JP2007084755A - Composite oxide particle for polishing, method for producing the same and slurry-shaped polishing material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composite oxide particle for polishing, having fine particle diameter and sharp distribution of the particle diameters as a particle for polishing achieving both of high profile irregularity and high-speed polishing efficiency, and further having high crystallinity and high purity. <P>SOLUTION: The composite oxide particle for polishing comprises a composite cerium oxide particle obtained by forming a solid solution of cerium oxide and aluminum, and is regulated so that the atomic ratio ä[Al]/[Ce] (wherein, [Al] mol% is the proportion of the Al in the composite cerium particle; and [Ce] mol% is the proportion of the cerium)} of the aluminum to the cerium which are the constituent elements of the particle may be within the range of 0.01-1, and the average primary particle diameter may be within the range of 1-200 nm. The particle is produced as follows. An aqueous solution containing a cerium ion and an aluminum ion is added to an aqueous alkali solution containing a hydroxyalkylamine, and the obtained precipitate is subjected to heat treatment within a temperature range of 110-300°C in the presence of water. The resultant precipitate is subjected to heat treatment in air. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a composite oxide particle for polishing that can be suitably used for surface polishing of a member made of a substance mainly composed of silica, such as glass, a lens, and a semiconductor wafer.

  In recent years, alumina-based and silicon-based slurries have been used for grinding silicon wafers and quartz wafers, as well as for polishing metal films and ceramic films formed on the surface of silicon wafers. For required members, CMP (Chemical Mechanical Polishing) polishing with cerium oxide slurry is often performed.

  The cerium oxide used for such precision polishing is often produced by using natural minerals such as monazite and bastonite as a starting material, and firing and pulverizing it. In some cases, a metal salt solution containing cerium ions is added to an alkaline aqueous solution to precipitate cerium hydroxide, and the resulting precipitate is subjected to dehydration treatment by baking. It is phenomenologically that these abrasives use a solid phase reaction (that is, a chemical action) between cerium oxide, which is an abrasive component, and silica, which is a component of an abrasive material such as glass. It is known.

  On the other hand, Patent Document 1 proposes nanocrystalline plate-like cerium oxide having high crystallinity and purity as particles suitable for use in polishing liquids, polishing sheets, and the like. A method for obtaining cerium particles and the like is also disclosed.

JP 2003-206475 A

  Conventional cerium oxide particles (cerium oxide abrasive grains for polishing) produced through the above-described firing / pulverization or firing dehydration treatment of precipitates, as described below, in terms of particle diameter, impurities, and crystallinity. Each had problems.

  That is, since the cerium oxide obtained by the conventional method has a particle size on the order of microns, scratches often referred to as scratches may remain on the material to be polished. In addition, since the conventional manufacturing method basically employs mechanical pulverization to make fine particles, it is impossible to obtain a specific particle shape, and a sharp particle size distribution is obtained. It was also difficult. Furthermore, when mechanical impact is applied, there is a problem that the cerium oxide particles are easily distorted and the crystallinity of the particles is lowered. This kind of crystallinity is a very important factor that affects the polishing efficiency of the abrasive. However, in the conventional manufacturing method, even if a spectrum based on cerium oxide is exhibited by X-ray diffraction or the like, the abrasive As for the crystallinity, the satisfactory one has not been obtained.

  In addition, although cerium oxide particles depend on the production method, generally, elements other than cerium originally contained in the raw material are likely to be present at the same time as cerium, so that there is a problem that it is difficult to obtain high-purity particles. This purity is particularly problematic when cerium oxide particles are used in a chemical polishing liquid or the like.

  On the other hand, according to the method described in Patent Document 1, nanoparticulate plate-like cerium oxide having high crystallinity and purity can be obtained. However, the hardness of the obtained cerium oxide and its reaction product is equal to or lower than the hardness of glass, so the polishing efficiency is higher for materials with higher hardness (higher hardness among glass). However, it is still not enough.

  The present invention has been made in view of such circumstances, and as a polishing particle capable of ensuring both high surface accuracy and high-speed polishing efficiency, the particle diameter is fine and has a sharp particle size distribution, and high crystallinity. The purpose is to realize composite oxide particles for polishing that are both highly resistant and highly pure.

  In order to achieve the above object, the composite oxide particles for polishing according to the present invention (Claim 1) have aluminum dissolved in cerium oxide, or unevenly distributed as aluminum oxide or aluminum oxide hydroxide near the surface of the cerium oxide particles. The atomic ratio between the constituent elements aluminum and cerium (the amount of Al in the composite cerium oxide particles is <Al> mol% and the amount of Ce is <Ce> mol% < Al> / <Ce>) is in the range of 0.01 to 1, and the average primary particle diameter is in the range of 1 nm to 200 nm. In the inventions according to claims 2 to 4, the abrasive composite oxide particles are dispersed in a liquid medium (water in the invention according to claim 3) to form a slurry-like abrasive.

  Here, the average primary particle diameter means a particle obtained by observing particles with a transmission electron microscope (TEM) and randomly selecting 200 particles and averaging the particle diameters. The shape of the composite cerium oxide particles is not particularly limited, and examples thereof include a spherical shape, a plate shape, and a rectangular parallelepiped shape. From the viewpoint of polishing efficiency, the shape is a plate shape that can be expected to have a polishing effect by an edge rather than a spherical shape. Is preferred. Further, the aluminum in the composite oxide particles for polishing of the present invention (aluminum in the composite oxide particles) does not necessarily need to be uniformly dissolved in the whole, and may be segregated in the vicinity of the surface.

  With the above-described configuration, it is possible to increase the mechanical hardness of the abrasive particles (abrasive grains) and simultaneously realize excellent polishing power and precision polishing ability. In the present invention, aluminum is used in addition to cerium oxide, but aluminum is a common metal element and is extremely excellent in terms of cost.

Moreover, the method of this invention manufactures said composite oxide particle for grinding | polishing by passing through the process of following (1)-(4) at least.
(1) A step of adding an aqueous solution containing cerium ions and aluminum ions to an alkaline aqueous solution containing oxyalkaliamines to generate a hydroxide or hydrate precipitate containing cerium and aluminum.
(2) A step of adjusting the hydroxide or hydrate precipitate obtained in the step (1) to pH 7-12.
(3) A step of hydrothermally treating the pH-adjusted precipitate obtained in the step (2) in the temperature range of 110 to 300 ° C. in the presence of water.
(4) The process of heat-processing the processed material obtained at the process of (3) in the temperature range of 300-1200 degreeC in the air.

  According to the composite oxide particles for polishing (composite cerium oxide particles) of the present invention, it is possible to realize an abrasive having both high surface accuracy due to the chemical action of cerium oxide and high polishing efficiency due to the mechano action of composite cerium oxide. Can do.

  According to the method of the present invention, the primary particles are prepared by a hydrothermal treatment step for adjusting the shape of the particles and dehydrating from the hydroxide or hydrate, and a step for heating the composite cerium oxide particles obtained in this step. The diameter can be controlled. As a result, composite cerium oxide particles having a uniform particle size distribution, less sintering and aggregation, and good crystallinity can be obtained. Further, if the shape is made plate-like by adding oxyalkaliamine to the alkaline solution, higher polishing efficiency can be expected.

  This manufacturing method is a novel manufacturing method that is completely different from the conventional solid-phase reaction manufacturing method. By passing through a hydrothermal treatment step, aluminum element is dissolved in cerium oxide in atomic order, and the resulting composite oxidation The cerium particles have extremely good crystallinity with an average particle diameter in the range of 1 nm to 200 nm. If this composite cerium oxide particle is used as an abrasive, a polishing efficiency higher than that of cerium oxide produced by the same method can be obtained, and even compared with cerium oxide produced by a conventional method such as Comparative Example 2 described later, Higher polishing efficiency can be obtained. The composite cerium oxide particles obtained in the present invention are particularly suitable as abrasives for polishing sheets and polishing liquids, and their industrial utility value is extremely high.

  In the method of the present invention, first, an aqueous solution containing cerium ions and aluminum ions is added to an alkaline aqueous solution containing oxyalkaliamine, and the resulting precipitate is heated in the temperature range of 110 to 300 ° C. in the presence of water. By adjusting the shape and particle size to the target, and then heat-treating this precipitate in air, the particle size distribution is uniform, sintering and agglomeration are extremely small, and the composite oxidation has good crystallinity. Obtain cerium particles.

  Thus, in the production of composite cerium oxide particles, by separating the process aimed at adjusting the shape and particle diameter and the process aimed at maximizing the physical properties inherent in the material, The composite cerium oxide particles having a plate shape and an average primary particle diameter in the range of 1 nm to 200 nm, which was impossible with the production method, can be obtained. The composite cerium oxide particles according to the present invention thus obtained have very little particle sintering and agglomeration, sharp particle size distribution, and at the same time extremely good crystallinity. It is especially powerful when used as an abrasive.

  In general, when preparing composite particles with solid solution, a solid-phase reaction in which fine particles are mixed and heat-treated at high temperature is often used. However, such a method does not necessarily overcome the non-uniformity of solid solution. In the production method of the present invention, since it is mixed and crystallized in the atomic order, the solid solution uniformity and crystallinity are extremely high. When this type of composite cerium oxide particles is used as an abrasive for chemical polishing, purity becomes important, and high purity is required. The composite cerium oxide particles of the present invention are sufficiently satisfactory in terms of purity, and are optimal as abrasives in this respect as well.

  The composite cerium oxide particles obtained by the present invention, that is, the composite oxide particles for polishing, are optimum abrasives for polishing semiconductors, optical fibers, lenses, and the like, and can be applied to a wide range of applications.

  Hereinafter, the production method of the composite oxide particles for polishing (composite selenium oxide particles) according to the present invention will be described in more detail. In the method of the present invention, the composite oxide particles for polishing are produced roughly through the steps of preparation of precipitate → hydrothermal treatment → heat treatment. FIG. 1 shows each process in more detail. In the following, description will be made by appropriately using reference numerals S1 to S9 of each process shown in FIG.

(Preparation of precipitate)
First, cerium salts such as cerium chloride, cerium nitrate, and cerium sulfate are dissolved in water to prepare an aqueous solution containing cerium ions (S1). In this case, an aqueous solution containing cerium ions may be used, and a solution obtained by dissolving cerium carbonate with a mineral acid can be used instead. Of these cerium salts, cerium chloride is most preferred for obtaining cerium oxide particles having a sharp particle size distribution.

  Next, an aluminum salt such as aluminum chloride, aluminum nitrate, or aluminum sulfate is added to the aqueous solution and dissolved (S1). In this case, an aqueous solution containing aluminum ions may be mixed in addition to the aqueous solution containing cerium ions.

  Apart from these, an alkaline aqueous solution to which alkylamine as a crystal growth controlling agent is added is prepared (S2). If this alkylamine is not added, the particles will not be plate-like and will be polyhedral. Even with polyhedral particles, sufficient performance can be expected, but if it is plate-like, it can still be expected in terms of polishing efficiency. Examples of the alkali include sodium hydroxide, potassium hydroxide, lithium hydroxide, and an aqueous ammonia solution, and examples of the alkylamine include monoethanolamine, triethanolamine, isobutanolamine, and propanolamine. Monoethanolamine is most suitable for obtaining complex composite cerium oxide particles.

  Next, an aqueous solution containing the cerium salt aqueous solution and the aluminum salt aqueous solution or both is dropped into the alkaline aqueous solution to which the crystal growth control agent (alkylamine) is added, and the hydroxide or hydration containing cerium and aluminum is added. A precipitate of the product is generated (S3). The pH of the suspension containing the precipitate is adjusted to a range of 7 to 12 (S4). The suspension is preferably aged at room temperature for about 1 day. This pH adjustment and aging are effective in obtaining composite cerium oxide particles having higher crystallinity at a relatively low temperature in the heat treatment in the subsequent step.

(Hydrothermal treatment)
Hydrothermal treatment is performed on the suspension containing the cerium hydroxide or hydrate precipitate using an autoclave or the like (S5). In this case, the suspension containing the precipitate may be subjected to hydrothermal treatment as it is, but the product and the residue other than the precipitate are removed by washing with water (S3-2), and then NaOH or the like is used. It is preferable to adjust the pH again. The pH value at this time is adjusted to be in the range of 7 to 12 as described above. If it is lower than this pH, crystal growth becomes insufficient during hydrothermal treatment, and if it is too high, the particle size distribution becomes wide and it becomes difficult to obtain particles with a desired small particle size.

  The hydrothermal treatment temperature is in the range of 110 ° C to 300 ° C. If the temperature is lower than this temperature, it is difficult to obtain a composite cerium oxide having a specific shape. If the temperature is higher than this temperature, the generated pressure becomes high, so that the apparatus becomes expensive and has no merit. The hydrothermal treatment time is preferably in the range of 1 hour to 4 hours. If the hydrothermal treatment time is too short, the growth to a specific shape becomes insufficient, and even if the hydrothermal time is too long, there is no particular problem, but only the production cost becomes high and is meaningless.

(Heat treatment)
The composite cerium oxide particles after the hydrothermal treatment are washed, filtered (S6), dried (S7), and then subjected to heat treatment (S8) to obtain an optimum particle size as an abrasive. The heating in this case is in-air heating because it is the least expensive to manufacture. If heat treatment is not performed, ultrafine particles from 1 nm can be obtained. After the heat treatment, before filtration, in order to simplify drainage and to finally obtain high-purity composite cerium oxide particles as described later, the pH is adjusted to around 6-9 by washing with water (S9). It is preferable to adjust to the neutral region.

  The heat treatment temperature is in the range of 300 ° C to 1200 ° C. If it is lower than this temperature, crystalline composite cerium oxide fine particles are difficult to obtain, and if it is too high, the particle size becomes too large due to sintering, and the particle size distribution becomes wider. In order to cause sintering to such an extent that primary particles form a neck by this heat treatment, the heating temperature is more preferably in the range of 600 ° C. to 1200 ° C. In this case, if the aggregate of primary particles obtained by sintering is in the range of 0.2 to 5 μm, the polishing efficiency may be improved.

  Composite cerium oxide particles can be obtained by this heat treatment, but if unreacted substances are further removed by washing or the like, higher purity cerium oxide particles can be obtained, so that it can be used as an abrasive for chemical polishing, etc. It is preferable to perform the water washing (S9) described above in the final step.

The composite cerium oxide particles obtained as described above have a particle diameter in the range of 1 nm to 200 nm, and are particularly preferable as a polishing sheet for finish polishing or polishing liquid. When the X-ray diffraction spectrum is measured, a peak corresponding to the crystal structure position of CeO ₂ having a substantially CaF ₂ structure is clearly observed, but a peak corresponding to the aluminum compound is not observed. Also, the crystal habit was clearly observed in the electron microscope observation, and it was confirmed that the crystal had extremely good crystallinity that could not be obtained by the conventional production methods.

  Examples of the present invention and comparative examples will be described below.

<Example 1>
An alkaline aqueous solution was prepared by dissolving 0.075 mol of sodium hydroxide and 10 ml of 2-aminoethanol in 80 ml of water. Separately, 0.0061 mol of cerium (III) chloride heptahydrate and 0.000007 mol of aluminum (III) chloride hexahydrate were dissolved in 40 ml of water to prepare. The atomic ratio of Ce to Al is 10:90. The latter cerium aluminum chloride mixed aqueous solution was dropped into the former alkaline aqueous solution to obtain a precipitate. The pH at this time was 10.8.

  The suspension containing the precipitate is stirred for 2 hours and then prepared with an aqueous sodium hydroxide solution until the pH is 8. The precipitate is aged in the state of suspension for 20 hours, and then the supernatant is removed. Then, the precipitate suspension was charged into an autoclave and hydrothermally treated at 200 ° C. for 2 hours. Then, it was washed with water 1000 times. The obtained product was filtered, dried in air at 90 ° C., and then lightly crushed in a mortar, and heat-treated at 600 ° C. for 1 hour in air to obtain composite cerium oxide particles. After the heat treatment, in order to remove unreacted substances and residues, they were further washed with an ultrasonic disperser and filtered and dried.

When the X-ray diffraction spectrum of the obtained composite cerium oxide particles was measured, a spectrum corresponding to cerium oxide having a CaF ₂ structure was observed. At this time, no peak indicating the presence of the aluminum compound as a mixture appeared. The presence of aluminum atoms was confirmed by fluorescent X-ray analysis. When the crystallite size was calculated from the peak width corresponding to the (111) plane of cerium oxide using the Scherrer method, the crystallite size was 15.3 nm. When the shape was observed with a transmission electron microscope, it was found to be plate-like particles having an average primary particle diameter of 22 nm.

<Example 2>
Regarding the ratio of aluminum chloride to cerium chloride in Example 1, 0.0006 moles of cerium (III) chloride heptahydrate and 0.0015 moles of aluminum (III) chloride hexahydrate were dissolved in 40 ml of water. Adjusted. The atomic ratio of Ce to Al is 20:80. Otherwise, composite cerium oxide particles were produced in the same manner as in Example 1.

When an X-ray diffraction spectrum was measured for the cerium oxide particles, a spectrum corresponding to cerium oxide having a CaF ₂ structure was observed as in Example 1. From the peak width corresponding to the (111) plane, the crystallite size determined using the Scherrer method was 13.6 nm. When observed with a transmission electron microscope, it was a plate-like particle having an average primary particle diameter of 14 nm.

<Example 3>
Composite cerium oxide particles were produced in the same manner as in Example 1 except that 2-aminoethanol was not added to the alkaline solution in the synthesis method of Example 1. When an X-ray diffraction spectrum was measured for the composite cerium oxide particles, a spectrum corresponding to cerium oxide having a CaF ₂ structure was observed as in Example 1. From the peak width corresponding to the (111) plane, the crystallite size determined using the Scherrer method was 22.4 nm. Observation with a transmission electron microscope revealed that the particles were polyhedral granular particles having an average primary particle diameter of 25 nm.

<Example 4>
Regarding the ratio of aluminum chloride to cerium chloride in Example 1, 0.0000375 moles of cerium (III) chloride heptahydrate and 0.0000375 moles of aluminum (III) chloride hexahydrate were dissolved in 40 ml of water. Adjusted. The atomic ratio of Ce to Al is 50:50. Further, composite cerium oxide particles were produced in the same manner as in Example 1 except that the heating condition was 1100 ° C. for 2 hours.

When an X-ray diffraction spectrum was measured for the cerium oxide particles, a spectrum corresponding to cerium oxide having a CaF ₂ structure was observed as in Example 1. From the peak width corresponding to the (111) plane, the crystallite size determined using the Scherrer method was 29.8 nm. When observed with a transmission electron microscope, it was a plate-like particle having an average primary particle diameter of 191 nm.

<Comparative example 1>
Regarding the ratio of aluminum chloride to cerium chloride in Example 1, 0.0075 mol of cerium (III) chloride heptahydrate was dissolved in water as a metal salt solution, and an aqueous solution was prepared without adding aluminum chloride. The atomic ratio of Ce to Al is Al: Ce is 0: 100. Other than that, cerium oxide particles were prepared in the same manner as in Example 1. When the X-ray diffraction spectrum of this composite cerium oxide particle was measured, a spectrum corresponding to cerium oxide having a CaF ₂ structure was observed, and it was obtained from the peak width corresponding to the (111) plane using the Scherrer method. The crystallite size was 38.2 nm. Further, observation with a transmission electron microscope revealed that the particles were plate-like particles having an average primary particle diameter of 41 nm.

<Comparative example 2>
After producing the precipitate in the method for synthesizing the composite cerium oxide particles of Example 1, the precipitate is washed as it is, filtered, dried and then heat-treated in the same manner as in Example 1 without performing hydrothermal treatment. Thus, composite cerium oxide particles were produced. When the X-ray diffraction spectrum of this composite cerium oxide particle was measured, a spectrum corresponding to cerium oxide having a CaF ₂ structure was observed, but a peak of a mixture that was considered to be γ-alumina was also observed. Further, when observed with a transmission electron microscope, it was found that the particle diameter was 50 to 3000 nm (average primary particle diameter 1240 nm) and the sintered body or coarse particles had an extremely wide particle diameter distribution.

<Comparative Example 3>
Regarding the ratio of aluminum chloride to cerium chloride in Example 1, 0.0000375 moles of cerium (III) chloride heptahydrate and 0.0000375 moles of aluminum (III) chloride hexahydrate were dissolved in 40 ml of water. Adjusted. The atomic ratio of Ce to Al is 50:50. Further, composite cerium oxide particles were prepared in the same manner as in Example 1 except that the hydrothermal treatment temperature was 310 ° C. and the heating condition was 1200 ° C. for 6 hours.

When an X-ray diffraction spectrum was measured for the cerium oxide particles, a spectrum corresponding to cerium oxide having a CaF ₂ structure was observed as in Example 1. From the peak width corresponding to the (111) plane, the crystallite size determined using the Scherrer method was 37.4 nm. When observed with a transmission electron microscope, it was a plate-like particle having an average primary particle diameter of 209 nm.

[Evaluation of crystal structure, particle shape, etc.]
From the X-ray diffraction spectrum, a crystal structure peak corresponding to cerium oxide was observed in each of the powders of the examples and comparative examples. However, for the powder of Comparative Example 2, a mixture phase derived from γ-alumina was confirmed, and it was found that composite cerium oxide particles could not be produced. For all powders, XRF (fluorescence X-ray analysis) and IPC (Ion-Pair Chromatography) analysis confirmed the presence of almost the same amount of aluminum atoms, and for all the examples, the spectrum was almost oxidized in a single phase. Since it was obtained at a position corresponding to cerium, it was found that all the obtained powders were composite cerium oxide particles.

  The composite cerium oxide particles obtained in Example 1, Example 2, Example 4, Comparative Example 1, and Comparative Example 3 are all plate-like in shape, excellent in crystallinity, and have a particle size of an abrasive sheet or an abrasive. It turns out that it exists in the optimal range when using it for a liquid. On the other hand, in Example 3 in which 2-aminoethanol was not added, the shape of the obtained particles was not plate-like but granular. It can be seen that the composite cerium oxide particles of Comparative Example 2 have a very large particle size and an extremely wide particle size distribution and are not suitable as an abrasive.

[Evaluation of polishing characteristics]
For the composite oxide particles obtained in each Example and Comparative Example, a polishing experiment was performed under the following conditions in order to evaluate the polishing characteristics.
(1) Material to be polished: Glass substrate for 2.5 inch hard disk (2) Polishing apparatus: MA-200 made by Musashino Electronics Co., Ltd. (3) Polishing pad: Polishing pad SUBA800
・ Load: 30 g / cm ²
・ Surface plate speed: 60rpm
Polishing time: 45 minutes Polishing liquid supply amount: 5 ml / min Polishing liquid concentration: 15% by weight

  The composite oxide particles obtained in each Example and Comparative Example were each dispersed in pure water at a concentration of 15% by weight, and dispersed with a paint conditioner for 30 minutes using YTZ beads having a diameter of 1 mm (manufactured by Nikkato). What adjusted pH to 11 with KOH was used for evaluation as polishing liquid. In the present invention, the pH is in the range of 3 to 12, preferably 6 to 12, and more preferably 9 to 12. Outside this range, dispersibility or difficulty in draining.

  Evaluation of polishing characteristics was performed as follows. First, a glass substrate was attached to a workpiece with a double-sided tape, and the weight was precisely weighed and polished. Next, the target abrasive after polishing is thoroughly washed with water so that no abrasive grains remain, and after sufficiently drying with an air gun, the weight is strictly measured, and the polishing amount is determined by the weight difference. evaluated. This removed weight was converted from the density and area to the polishing rate. The presence or absence of scratches was confirmed with a digital microscope. Table 1 summarizes the synthesis conditions of the composite cerium oxide particles of the above Examples and Comparative Examples, the average particle diameter estimated from transmission electron micrographs, and the results of polishing experiments with these samples.

  As can be seen from Table 1, the composite oxide particles of Examples 1, 2, and 3 have a polishing efficiency of 70 to 85, which is considerably better than the plate-like cerium oxide particles of Comparative Example 1. In Comparative Example 2, it is considered that the cerium oxide and the aluminum compound are in two phases, but the polishing efficiency is actually lower than that of the plate-like cerium oxide of Comparative Example 1, which is the result of Comparative Example 1 subjected to hydrothermal treatment. This is because the crystallinity is inferior to the sample. In addition, the sample of Comparative Example 2 has a large particle size of several microns, and scratches are generated, which is inappropriate as an abrasive. Comparing Examples 1 and 3, the powder of Example 3 to which 2-aminoethanol was not added is granular, not plate-like, but has sufficient polishing efficiency with respect to cerium oxide of Comparative Example 1. The plate-like composite cerium oxide particles of Example 1 are still better because of their crystallinity. Moreover, when Example 4 and Comparative Example 3 are compared, the average primary particle diameter of Example 4 is 191 nm, and that of Comparative Example 3 is 209 nm. In addition, since the polishing efficiency of Example 4 is 78 nm / min and that of Comparative Example 3 is 60 nm / min, it can be said that the effect of the addition of aluminum appears up to a particle size of about 200 nm.

It is process drawing which shows an example of the manufacturing process of the composite oxide particle for grinding | polishing (composite cerium oxide particle) which concerns on this invention.

Claims (7)

  It is composed of composite cerium oxide particles in which aluminum is dissolved in cerium oxide, and the atomic ratio of aluminum and cerium, which are constituent elements of the particles (the amount of Al in the composite cerium oxide particles is <Al> mol%, and Polishing composite oxide in which <Al> / <Ce>) is in the range of 0.01 to 1 and the average primary particle diameter is in the range of 1 nm to 200 nm when the Ce amount is <Ce> mol% particle.   A slurry-like abrasive prepared by dispersing the composite oxide particles for polishing according to claim 1 in a liquid medium.   The slurry-like abrasive according to claim 2, wherein the liquid medium is water.   The slurry-like abrasive according to claim 2 or 3, wherein the slurry contains a dispersant. A method for producing the composite oxide particles for polishing according to claim 1, comprising the following steps (1) to (3).
(1) A step of adding an aqueous solution containing cerium ions and aluminum ions to an alkaline aqueous solution containing oxyalkaliamines to generate a hydroxide or hydrate precipitate containing cerium and aluminum.
(2) A step of adjusting the hydroxide or hydrate precipitate obtained in the step (1) to pH 7-12.
(3) A step of hydrothermally treating the pH-adjusted precipitate obtained in the step (2) in the temperature range of 110 to 300 ° C. in the presence of water.   The manufacturing method of the complex oxide particle for grinding | polishing of Claim 5 including the process of heat-processing the processed material obtained at the process of said (3) in the temperature range of 300-1200 degreeC in the air.   The step of washing the hydroxide or hydrate precipitate obtained in the step (1) with water is provided between the step (1) and the step (2). 6. A method for producing composite oxide particles for polishing according to 6.

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