KR102529505B1 - Apparatus for preparing ceria particle and manufacturing method of ceria particle using the same - Google Patents

Abstract

The present invention relates to an apparatus capable of providing ceria particles with significantly improved polishing characteristics with excellent process efficiency, and specifically, the apparatus for manufacturing ceria particles according to one embodiment of the present invention includes: a plasma reactor which is accommodated inside a body; a plasma generating part which generates plasma through a plurality of plasma electrodes positioned for one end to be exposed inside the plasma reactor; and a magnetic field supply part which applies a magnetic field to the plasma reactor by a magnetic field generating source.

Description

Apparatus for preparing ceria particle and manufacturing method of ceria particle using the same}

The present invention relates to an apparatus for manufacturing ceria particles and a method for manufacturing ceria particles using the same, and more specifically, to manufacturing ceria particles capable of improving polishing properties with improved process efficiency in manufacturing ceria particles for polishing. It relates to an apparatus and a method for manufacturing ceria particles using the same.

Dispersants or additives for chemical reactions between abrasive particles such as metal oxides for mechanical polishing and semiconductor substrates, which are objects to be polished, for the chemical mechanical polishing (CMP) process, which is usually performed for planarization of semiconductor wafers during the semiconductor process A polishing slurry obtained by mixing and dispersing the same in deionized water is used. In particular, a slurry containing ceria particles is used in a shallow trench isolation (STI) process for selectively polishing a silicon oxide film.

When ceria particles are used as abrasive particles, polishing properties such as selectivity and flatness vary depending on the material properties of the ceria particles themselves, so the physical and chemical properties of the ceria particles greatly contribute to improving the polishing properties.

In addition, since the slurry containing expensive ceria particles is being employed not only in the STI process but also in the pre-metal dielectric (PMD) process, reduction in manufacturing cost through simplification of the manufacturing process is required.

Such ceria particles may be manufactured through various manufacturing processes, and may be manufactured through a gas phase method, a solid phase method, or a liquid phase method depending on the phase of the particles to be produced.

The vapor phase method includes, for example, a vaporization method, a thermal decomposition method, a flame combustion decomposition method, etc., but has a disadvantage in that manufacturing productivity is low because the amount of energy consumed for the production of abrasive particles is high and the equipment cost is high.

In addition, there are sintering methods and mechanochemical synthesis methods in the solid phase method, but they have disadvantages in that they need to be reacted at high temperatures for a long time, and a step of reducing the particle size by performing a milling process after the reaction is added. In addition, particles refined by the milling process have sharp edges due to their crystallinity, causing fine scratches during the chemical mechanical polishing process.

In addition, the liquid phase method includes the sol-gel method and the precipitation method, but these methods have the disadvantage of high material cost and excessive generation of waste liquid after the process.

In order to compensate for the disadvantages of these various manufacturing processes, Korean Patent Registration No. 10-1117525 provides cerium oxide abrasive particles using a hydrothermal reaction that dissolves the sharp particle surfaces of cerium oxide abrasive particles pulverized through a milling process. The manufacturing process is complicated, and the process time for hydrothermal reaction must be increased in order to improve polishing properties.

Accordingly, there is a need to develop a ceria particle manufacturing device capable of manufacturing ceria particles with improved polishing characteristics with improved process efficiency and a method of manufacturing ceria particles using the same.

Republic of Korea Patent No. 10-1117525

An object of the present invention is to provide an apparatus for producing ceria particles capable of efficiently producing ceria particles having excellent polishing properties.

Another object of the present invention is to provide a manufacturing method capable of manufacturing ceria particles having excellent polishing properties using the ceria particle manufacturing apparatus according to an embodiment of the present invention.

An apparatus for manufacturing ceria particles according to an aspect of the present invention includes a plasma reactor accommodated inside a body; a plasma generator generating plasma through a plurality of plasma electrodes positioned so that one end is exposed inside the plasma reactor; and a magnetic field supply unit for applying a magnetic field to the plasma reactor by a magnetic field generating source. includes

In the apparatus for manufacturing ceria particles according to an embodiment of the present invention, the plurality of plasma electrodes may be positioned to face each other.

In the apparatus for manufacturing ceria particles according to an embodiment of the present invention, the plasma reactor may include an opening through which the ceria precursor fluid is introduced and at least 2n+2 (n is a natural number of 1 or more) wall surfaces.

In the apparatus for manufacturing ceria particles according to an embodiment of the present invention, the magnetic field generating source may be located on at least one wall surface.

In the apparatus for manufacturing ceria particles according to an embodiment of the present invention, the magnetic field source may include a permanent magnet or an electromagnet.

In the apparatus for manufacturing ceria particles according to an embodiment of the present invention, the magnetic field source is any one selected from the group consisting of a plurality of N-pole magnets, a plurality of S-pole magnets, and a combination of N-pole magnets and S-pole magnets. It may be provided on the wall.

In the apparatus for manufacturing ceria particles according to an embodiment of the present invention, 2n to 4(n+1) (n is a natural number of 1 or more) permanent magnets may be provided on the wall surface.

In the apparatus for manufacturing ceria particles according to an embodiment of the present invention, magnets having different polarities are positioned on at least two walls adjacent to each other among the wall surfaces, and magnets having the same polarities are provided to face each other. it may be

In the apparatus for manufacturing ceria particles according to an embodiment of the present invention, magnets having the same polarity are positioned on at least two walls adjacent to each other among the wall surfaces, but magnets having different polarities are provided to face each other. it may be

In the apparatus for manufacturing ceria particles according to an embodiment of the present invention, magnets having the same polarity are positioned on at least two walls adjacent to each other among the walls, and the magnets having the same polarity are provided to face each other. it may be

In the apparatus for manufacturing ceria particles according to an embodiment of the present invention, the permanent magnet may be a N-pole magnet or an S-pole magnet provided on the wall surface.

In the apparatus for manufacturing ceria particles according to an embodiment of the present invention, the electromagnet may include a plurality of coils.

In the apparatus for manufacturing ceria particles according to an embodiment of the present invention, the coils may be provided on the wall surface to face each other.

In the apparatus for manufacturing ceria particles according to an embodiment of the present invention, the magnetic field source may be located on an outer wall of the plasma reactor.

In the apparatus for manufacturing ceria particles according to an embodiment of the present invention, the outer wall may be flat.

In another aspect, the present invention provides a method for manufacturing ceria particles.

A method for producing ceria particles provided according to another aspect of the present invention includes the steps of a) preparing a fluid containing a ceria precursor and a solvent; b) applying a magnetic field to the plasma reactor through a magnetic field generator after injecting the fluid into the plasma reactor; and c) generating plasma within the plasma reactor; includes

In the method for manufacturing ceria particles according to an embodiment of the present invention, the intensity of the magnetic field applied in step b) may be 4 gauss or more.

In the method of manufacturing ceria particles according to an embodiment of the present invention, the plasma generated in step c) may be confined by the magnetic field applied in step b).

In the method for manufacturing ceria particles according to an embodiment of the present invention, in step c), plasma is generated by supplying power of 500 to 1500 W to a plurality of plasma electrodes positioned so that one end is exposed inside the plasma reactor. it may be

In the method for producing ceria particles according to an embodiment of the present invention, after the step c), the ceria particles produced may be precipitated in the solvent.

In the method for manufacturing ceria particles according to an embodiment of the present invention, the ceria particles may have a size of 6 to 10 nm, and a density of the ceria particles may be 7 to 7.2 g/cm ³ .

An apparatus for manufacturing ceria particles according to an embodiment of the present invention includes a plasma reactor accommodated inside a body; A plasma generator generating plasma through a plurality of plasma electrodes positioned so that one end thereof is exposed inside the plasma reactor; and a magnetic field supply unit for applying a magnetic field to the plasma reactor by a magnetic field generating source. By including the, there is an advantage in that it is possible to provide ceria particles with remarkably improved polishing characteristics with excellent process efficiency by effectively confining the plasma generated in the plasma generating unit.

1 is a schematic plan view schematically showing an apparatus for manufacturing ceria particles according to an embodiment of the present invention.
2 is a schematic plan view schematically illustrating an apparatus for manufacturing ceria particles according to another embodiment.
3 and 4 are plan views schematically showing a ceria particle manufacturing apparatus provided on the wall surface of the plasma reactor 30 using a plurality of N-pole magnets and a plurality of S-pole magnets as magnetic field generating sources 200, respectively.
FIG. 5 is a schematic plan view schematically showing an apparatus for manufacturing ceria particles including a magnetic field supplying unit 20 equipped with a plurality of coils as a magnetic field generating source 200. Referring to FIG.
6 is a schematic plan view schematically illustrating one wall surface of the plasma reactor 30 where the plasma electrode 100 according to another embodiment is located.
7(a) and 7(b) show an apparatus for manufacturing ceria particles including a rotating body 40 having a shape similar to or identical to that of the plasma reactor 30 and ceria including a circular rotating body 40, respectively. It is a planar schematic diagram schematically showing the particle production device.
8(a) and 8(b) are diagrams showing digital images of ceria particles prepared according to Example 1 and Comparative Example 1, respectively.
9 is a diagram showing a transmission electron microscope (TEM) image of ceria particles prepared according to Example 1;

Hereinafter, the present invention will be described in more detail through specific examples or examples including the accompanying drawings. However, the following specific examples or examples are only one reference for explaining the present invention in detail, but the present invention is not limited thereto, and may be implemented in various forms.

Also, unless defined otherwise, all technical and scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms used for description in the present invention are merely to effectively describe specific embodiments and are not intended to limit the present invention.

Also, the singular forms used in the specification and appended claims may be intended to include the plural forms as well, unless the context dictates otherwise.

In addition, when a part "includes" a certain component, it means that it may further include other components without excluding other components unless otherwise stated.

An apparatus for producing ceria particles provided according to an aspect of the present invention includes a plasma reactor accommodated inside a body; A plasma generator generating plasma through a plurality of plasma electrodes positioned so that one end thereof is exposed inside the plasma reactor; and a magnetic field supply unit for applying a magnetic field to the plasma reactor by a magnetic field generating source. includes

Since the apparatus for manufacturing ceria particles according to an embodiment of the present invention includes a magnetic field supply unit for applying a magnetic field by a magnetic field generator to a plasma reactor, the plasma generated in the plasma generator can be effectively confined by the applied magnetic field. There is an advantage in that ceria particles can be produced with excellent process efficiency in a reactor.

In addition, there is an advantage in that the energy supplied for plasma discharge can be significantly reduced through the plasma confinement effect by the applied magnetic field, and when performing a polishing process using ceria particles manufactured by increasing the relative density of the ceria particles produced It has the advantage of significantly improving the polishing properties.

In one embodiment, the plasma reactor may include an opening through which the ceria precursor fluid is introduced and at least 2n+2 (n is a natural number of 1 or more) wall surfaces.

In this case, the plasma reactor may include two openings to introduce the ceria precursor fluid, and the two openings may be provided at both ends of the plasma reactor.

Specifically, the plasma reactor may be accommodated inside the body, the ceria precursor fluid may be supplied into the body through a supply pipe communicating with the body, and the ceria precursor fluid supplied into the body may be introduced into the plasma reactor through the aforementioned opening. that can be introduced. In this case, the areas of the openings provided at both ends of the plasma reactor may be the same as or different from each other.

As can be seen in the method of manufacturing ceria particles to be described later, the ceria precursor fluid introduced into the plasma reactor can be produced into ceria particles by plasma generated under a condition in which a magnetic field is applied. At this time, in the plasma reactor, a magnetic field is applied The underwater plasma discharge may be performed under the conditions.

In one embodiment, the wall surface included in the plasma reactor may mean a surface other than the surface where the aforementioned opening is located, and in this case, the wall surface is composed of at least 2n+2 (n is a natural number of 1 or more). can

As a specific example, the plasma reactor is selected from among square pillars, hexagonal pillars, octagonal pillars, decagonal pillars, dodecagonal pillars, quadrangular pillars, hexadecimal pillars, octagonal pillars, twenty-pointed pillars, and circular pillars with openings at both ends. It can be in either form.

In one embodiment, a plasma reactor of the type described above may include a magnetic field generator positioned on one or more walls.

At this time, the wall on which the magnetic field source is located may mean an inner wall or an outer wall of the plasma reactor, but does not exclude an inner surface between the inner wall and the outer wall constituting the plasma reactor. That is, the above-described magnetic field generating source may include being inserted into a wall constituting the plasma reactor.

As an advantageous example, the magnetic field generating source may be located on an outer wall of the plasma reactor.

The magnetic field applied by the magnetic field generator may affect particle characteristics, such as size, size uniformity, and relative density of ceria particles, as can be seen in the manufacturing method of ceria particles to be described later. It may be advantageous to place the magnetic field source on the outer wall of the plasma reactor in order to easily adjust the characteristics of the ceria particles.

In one embodiment, the outer wall of the plasma reactor where the magnetic field source is located may be flat.

Specifically, when the outer wall of the plasma reactor is flat, a uniform magnetic field can be applied to the inside of the plasma reactor by a magnetic field generator located on the outer wall, and thus the confinement effect of the plasma generated inside the plasma reactor can also be uniformly displayed. In addition, there is an advantage in that particle characteristics such as the size or relative density of finally manufactured ceria particles can be uniformly displayed.

In one embodiment, the magnetic field generating source located on one or more walls of the plasma reactor may include a permanent magnet or an electromagnet.

For example, the permanent magnet may be any one or more selected from among ferrite magnets, samarium-cobalt magnets, Alico magnets, and neodymium magnets, but without limitation, as long as a magnetic field capable of confining the plasma generated in the plasma reactor can be applied. can be used

As a specific example, the magnetic field generator may be any one selected from the group consisting of a plurality of N-pole magnets, a plurality of S-pole magnets, and a combination of N-pole magnets and S-pole magnets provided on the wall surface of the plasma reactor.

At this time, the plurality of magnets may be magnets provided on one or all wall surfaces of the plasma reactor, and the plasma generated inside the plasma reactor by a magnetic field applied into the plasma according to the polarity and / or position of the magnets provided. The restraining effect may appear differently, and through this, the properties of the ceria particles produced can be controlled.

In one embodiment, 2n to 4 (n+1) permanent magnets may be provided on the wall surface of the plasma reactor. Here, n is a natural number greater than or equal to 1, and may be the same natural number as n indicated by the number of walls described above.

As a specific example, when the number of walls of the plasma reactor is 4 (n = 1), the number of permanent magnets provided on the wall of the plasma reactor may be 2 to 8, and when the number of walls is 6 (n = 2), the number of permanent magnets is 4 to 12. Number of permanent magnets may be provided on the wall, and when the number of walls is 8 (n = 3), 6 to 16 permanent magnets may be provided on the wall.

At this time, a plurality of plasma electrodes positioned so that one end is exposed inside the plasma reactor included to generate plasma may be positioned on the wall surface of the plasma reactor, and the above-described permanent magnet is positioned on the same wall surface where the plasma electrode is positioned. Alternatively, when the permanent magnets are positioned on the same wall surface, two permanent magnets may be positioned with the plasma electrode interposed therebetween.

In the case where the number of walls of the plasma reactor is four, for example, the plasma reactor may have a pair of plasma electrodes positioned opposite to each other, that is, two plasma electrodes may be located on the walls. At this time, the plasma electrode is not located A permanent magnet may be located on each of the remaining walls, so that a total of two permanent magnets may be provided.

In addition, the plasma electrodes may be positioned on two pairs of plasma electrodes, that is, four walls facing each other in the plasma reactor. At this time, each wall is provided with two permanent magnets with the plasma electrode in between, so that a total of 8 It is possible to place two permanent magnets.

In one embodiment, a plurality of plasma electrodes may be positioned to face each other.

As a specific example, 1 to (n+1) pairs of plasma electrodes may be included in the plasma reactor based on a pair of plasma electrodes positioned opposite to each other. In this case, n may be the same natural number as n indicated by the number of walls described above.

As another example, the electromagnet included in the magnetic field generating source may include a plurality of coils, and the coil may be any one selected from a rectangular coil, a circular coil, and a solenoid coil according to a shape.

Hereinafter, an apparatus for manufacturing ceria particles according to an embodiment of the present invention will be described in more detail through drawings.

1 is a schematic plan view schematically showing an apparatus for manufacturing ceria particles according to an embodiment of the present invention.

Referring to FIG. 1 , an apparatus for manufacturing ceria particles according to an embodiment of the present invention is a plasma generating unit in which plasma is generated through a plurality of plasma electrodes 100 positioned so that one end thereof is exposed inside a plasma reactor 30 ( 10) and a magnetic field supply unit 20 for applying a magnetic field by the magnetic field generating source 200 positioned on one or more walls of the plasma reactor 30. At this time, the plasma reactor 30 may be accommodated and positioned inside the body (not shown).

The plasma electrode 100 can generate plasma into the plasma reactor 30 by power supplied from a separately provided external power supply, and the generated plasma is generated from the magnetic field generator 200 located on the wall of the plasma reactor 30. It can be confined by the resulting magnetic field.

As described above, the magnetic field generating source 200 may be provided on the wall surface of the plasma reactor 30 as a combination of an N-pole magnet and a S-pole magnet, and at least two of the wall surfaces are adjacent to each other, and each wall has a polarity. Although different magnets are positioned, magnets having the same polarity may be provided to face each other. At this time, each of the provided magnets may be located except for a wall surface where a pair of plasma electrodes 100 located facing each other are located.

Here, the two walls adjacent to each other refer to two walls in which each wall is in contact with each other or abutting both ends of the wall on which the plasma electrode 100 is located with the wall on which the plasma electrode 100 is located. It may mean that there are two walls. “Two adjacent walls” described below may be interpreted as having the same meaning as described above.

2 is a schematic plan view schematically illustrating an apparatus for manufacturing ceria particles according to another embodiment.

Referring to FIG. 2, the magnetic field generating source 200 is located on the wall of the plasma reactor 30 by a combination of an N-pole magnet and a S-pole magnet, and is located on at least two walls adjacent to each other among the walls, so that the polarities of each wall are different. The same magnets are located, but magnets having different polarities may be provided to face each other.

In addition, in another embodiment, magnets having the same polarity are positioned on at least two adjacent walls of the plasma reactor 30, and the magnets having the same polarity may face each other.

For example, the magnetic field generating source 200 may include a plurality of magnets having the same polarity positioned on a wall surface of the plasma reactor 30 .

3 and 4 are plan views schematically showing a ceria particle manufacturing apparatus provided on the wall surface of the plasma reactor 30 using a plurality of N-pole magnets and a plurality of S-pole magnets as magnetic field generating sources 200, respectively.

In one embodiment, an electromagnet including a plurality of coils may be used as the magnetic field generating source 200 to apply the magnetic field.

FIG. 5 is a schematic plan view schematically illustrating an apparatus for manufacturing ceria particles including a magnetic field supplying unit 20 having a plurality of coils as a magnetic field generating source 200. As shown in FIG.

As shown in FIG. 5 , a plurality of coils may be provided on a wall surface of the plasma reactor 30 to face each other.

When an electromagnet including a plurality of coils located opposite to each other is used as the magnetic field generating source 200, the direction and/or strength of the magnetic field applied into the plasma reactor 30 can be easily adjusted. It has the advantage of being easily controllable.

6 is a schematic plan view schematically illustrating one wall surface of the plasma reactor 30 where the plasma electrode 100 according to another embodiment is located.

Referring to FIG. 6 , a plurality of magnetic field generating sources 200 may be positioned on the same wall surface as one wall surface of the plasma reactor 30 with the plasma electrode 100 located on the wall surface therebetween. At this time, of course, a permanent magnet or an electromagnet may be included as the magnetic field generating source 200 .

Also, as another embodiment, the apparatus for manufacturing ceria particles may further include a rotating body 40 positioned between a body (not shown) and the plasma reactor 30 .

7(a) and 7(b) show an apparatus for manufacturing ceria particles including a rotating body 40 having a shape similar to or identical to that of the plasma reactor 30 and ceria including a circular rotating body 40, respectively. It is a planar schematic diagram schematically showing the particle production device.

At this time, the plurality of plasma electrodes 100 may be positioned to face each other on the wall surface of the plasma reactor 30, and the plurality of magnetic field generating sources 200 may be positioned on the wall surface of the rotating body 40.

The rotating body 40 can rotate in a direction perpendicular to gravity, and a more uniform magnetic field is applied to the inside of the plasma reactor 30 by the magnetic field generating source 200 located on the wall surface of the rotating body 40 The plasma confinement effect can be further improved.

In another aspect, the present invention provides a method for manufacturing ceria particles.

A method for producing ceria particles according to an embodiment of the present invention includes the steps of a) preparing a fluid containing a ceria precursor and a solvent; b) applying a magnetic field to the plasma reactor through a magnetic field generator after injecting the prepared fluid into the plasma reactor; and c) generating plasma within the plasma reactor; includes

Ceria particles according to an embodiment of the present invention are manufactured by injecting a fluid containing a ceria precursor into a plasma reactor and then generating plasma under the condition that a magnetic field is applied to the plasma reactor, and the manufacturing process is extremely simple unlike the prior art. Advantages include not only significantly reducing the energy applied for plasma discharge through the plasma confinement effect by the applied magnetic field, but also significantly improving the efficiency of producing ceria particles using plasma in a plasma reactor. there is.

Hereinafter, the manufacturing method of ceria particles will be described in detail for each step.

First, a) preparing a fluid containing a ceria precursor and a solvent.

In one embodiment, the ceria precursor may include cerium having a trivalent and/or tetravalent oxidation number, and for example, Ce(NO ₃ ) ₃ , Ce(NO ₃ ) ₃ xH ₂ O, (NH ₄ ) ₂ Ce(NO ₃ ) ₆ , (NH4) ₂ Ce(NO ₃ ) ₆ xH ₂ O, Ce(NH ₄ ) ₄ (SO ₄ ) ₄ , Ce(NH ₄ ) ₄ (SO ₄ ) ₄ xH ₂ O, Ce ₂ (CO ₃ ) ₃ , Ce(OH) ₄ , CeC ₂ , Ce(O ₂ C ₂ H ₃ ) ₃ xH ₂ O, CeBr ₃ , Ce ₂ (CO ₃ ) ₃ xH ₂ O, CeCl ₃ xH ₂ O, CeCl ₃ , CeF ₃ , CeF ₄ , Ce ₂ (C ₂ O ₄ ) ₃ , Ce(SO ₄ ) ₂ , Ce(SO ₄ ) ₂ xH ₂ O, Ce ₂ (SO ₄ ) ₃ , and It may be one or more selected from Ce ₂ (SO ₄ ) ₃ xH ₂ O.

In one embodiment, a fluid including a ceria precursor and a solvent is injected into a plasma reactor and then produced into ceria particles through plasma discharge under a condition in which a magnetic field is applied. At this time, the solvent included in the fluid performs underwater plasma discharge. Any solvent that can be used may be used without limitation.

For example, the solvent may include at least one of deionized water and an organic solvent, and advantageously may be a mixed solvent of deionized water and an organic solvent, and the organic solvent may be an alcohol-based solvent including polyol. , ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, methyl alcohol, isopropyl alcohol, ethanol, methoxyethanol, acetone, toluene, and the like.

As a specific example, when the solvent included in the fluid is a mixture of deionized water and organic solvent, the volume ratio of deionized water: organic solvent may be 1: 0.01 to 10, specifically 1: 0.05 to 5, More specifically, it may be 1: 0.1 to 1.

When a ceria precursor is mixed with a solvent in which deionized water and an organic solvent are mixed, natural precipitation occurs, which has the advantage of improving process efficiency through underwater plasma discharge, which will be described later.

In one embodiment, the concentration of the fluid including the ceria precursor and the solvent may be 100 to 800 mM, specifically 200 to 600 mM, and more specifically 250 to 450 mM.

In one embodiment, the fluid may further include a catalyst.

As a specific example, the fluid may include 0.001 to 10 vol%, specifically 0.001 to 5 vol%, and more specifically 0.01 to 1 vol% of the catalyst based on the total volume of the fluid. When the catalyst is included in the fluid within the above range, the synthesis amount of ceria particles generated by plasma discharge can be improved and the plasma discharge efficiency can be improved, and thus the size and/or shape of ceria particles produced can be improved. can be controlled

In one embodiment, the catalyst is KNO ₃ , CH ₃ COOK, K ₂ SO ₄ , KCl, LiOH, KOH, Ca(OH) ₂ , Ni(OH) ₂ , Mg(OH) ₂ , KF, NaOH, NaF, Na ₂ O, CH ₃ COONa, Na ₂ SO ₄ , C ₅ H ₅ N, NaOCl, K ₂ C ₂ O ₄ , NH ₄ OH, and N ₂ H ₄ It may be at least one selected from, preferably NH ₄ OH And N ₂ H ₄ It may be one or more selected from.

Then, b) injecting the prepared fluid into the plasma reactor, and then applying a magnetic field to the plasma reactor through a magnetic field generator.

Specifically, after injecting the fluid into the plasma reactor, the magnetic field applied to the plasma reactor may be applied through the aforementioned magnetic field generator.

More specifically, the magnetic field source may include a permanent magnet or an electromagnet as described above, and the direction and/or strength of the applied magnetic field may be controlled through various variables such as the location, size, and number of the magnetic field source, which will be described later. In the step of generating the plasma, the magnetic field applied to the plasma reactor may be controlled through the above-described various variables as needed in order to effectively confine the generated plasma and improve process efficiency.

As an advantageous example, the strength of the magnetic field applied to the plasma reactor may be 4 gauss or more.

As a specific example, the strength of the magnetic field applied to the plasma reactor may be 4 gauss or more, 5 gauss or more, 6 gauss or more, 7 gauss or more, 8 gauss or more, and may be substantially 20 gauss or less.

When plasma is generated in the step of generating plasma to be described later under the condition that a magnetic field is applied to the plasma reactor, the plasma generated in the plasma reactor is confined to improve the formation efficiency of ceria particles, and the free electrons included in the plasma are confined. is attached to the surface of the formed ceria particles to effectively suppress agglomeration between ceria particles, and also has the advantage of improving energy efficiency by reducing externally applied energy for plasma discharge. In order to exhibit these excellent effects, it is preferable that the intensity of the magnetic field applied to the plasma reactor satisfies the aforementioned range.

Then, c) generating plasma in the plasma reactor is performed.

In one embodiment, the plasma is generated by supplying power of 500 to 1500 W, specifically 1000 to 1480 W, and more specifically 1300 to 1450 W to a plurality of plasma electrodes positioned so that one end is exposed inside the plasma reactor. can

As a specific example, the above-described power may be supplied from a plasma power source, and at this time, the supply voltage may be 120 to 300V, preferably 150 to 250V, more preferably 190 to 210V, The supply current may be applied at 0.1 to 30 A, preferably 1 to 20 A, more preferably 5 to 10 A.

In one embodiment, the plasma power may be supplied by a plasma power supply capable of supplying any one power selected from alternating current, direct current, high voltage pulse, radio frequency (RF), and microwave. The invention is not limited thereto.

As described above, the ceria particles may be produced through plasma discharge under the condition that a magnetic field is applied to the plasma reactor. At this time, the manufactured ceria particles may exist in a state of being precipitated in a solvent included in the fluid.

In general, manufactured ceria particles are provided through a purification process. Since the ceria particles manufactured according to an embodiment of the present invention are precipitated in a solvent, the efficiency of the purification process can also be improved.

In one embodiment, the ceria particles may have a size of 1 to 20 nm, specifically 3 to 15 nm, and more specifically 6 to 10 nm. In this case, the ceria particles having a size distribution within the aforementioned range may be primary particles, not aggregates aggregated between particles.

As a specific example, the density of the ceria particles included in the aforementioned size range may be 6.8 to 7.22 g/cm ³ , substantially 6.9 to 7.2 g/cm ³ , and more substantially 7.0 to 7.2 g/cm ³ .

As such, ceria particles manufactured through plasma discharge under the condition of applying a magnetic field have relative density characteristics of 95% or more, 96% or more, 97% or more, 98% or more, and substantially 99.99% or less due to the dense structure of the particles. When such ceria particles are used as abrasive particles, there is an advantage in providing excellent abrasive properties.

In addition, it goes without saying that ceria particles having a coarser size as well as ceria particles within the above-described size range may be manufactured by controlling conditions of the applied magnetic field and plasma discharge conditions.

For example, the coarse-sized ceria particles may have a size of 10 to 500 nm, specifically 20 to 300 nm, and more specifically 20 to 200 nm.

Hereinafter, the manufacturing method of ceria particles for polishing according to the present invention will be described in more detail through examples. However, the following examples are only one reference for explaining the present invention in detail, but the present invention is not limited thereto, and may be implemented in various forms.

Also, unless defined otherwise, all technical and scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description herein is merely to effectively describe specific embodiments and is not intended to limit the present invention.

(Examples 1 to 4)

A ceria precursor fluid was prepared by mixing 600 g of the ceria precursor Ce(NO ₃ ) ₃ 6H ₂ O with 4 L of a solvent in which deionized water and ethanol were mixed at a volume ratio of 1:0.5.

Thereafter, the prepared ceria precursor fluid was injected into an octagonal columnar plasma reactor (10 L capacity) equipped with openings at both ends.

At this time, the plasma reactor was installed to be accommodated inside the body, and two pairs of plasma electrodes positioned opposite to each other were positioned, and each plasma electrode was spaced apart with one wall of the plasma reactor in between.

Neodymium magnets (width: 250 mm, length: 750 mm, thickness: 7 mm) were provided on each outer wall of the plasma reactor where the plasma electrode was not located to apply a magnetic field to the plasma reactor, and the strength of the applied magnetic field was 4.67 Gauss.

Subsequently, ceria particles were prepared by plasma discharging for 10 minutes by supplying a voltage of 200 V and a current of 7 A with a 60 Hz AC power supply.

Examples 1 to 4 were classified according to the polarity of the neodymium magnet located on the outer wall of the plasma reactor.

In Example 1, an N-pole magnet is placed on each wall surface in contact with both ends of the one wall surface based on one wall surface where one plasma electrode is located, and a S-pole magnet is attached to the other wall surface facing the N-pole magnet. did

Embodiment 2 places N-pole magnets and S-pole magnets on each wall surface in contact with both ends of the one wall surface based on one wall surface where one plasma electrode is located, but the remaining magnets of the same polarity are positioned opposite to each other. An N-pole magnet and a S-pole magnet were attached to the wall.

In Examples 3 and 4, only the N-pole magnet and the S-pole magnet were attached to the outer wall of the plasma reactor where the plasma electrode was not located.

(Example 5)

It was carried out in the same manner as in Example 1, except that an electromagnet was installed on the outer wall of the plasma reactor and then a magnetic field was applied.

(Example 6)

The same procedure as in Example 1 was performed, but a rotating body was provided between the body and the plasma reactor, and a neodymium magnet was provided on the wall of the rotating body to apply a magnetic field, but the rotating body was rotated at a speed of 200 rpm during plasma discharge. Excluding the same was carried out.

(Comparative Example 1)

In the same manner as in Example 1, ceria particles were prepared by plasma discharge without applying a magnetic field.

Unlike Examples 1 to 6, in Comparative Example 1 in which ceria particles were produced through plasma discharge without applying a magnetic field, about 1540 W of power was consumed for plasma discharge, but 1400 W of power was consumed for plasma discharge under the condition that a magnetic field was applied. It was confirmed that energy efficiency in manufacturing ceria particles can be improved by reducing the amount of power of 140 W as the magnetic field is applied.

8(a) and 8(b) are diagrams showing digital images of ceria particles prepared according to Example 1 and Comparative Example 1, respectively.

It was observed that the ceria particles of Example 1 prepared through plasma discharge under the condition of applying a magnetic field existed in a state of being precipitated in a solvent, whereas the ceria particles of Comparative Example 1 were observed to be dispersed in a solvent. As in Example 1, it can be seen that when the ceria particles are present in the solvent in a precipitated state, the purification process efficiency can be remarkably improved in a generally performed purification process. Although not shown in the figure, it was confirmed that the ceria particles prepared according to Examples 2 to 6 also existed in a state of being precipitated in the solvent, similarly to Example 1.

9 is a diagram showing a transmission electron microscope (TEM) image of ceria particles prepared according to Example 1;

As shown in FIG. 9 , it can be seen that there are almost no agglomerated aggregates in the ceria particles, and it is observed that the size of the ceria particles is in the range of 6.6 nm to 9.1 nm.

In addition, it was confirmed that the ceria particles prepared according to Example 1 had a density of about 7.12 g/cm ³ , which indicates that the ceria particles produced had a very dense structure with a relative density of about 98.6%. When ceria particles having such a dense structure are used as abrasive particles, there is an advantage in that polishing characteristics can be remarkably improved.

On the other hand, the relative density of the ceria particles prepared according to Comparative Example 1 was about 91%, confirming that the density of the particles was significantly inferior to that of Example 1.

It was confirmed that the size distribution characteristics of the additionally prepared ceria particles were most excellent in the ceria particles prepared according to Example 6.

Although the present invention has been described through specific details and limited examples as described above, this is only provided to help a more general understanding of the present invention, the present invention is not limited to the above examples, and the present invention belongs Various modifications and variations from these descriptions are possible to those skilled in the art.

Therefore, the spirit of the present invention should not be limited to the described embodiments, and it will be said that not only the claims to be described later, but also all modifications equivalent or equivalent to these claims belong to the scope of the present invention. .

Claims (21)

A plasma reactor accommodated inside the body;
a plasma generator generating plasma through a plurality of plasma electrodes positioned so that one end is exposed inside the plasma reactor; and
a magnetic field supply unit for applying a magnetic field to the plasma reactor by a magnetic field generating source; including,
The plasma reactor includes an opening through which a liquid containing a ceria precursor is introduced and at least 2n+2 (n is a natural number of 1 or more) wall surfaces,
The magnetic field generator is located on an outer wall of the plasma reactor. According to claim 1,
The plurality of plasma electrodes are positioned to face each other. delete delete According to claim 1,
The magnetic field generator includes a permanent magnet or an electromagnet. According to claim 5,
The magnetic field generating source is one selected from the group consisting of a plurality of N-pole magnets, a plurality of S-pole magnets, and a combination of N-pole magnets and S-pole magnets, provided on the wall surface. According to claim 5,
2n to 4 (n + 1) (n is a natural number of 1 or more) permanent magnets provided on the wall surface. According to claim 5,
The apparatus for producing ceria particles, wherein magnets having different polarities are positioned on at least two wall surfaces adjacent to each other among the wall surfaces, and magnets having the same polarity are provided to face each other. According to claim 5,
Wherein at least two of the walls are adjacent to each other, magnets having the same polarity are positioned on each wall, and magnets having different polarities are provided to face each other. According to claim 5,
The apparatus for manufacturing ceria particles, wherein magnets having the same polarity are positioned on at least two wall surfaces adjacent to each other among the wall surfaces, and the magnets having the same polarity are provided to face each other. According to claim 10,
The permanent magnet is a ceria particle manufacturing apparatus in which an N-pole magnet or an S-pole magnet is provided on the wall surface. According to claim 5,
Wherein the electromagnet includes a plurality of coils. According to claim 12,
The apparatus for manufacturing ceria particles, wherein the coils are provided on the wall surface to face each other. delete According to claim 1,
The outer wall is a flat ceria particle manufacturing apparatus. a) preparing a liquid containing a ceria precursor and a solvent;
b) applying a magnetic field to the plasma reactor through a magnetic field generator positioned on an outer wall of the plasma reactor after injecting the fluid into the plasma reactor; and
c) generating plasma in the plasma reactor; Method for producing ceria particles comprising a. According to claim 16,
The method of manufacturing ceria particles in which the strength of the magnetic field applied in step b) is 4 gauss or more. According to claim 16,
A method of manufacturing ceria particles in which the plasma generated in step c) is confined by the magnetic field applied in step b). According to claim 16,
In the step c), the plasma is generated by supplying power of 500 to 1500 W to a plurality of plasma electrodes positioned so that one end is exposed inside the plasma reactor. According to claim 16,
After the step c), the ceria particles produced are precipitated in the solvent and exist. According to claim 20,
The ceria particles include a size of 6 to 10 nm, and a density of the ceria particles is 7 to 7.2 g/cm ³ .

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