application discloses an aluminum oxide material, a preparation method thereof, and an application thereof. The aluminum oxide material can be used for planarizing materials, thereby helping to improve the stability of the planarizing materials and improve the planarization efficiency.

[0006] In a first aspect, the present application provides an aluminum oxide material, comprising aluminum oxide particles, wherein the aggregation index of the aluminum oxide particles is less than or equal to 10%, and the hydrated particle size of the aluminum oxide particles is 135 to 165 nm.

[0007] The aluminum oxide material can be used for planarization materials, which helps to improve the stability of the planarization materials and improve the planarization efficiency.

[0008] In one possible embodiment, the contents of sodium, potassium, iron and calcium in the alumina material are all less than 200 ppb.

[0009] The aluminum oxide material contains less metal impurities, which helps to improve the stability of the planarization material and improve the planarization efficiency.

[0010] In second aspect, the present application provides a method for preparing an alumina material, comprising: subjecting a slurry comprising alumina to a first centrifugation, and then taking an upper slurry; wherein the separation factor of the first centrifugation is greater than or equal to 600g; diluting the upper slurry to obtain a diluted material; wherein the ratio of the volume of the diluted material to the volume of the upper slurry is greater than or equal to 5.5; subjecting the diluted material to a second centrifugation, and then taking a lower slurry to obtain the alumina material.

[0011] In the above-mentioned preparation method (gradation purification method), the slurry including alumina is first subjected to a first centrifugation (primary classification), and the separation factor of the first centrifugation is greater than or equal to 600g. After the first centrifugation (primary classification) is completed, the part deposited at the bottom during the classification process is discarded, and the upper slurry is collected, which helps to remove large-particle particles. The upper slurry is diluted, and the dilution ratio is greater than or equal to 5.5, which can further disperse the alumina particles. Then a second centrifugation (secondary classification) is performed. After the second centrifugation (secondary classification) is completed, the upper slurry is discarded, and the lower slurry is taken (the part deposited at the bottom is collected), which can further remove small-particle particles and regulate the particle size distribution of the alumina particles, thereby obtaining alumina particles with a narrow particle size distribution, whose aggregation index (polydispersity factor or PDI) can be less than or equal to 10%, and the hydrated particle size of the alumina particles can also be reduced.

[0012] In addition, during the above-mentioned dilution process, the metal impurities (such as sodium, potassium, iron, and calcium) in the slurry including alumina will be further dispersed, and thus during the second centrifugation, under the action of the high separation factor, they will enter the upper slurry after the second centrifugation, thereby being separated from the alumina particles in the lower slurry. The metal impurity content in the alumina particles can be controlled and thus reduced, while taking into account a higher alumina particle yield, which can be no less than 30%.

[0013] Therefore, the above preparation method (gradation purification method) can regulate the particle size distribution of alumina particles through the synergistic effect of the above "primary classification" + "dilution" + "secondary classification", and obtain alumina particles with a narrow particle size distribution and a smaller hydrated particle size. It can also reduce the metal impurity content (gold impurity content) in the alumina particles while taking into account a higher yield, which is not less than 30%.

[0014] In a possible embodiment, the separation factor of the first centrifugation is 600-1500 g.

[0015] The separation factor of the first centrifugation is 600-1500g. After the first centrifugation (one classification) is completed, the part deposited at the bottom during the classification process is discarded and the upper slurry is collected, which better removes large-particle particles, better reduces the aggregation index and hydration particle size of the alumina material, and also helps to reduce the content of metal impurities.

[0016] In one possible embodiment, the separation factor of the first centrifugation is 1200-1500 g.

[0017] The separation factor of the first centrifugation is 1200-1500g. After the first centrifugation (one classification) is completed, the part deposited at the bottom during the classification process is discarded and the upper slurry is collected, which further better removes large-particle particles, better reduces the aggregation index and hydration particle size of the alumina material, and also helps to reduce the content of metal impurities.

[0018] In a possible implementation manner, the volume ratio of the diluted material to the upper slurry is 6-25.

[0019] The volume ratio of the diluted material to the upper slurry is 6 to 25, which helps to better disperse the material, thereby better reducing the aggregation index and hydration particle size of the alumina material, and also helps to reduce the content of metal impurities.

[0020] In a possible implementation manner, the volume ratio of the diluted material to the upper slurry is 20-25.

[0021] The volume ratio of the diluted material to the upper slurry is 20-25, which helps to better disperse the material, thereby better reducing the aggregation index and hydration particle size of the alumina material, and also helps to reduce the content of metal impurities.

[0022] In one possible embodiment, the separation factor of the second centrifugation is 10,000-16,000 g.

[0023] The separation factor of the second centrifugation is 10,000 to 16,000 g. After the second centrifugation (secondary classification) is completed, the upper slurry is discarded and the lower slurry is taken (the part accumulated at the bottom is collected). This can further remove small-sized particles and adjust the particle size distribution of the alumina particles, thereby obtaining alumina particles with a narrower particle size distribution and a smaller hydrated particle size, and can also further reduce the content of metal impurities in the alumina material.

[0024] In one possible embodiment, the hydrated particle size of the aluminum oxide in the slurry comprising aluminum oxide is 180 to 250 nm.

[0025] Under the above-mentioned preparation method (graded purification method) system, by further regulating the hydrated particle size (Dz) of alumina in the slurry including alumina to 180-250 nm, it is helpful to prepare alumina nanoparticles having a hydrated particle size of 135-155 nm and an aggregation index (PDI) less than or equal to 10%.

[0026] In a possible embodiment, the solid content of the alumina slurry is 5% to 30%, which helps to produce alumina particles with narrow particle size distribution and low metal impurity content while taking into account the efficiency of classification and purification.

[0027] In one possible embodiment, the contents of sodium, potassium, iron, and calcium in the alumina slurry are all less than 2 ppm, which helps to produce alumina particles with contents of sodium, potassium, iron, and calcium less than 200 ppb.

[0028] In a third aspect, the present application provides a planarization material, comprising the above-mentioned aluminum oxide material or the aluminum oxide material obtained according to the above-mentioned preparation method.

[0029] Based on the aluminum oxide material, the planarization material has higher stability and planarization efficiency.

[0030] Specifically, in the planarization material, the mass percentage of the aluminum oxide material is 0.05% to 1%. By controlling the content of the aluminum oxide material to meet the above range, it is helpful to improve the stability and planarization efficiency of the planarization material.

[0031] In one possible embodiment, in an environment with a temperature of ≤60°C, the hydrated particle size of the planarization material remains stable for ≥7 days. The term "stable" means that the absolute value of the change in the hydrated particle size of the planarization material is ≤5 nm. This indicates that the planarization material has high stability.

[0032] In one possible embodiment, the step height difference of the planarized material is This shows that the planarization material has a high planarization efficiency.

[0033] In a possible embodiment, the planarization speed of the planarization material is The planarization material has a high planarization speed. DETAILED DESCRIPTION

[0034] To enable those skilled in the art to better understand the solutions of the present application, the present application is further described in detail below. The specific embodiments listed below are merely descriptions of the principles and features of the present application. The examples cited are only used to explain the present application and do not limit the scope of the present application. Based on the embodiments of the present application, all other implementation methods obtained by those of ordinary skill in the art without making creative efforts are within the scope of protection of this application.

[0035] Limited by existing preparation processes, alumina (Al2O3) materials generally suffer from problems such as excessively large aggregation indexes, i.e., overly wide particle size distributions, and excessively high metal impurity content. For example, existing methods for synthesizing alumina include calcining, grinding, and pulverizing a precursor. The resulting alumina has a wide particle size distribution, i.e., a relatively large aggregation index (PDI). Furthermore, the quality of planarized materials prepared using alumina with an excessively wide particle size distribution is difficult to control, and is prone to aging and unstable planarization efficiency. Furthermore, the hydrated particle size and impurity content of alumina can significantly impact its application in planarized materials.

[0036] In order to overcome the defects in the prior art, in the first aspect, an embodiment of the present application provides an aluminum oxide material, the aluminum oxide material includes aluminum oxide particles, the aggregation index of the aluminum oxide particles is less than or equal to 10%, and the hydrated particle size of the aluminum oxide particles is 135 to 165 nm.

[0037] Illustratively, the alumina particles have an aggregation index (polydispersity index or PDI) less than or equal to 10%, such as 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, or a range consisting of any two thereof.

[0038] The aggregation index in this application refers to the particle size distribution of the aluminum oxide particles. An aggregation index (polydispersity factor or PDI) of the aluminum oxide particles less than or equal to 10% indicates that the particle size distribution of the aluminum oxide particles is narrow.

[0039] Illustratively, the hydrated particle size of the aluminum oxide particles is 135 to 165 nm, such as 135, 140, 145, 150, 155, 160, 165 nm, or a range consisting of any two thereof.

[0040] The hydrated particle size can be obtained by testing through the following process: the alumina material is prepared into a slurry and stirred thoroughly, a sample is diluted to 1%, and after ultrasonic dispersion, it is tested using a dynamic light scattering (DLS) device. The obtained cumulative average value of the hydrated particle size Dz (Z-mean) is the hydrated particle size.

[0041] The above-mentioned aluminum oxide material can be used to prepare a planarization material, which helps to improve the stability and planarization efficiency of the planarization material.

[0042] The above-mentioned aluminum oxide material has good application prospects in the field of planarization materials.

[0043] In some embodiments, the content of sodium, potassium, iron, and calcium in the alumina material is less than 200 ppb.

[0044] The contents of sodium, potassium, iron and calcium in the alumina material are all less than 200 ppb, indicating that the content of metal impurities in the alumina material is relatively low, which helps to improve the stability and planarization efficiency of the planarization material.

[0045] In a second aspect, an embodiment of the present application provides a method for preparing an alumina material, comprising: subjecting a slurry comprising alumina to a first centrifugation, and then taking an upper slurry; wherein the separation factor of the first centrifugation is greater than or equal to 600 g; diluting the upper slurry to obtain a diluted material; wherein the ratio of the volume of the diluted material to the volume of the upper slurry is greater than or equal to 5.5; subjecting the diluted material to a second centrifugation, and then taking a lower slurry to obtain an alumina material.

[0046] According to research and analysis, in the above-mentioned preparation method (gradation purification method), the slurry including alumina is first subjected to a first centrifugation (primary classification), and the separation factor of the first centrifugation is greater than or equal to 600g. After the first centrifugation (primary classification) is completed, the part deposited at the bottom during the classification process is discarded, and the upper slurry is collected, which helps to remove large-size particles. The upper slurry is diluted, and the dilution ratio is greater than or equal to 5.5, which can further disperse the alumina particles. Then, a second centrifugation (secondary classification) is performed. After the second centrifugation (secondary classification) is completed, the upper slurry is discarded, and the lower slurry is taken (the part deposited at the bottom is collected), which can further remove small-size particles. , regulating the particle size distribution of the alumina particles, thereby obtaining alumina particles with a narrow particle size distribution, whose aggregation index (polydispersity factor or PDI) can be less than or equal to 10%, and the hydrated particle size of the alumina particles can also be reduced; in addition, during the above-mentioned dilution process, the metal impurities (such as sodium, potassium, iron, and calcium) in the slurry including alumina will be further dispersed, and thus in the process of the second centrifugation, under the action of the high separation factor, enter the upper slurry after the second centrifugation, thereby being separated from the alumina particles in the lower slurry, which can regulate and further reduce the content of metal impurities in the alumina particles, while taking into account a higher alumina particle yield, which can be no less than 30%.

[0047] Therefore, the above preparation method (gradation purification method) can regulate the particle size distribution of alumina particles through the synergistic effect of the above "primary classification" + "dilution" + "secondary classification", and obtain alumina particles with a narrow particle size distribution and a smaller hydrated particle size. It can also reduce the metal impurity content (gold impurity content) in the alumina particles while taking into account a higher yield, which is not less than 30%.

[0048] The aluminum oxide material (nanoparticles) obtained according to the above-mentioned preparation method (graded purification method) is dispersed in water to obtain a slurry. The hydrated particle size distribution of the aluminum oxide in the slurry is narrow and the metal impurity content (gold impurity content) is low. It has good application prospects in the planarization scenario and helps to improve the stability and planarization efficiency of the planarization material.

[0049] In one possible embodiment, the separation factor of the first centrifugation is 600-1500 g.

[0050] Illustratively, the separation factor of the first centrifugation can be 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500 g, or a range consisting of any two thereof.

[0051] The separation factor of the first centrifugation is 600-1500g. After the first centrifugation (one classification) is completed, the part deposited at the bottom during the classification process is discarded and the upper slurry is collected, which better removes large-particle particles, better reduces the aggregation index and hydration particle size of the alumina material, and also helps to reduce the content of metal impurities.

[0052] In one possible embodiment, the separation factor of the first centrifugation is 1200-1500 g.

[0053] The separation factor of the first centrifugation is further controlled to be 1200-1500g. After the first centrifugation (one classification) is completed, the part deposited at the bottom during the classification process is discarded, and the upper slurry is collected, which further better removes large-particle particles, better reduces the aggregation index and hydration particle size of the alumina material, and also helps to reduce the content of metal impurities.

[0054] In one possible embodiment, the volume ratio of the diluted material to the upper slurry is 6-25.

[0055] Illustratively, the ratio of the volume of the dilution material to the upper slurry can be 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25 or a range consisting of any two thereof.

[0056] The volume ratio of the diluted material to the upper slurry is 6 to 25, which helps to better disperse the material, thereby better reducing the aggregation index and hydration particle size of the alumina material, and also helps to reduce the content of metal impurities.

[0057] In one possible embodiment, the volume ratio of the diluted material to the upper slurry is 20-25.

[0058] Further controlling the volume ratio of the diluted material to the upper slurry to 20-25 helps to better disperse the material, thereby better reducing the aggregation index and hydration particle size of the alumina material, and also helps to reduce the content of metal impurities.

[0059] In one possible embodiment, the separation factor of the second centrifugation is 10,000-16,000 g.

[0060] The separation factor of the second centrifugation is 10,000 to 16,000 g. After the second centrifugation (secondary classification) is completed, the upper slurry is discarded and the lower slurry is taken (the part accumulated at the bottom is collected). This can further remove small-sized particles and adjust the particle size distribution of the alumina particles, thereby obtaining alumina particles with a narrower particle size distribution and a smaller hydrated particle size, and can also further reduce the content of metal impurities in the alumina material.

[0061] In one possible embodiment, the separation factor of the second centrifugation is 10,000-12,000 g.

[0062] The separation factor of the second centrifugation is 10,000 to 12,000 g. After the second centrifugation (secondary classification) is completed, the upper slurry is discarded and the lower slurry is taken (the part accumulated at the bottom is collected). This can further remove small-sized particles and adjust the particle size distribution of the alumina particles, thereby obtaining alumina particles with a narrower particle size distribution and a smaller hydrated particle size, and can also further reduce the content of metal impurities in the alumina material.

[0063] The above separation factor (Fr) is the main indicator for measuring the performance of centrifuge (centrifuge separator), and its calculation formula is as follows:

[0064] Fr=1.1×10 -3 Rn 2

[0065] Where R is the radius of the separated material in the centrifuge container from the centrifugal center point (unit: meter); n is the operating speed of the centrifuge (rpm).

[0066] The first centrifugation and the second centrifugation processes can be performed using a centrifuge, which can include one or more of a desktop centrifuge, a plate centrifuge, a screw centrifuge, a tubular centrifuge, and a disc centrifuge.

[0067] The slurry including alumina may be prepared by mixing alumina raw materials with water.

[0068] Alumina (such as α-Al2O3) raw materials inevitably contain large particles with too large particle size and small particles with too small particle size. Large particles will cause scratches during the polishing process, and small particles will cause residues during the polishing process, both of which will reduce the polishing effect.

[0069] Therefore, in one possible embodiment, the hydrated particle size of the aluminum oxide in the slurry comprising aluminum oxide is 180 to 250 nm.

[0070] Under the above-mentioned preparation method (graded purification method) system, by further regulating the hydrated particle size (Dz) of alumina in the slurry including alumina to 180-250 nm, it is helpful to prepare alumina nanoparticles having a hydrated particle size of 135-155 nm and an aggregation index (PDI) less than or equal to 10%.

[0071] In one possible embodiment, the solid content of the slurry comprising aluminum oxide is 5% to 30%, which helps to produce aluminum oxide particles with narrow particle size distribution and low metal impurity content while taking into account the efficiency of classification and purification.

[0072] In one possible embodiment, the contents of sodium, potassium, iron, and calcium in the alumina slurry are all less than 2 ppm, which helps to produce alumina particles with contents of sodium, potassium, iron, and calcium less than 200 ppb.

[0073] In a third aspect, the present application provides a planarization material, comprising the above-mentioned aluminum oxide material or the aluminum oxide material obtained according to the above-mentioned preparation method.

[0074] Based on the aluminum oxide material, the planarization material has higher stability and planarization efficiency.

[0075] Specifically, in the planarizing material, the mass percentage of the aluminum oxide material can be 0.05% to 1%, for example, 0.05%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1% or a range consisting of any two of them.

[0076] By controlling the content of the aluminum oxide material to meet the above range, the stability of the planarization material and the planarization efficiency can be improved.

[0077] In a possible embodiment, in an environment with a temperature ≤ 60° C., the hydrated particle size of the planarized material remains stable for ≥ 7 days, wherein the hydrated particle size of the planarized material remains stable means that the absolute value of the change in the hydrated particle size of the planarized material is ≤ 5 nm.

[0078] In one possible embodiment, the step height difference of the planarized material is This shows that the planarization material has a high planarization efficiency.

[0079] In one possible embodiment, the planarization speed of the planarized material is The planarization material has a high planarization speed.

[0080] The present invention is further described below by means of specific examples and comparative examples. Unless otherwise specified, the reagents, materials and instruments used below are all conventional reagents, materials and instruments, which are all commercially available, and the reagents and materials involved can also be synthesized by conventional synthesis methods.

[0081] Example 1

[0082] This embodiment provides a method for preparing an aluminum oxide material (nanoparticles) (a method for fractional purification), comprising:

[0083] mixing an alumina raw material with water to obtain a slurry comprising alumina (raw material), wherein the alumina slurry (raw material) has a hydrated particle size of 178 nm, a solid content of 5%, a sodium content of 350 ppb, a potassium content of 260 ppb, an iron content of 180 ppb, and a calcium content of 450 ppb;

[0084] The slurry (raw material) comprising alumina is subjected to a first centrifugation (first classification), and then an upper layer of the slurry is collected; wherein the separation factor of the first centrifugation (first classification) is 1500 g;

[0085] diluting the upper slurry with water to obtain a diluted material; wherein the ratio of the volume of the diluted material to the volume of the upper slurry (dilution ratio) is 6 (6x);

[0086] The diluted material is subjected to a second centrifugation (secondary classification), and then the lower layer of slurry is taken to obtain aluminum oxide material (nanoparticles); wherein the separation factor of the second centrifugation (secondary classification) is 16000g.

[0087] Example 2

[0088] This embodiment is basically the same as the first embodiment, except that:

[0089] The ratio of the volume of the diluted material to the volume of the upper slurry (dilution ratio) is 12 (12x); other conditions remain unchanged.

[0090] Example 3

[0091] This embodiment is basically the same as the first embodiment, except that:

[0092] The ratio of the volume of the diluted material to the volume of the upper slurry (dilution ratio) is 25 (25x); other conditions remain unchanged.

[0093] Example 4

[0094] This embodiment is basically the same as embodiment 3, except that:

[0095] The separation factor of the first centrifugation (first fractionation) was 1000 g; other conditions remained unchanged.

[0096] Example 5

[0097] This embodiment is basically the same as embodiment 3, except that:

[0098] The separation factor of the first centrifugation (first fractionation) was 600 g; other conditions remained unchanged.

[0099] Example 6

[0100] This embodiment is basically the same as embodiment 3, except that:

[0101] The separation factor of the second centrifugation (secondary fractionation) was 14000 g; other conditions remained unchanged.

[0102] Example 7

[0103] This embodiment is basically the same as embodiment 3, except that:

[0104] The separation factor of the second centrifugation (secondary fractionation) was 10,000 g; other conditions remained unchanged.

[0105] Example 8

[0106] This embodiment is basically the same as embodiment 3, except that:

[0107] The hydrated particle size of alumina in the slurry including alumina (original material) was ∼190 nm; other conditions remained unchanged.

[0108] Example 9

[0109] This embodiment is basically the same as embodiment 3, except that:

[0110] The hydrated particle size of alumina in the slurry including alumina (original material) was ∼250 nm; other conditions remained unchanged.

[0111] Example 10

[0112] This embodiment is basically the same as embodiment 3, except that:

[0113] The hydrated particle size of alumina in the slurry including alumina (original material) was ∼220 nm; other conditions remained unchanged.

[0114] Example 11

[0115] This embodiment is basically the same as embodiment 3, except that:

[0116] The solid content of the slurry including alumina (original material) was 15%; other conditions remained unchanged.

[0117] Example 12

[0118] This embodiment is basically the same as embodiment 3, except that:

[0119] The solid content of the slurry including alumina (original material) was 30%; other conditions remained unchanged.

[0120] Example 13

[0121] This embodiment is basically the same as embodiment 3, except that:

[0122] The slurry (raw material) including alumina had a sodium content of 1.9 ppm, a potassium content of 1.9 ppm, an iron content of 1.9 ppm, and a calcium content of 1.9 ppm.

[0123] Example 14

[0124] This embodiment is basically the same as embodiment 3, except that:

[0125] The separation factor of the first centrifugation (primary fractionation) was 1300 g, and the separation factor of the second centrifugation (secondary fractionation) was 11000 g; other conditions remained unchanged.

[0126] Example 15

[0127] This embodiment is basically the same as embodiment 3, except that:

[0128] The ratio of the volume of the diluted material to the volume of the upper slurry (dilution ratio) is 22 (22x); other conditions remain unchanged.

[0129] Example 16

[0130] This embodiment is basically the same as embodiment 3, except that:

[0131] The separation factor of the first centrifugation (first fractionation) was 1550 g; other conditions remained unchanged.

[0132] Example 17

[0133] This embodiment is basically the same as embodiment 3, except that:

[0134] The separation factor of the second centrifugation (secondary fractionation) was 9500 g; other conditions remained unchanged.

[0135] Example 18

[0136] This embodiment is basically the same as embodiment 3, except that:

[0137] The ratio of the volume of the diluted material to the volume of the upper slurry (dilution ratio) is 5.5 (5.5x); other conditions remain unchanged.

[0138] Comparative Example 1

[0139] This comparative example is basically the same as Example 3, except that:

[0140] The separation factor of the first centrifugation (first fractionation) was 550 g; other conditions remained unchanged.

[0141] Comparative Example 2

[0142] This comparative example is the slurry including alumina of Example 1 (original material).

[0143] Comparative Example 3

[0144] This comparative example is the slurry including alumina of Example 8 (original material).

[0145] Comparative Example 4

[0146] This comparative example is the slurry including alumina of Example 9 (original material).

[0147] Comparative Example 5

[0148] This comparative example is the slurry including alumina of Example 10 (original material).

[0149] Comparative Example 6

[0150] This comparative example is the slurry including alumina of Example 13 (original material).

[0151] Test example

[0152] 1. The following parameters of the aluminum oxide materials (nanoparticles) of the above embodiments and comparative examples were tested:

[0153] Hydrated particle size: After thoroughly stirring the slurry to be tested, a sample is diluted to 1%, and after ultrasonic dispersion, the sample is measured using a dynamic light scattering (DLS) device. The obtained cumulative average value Dz (Z-mean) is the hydrated particle size.

[0154] Aggregation index (polydispersity factor or PDI): This index is the result calculated by the test software after parameter fitting of relevant data, and is used to characterize the size polydispersity of nanomaterials.

[0155] Metal impurity (sodium, potassium, iron, calcium) content: After thoroughly stirring the slurry to be tested, a sample was diluted to 0.1%. The sample was added to a mixture of concentrated sulfuric acid / concentrated nitric acid / hydrofluoric acid and digested by microwave heating. The results were then measured by inductively coupled plasma atomic emission spectroscopy (ICP-OES).

[0156] 2. Test results

[0157] Table 1

[0158]

[0159]

[0160] Data analysis: The particle size distribution PDI of each embodiment is less than 10%, and the yield is not less than 30%, which proves that the graded purification method of the embodiment of the present application can obtain alumina particles with a narrow particle size distribution while achieving a higher yield.

[0161] Test Example 2

[0162] The aluminum oxide nanoparticles of Examples 1-18 and Comparative Example 1 were prepared into a planarized material, which included 0.1% by mass of an aluminum oxide material coated with a negatively charged dispersant on the surface, ferric nitrate, malonic acid, hydrogen peroxide and other ingredients.

[0163] The performance of the planarization material is tested, such as quality stability (represented by the aging stability of the planarization material in a 60-degree Celsius oven), planarization efficiency (represented by the height difference between the long and short channel steps after planarization), and planarization speed.

[0164] 1. The following parameters were tested for the above examples and comparative examples:

[0165] Aging stability of the planarized material: The planarized material was placed in a 60°C oven for aging testing. Samples were taken daily and then cooled to room temperature for particle size testing. When the difference between the hydrated particle size and the initial hydrated particle size was greater than 5nm, the planarized material was considered unstable.

[0166] Long-Short Channel Step Height Difference: After planarizing a 300nm aluminum pattern using a planarizing material, the step height difference between the 50 / 50 long channel position and the 1 / 1 short channel position is used to characterize the planarization efficiency. The smaller the value, the higher the planarization efficiency.

[0167] Planarization speed: Planarization speed achieved by planarizing a 300nm aluminum wafer using planarization material.

[0168] 2. Test results

[0169] Table 2

[0170]

[0171] Data analysis: The polishing liquid prepared using the aluminum oxide particles of each embodiment has good stability and high planarization efficiency, while also taking into account a high polishing speed.

[0172] The above preferred embodiments further illustrate the purpose, technical solutions and advantages of the present application in detail. It should be understood that the above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. An aluminum oxide material, characterized in that: The aluminum oxide material includes aluminum oxide particles. The aggregation index of the aluminum oxide particles is less than or equal to 10%. The hydrated particle size of the aluminum oxide particles is 135-165 nm.

2. The aluminum oxide material according to claim 1, characterized in that The contents of sodium, potassium, iron and calcium in the alumina material are all less than 200 ppb.

3. A method for preparing an aluminum oxide material, characterized in that: include: subjecting the slurry comprising aluminum oxide to a first centrifugation, and then collecting an upper layer of the slurry; wherein the separation factor of the first centrifugation is greater than or equal to 600 g; diluting the upper slurry to obtain a diluted material; wherein the volume ratio of the diluted material to the upper slurry is greater than or equal to 5.5; The diluted material is subjected to a second centrifugation, and then a lower layer of slurry is taken to obtain the alumina material.

4. The preparation method according to claim 3, characterized in that The separation factor of the first centrifugation is 600-1500g; and / or, the volume ratio of the dilution material to the upper slurry is 6 to 25; And / or, the separation factor of the second centrifugation is 10000-16000 g.

5. The preparation method according to claim 3 or 4, characterized in that The hydrated particle size of the aluminum oxide in the aluminum oxide slurry is 180 to 250 nm; and / or, the solid content of the slurry comprising alumina is 5% to 30%; And / or, the contents of sodium, potassium, iron and calcium in the slurry comprising alumina are all less than 2 ppm.

6. A planarization material, characterized in that: The invention comprises the aluminum oxide material according to claim 1 or 2 or the aluminum oxide material obtained according to the preparation method according to any one of claims 3 to 5.

7. The planarization material according to claim 6, characterized in that: In the planarization material, the mass percentage of the aluminum oxide material is 0.05% to 1%.

8. The planarization material according to claim 6 or 7, characterized in that: In an environment with a temperature of ≤60° C., the hydrated particle size of the planarization material remains stable for ≥7 days, wherein the hydrated particle size of the planarization material remains stable means that the absolute value of the change in the hydrated particle size of the planarization material is ≤5 nm.

9. The planarization material according to any one of claims 6 to 8, characterized in that: The step height difference of the planarized material is 10. The planarization material according to any one of claims 6 to 9, characterized in that: The planarization speed of the planarization material is

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