KR101483449B1 - Method of manufacturing cerium based polishing particle and the cerium based polishing particle thereof - Google Patents

Abstract

The present invention relates to a method for manufacturing cerium-based polishing particles and cerium-based polishing particles thereby. The method for manufacturing cerium-based polishing particles and cerium-based polishing particles thereby according to the present invention are capable of controlling shapes and sizes of cerium-based polishing particles according to synthesis temperature, synthesis time, calcination temperature and calcination time of a mixture, exhibit excellent polishing rate and selectivity in CMP polishing and are capable of reducing defects and scratches, thereby improving productivity in semiconductor device manufacture.

Description

TECHNICAL FIELD The present invention relates to a cerium-based abrasive grain, and more particularly, to a cerium-based abrasive grain and a cerium-

The present invention relates to a process for producing cerium-based abrasive grains and a cerium-based abrasive grain therefrom.

Generally, chemical mechanical polishing (CMP) is used to polish a semiconductor thin film, which includes a metal oxide abrasive for mechanical polishing, a dispersant and an additive for chemical reaction with a semiconductor substrate to be polished A polishing slurry prepared by dispersing and mixing in deionized water is used. This polishing slurry has good dispersibility, has an excellent polishing rate, and is required to generate few defects such as scratches on the surface of a semiconductor substrate after polishing.

The cerium oxide slurry has a characteristic of selectively polishing silicon oxide as compared with silicon nitride, and is suitable for a shallow trench isolation (STI) process. Due to the characteristics showing non-Prestonian behavior, Is also usefully used as a high-level slurry in an interlevel dielectric (ILD) process, which is required.

In the STI CMP, the etch selectivity between the trench filling profile (STI Fill Profile) and the oxide film and the poly film formed in the upper region of the trench allows the STI fill oxide film to be recessed in the field region, Dishing phenomenon occurs. Conventional cerium-based abrasive grains are likely to include large particles together with generation of fine particles generated in the pulverizing process. This affects the polishing depending on the pattern density through the nonuniformity and the angular shape of the abrasive grains, and thus is greatly influenced by scratches and defects. In recent years, wirings in the semiconductor process have become finer and the interval between the chips has been reduced, so that the incidence of scratches and defects and the property of reducing the size thereof have been demanded.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a method of manufacturing cerium-based abrasive grains capable of reducing defects and scratches while maintaining a proper polishing rate, Based abrasive grains.

However, the problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the following description.

According to a first aspect of the present invention, there is provided a process for preparing a cerium precursor, comprising: mixing a cerium precursor material, a basic material and water to synthesize a mixture; Drying the mixture; And calcining the dried mixture to obtain cerium oxide. The present invention also provides a process for producing cerium-based abrasive grains.

The step of synthesizing may be carried out at room temperature to 100 < 0 > C.

The synthesizing step may be performed for 1 to 1.5 hours.

The drying may be performed at a temperature ranging from room temperature to 100 < 0 > C.

The drying step may include at least one selected from the group consisting of natural drying, hot air drying and thermal drying.

The calcining step may be performed at a temperature of from room temperature to 1000 < 0 > C.

The calcining step may be performed for 0.1 to 6 hours.

And controlling the synthesis temperature and the synthesis time to control the size and shape of the cerium-based abrasive grains.

And controlling the size and shape of the cerium-based abrasive grains by controlling the calcination temperature and the calcination time.

The synthesis temperature is from room temperature to 60 占 폚, the calcination time is from 1 hour to 1.5 hours, and the cerium-based abrasive grains may be spherical.

Wherein the calcining temperature is from 350 ° C to 500 ° C, the calcining time is from 1 hour to 1.5 hours, the cerium abrasive grains are angular, the calcining temperature is from 500 ° C to 900 ° C, Hour, and the cerium-based abrasive grains may be spherical.

Wherein the calcining temperature is from 350 to 500 캜, the calcining time is from 1 to 1.5 hours, the cerium abrasive grain is from 15 to 25 nm, the calcining temperature is from 500 캜 to 900 캜, To 5 hours, and the cerium-based abrasive grains may be from 25 nm to 80 nm.

The cerium precursor material may include at least one selected from the group consisting of cerium carbonate, cerium nitrate, cerium acetate, cerium sulfate, cerium ammonium nitrate, cerium oxide, cerium hydroxide, and salts thereof.

The basic material is selected from the group consisting of KNO ₃ , CH ₃ COOK, K ₂ SO ₄ , KCl, KOH, 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 ,} propylamine, butylamine, diethylamine, dipropylamine, dibutylamine _, triethylamine, tributylamine, monoethanolamine, diethanolamine, triethanolamine, 2-dimethylamino- 1-propanol, 2-amino-1-propanol, 2-dimethylamino-1-propanol, 2- Diethylamino-1-ethanol, 2-ethylamino-1-ethanol, 1- (dimethylamino) 2-propanol, N-methyldiethanolamine, N-propyldiethanolamine , N-isopropyldiethanolamine, N- (2-methylpropyl) diethanolamine, N-butyldiethanolamine, Nt-butylethanolamine, N-cydecylhexyldiethanolamine, 2- , 2-diethylaminoethanol, 2-dipropyl Amino-2-pentanol, 2- [bis (2-hydroxyethyl) amino] -2-methyl-2-methylaminoethanol, 2- (2-hydroxyethyl) amino] -2-propanol, N, N-bis (2-hydroxypropyl) ethanolamine, 2- Tris (hydroxymethyl) aminomethane, and tri-isopropanolamine.

The second aspect of the present invention provides the cerium-based abrasive particles produced by the manufacturing method of the first aspect of the present invention.

The cerium-based abrasive grains may be angular or spherical.

The cerium-based abrasive particles may include primary particles and secondary particles, the primary particles may have a particle diameter of 5 to 50 nm, and the secondary particles may have a particle diameter of 50 to 200 nm or less.

The cerium-based abrasive grains may have a peak area intensity ratio defined by the peak area of the (111) plane with respect to the peak area of the (200) plane of the XRD pattern by X-ray diffraction analysis of 3.0 to 4.5.

The method for producing cerium-based abrasive grains according to the present invention and the cerium-based abrasive grains thereby can control the shape and size of the cerium-based abrasive grains depending on the synthesis temperature, synthesis time, calcination temperature and calcination time of the mixture, It exhibits excellent polishing rate and selectivity at the time of polishing and can reduce defects and scratches. Therefore, productivity improvement can be expected in the production of semiconductor devices.

1 is a flowchart showing a method of manufacturing a cerium-based abrasive grain according to an embodiment of the present invention.
2A to 2C are SEM images of cerium oxide abrasive particles according to an embodiment of the present invention.
3 is an SEM image of Embodiment 2 of the present invention.
4 is an SEM image of Embodiment 4 of the present invention.
5 is an SEM image of Comparative Example 2 of the present invention.
6 is an SEM image of Comparative Example 4 of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. Also, terminologies used herein are terms used to properly represent preferred embodiments of the present invention, which may vary depending on the user, intent of the operator, or custom in the field to which the present invention belongs. Therefore, the definitions of these terms should be based on the contents throughout this specification. Like reference symbols in the drawings denote like elements.

Throughout the specification, when an element is referred to as "comprising ", it means that it can include other elements as well, without excluding other elements unless specifically stated otherwise.

Hereinafter, the method for producing the cerium-based abrasive particles of the present invention and the cerium-based abrasive particles therefrom will be described in detail with reference to examples and drawings. However, the present invention is not limited to these embodiments and drawings.

According to a first aspect of the present invention, there is provided a process for preparing a cerium precursor, comprising: mixing a cerium precursor material, a basic material and water to synthesize a mixture; Drying the mixture; And calcining the dried mixture to obtain cerium oxide. The present invention also provides a process for producing cerium-based abrasive grains.

1 is a flowchart showing a method of manufacturing a cerium-based abrasive grain according to an embodiment of the present invention.

First, a cerium precursor material, a basic material, and water are mixed to synthesize a mixture (110).

The cerium precursor material may include at least one selected from the group consisting of cerium carbonate, cerium nitrate, cerium acetate, cerium sulfate, cerium ammonium nitrate, cerium oxide, cerium hydroxide, and salts thereof.

The basic material is selected from the group consisting of KNO ₃ , CH ₃ COOK, K ₂ SO ₄ , KCl, KOH, 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 ,} propylamine, butylamine, diethylamine, dipropylamine, dibutylamine _, triethylamine, tributylamine, monoethanolamine, diethanolamine, triethanolamine, 2-dimethylamino- 1-propanol, 2-amino-1-propanol, 2-dimethylamino-1-propanol, 2- Diethylamino-1-ethanol, 2-ethylamino-1-ethanol, 1- (dimethylamino) 2-propanol, N-methyldiethanolamine, N-propyldiethanolamine , N-isopropyldiethanolamine, N- (2-methylpropyl) diethanolamine, N-butyldiethanolamine, Nt-butylethanolamine, N-cydecylhexyldiethanolamine, 2- , 2-diethylaminoethanol, 2-dipropyl Amino-2-pentanol, 2- [bis (2-hydroxyethyl) amino] -2-methyl-2-methylaminoethanol, 2- (2-hydroxyethyl) amino] -2-propanol, N, N-bis (2-hydroxypropyl) ethanolamine, 2- Tris (hydroxymethyl) aminomethane, and tri-isopropanolamine.

The basic material may be formed by cutting off the surface of the abrasive grains to make the angular shape into a spherical shape.

The acid dissociation constant pKa of the basic substance may be smaller than the acid dissociation constant pKa of the carbonic acid, and the acid dissociation constant pKa of the basic substance may be 7 or more.

The cerium precursor material is cerium carbonate, the basic substance is a KNO _3, wherein the cerium carbonate and the mixing ratio is KNO ₃ KNO ₃ with respect to 1 mole of cerium carbonate may be in the range of 0.1 to 2 moles.

The remaining components of the mixture may be water, preferably ultra pure water.

The step of synthesizing may be carried out at room temperature to 100 < 0 > C.

The synthesizing step may be performed for 1 to 1.5 hours.

And controlling the synthesis temperature and the synthesis time to control the size and shape of the cerium-based abrasive grains. The synthesis temperature is from room temperature to 60 占 폚, the calcination time is from 1 hour to 1.5 hours, and the cerium-based abrasive grains may be spherical.

The mixture is then dried (120).

The drying may be performed at a temperature ranging from room temperature to 100 < 0 > C.

The drying may include at least one selected from the group consisting of natural drying, hot air drying, and thermal drying. Preferably, the drying may be performed using a hot air drier.

The mixture is then calcined to yield cerium oxide (130).

The calcining step may be performed at a temperature of from room temperature to 1000 < 0 > C. The calcining step may maintain an oxidizing atmosphere in which air is sufficiently supplied. The calcining step may be performed for 0.1 to 6 hours. In some cases, the calcination process may be performed by adjusting the partial pressure of oxygen. Preferably, the calcination process can be performed at a temperature of 600 to 900 DEG C for about 1 hour. Cerium carbonate may be formed of cerium oxide through the calcination process.

And controlling the size and shape of the cerium-based abrasive grains by controlling the calcination temperature and the calcination time.

Wherein the calcining temperature is from 350 ° C to 500 ° C, the calcining time is from 1 hour to 1.5 hours, the cerium abrasive grains are angular, the calcining temperature is from 500 ° C to 900 ° C, Hour, and the cerium-based abrasive grains may be spherical.

As the calcination temperature becomes higher and the calcination time becomes longer, the particle shape can be controlled to be spherical.

The cerium-based abrasive grains may be angular or spherical. The cerium-based abrasive grains can be controlled to have a rectangular shape or a spherical shape by cutting the surface of the abrasive grains by a basic material contained in the cerium-based abrasive grains to make the angular shape into a spherical shape. 2A to 2C are SEM images of cerium oxide abrasive particles according to an embodiment of the present invention. It can be seen that the size of the cerium oxide abrasive grains can be gradually increased from FIG. 2A to FIG. 2C. As described above, the desired particle size can be controlled through temperature control in the calcination process. The higher the calcination temperature and the longer the calcination time, the larger the particle size can be controlled.

The spherical shape of the cerium-based abrasive particles means less dishing and fewer defects and scratches. The spherical degree of the cerium-based abrasive grains can be measured by XRD (GS / Air), TEM (particle formation and particle size confirmation) and FE-SEM (particle formation and particle size confirmation).

Wherein the calcining temperature is from 350 to 500 캜, the calcining time is from 1 to 1.5 hours, the cerium abrasive grain is from 15 to 25 nm, the calcining temperature is from 500 캜 to 900 캜, To 5 hours, and the cerium-based abrasive grains may be from 25 nm to 80 nm.

The higher the calcination temperature and the longer the calcination time, the larger the particle size can be controlled.

The cerium-based abrasive grains having a desired shape and size can be easily obtained according to the above-mentioned production method of the cerium-based abrasive grains, and the cerium-based abrasive grains having a desired shape and size can be easily prepared. have. Accordingly, by providing such cerium-based abrasive grains, it is very easy to provide a desired CMP slurry containing a desired shape and size.

The second aspect of the present invention provides the cerium-based abrasive particles produced by the manufacturing method of the first aspect of the present invention.

The cerium-based abrasive grains may be angular or spherical.

The cerium-based abrasive particles may include primary particles and secondary particles, the primary particles may have a particle diameter of 5 to 50 nm, and the secondary particles may have a particle diameter of 50 to 200 nm or less.

The cerium-based abrasive grains may have a peak area intensity ratio defined by the peak area of the (111) plane with respect to the peak area of the (200) plane of the XRD pattern by X-ray diffraction analysis of 3.0 to 4.5.

In the XRD pattern of the cerium-based abrasive grains, the peak of the (111) plane is a peak having a 2? Value of 27 to 30, the peak of the (200) plane is a peak of 32 to 34.5, Lt; RTI ID = 0.0 > 46 < / RTI > The peak area means the integral area occupied by each peak. Peak intensity refers to the peak intensity of each peak appearing after XRD measurement.

In the present invention, the "peak area ratio" is a value calculated by taking the peak area of the (200) plane as the denominator and the peak area of the (111) plane as the numerator. When the peak area ratio calculated from the XRD pattern of the calcined cerium oxide is less than 0.5, the strength of the particles is too weak to lower the polishing rate during polishing after the production of the slurry, and when the peak area ratio exceeds 4.5, the strength of the particles becomes strong, There is a possibility of scratching. The peak area ratio can be controlled by controlling the partial pressure of oxygen during the calcination or by adding a process capable of blocking contact with oxygen during the calcination process and subjecting it to a calcination process.

The peak area of the (111) plane and the peak area ratio of the (200) plane of the cerium oxide particles are related to the strength of the particles and defects and scratches during CMP polishing after slurry preparation. The cerium oxide particles calcined in the oxygen atmosphere generally have a peak area ratio of the (111) plane and a peak area ratio of the (200) plane in the range of approximately 3.0 to 4.5, and the peak area ratio of the cerium oxide particles calcined in the oxygen- To 3.0. Generally, when oxygen deficiency occurs, the peak area ratio becomes small, and the non-stoichiometric structure due to the oxygen deficiency of cerium oxide is generated, so that the strength of the cerium oxide particles is weakened.

A third aspect of the present invention provides a slurry composition comprising cerium-based abrasive particles produced according to the first aspect of the present invention.

The method for producing cerium-based abrasive grains according to the present invention and the cerium-based abrasive grains thereby can control the shape and size of the cerium-based abrasive grains depending on the synthesis temperature, synthesis time, calcination temperature and calcination time of the mixture, It exhibits excellent polishing rate and selectivity at the time of polishing and can reduce defects and scratches. Therefore, productivity improvement can be expected in the production of semiconductor devices.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the following examples are for illustrative purposes only and are not intended to limit the scope of the present invention.

[Example 1]

1000 g of cerium carbonate as a cerium precursor material, 10 g of KNO ₃ as a basic substance and 800 g of ultrapure water were placed in a glass beaker and stirred and rotated at a temperature of 60 캜 for 1 hour to synthesize a cerium carbonate mixture. Subsequently, the cerium carbonate mixture was dried at a temperature of 85 캜 by using a hot-air drier. Subsequently, the dried particles were calcined in a box-shaped electric furnace at a temperature of 600 DEG C for 4 hours under atmospheric pressure to prepare cerium oxide particles.

[Example 2]

Cerium oxide particles were prepared in the same manner as in Example 1, except that the calcination temperature was calcined at 700 캜.

[Example 3]

Cerium oxide particles were produced in the same manner as in Example 1 except that the calcination was performed at a calcination temperature of 800 占 폚.

[Example 4]

Cerium oxide particles were produced in the same manner as in Example 1 except that the calcination was carried out at a temperature of 900 占 폚.

[Comparative Example 1]

1000 g of cerium carbonate as a cerium precursor material was dried at 85 캜 using a hot air drier. Subsequently, the dried particles were calcined in a box-shaped electric furnace at a temperature of 600 DEG C for 4 hours under atmospheric pressure to prepare cerium oxide particles.

[Comparative Example 2]

Cerium oxide particles were produced in the same manner as in Comparative Example 1, except that the calcination temperature was calcined at 700 캜.

[Comparative Example 3]

Cerium oxide particles were produced in the same manner as in Comparative Example 1, except that the calcination was performed at a calcination temperature of 800 占 폚.

[Comparative Example 4]

The cerium oxide particles were produced in the same manner as in Comparative Example 1, except that the calcination temperature was 900 ° C.

Synthesis time
(hr) Synthesis temperature
(° C) Drying temperature
(° C) Calcination temperature
(° C) G / S
(Primary particle)
(nm) SEM
size
(nm) particle
shape area
Intensity ratio Example 1 One 60 85 600 20 15-20 rectangle 4.1 Example 2 700 30 30 to 40 4 Example 3 800 100 90-120 3.8 Example 4 900 150 150 ~ 180 3.7 Comparative Example 1 - - 85 600 15 20 ~ 30 Square 2.7 Comparative Example 2 - - 700 22 20 to 50 2.7 Comparative Example 3 - - 800 70 70-100 2.4 Comparative Example 4 - - 900 120 100 to 150 2.0

4 is an SEM image of Example 4 of the present invention, FIG. 5 is an SEM image of Comparative Example 2 of the present invention, and FIG. 6 is a SEM image of Comparative Example 2 of the present invention 4 is an SEM image. The cerium oxide particles of Examples 2 and 4 of the present invention are spherical, and the cerium oxide particles of Comparative Examples 2 and 4 are angular.

Table 1 shows the particle size and shape of cerium oxide of Examples 1 to 4 and Comparative Examples 1 to 4 of the present invention. As shown in Table 1, the cerium oxide particles of Examples 1 to 4 of the present invention can be formed into spherical shapes of abrasive particles by synthesis of cerium carbonate, a basic substance and water, and the particle size can be controlled as desired Can be confirmed. And that the powder particles of Examples 1 to 4 including the synthesis step have a higher particle growth rate and a higher area intensity ratio. In addition, it can be confirmed that the size of the cerium oxide particles increases as the calcination temperature increases. Thus, it was confirmed that particles can be grown to a desired size by controlling the temperature and time in the calcining process.

While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. This is possible. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined by the equivalents of the claims, as well as the claims.

Claims (16)

Mixing a cerium precursor material, a basic material and water to synthesize a mixture;
Drying the mixture; And
Calcining the dried mixture to obtain cerium oxide;
Based abrasive grains, the method comprising
Controlling the size and shape of the cerium-based abrasive grains by controlling the calcination temperature and the calcination time,
The calcining temperature is 350 ° C to 500 ° C, the calcining time is 1 hour to 1.5 hours, the cerium-based abrasive grains are angular,
Wherein the calcining temperature is 500 ° C to 900 ° C, the calcining time is 1 hour to 5 hours, and the cerium-based abrasive particles are spherical.
Method for manufacturing cerium abrasive particles.
The method according to claim 1,
Wherein the synthesizing step is carried out at a temperature of from room temperature to 100 캜 for 1 to 1.5 hours.
The method according to claim 1,
Wherein the drying step is performed at a temperature of from room temperature to 100 占 폚.
The method according to claim 1,
Wherein the step of drying comprises at least one selected from the group consisting of natural drying, hot air drying and thermal drying.
The method according to claim 1,
Wherein the calcining step is performed at room temperature to 1000 캜 for 0.1 to 6 hours.
The method according to claim 1,
And the size and shape of the cerium-based abrasive grains are controlled by controlling the synthesis temperature and the synthesis time.
delete The method according to claim 1,
Wherein the synthesis temperature is from room temperature to 60 deg. C, the calcination time is from 1 hour to 1.5 hour, and the cerium-based abrasive grains are spherical.
delete The method according to claim 1,
The calcining temperature is from 350 to 500 ° C, the calcining time is from 1 to 1.5 hours, the cerium-based abrasive particle is from 15 nm to 25 nm,
Wherein the calcining temperature is 500 ° C to 900 ° C, the calcining time is 1 hour to 5 hours, and the cerium-based abrasive grains are 25 nm to 80 nm.
Method for manufacturing cerium abrasive particles.
The method according to claim 1,
Wherein the cerium precursor material comprises at least one selected from the group consisting of cerium carbonate, cerium nitrate, cerium acetate, cerium sulfate, cerium ammonium nitrate, cerium oxide, cerium hydroxide and salts thereof. ≪ / RTI >
The method according to claim 1,
The basic material is selected from the group consisting of KNO ₃ , CH ₃ COOK, K ₂ SO ₄ , KCl, KOH, 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 ,} propylamine, butylamine, diethylamine, dipropylamine, dibutylamine _, triethylamine, tributylamine, monoethanolamine, diethanolamine, triethanolamine, 2-dimethylamino- 1-propanol, 2-amino-1-propanol, 2-dimethylamino-1-propanol, 2- Diethylamino-1-ethanol, 2-ethylamino-1-ethanol, 1- (dimethylamino) 2-propanol, N-methyldiethanolamine, N-propyldiethanolamine , N-isopropyldiethanolamine, N- (2-methylpropyl) diethanolamine, N-butyldiethanolamine, Nt-butylethanolamine, N-cydecylhexyldiethanolamine, 2- , 2-diethylaminoethanol, 2-dipropyl Amino-2-pentanol, 2- [bis (2-hydroxyethyl) amino] -2-methyl-2-methylaminoethanol, 2- (2-hydroxyethyl) amino] -2-propanol, N, N-bis (2-hydroxypropyl) ethanolamine, 2- Tris (hydroxymethyl) aminomethane, and tris (isopropanolamine). ≪ / RTI >
A cerium-based abrasive grain produced by the method of any one of claims 1 to 6, 8, 10 to 12.
14. The method of claim 13,
Wherein the cerium-based abrasive grains are angular or spherical.
14. The method of claim 13,
Wherein the cerium-based abrasive particles comprise primary particles and secondary particles,
Wherein the primary particles have a particle diameter of 5 to 50 nm and the secondary particles have a particle diameter of 50 to 200 nm or less.
14. The method of claim 13,
Wherein said cerium-based abrasive particles have a peak area intensity ratio of 3.0 to 4.5 as defined by a peak area of a (111) face with respect to a peak area of a (200) face of an XRD pattern by X-ray diffraction analysis.

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