WO2003044123A1

WO2003044123A1 - Particles for use in cmp slurries and method for producing them

Info

Publication number: WO2003044123A1
Application number: PCT/US2002/035672
Authority: WO
Inventors: Xiangdong Feng; Yie-Shein Her
Original assignee: Ferro Corporation
Priority date: 2001-11-16
Filing date: 2002-11-06
Publication date: 2003-05-30
Also published as: US20050003744A1; AU2002359356A1

Abstract

The present invention provides a process for producing particles suitable for use as abrasives in chemical-mechanical polishing slurries. The process according to the invention includes mixing at least one crystallization promoter such as Ti[OCH(CH3)2)]4 with at least one cerium compound and at least one solvent, and subjecting said mixture to hydrothermal treatment at a temperature of from about 60 °C to about 700 °C to produce the particles. Particles formed in accordance with the present invention exhibit a large crystallite size, and can be used to polish silicon-containing substrates to a high degree of planarity at a relatively high rate.

Description

Title: PARTICLES FOR USE IN CMP SLURRIES AND METHOD FOR PRODUCING THEM

Cross-Reference to Related Application

[0001] This application is a continuation-in-part of Application Serial No.

09/992,485 filed November 16, 2001.

Field of Invention

[0002] The present invention provides a process for producing abrasive

particles and abrasive particles produced according to the process.

Background of the Invention

[0003] Chemical-mechanical polishing (CMP) slurries are used, for

example, to planarize surfaces during the fabrication of semiconductor chips

and the like. CMP slurries typically include reactive chemical agents and

abrasive particles dispersed in a liquid carrier. The abrasive particles perform

a grinding function when pressed against the surface being polished using a

polishing pad.

[0004] It is well known that the size, composition, and morphology of the

abrasive particles used in a CMP slurry can have a profound effect on the

polishing rate. Over the years, CMP slurries have been formulated using

abrasive particles formed of, for example, alumina (Al₂0₃), eerie oxide (Ce0₂),

iron oxide (Fe₂0₃), silica (Si0₂), silicon carbide (SiC), silicon nitride (Si₃N₄), tin oxide (Sn0₂), titania (Ti0₂), titanium carbide (TiC), tungstic oxide (W0₃), yttria

(Y₂0₃), zirconia (Zr0₂), and combinations thereof. Of these oxides, eerie

oxide (Ce0₂) is the most efficient abrasive in CMP slurries for planarizing

silicon dioxide insulating layers in semiconductors because of its high

polishing activity.

[0005] Calcination is by far the most common method of producing

abrasive particles for use in CMP slurries. During the calcination process,

precursors such as carbonates, oxalates, nitrates, and sulphates, are

converted into their corresponding oxides. After the calcination process is

complete, the resulting oxides must be milled to obtain particle sizes and

distributions that are sufficiently small to prevent scratching.

[0006] The calcination process, although widely used, does present

certain disadvantages. For example, it tends to be energy intensive and thus

relatively expensive. Toxic and/or corrosive gaseous byproducts can be

produced during calcination. In addition, it is very difficult to avoid the

introduction of contaminants during the calcination and subsequent milling

processes. Finally, it is difficult to obtain a narrow distribution of appropriately

sized abrasive particles.

[0007] It is well known that CMP slurries containing contaminants and/or

over-sized abrasive particles can result in undesirable surface scratching

during polishing. While this is less critical for coarse polishing processes, in the production of critical optical surfaces, semiconductor wafers, and

integrated circuits, defect-free surfaces are required. This is achievable only

when the abrasive particles are kept below about 1.0 μm in diameter and the

CMP slurry is free of contaminants. The production of abrasive particles

meeting these requirements by conventional calcination and milling

techniques is extremely difficult and often not economically feasible.

[0008] An alternative method of forming abrasive particles for use in CMP

slurries is hydrothermal synthesis, which is also known as hydrothermal

treatment. In this process, basic aqueous solutions of metal salts are held at

elevated temperatures and pressures for varying periods of time to produce

small particles of solid oxide suspended in solution. A method of producing

eerie oxide (Ce0₂) particles via hydrothermal treatment is disclosed, for

example, in Wang, U.S. Pat. No. 5,389,352.

[0009] The production of abrasive particles by hydrothermal treatment

provides several advantages over the calcination/milling process.

Unfortunately, however, abrasive particles formed by conventional

hydrothermal treatment processes tend not to provide desired high polishing

rates. Summary of Invention

[0010] The present invention provides a process for producing abrasive

particles suitable for use in chemical-mechanical polishing slurries. The

process according to the invention comprises mixing a crystallization

promoter such as titanium (IV) isopropoxide with a cerium compound and a

solvent, optionally adjusting the pH to greater than 7.0 using one or more

bases, and subjecting the mixture to hydrothermal treatment at a temperature

of from about 60°C to about 700°C to produce particles. Although the precise

mechanism is not yet precisely understood, the presence of a crystallization

promoter in the solution during hydrothermal treatment results in the

formation of particles with larger than expected crystallite sizes. Particles

formed in this manner polish surfaces at a much higher rate than particles

formed by conventional hydrothermal processes.

[0011] The foregoing and other features of the invention are hereinafter

more fully described and particularly pointed out in the claims, the following

description setting forth in detail certain illustrative embodiments of the

invention, these being indicative, however, of but a few of the various ways in

which the principles of the present invention may be employed. Brief Description of the Drawings

[0012] Fig. 1 is a graph showing the particle size distribution of particles

formed in Example 1.

Detailed Description of Preferred Embodiments

[0013] The present invention provides a process for producing abrasive

particles suitable for use in chemical-mechanical polishing slurries without the

need for calcination and/or milling. The process comprises mixing a

crystallization promoter with a cerium compound and a solvent, optionally

adjusting the pH to higher than 7.0 using one or more bases, and subjecting

the mixture to hydrothermal treatment at a temperature of from about 60°C to

about 700°C to produce particles.

[0014] The preferred cerium compound for use in the method according to

the invention is (NH₄)₂Ce(N0₃)₆ (ammonium cerium (IV) nitrate). However, it

will be appreciated that other cerium compounds can also be used. The

valence of the cerium in the cerium compound is not per se critical, but eerie

(IV) compounds are preferred over cerous (III) compounds. Suitable cerium

compounds for use in the invention include, for example, cerium nitrate,

cerium chloride, cerium sulfate, cerium bromide, and cerium iodide.

[0015] The mixture must also comprise one or more crystallization

promoters. The presently most preferred crystallization promoter is a titanium compound, namely Ti[OCH(CH₃)₂)]₄ (titanium (IV) isopropoxide), but other

titanium compounds can be also used, such as, for example, titanium

chloride, titanium sulfate, titanium bromide, and titanium oxychloride.

Compounds of metals other than titanium can also be used as crystallization

promoters, as can non-metallic compounds such as nitrogenous cyclic

polymers, poly glycols, alcohols, and ketones. In some cases, the

crystallization promoter can also serve as the solvent. Use of a crystallization

promoter is essential in order to obtain particles having a relatively large

crystallite size.

[0016] As noted above, it is possible to use compounds of metals other

than titanium such as alkaline earth metals (group IIA of the periodic table),

transition metals (element 21 , scandium, through element 29, copper;

element 39, yttrium, through element 47, silver; element 57, lanthanum,

through element 79, gold; and element 89, actinium, and higher), aluminum,

zinc, gallium, germanium, cadmium, indium, tin, antimony, mercury, thallium,

lead, bismuth, and polonium. Scandium compounds, in particular, can be

used to produce cerium oxide (Ce0₂) particles according to the process of the

invention that have relatively large crystallite sizes. However, for reasons that

are presently unknown, particles formed using scandium compounds as

crystallization promoters are not as effective as abrasives in CMP polishing

applications as compared to particles formed using titanium compounds as

crystallization promoters. [0017] One or more bases can be optionally added to raise the pH of the

mixture to greater than 7.0 and assist in the formation of a mixture having a

gel-like consistency. Suitable bases include, for example, ammonium

hydroxide, potassium hydroxide, organoamines such as ethyl amine and

ethanol amine, and/or polyorganoamines such as polyethylene imine. The

gel-like mixture formed upon adding a base will break down into small

particles upon rapid stirring.

[0018] Other compounds such as urea, for example, can be used as

precursors for a base. Urea does not act as a base until it is heated, so it

does not tend to form a gel-like mixture when added, but rather will form a

clear solution. Moreover, when urea is used, the pH of the mixture will

generally not be greater than 7.0.

[0019] The mixture, whether in the form of a gel or a clear solution, is then

subjected to hydrothermal treatment. This is typically accomplished by

heating the mixture in a sealed stainless steel vessel to a temperature of from

about 60°C to about 700°C for a period of time of from about 10 minutes to

many hours. At the completion of the reaction, the stainless steel vessel can

be quenched in cold water, or it can be permitted to cool gradually over time.

The mixture can be, but need not be, stirred during hydrothermal treatment. It

is also possible to carry out the reaction in an autoclave unit with constant

stirring. [0020] Testing has shown that the average particle size (diameter) of the

particles formed during the hydrothermal treatment can be controlled by

varying the initial concentration of the cerium compound, with higher initial

cerium ion concentrations tending to produce particles having a larger

average particle size. The use of precursors of bases such as urea tends to

produce smaller particles. Reaction time, temperature, and pH appear to

have little or no effect on particle size. A range of particle sizes from about 5

nm to about 10,000 nm can be obtained via the process, but particles having

an average diameter within the range of from about 50 nm to about 250 nm

are most preferred.

[0021] Although the mechanism is not fully known at this time, for some

reason the presence of a crystallization promoter such as Ti[OCH(CH₃)₂)]₄

(titanium (IV) isopropoxide) is critical in order to produce abrasive particles

having a large crystallite size, which can be determined using well-known X-

ray diffraction methods. For example, when subjected to identical

hydrothermal conditions (i.e., temperature, time, pH, etc.), a solution

containing a titanium (IV) isopropoxide crystallization promoter produced

particles having an average crystallite size of 21 OA whereas a solution

containing no titanium (IV) isopropoxide crystallization promoter produced

particles having a an average crystallite size of only 42A. For some reason,

the presence of a crystallization promoter in the solution accelerates the

crystal growth of crystallites during hydrothermal treatment, which is a desirable attribute for abrasive particles used in CMP slurries. Tests have

shown that CMP slurries formed using particles having larger crystallite sizes

tend to polish surfaces such as tetraethoxyorthosilicate (TEOS) silicon dioxide

films at a much higher rate than CMP slurries formed using particles having

smaller crystallite sizes.

[0022] The abrasive particles formed in accordance with the method of the

invention, in addition to exhibiting a crystallite size of greater than about

20θA, predominantly comprise cerium oxide (Ce0₂) having a cubic crystal

structure. Elemental analysis of abrasive particles formed using a titanium

compound as a crystallization promoter show the presence of titanium atoms

in the cubic crystal structure. There is no titanium dioxide observed by X-ray

diffraction, and no anatase or rutile crystal structure. It is hypothesized that

the titanium atoms are incorporated into the cubic cerium oxide crystal

structure, replacing cerium atoms in such structure. This same phenomenon

is noted when compounds of metals other than titanium are used as

crystallization promoters. When a crystallization promoter selected from the

group consisting of nitrogenous cyclic polymers, poly glycols, alcohols, and

ketones is used, the cerium oxide particles will exhibit a cubic crystal lattice

structure wherein carbon atoms obtained from the crystallization promoter are

incorporated into the cubic crystal lattice structure. [0023] It will be appreciated that certain metallic compounds, such as

titanium compounds, tend to rapidly decompose in aqueous media, which

reduces their efficiency in promoting the formation of particles having larger

crystallite sizes. Accordingly, it is preferable for one or more stabilizing

compounds such as, for example, acetyl acetone, to be present with the

crystallization promoters in order to prevent or delay the decomposition of

such compounds. When stabilized in this manner, the crystallization

promoters have sufficient time to homogeneously mix with the cerium

compounds at a molecular level, particularly before a gel-like mixture is

formed upon the addition of one or more bases. Applicants have discovered

that when the crystallization promoters are stabilized in this manner, the

particles formed during hydrothermal treatment tend to have substantially

larger crystallite sizes.

[0024] The particles formed according to the process of the invention are

particularly well suited for use in CMP slurries. CMP slurries can be formed

using the particles as obtained via the process or by adding water, acid

and/or base to adjust the abrasive concentration and pH to desired levels.

Alternatively, the abrasive particles formed according to the invention can be

bonded to a polishing pad.

[0025] Surfaces that can be polished using abrasive particles according to

the invention include, but are not limited to TEOS silicon dioxide, spin-on glass, organosilicates, silicon nitride, silicon oxynitride, silicon, silicon carbide,

computer memory hard disk substrates, silicon-containing low-k dielectrics,

and silicon-containing ceramics. The abrasive particles according to the

invention are particularly useful for polishing layers in semiconductor devices.

[0026] The following examples are intended only to illustrate the invention

and should not be construed as imposing limitations upon the claims.

Example 1

[0027] In a 1000 ml plastic bottle, 41.6 grams of (NH₄)₂Ce(N0₃)₆

(ammonium cerium (IV) nitrate) was dissolved in 500 ml deionized H₂0 (Dl-

water) and 1.2 grams CH₃COCH₂OCCH₃ (acetyl acetone) to form a solution.

2.4 grams of Ti[OCH(CH₃)₂)]₄ (titanium (IV) isopropoxide) was added to the

solution followed by the addition of 36 grams of C₂H₅NH₂ (ethylamine) with

stirring. A sufficient quantity of Dl-water was then added to reach a final

volume of 800 ml. The solution was stirred for 5 minutes and then transferred

to a clean 1000 ml stainless steel vessel. The stainless steel vessel was

closed and sealed, shaken for 5 minutes, and then placed into a furnace and

heated at 300°C for 6.0 hours. The stainless steel vessel was then removed

from the furnace and allowed to cool to room temperature. The reaction

product formed in the vessel was transferred to a clean 1000 ml plastic bottle.

As shown in Fig. 1 , the reaction product consisted of a dispersion of Ce0₂

(cerium oxide) particles having a narrow size distribution (D₅₀ = 87 nm; D₉₀ = 101 nm; and D₁₀ = 68 nm). The cerium oxide particles had an average

crystallite size of 21 OA.

Example 2

(Comparative Example)

[0028] A dispersion of cerium oxide particles was formed using the same

materials and procedures as set forth in Example 1 , except that no

Ti[OCH(CH₃)₂)]₄ (titanium (IV) isopropoxide) was used. The cerium oxide

particles thus formed had a narrow size distribution (D₅₀ = 89 nm; D₉₀ = 99

nm; and D₁₀ = 72 nm) similar to the cerium oxide particles formed in Example

1 , but the average crystallite size was only 42A.

Example 3

[0029] A dispersion of cerium oxide particles was formed using the same

materials and procedures as set forth in Example 1 , except that no acetyl

acetone (CH₃COCH₂OCCH₃) was used. The cerium oxide particles thus

formed had a narrow size distribution (D₅₀ = 80 nm; D₉₀ = 97 nm; and D₁₀ = 60

nm) similar to the cerium oxide particles formed in Example 1 , but the

average crystallite size was only 9θA.

Example 4

[0030] Four chemical-mechanical polishing slurries were formed using

cerium oxide particles. Slurry A consisted of 100 parts by weight of the cerium oxide nanoparticle dispersion formed in Example 1. Slurry B was

identical to Slurry A, except that the cerium oxide nanoparticle dispersion

formed in Example 2 was used instead of the cerium oxide nanoparticle

solution formed in Example 1. Slurry C was identical to Slurry A, except that

the cerium oxide nanoparticle dispersion formed in Example 3 was used

instead of the cerium oxide nanoparticle solution formed in Example 1. Slurry

D was identical to Slurry A, except that the cerium oxide nanoparticle

dispersion comprised conventional calcined cerium oxide (Ferro Electronic

Material Systems SRS-616A) having an average particle size of D₅₀ = 141 nm

dispersed in water at a pH of 10.0. Identical TEOS Si0₂ (silicon dioxide)

wafers were polished using Slurries A, B, C, and D, respectively. The

polishing was performed using a Strasbaugh 6EC polisher, a Rodel IC1000

pad with Suba IV backing at a down pressure of 3.2 psi, and a table rotation

speed of 60 rpm, and slurry flow rate of 150 ml/min. The wafer polished using

Slurry A had a Si0₂ removal rate of 3500 A/min and produced a surface

having a root-mean-square average roughness of O.δA. The wafer polished

using Slurry B had a Si0₂ removal rate of 85 A/min and produced a surface

having a root-mean-square average roughness of 1.θA. The wafer polished

using Slurry C had a Si0₂ removal rate of 1875 A/min and produced a surface

having a root-mean-square average roughness of 2.0A. And, the wafer

polished using Slurry D had a Si0₂ removal rate of 4200 A/min and produced

a surface having a root-mean-square average roughness of 3.0A. Example 5

[0031] 32.34 grams of ammonium cerium (IV) nitrate was dissolved in 50

ml Dl-water in a 100 ml beaker and heated to 90°C under stirring to form an

aqueous solution. Another solution containing 0.02 grams polyvinyl

pyrrolidone (PVP) having a weight average molecular weight of about 29,000

admixed in 380 grams of 6M KOH in a 500 ml beaker was heated to 90°C.

The aqueous cerium solution was then added to the KOH solution under

constant stirring for 30 minutes. The temperature was kept at 90°C. A white

precipitate was filtered off and washed with water until the pH of the filtrate

was below 10. The precipitate was then dispersed in Dl-water to make a total

volume of 100ml, ultrasonicated for 5 minutes and transferred into a 150 ml

steel vessel and sealed. The steel vessel was then placed in a pre-heated

oven at 250°C for 6 h for hydrothermal treatment. At the end of the

hydrothermal treatment, the vessel was quenched in cold water to room

temperature and the slurry was removed. The so-obtained cerium oxide

particles had an average particle diameter D₅₀ of 300 nm and an average

crystallite size of 130A.

Example 6

[0032] The same process as described in Example 5 was repeated except

that PVP was replaced with 0.02 gram of polyethylene glycol having a weight

average molecular weight of about 600. The so-obtained cerium oxide particles had an average particle diameter D₅₀ of 100 nm and an average

crystallite size of 150A.

Example 7

[0033] 50 grams of ammonium cerium (IV) nitrate was dissolved in 50 ml

Dl-water in a 100 ml beaker and heated to 90°C under stirring to form an

aqueous cerium solution. Another solution comprising a mixture of 139.32

grams KOH, 234.09 grams Dl-water, 21.465 grams methanol, and 10.125

grams acetone was heated to 90°C in a 500 ml beaker. The aqueous cerium

solution was then added to the KOH solution under constant stirring for 30

minutes. The temperature was kept at 90°C. A white precipitate was filtered

off and washed with water until the pH of the filtrate was below 10. The

precipitate was then dispersed in water to make a total volume of 100ml,

ultrasonicated for 5 minutes and transferred into a 150 ml steel vessel and

sealed. The steel vessel was then placed in a pre-heated oven at 250°C for 6

hours for hydrothermal treatment. At the end of the hydrothermal treatment,

the vessel was quenched in cold water to room temperature and the slurry

was removed. The so-obtained cerium oxide particles had an average

particle diameter D₅₀ of 110 nm and an average crystallite size of 130A.

Example 8

[0034] 22.3 grams of ammonium cerium (IV) nitrate was dissolved in 40 ml

Dl-water in a 100ml beaker. Then, 2.59 grams of a mixture solution

containing 1.177 grams of acetyl acetone and 1.413 grams of titanium (IV) isopropoxide was added into the ammonium cerium (IV) nitrate solution under

stirring. In another beaker, 20.7 grams of concentrated ammonium hydroxide

(57 wt% NH₄OH) was mixed with 20 grams of Dl-water. The solution

containing ammonium cerium (IV) nitrate and titanium (IV) isopropoxide was

then added into the ammonium hydroxide solution under stirring, stirred for

another 3 minutes, and additional Dl-water added to a total final volume of

100 ml. The mixture was ultrasonicated for 5 minutes, transferred to a 150 ml

steel vessel, and tightly sealed. The steel vessel was then placed in an oven

preheated at 300°C for 6 hours for hydrothermal treatment. At the end of the

hydrothermal treatment, the vessel was quenched in cold water to room

temperature and the slurry was removed. The so-obtained cerium oxide

particles had an average particle diameter D₅₀ of 97 nm and an average

crystallite size of 26θA.

Example 9

[0035] 71.6 grams of ammonium cerium (IV) nitrate and 35.1 grams of

urea were dissolved in 700 ml Dl-water in a 1000 ml beaker. Then, 7.52

grams of a mixture solution containing 3.418 grams of acetyl acetone and

4.102 grams of titanium (IV) isopropoxide was added into the ammonium

cerium (IV) nitrate solution under stirring. Additional Dl-water was added to

mixture to a total final volume of 1286 ml. Finally, the mixture was transferred

to a 2000 ml steel vessel and tightly sealed. The sealed steel vessel was

then placed in an oven preheated at 300°C for 3 hours for hydrothermal treatment. At the end of the hydrothermal treatment, the vessel was

quenched in cold water to room temperature and the slurry was removed.

The so-obtained cerium oxide particles had an average diameter D₅₀ of 860

nm and an average crystallite size of 2480A.

Example 10

[0036] The process as described in Example 9 was repeated except that

ammonium cerium (IV) nitrate was replaced with 56.4 grams of Ce(N0₃)₃

(cerium (III) nitrate). The so-obtained cerium oxide particles had an average

diameter D₅₀ of 910 nm and an average crystallite size of 2220A.

[0037] Additional advantages and modifications will readily occur to those

skilled in the art. Therefore, the invention in its broader aspects is not limited

to the specific details and illustrative examples shown and described herein.

Accordingly, various modifications may be made without departing from the

spirit or scope of the general inventive concept as defined by the appended

claims and their equivalents.

Claims

What is Claimed:

1. A process for producing abrasive particles comprising mixing a

crystallization promoter with a cerium compound and a solvent to form a

mixture, and subjecting the mixture to hydrothermal treatment at a

temperature of from about 60°C to about 700°C to produce the abrasive

particles.

2. The process according to claim 1 wherein the mixture further

comprises urea and/or at least one pH adjuster selected from the group

consisting of organic acids, organic bases, inorganic acids and inorganic

bases.

3. The process according to claim 1 wherein the cerium compound

is ammonium cerium (IV) nitrate.

4. The process according to claim 1 wherein the crystallization

promoter is one or more selected from the group consisting of compounds of

alkaline earth metals, transition metals, aluminum, zinc, gallium, germanium,

cadmium, indium, tin, antimony, mercury, thallium, lead, bismuth, and

polonium.

5. The process according to claim 4 wherein the crystallization

promoter comprises a titanium compound.

6. The process according to claim 5 wherein the titanium

compound is selected from the group consisting of titanium (IV) isopropoxide,

titanium chloride, titanium sulfate, titanium bromide, and titanium oxychloride.

7. The process according to claim 5 wherein the titanium

compound is titanium (IV) isopropoxide.

8. The process according to claim 5 wherein the titanium

compound is titanium oxychloride.

9. The process according to claim 1 wherein the crystallization

promoter is selected from the group consisting of nitrogenous cyclic polymers,

poly glycols, alcohols, and ketones.

10. The process according to claim 9 wherein the nitrogenous cyclic

polymer is polyvinyl pyrrolidone.

11. The process according to claim 9 wherein the poly glycol is

selected from polyethylene glycol and polypropylene glycol.

12. The process according to claim 9 wherein the alcohol is

methanol.

13. The process according to claim 9 wherein the ketone is

acetone.

14. The process according to claim 1 wherein the solvent is one or

more selected from the group consisting of water, alcohols, glycols, and

ketones.

15. The process according to claim 14 wherein the alcohol is one or

more selected from the group consisting of ethanol, isopropanol, butanol and

butanediol.

16. The process according to claim 14 wherein the glycol is selected

from ethylene glycol and propylene glycol.

17. The process according to claim 14 wherein the ketone is

acetone.

18. The process according to claim 1 wherein the mixture further

comprises at least one compound that delays the decomposition of the

crystallization promoter.

19. The process according to claim 18 wherein the compound that

delays the decomposition of the crystallization promoter is one or more

selected from the group consisting of acetyl acetone, ethytyl acetone and

EDTA.

20. The process according to claim 18 wherein the compound that

delays the decomposition of the crystallization promoter comprises acetyl

acetone.

21. Abrasive particles formed in accordance with the process of

claim 1.

22. Abrasive particles comprising cerium oxide having a cubic

crystal lattice structure, wherein atoms of one or more metals selected from

the group consisting of alkaline earth metals, transition metals, aluminum,

zinc, gallium, germanium, cadmium, indium, tin, antimony, mercury, thallium,

lead, bismuth, and polonium are incorporated into the cubic crystal lattice

structure, said particles having an average particle size (D₅₀) within the range

of from about 5 nm to about 10,000 nm and an average crystallite size of

greater than about 6θA.

23. Abrasive particles according to claim 22 wherein the particles

have an average particle size (D₅₀) within the range of from about 50 nm to

about 250 nm and an average crystallite size of greater than about 20θA.

24. Abrasive particles comprising cerium oxide having a cubic

crystal lattice structure, wherein carbon atoms obtained from a crystallization

promoter selected from the group consisting of nitrogenous cyclic polymers,

poly glycols, alcohols, and ketones, are incorporated into the cubic crystal

lattice structure, said particles having an average particle size (D₅₀) within the

range of from about 5 nm to about 10,000 nm and an average crystallite size

of greater than about 6θA.

25. Abrasive particles according to claim 24 wherein the particles

have an average particle size (D₅₀) within the range of from about 50 nm to

about 250 nm and an average crystallite size of greater than about 20θA.

26. A method of polishing a silicon-containing surface comprising

abrading the surface with abrasive particles according to claim 22.

27. The method according to claim 26 wherein the silicon-containing

surface is selected from the group consisting of TEOS silicon dioxide, spin-on

glass, organosilicates, silicon nitride, silicon oxynitride, silicon, silicon carbide,

computer memory hard disk substrates, silicon-containing low-k dielectrics,

and silicon-containing ceramics.

28. The method according to claim 26 wherein the abrasive

particles are bonded to a polishing pad and/or dispersed in a chemical-

mechanical polishing slurry.

29. A method of polishing a silicon-containing surface comprising

abrading the surface with abrasive particles according to claim 24.

30. The method according to claim 29 wherein the silicon-containing

surface is selected from the group consisting of TEOS silicon dioxide, spin-on

computer memory hard disk substrates, silicon-containing low-k dielectrics,

and silicon-containing ceramics.

31. The method according to claim 29 wherein the abrasive

particles are bonded to a polishing pad and/or dispersed in a chemical-

mechanical polishing slurry.

32. A semiconductor device comprising a layer polished using

abrasive particles according to claim 22.

33. A semiconductor device comprising a layer polished using

abrasive particles according to claim 24.