U.S. patent application number 16/189207 was filed with the patent office on 2019-03-14 for polishing slurry composition.
This patent application is currently assigned to Dongjin Semichem Co., Ltd.. The applicant listed for this patent is Dongjin Semichem Co., Ltd.. Invention is credited to Sung Hoon Jin, Jae Hyun Kim, Min Gun Lee, Hye Jung Park, Jong Dai Park, Jong Chul Shin.
Application Number | 20190077993 16/189207 |
Document ID | / |
Family ID | 60325360 |
Filed Date | 2019-03-14 |
![](/patent/app/20190077993/US20190077993A1-20190314-M00001.png)
United States Patent
Application |
20190077993 |
Kind Code |
A1 |
Park; Hye Jung ; et
al. |
March 14, 2019 |
POLISHING SLURRY COMPOSITION
Abstract
Disclosed is a chemical-mechanical polishing slurry composition
having a small change in pH over time under an acidic condition and
thus being easy to store for a long time. The chemical-mechanical
polishing slurry composition includes an abrasive; an amount of
about 0.000006 to 0.01 weight % of an aluminum component based on
the total weight of the polishing slurry composition; and water.
The number of silanol groups on a surface of the abrasive and a
content of the aluminum component satisfy the requirements of
following Equation 1: 0.0005.ltoreq.(S*C)*100.ltoreq.4.5, [Equation
1] wherein, S is the number of the silanol groups present on 1
nm.sup.2 of the abrasive surface (unit: number/nm.sup.2), and C is
the content of the aluminum component (weight %) in the slurry
composition.
Inventors: |
Park; Hye Jung; (Hwaseong,
KR) ; Kim; Jae Hyun; (Seoul, KR) ; Park; Jong
Dai; (Seoul, KR) ; Lee; Min Gun; (Seoul,
KR) ; Shin; Jong Chul; (Hwaseong, KR) ; Jin;
Sung Hoon; (Hwaseong, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Dongjin Semichem Co., Ltd. |
Incheon |
|
KR |
|
|
Assignee: |
Dongjin Semichem Co., Ltd.
|
Family ID: |
60325360 |
Appl. No.: |
16/189207 |
Filed: |
November 13, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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PCT/KR2017/005118 |
May 17, 2017 |
|
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16189207 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L 21/304 20130101;
C09G 1/02 20130101; H01L 21/31053 20130101; C09K 3/1436 20130101;
H01L 21/3212 20130101 |
International
Class: |
C09G 1/02 20060101
C09G001/02 |
Foreign Application Data
Date |
Code |
Application Number |
May 19, 2016 |
KR |
10-2016-0061230 |
Claims
1. A polishing slurry composition comprising: an abrasive; an
amount of about 0.000006 to 0.01 weight % of an aluminum component
based on the total weight of the polishing slurry composition; and
a solvent.
2. The polishing slurry composition of claim 1, wherein the solvent
comprises water.
3. The polishing slurry composition of claim 1, wherein the
abrasive comprises one or more selected from the group consisting
of fumed silica and colloidal silica.
4. The polishing slurry composition of claim 1, wherein the
polishing slurry composition comprises the abrasive in an amount of
about 0.001 to 20 weight % based on the total weight of the
polishing slurry composition.
5. The polishing slurry composition of claim 3, wherein a number of
silanol groups on a surface of the abrasive is from about 1 to
about 10 mnm.sup.2.
6. The polishing slurry composition of claim 1, wherein the
aluminum component comprises one or more selected from the group
consisting of an aluminum salt, an aluminum atom and an aluminum
ion.
7. The polishing slurry composition of claim 6, wherein the
aluminum component is attached or absorbed on a surface of the
abrasive.
8. The polishing slurry composition of claim 6, wherein the
aluminum component further comprises one or more selected from the
group consisting of chloride (Cl), sulfate (SO.sub.4), ammonium
(NH.sub.4), potassium (K), hydroxide (OH), a methylate (CH.sub.3)
and phosphorus (P).
9. The polishing slurry composition of claim 3, wherein a number of
silanol groups on a surface of the abrasive and a content of the
aluminum component satisfy the requirement of the following
Equation 1: 0.0005.ltoreq.(S*C)*100.ltoreq.4.5, [Equation 1]
wherein, S is the number of the silanol groups present on 1
nm.sup.2 of the surface of the abrasive (unit: number/nm.sup.2),
and C is the content of the aluminum component (weight %) in the
polishing slurry composition.
10. The polishing slurry composition of claim 1, further
comprising: a pH adjusting agent comprising one or more selected
from the group consisting of nitric acid, hydrochloric acid,
sulfuric acid, potassium hydroxide, sodium hydroxide,
tetramethylammonium hydroxide, and tetrabutylammonium
hydroxide.
11. The polishing slurry composition of claim 1, further
comprising: an amount of about 0.005 to 10 weight % of an oxidizing
agent based on the total weight of the polishing slurry
composition.
12. The polishing slurry composition of claim 1, further
comprising: an amount of about 0.0001 to 0.05 weight % of a biocide
based on the total weight of the polishing slurry composition.
13. The polishing slurry composition of claim 1, further
comprising: an amount of about 0.00001 to 0.5 weight % of a
catalyst comprising nano ferrosilicon or iron salt compound based
on the total weight of the polishing slurry composition.
14. A polishing slurry composition comprising: an amount of about
0.001 to 20 weight % of an abrasive; an amount of about 0.000006 to
0.01 weight % of an aluminum component; an amount of about 0.00001
to 0.5 weight % of a catalyst comprising nano ferrosilicon or iron
salt compound; and a solvent constituting the remaining balance of
the polishing slurry composition, wherein all the weight % are
based on the total weight of the polishing slurry composition.
15. The polishing slurry composition of claim 14, wherein the
solvent comprises water.
16. The polishing slurry composition of claim 14, further
comprising: a pH adjusting agent to adjust the pH to 1 to 6; and an
amount of about 0.0001 to 0.05 weight % of a biocide based on the
total weight of the polishing slurry composition, and wherein the
pH adjusting agent comprises one or more selected from the group
consisting of nitric acid, hydrochloric acid, sulfuric acid,
potassium hydroxide, sodium hydroxide, tetramethylammonium
hydroxide, and tetrabutylammonium hydroxide.
17. The polishing slurry composition of claim 14, further
comprising: an amount of about 0.005 to 10 weight % of an oxidizing
agent based on the total weight of the polishing slurry
composition.
18. A polishing slurry composition comprising: an amount of about
0.001 to 20 weight % of an abrasive; an amount of about 0.000006 to
0.01 weight % of an aluminum component; an amount of about 0.00001
to 0.5 weight % of a catalyst comprising nano ferrosilicon or iron
salt compound; an amount of about 0.005 to 10 weight % of an
oxidizing agent; and a solvent constituting the remaining balance
of the polishing slurry composition, wherein the solvent comprises
water, all the weight % are based on the total weight of the
polishing slurry composition.
19. The polishing slurry composition of claim 14, wherein a number
of silanol groups on a surface of the abrasive and the content of
the aluminum component satisfy the requirement of the following
Equation 1: 0.0005.ltoreq.(S*C)*100.ltoreq.4.5, [Equation 1]
wherein, S is the number of the silanol groups present on 1
nm.sup.2 of the surface of the abrasive (unit: number/nm.sup.2),
and C is the content of the aluminum component (weight %) in the
polishing slurry composition.
20. The polishing slurry composition of claim 18, wherein a number
of silanol groups on a surface of the abrasive and the content of
the aluminum component satisfy the requirement of the following
Equation 1: 0.0005.ltoreq.(S*C)*100.ltoreq.4.5, [Equation 1]
wherein, S is the number of the silanol groups present on 1
nm.sup.2 of the surface of the abrasive (unit: number/nm.sup.2),
and C is the content of the aluminum component (weight %) in the
polishing slurry composition.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation-in-part application of
International Patent Application No. PCT/KR2017/005118, filed May
17, 2017, which claims the benefit of priority of Korean Patent
Application No. 10-2016-0061230, filed May 19, 2016, which are
hereby expressly incorporated by reference in their entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to a polishing slurry
composition, particularly to a chemical-mechanical polishing slurry
composition. The polishing slurry composition of the present
invention may prevent change such as pH of the slurry composition
over time under an acidic condition and thus may have good storage
property for a long time.
BACKGROUND OF THE INVENTION
[0003] A semiconductor chip to which an integrated circuit
technology is applied includes a number of functional elements such
as transistors, capacitors, resistors, and the like, and these
individual functional elements are connected to each other by a
wire patterned in a predetermined shape to form a circuit. The size
of the integrated semiconductor chip has been reduced and the
functionality thereof has been expanded over several generations.
In the related arts, as the size of the electrical elements has
been reduced, multilevel interconnection technologies of the
electrical elements have been actively studied and developed. For
example, for manufacturing the semiconductor device with the
multilevel interconnection, the planarization process of metal film
should be carried out. Generally, it is not easy to polish the
metal film because of the metal film having high strength,
therefore for effectively polishing the metal film, the metal film
is transformed to metal oxide which has relatively low strength and
then is polished. For example, when silica is used as an abrasive
in the slurry composition for polishing a metal film, the longer
the storage time of the slurry composition in an acidic condition,
the more changes such as an increase in particle size or pH over
time, which may lead to problems in its shelf life time.
SUMMARY OF THE INVENTION
[0004] Provided herein, inter alia, is a polishing slurry
composition, or a chemical-mechanical polishing slurry composition.
The polishing slurry composition may have a long-term storage
stability with a little change in chemical and/or physical
condition even in long-term storage, while maintaining excellent
polishing performance, in an acidic condition.
[0005] In one aspect, the present invention provides a polishing
slurry composition (or "chemical-mechanical slurry polishing
composition") that may include an abrasive; an amount of about
0.000006 to 0.01 weight % of an aluminum component based on the
total weight of the polishing slurry composition; and a solvent.
The solvent may suitably include water.
[0006] The abrasive may suitably include one or more selected from
the group consisting of fumed silica and colloidal silica. The
polishing slurry composition may suitably include the abrasive in
an amount of about 0.001 to 20 weight % based on the total weight
of the polishing slurry composition. Preferably, a number of
silanol groups on a surface of the abrasive may be from about 1 to
about 10/nm.sup.2.
[0007] The aluminum component may suitably include one or more
selected from the group consisting of an aluminum salt, an aluminum
atom and an aluminum ion. The aluminum component may be attached or
absorbed on the surface of the abrasive. The aluminum component may
further include one or more selected from the group consisting of
chloride (Cl), sulfate (SO.sub.4), ammonium (NH.sub.4), potassium
(K), hydroxide (OH), a methylate (CH.sub.3) and phosphorus (P).
Preferably, the number of the silanol groups on the surface of the
abrasive and the content of the aluminum component may satisfy the
requirement of the following Equation 1:
0.0005.ltoreq.(S*C)*100.ltoreq.4.5, [Equation 1]
[0008] wherein, S is the number of the silanol groups present on 1
nm.sup.2 of the surface of the abrasive (unit: number/nm.sup.2),
and C is the content of the aluminum component (weight %) in the
slurry composition.
[0009] The polishing slurry composition may further include an
amount of about 0.005 to 10 weight % of an oxidizing agent based on
the total weight of the polishing slurry composition. The polishing
slurry composition may further include an amount of about 0.0001 to
0.05 weight % of a biocide based on the total weight of the
polishing slurry composition. The polishing slurry composition may
further include an amount of about 0.00001 to 0.5 weight % of a
catalyst including nano ferrosilicon or iron salt compound based on
the total weight of the polishing slurry composition.
[0010] In an another aspect, provided is a polishing slurry
composition that may include an amount of about 0.001 to 20 weight
% of an abrasive; an amount of about 0.000006 to 0.01 weight % of
aluminum; an amount of about 0.00001 to 0.5 weight % of a catalyst
including nano ferrosilicon or iron salt compound; and a solvent
constituting the remaining balance of the polishing slurry
composition, all the weight % are based on the total weight of the
polishing slurry composition. Preferably, the solvent may include
water.
[0011] The polishing slurry composition may further include a pH
adjusting agent to adjust the pH to 1 to 6; and an amount of about
0.0001 to 0.05 weight % of a biocide based on the total weight of
the polishing slurry composition. Preferably, the pH adjusting
agent may suitably include one or more selected from the group
consisting of nitric acid, hydrochloric acid, sulfuric acid,
potassium hydroxide, sodium hydroxide, tetramethylammonium
hydroxide, and tetrabutylammonium hydroxide. The polishing slurry
composition may further include an amount of about 0.005 to 10
weight % of an oxidizing agent based on the total weight of the
polishing slurry composition. Preferably, the number of the silanol
groups on the surface of the abrasive and the content of the
aluminum component may satisfy the requirement of the above
Equation 1.
[0012] Further provided is a polishing slurry composition that may
include: an amount of about 0.001 to 20 weight % of an abrasive; an
amount of about 0.000006 to 0.01 weight % of an aluminum component;
an amount of about 0.00001 to 0.5 weight % of a catalyst including
nano ferrosilicon or iron salt compound; an amount of about 0.005
to 10 weight % of an oxidizing agent; and a solvent constituting
the remaining balance of the polishing slurry composition, all the
weight % are based on the total weight of the polishing slurry
composition. Preferably, the solvent may include water.
[0013] According to various aspects of the present invention, by
including the aluminum component, the slurry composition according
to the present invention may have superior stability having
improved shelf life time suitable for long time storage, and
increase of scratches or polishing rate change may be prevented
when using the polishing slurry composition. To the contrary, a
conventional slurry composition may have decreased polishing
performance and cause scratch and the polishing rate change due to
the pH increase in the acidic region during with a long time.
[0014] Other aspects of the invention are disclosed infra.
DETAILED DESCRIPTION OF THE INVENTION
[0015] The terminology used herein is for the purpose of describing
particular embodiments only and is not intended to be limiting. As
used herein, the singular forms "a," "an" and "the" are intended to
include the plural forms as well, unless the context clearly
indicates otherwise. It will be further understood that the terms
"comprise", "include", "have", etc. when used in this
specification, specify the presence of stated features, regions,
integers, steps, operations, elements and/or components but do not
preclude the presence or addition of one or more other features,
regions, integers, steps, operations, elements, components, and/or
combinations thereof.
[0016] Further, unless specifically stated or obvious from context,
as used herein, the term "about" is understood as within a range of
normal tolerance in the art, for example within 2 standard
deviations of the mean. "About" can be understood as within 10%,
9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, 0.05%, or 0.01% of
the stated value. Unless otherwise clear from the context, all
numerical values provided herein are modified by the term
"about."
[0017] Unless otherwise defined, all terms including technical and
scientific terms used herein have the same meaning as commonly
understood by one of ordinary skill in the art to which this
invention belongs. It will be further understood that terms, such
as those defined in commonly used dictionaries, should be
interpreted as having a meaning that is consistent with their
meaning in the context of the relevant art and the present
disclosure, and will not be interpreted in an idealized or overly
formal sense unless expressly so defined herein.
[0018] Hereinafter, the present invention will be described in
detail.
[0019] In an aspect of the present invention, provided is a
polishing slurry composition (or "chemical-mechanical polishing
slurry composition") that includes an abrasive, and an aluminum
component. In certain embodiments, the polishing slurry composition
may include an abrasive containing silanol groups on a surface
thereof, an aluminum component and a solvent. The slurry
composition may provide improvement in polishing speed and cause
less scratch formation. Additionally, the slurry composition may
also have substantially improved stability and thus, for example,
may be stored for a long period of time.
[0020] The "abrasive" as used herein refers to a material used for
treating, modifying or improving a surface of an object by means of
grinding, polishing, rubbing, sanding, finishing, or the like as
applying friction to the surface together with the material. The
abrasive, or the abrasive composition, may include modification or
functional chemical groups imparting chemical and/or physical
effects. For example, such modification may change or maintain
various acid/base properties in the abrasive composition. In
addition, the abrasive may include particles having suitable size
or shapes to improve grinding or surface treating efficiency.
Preferably, the abrasive may include particles having a diameter in
nanometer scale length, for example, less than about 900 nm, less
than about 800 nm, less than about 700 nm, less than about 600 nm,
less than about 500 nm, less than about 400 nm, less than about 300
nm, or less than about 200 nm.
[0021] In certain embodiments, the abrasive may be used for
polishing a film on an object, for example, an oxide film. The
abrasive may include a silica-based abrasive such as fumed silica,
colloidal silica, or a mixture thereof is used. The abrasive may be
a silica-based abrasive, as such the abrasive may suitably include
silanol groups (--SiOH, or --SiO.sup.-) on the surface. The
particle size of the abrasive may range of about 5 to 200 nm, or
particularly of about 10 to 150 nm. The content of the abrasive in
the polishing slurry composition may be of about 0.001 to 20 weight
%, of about 0.01 to 10 weight %, or particularly of about 0.1 to 5
weight %, based on the total weight of the polishing slurry
composition. When the particle size of the abrasive is less than
the predetermined range, for example, less than about 5 nm, or its
content is less than the predetermined amount, for example, less
than about 0.001 weight %, the polishing rate of the metal film may
be reduced. When the particle size of the abrasive is greater than
the predetermined range, for example, greater than about 200 nm, or
its content is greater than the predetermined amount, for example,
greater than about 20 weight %, scratches on the metal film and the
silicon oxide film may occur excessively.
[0022] The silanol group on the surface of the silica-based
abrasive, i.e. a Si--OH or Si--O.sup.- functional group, may affect
polishing rate of the abrasive. For instance, as the number of the
silanol groups is increased on the surface of the abrasive, the
polishing rate may be improved. When the abrasive has suitable
amount of silanol groups having chemical activity on the surface of
the abrasive, the abrasive may easily bond with the hydroxyl group
on the surface of the oxide film and the surface of the oxide film
may be easily removed by physical friction, so that the polishing
rate may increase. In addition, the more the silanol groups, the
lower the Si--O--Si condensation degree and the less the physical
friction, so the scratches may be reduced. On the other hand, when
the amount of silanol groups is excessively large on the surface of
the abrasive, the dispersion stability in the acidic condition may
be lowered and the pH may be changed during storage for a long
time. When a storage stability problem such as a pH change occurs,
even if the polishing performance such as a polishing rate is
excellent, the product quality may not be maintained for a long
period of time (e.g., for at least 3 to 6 months of storage life of
a conventional slurry product) and may be reduced the
merchantability.
[0023] The slurry composition may suitably include a silica-based
abrasive having the number of the silanol groups on the surface of
the abrasive of about 1 to 10 number/nm.sup.2, of about 1 to 8
number/nm.sup.2, or particularly of about 2 to 5 number/nm.sup.2,
thereby improving the polishing rate of the slurry composition and
suppressing the occurrence of scratches. When the number of the
silanol groups is less than about 1 number/nm.sup.2, the polishing
rate may be substantially reduced so that nonuniformity and
scratches are increased. When the number of the silanol groups is
greater than about 10 number/nm.sup.2, the synergistic effect of
the polishing rate may be reduced, and the activity of the surface
of the abrasive may increase substantially so that the dispersion
stability may be decreased, and aggregation and precipitation may
occur.
[0024] The aluminum component as used in the chemical-mechanical
polishing slurry composition of the present invention may be a pH
stabilizer, which suppresses changes in pH during long-term storage
of the slurry composition, thereby improving the stability of the
slurry composition. The aluminum component may suitably include one
or more aluminum salts (aluminum salt compounds). The aluminum
component may further include one or more of a halide ion such as
bromide (Br), chloride (Cl), or fluoride (F), a sulfate (SO.sub.4),
an ammonium (NH.sub.4), a metal ion such as sodium (Na), or
potassium (K), a hydroxide (OH), an alkyl group such as methyl
(CH.sub.3) or ethyl (CH.sub.2CH.sub.3), and a phosphorus (P). The
aluminum component may suitably include one or more of a chloride
(Cl), a sulfate (SO.sub.4), and a potassium (K). For example, the
aluminum component can include one or more selected from a group of
aluminum chloride (e.g., AlCl.sub.3), aluminum sulfate (e.g.,
Al.sub.2(SO.sub.4).sub.3), ammonium aluminum sulfate (e.g.,
(NH.sub.4)Al(SO.sub.4).sub.2), aluminum potassium sulfate (e.g.,
KAl(SO.sub.4).sub.2), aluminum hydroxide (e.g., Al(OH).sub.3),
trimethyl aluminum (e.g., C.sub.6H.sub.18Al.sub.2), and aluminum
phosphide (e.g., AlP). For example, the aluminum component may be
aluminum chloride, aluminum sulfate, ammonium aluminum sulfate,
aluminum potassium sulfate and mixture thereof; or aluminum
chloride, aluminum sulfate, aluminum potassium sulfate and mixture
thereof; or particularly aluminum chloride, aluminum sulfate and
mixture thereof. Further, the aluminum component may be present in
the slurry composition in the form of an aluminum salt and/or in
combination with an abrasive and/or an aluminum ion. The polishing
slurry composition of the present invention may include the
aluminum component, which may be present in one or more state
selected from the group consisting of an aluminum salt, an aluminum
atom adsorbed on the abrasive surface, and an aluminum ion (e.g.,
Al.sup.2+, or Al.sup.3+).
[0025] In certain embodiments, the chemical-mechanical polishing
slurry composition of the present invention may include the content
of the aluminum component in an amount of about 0.000006 to 0.01
weight %, or particularly of about 0.0001 to 0.005 weight %, based
on the total weight of the slurry composition. When the content of
aluminum component is less than the predetermined amount, for
example, less than about 0.000006 weight %, suppressing of the pH
change with time may not be sufficient. When the content of
aluminum component is greater than the predetermined amount, for
example, greater than about 0.01 weight %, the particle size may be
increased. For example, when the content of the aluminum component
in slurry is greater than about 0.01 weight % in the acidic
condition, the electric double layer is compressed regardless of
the number of the silanol groups on the surface of the silica to
cause aggregation of the abrasive and increase the particle size.
The higher the ion concentration or the larger the valence of the
ion, the more the electric double layer may be compressed to occur
the flocculation. Preferably, the pH may be effectively stabilized
without increasing the particle size just by adding the
predetermined amount of the aluminum component. In addition,
excessive use of aluminum component may be undesirable because it
may contaminate the semiconductor process.
[0026] According to an aspect of the present invention, in the
slurry composition of the present invention, when the number of the
silanol groups on the surface of the abrasive and the content of
the aluminum component satisfy the requirements of the following
Equation 1, the pH change during the long-term storage of the
slurry composition may be effectively suppressed and the slurry
composition may be stabilized.
0.0005.ltoreq.(S*C)*100.ltoreq.4.5, [Equation 1]
[0027] wherein, S is the number of the silanol groups present on 1
nm.sup.2 on the abrasive surface (unit: number/nm.sup.2), and C is
the content of the aluminum component (weight %) in the slurry
composition. The silanol group number may be measured by typically
used analysis methods in the related arts, for example, nuclear
magnetic resonance (NMR) analysis, thermogravimetric analysis
(TGA), Fourier transform infrared spectroscopy (FT-IR), titration
using NaOH and the like.
[0028] When the content of the aluminum component is greater than
the predetermined level, the more the number of the silanol
groups(S) on the surface of the abrasive is, the more the thickness
of the electric double layer may be compressed and then the
dispersibility may be substantially decreased. Therefore, depending
on the number of the silanol groups on the surface of the abrasive,
when the excessive amount of aluminum component is contained, the
dispersion stability may be deteriorated due to the increase in
particle size. That is, the pH stabilizing effect may be obtained
without increasing the particle size, by containing the
predetermined amount of the aluminum components satisfying the
requirements of Equation 1 depending on to the number of the
silanol groups on the surface of the abrasive. When the product of
the number of the silanol groups (S) on the surface of the abrasive
and the content of the aluminum component (C) ((S*C)*100) is
greater than 4.5, a pH stabilizing effect may be obtained, however,
the stability of the surface of the abrasive particles decreases
and the particle size increases. On the contrary, when the product
of the number of the silanol groups (S) on the surface of the
abrasive and the content of the aluminum component (C) ((S*C)*100)
is less than 0.0005, a pH stabilizing effect may not be
sufficiently obtained. That is, in order to obtain long-term
storage stability of the slurry composition, it is important that
the product ((S*C)*100) of the number of the silanol groups (S) and
the content of the aluminum component (C) is not greater than
4.5.
[0029] The remaining component constituting the chemical-mechanical
polishing slurry composition may be a solvent. The solvent may
suitably include a polar solvent such as water. Preferably, the
solvent may be water such as deionized water and distilled water.
The content of water may be of about 79.95 to 99 weight %, or
particularly, of about 89.95 to 99 weight % based on the total
weight of the slurry composition. The solvent (e.g., water) may
constitute the remaining balance of the slurry composition. For
example, when the composition of the present invention includes an
abrasive, an aluminum component and other additives used as needed,
the other component except for the abrasive, the aluminum component
and the additives is water. The pH of the chemical-mechanical
polishing slurry composition may be of about 1 to 6, or
particularly of about 1 to 4. When the pH of the slurry composition
is greater than the predetermined value, for example, greater than
about 6, an oxide film may not be sufficiently formed, and the
polishing rate may be decreased.
[0030] The chemical-mechanical polishing slurry composition
according to the present invention may further comprise a pH
adjusting agent and/or a biocide, if necessary. The biocide as used
herein refers to a material, which may be a natural or synthetic
material, used to prohibit growth of microorganism.
[0031] The pH adjusting agent as used herein may adjust the pH of
the slurry composition to about 1 to 6, or particularly to about 1
to 4, and any pH adjusting agent (acid, base) used in a
conventional slurry composition may be used without limitation. For
example, the pH adjusting agent may suitably include one or more
acids, for example, selected from the group consisting of nitric
acid, hydrochloric acid, and sulfuric acid, bases such as potassium
hydroxide, sodium hydroxide, tetramethylammonium hydroxide, and
tetrabutylammonium hydroxide, or particularly, tetramethylammonium
hydroxide, and tetrabutylammonium hydroxide. The content of the pH
adjusting agent may be of about 0.0005 to 5 weight %, or
particularly of about 0.001 to 1 weight % based on the total weight
of the slurry composition. When the content of the pH adjusting
agent is out of the above range, the pH of the slurry composition
may become difficult to control, and the pH adjusting agent may act
as a metal impurity to cause wafer contamination and defects.
[0032] The biocide as used herein may prevent the
chemical-mechanical polishing slurry composition from being
contaminated by microorganisms such as bacteria and fungi, and a
commonly used product may be used. Preferably, the biocide may
suitably include isothiazolinone or a derivative thereof.
Non-limiting examples of the biocide may include one or more
selected from the group consisting of methyl isothiazolinone (MIT,
MI), chloromethyl isothiazolinone (CMIT, CMI, MCI),
benzisothiazolinone (BIT), octylisothiazolinone (OIT, OI),
dichlorooctylisothiazolinone (DCOIT, DCOI), and
butylbenzisothiazolinone (BBIT). The content of the biocide may be
of about 0.0001 to 0.05 weight %, or particularly of about 0.001 to
0.01 weight % by weight, based on the total weight of the slurry
composition. When the content of the biocide is less than the
predetermined amount, for example, less than about 0.0001 weight %,
the effect of inhibiting microorganisms may not be sufficient, and
when the content of the biocide is greater than about 0.05 weight
%, the dispersibility of the slurry composition may be
deteriorated.
[0033] The slurry composition according to the present invention
can be used for polishing a metal film and an insulating film
(e.g., oxide film such as SiO.sub.2). Further, the slurry
composition may include an oxidizing agent when the object to be
polished is a metal film such as tungsten (W), aluminum (Al),
copper (Cu) and the like. The oxidizing agent as used herein may
rapidly form an oxide film on the surface of the metal film to
facilitate the polishing of the metal film, and a conventional
oxidizing agents used in the slurry composition for
chemical-mechanical polishing may be used without limitation. The
oxidizing agent may suitably include one or more selected from
hydrogen peroxide and potassium iodate. The oxidizing agent may
oxidize a metal film such as a wafer, a substrate, or the like to a
corresponding oxide. The content of the oxidizing agent may be of
about 0.005 to 10 weight %, or particularly of about 0.2 to 5
weight %, based on the total weight of the slurry composition. When
the content of the oxidizing agent is less than about the
predetermined amount, for example, less than about 0.005 weight %,
the polishing rate of the metal film may be decreased, and when is
content is greater than about the predetermined amount, for
example, greater than about 20 weight %, the polishing efficiency
may be decreased.
[0034] For example, when the object to be polished is a tungsten
metal film, the slurry composition may further include a catalyst.
As the catalyst, a catalyst commonly used in a slurry composition
for chemical-mechanical polishing may be used without limitation.
The catalyst may suitably include nano ferrosilicon (e.g., FeSi
particles having a size in nanoscale), iron salt compounds (e.g.,
iron nitrate, iron chloride, iron sulfate, iron acetate, and the
like) and the like. The content of the catalyst may be of about
0.00001 to 0.5 weight %, or particularly of about 0.001 to 0.05
weight %, based on the total weight of the slurry composition. When
the content of the catalyst is less than the predetermined amount,
for example, less than about 0.00001 weight %, the polishing rate
of the metal film may be decreased. When its content is greater
than about 0.5 weight %, the reactivity may increase excessively,
and the polishing rate may become uneven.
[0035] In certain embodiments, the chemical-mechanical polishing
slurry may include an amount of about 0.001 to 20 weight % of
abrasive, an amount of about 0.000006 to 0.01 weight % of aluminum
and the remaining balance of water, based on the total weight of
the slurry composition. The chemical-mechanical polishing slurry
may be suitably prepared by mixing and stirring, however the
methods thereof are not limited thereto. Further, if necessary, the
chemical-mechanical polishing slurry composition may further
include an amount of about 0.0005 to 5 weight % of a pH adjusting
agent, an amount of about 0.0001 to 0.05 weight % of a biocide, an
amount of about 0.005 to 10 weight % of an oxidizing agent and an
amount of about 0.00001 to 0.5 weight % of a catalyst, based on the
total weight of the polishing slurry composition.
EXAMPLE
[0036] Hereinafter, the present invention will be described in more
detail with reference to Examples, but the present invention is not
limited by the following Examples.
Examples 1-11 and Comparative Examples 1-4: Manufacturing Slurry
Composition
[0037] Components shown in following Table 1 were mixed at room
temperature and stirred with a mechanical stirrer to prepare the
slurry compositions (Examples 1 to 11, Comparative Examples 1 to
4).
TABLE-US-00001 TABLE 1 pH stabilizer Aluminum Abrasive component
Catalyst content content content content Silica (weight %) Kind
(weight %) (weight %) kind (weight %) pH Example 1 Colloidal 5
Aluminum 0.0001 0.000006 -- -- 3 silica chloride Example 2
Colloidal 5 Aluminum 0.01 0.002 -- -- 3 silica chloride Example 3
Colloidal 5 Aluminum 0.05 0.01 -- -- 3 silica chloride Example 4
Colloidal 5 Aluminum 0.01 0.0016 -- -- 3 silica sulfate Example 5
Colloidal 5 Aluminum 0.01 0.0006 -- -- 3 silica potassium sulfate
Example 6 Colloidal 5 Ammonium 0.01 0.001 -- -- 3 silica aluminum
sulfate Example 7 Fumed 5 Aluminum 0.01 0.002 Nano ferro 0.003 3
silica chloride silicon Example 8 Fumed 5 Aluminum 0.01 0.0006 Nano
ferro 0.003 3 silica potassium silicon sulfate Example 9 Fumed 5
Ammonium 0.02 0.002 Iron nitrate 0.015 3 silica aluminum sulfate
Example 10 Fumed 5 Ammonium 0.02 0.002 Iron sulfate 0.015 3 silica
aluminum sulfate Example 11 Fumed 5 Ammonium 0.02 0.002 Ferric
0.015 3 silica aluminum chloride sulfate Comparative Colloidal 5 --
-- -- -- -- 3 Example 1 silica Comparative Fumed 5 -- -- -- Nano
ferro 0.003 3 Example 2 silica silicon Comparative Colloidal 5
Aluminum 0.00002 0.000004 -- -- 3 Example 3 silica chloride
Comparative Colloidal 5 Aluminum 0.08 0.016 -- -- 3 Example 4
silica chloride
Experimental Example 1: Identifying Change of Slurry Composition
Over Time
[0038] The slurry compositions prepared in Examples 1 to 11 and
Comparative Examples 1 to 4 were stored at room temperature for 6
months, and then changes in pH and particle size with time were
measured using a pH analyzer (Metrohm 704, Metrohm) and a particle
size analyzer (ELS-Z, Otsuka Electronics). The change with time of
pH is shown in the following Table 2, and the change with time
(unit: nm) of the particle size is shown in Table 3 below.
TABLE-US-00002 TABLE 2 Storage 0.sup.th 15.sup.th 30.sup.th
60.sup.th 120.sup.th 150.sup.th 180.sup.th No. temperature day day
day day day day day Example 1 Room 2.99 3.01 3.05 3.07 3.07 3.08
3.07 temperature Example 2 Room 3.02 3 2.99 3.01 3 3 3.01
temperature Example 3 Room 3 2.98 3.01 3 2.99 3.01 3.00 temperature
Example 4 Room 3.03 3 3.02 3.01 3.03 3 3.02 temperature Example 5
Room 2.98 3.01 3 3.02 2.99 3.01 3.01 temperature Example 6 Room
3.02 2.99 3 3.01 3.03 3 2.99 temperature Example 7 Room 3.01 3 2.99
3.01 3.02 3 3.01 temperature Example 8 Room 3 3.01 3 3 3.01 3.02
3.02 temperature Example 9 Room 3 3 2.99 3.01 3.03 3.02 3.03
temperature Example 10 Room 2.99 2.98 3 3.01 3 3.02 3.02
temperature Example 11 Room 3 3.01 3 3.02 3.01 3.01 3.03
temperature Comparative Room 3.01 3.12 3.15 3.21 3.32 3.57 3.78
Example 1 temperature Comparative Room 3 3.1 3.13 3.17 3.21 3.33
3.34 Example 2 temperature Comparative Room 3.01 3.07 3.12 3.13
3.16 3.18 3.22 Example 3 temperature Comparative Room 3.01 3.01 3
3.02 3 3.03 3.02 Example 4 temperature
TABLE-US-00003 TABLE 3 Storage 0.sup.th 15.sup.th 30.sup.th
60.sup.th 120.sup.th 150.sup.th 180.sup.th No. temperature day day
day day day day day Example 1 Room 89 90 90 89 91 91 91 temperature
Example 2 Room 91 89 91 88 90 92 91 temperature Example 3 Room 90
91 90 90 89 92 92 temperature Example 4 Room 90 89 90 90 91 90 91
temperature Example 5 Room 88 90 89 89 90 91 92 temperature Example
6 Room 91 91 90 91 90 90 91 temperature Example 7 Room 109 110 110
109 111 110 111 temperature Example 8 Room 111 110 111 109 111 111
110 temperature Example 9 Room 110 109 110 110 110 111 110
temperature Example 10 Room 110 110 111 110 109 110 111 temperature
Example 11 Room 109 110 111 110 110 111 113 temperature Comparative
Room 90 90 90 93 93 96 101 Example 1 temperature Comparative Room
110 109 109 112 113 113 115 Example 2 temperature Comparative Room
90 89 89 92 91 93 94 Example 3 temperature Comparative Room 91 107
120 141 185 225 260 Example 4 temperature
[0039] As shown in Table 2, as Comparative Example 3 included an
amount of 0.000004 weight % of the aluminum component, the change
in pH over time was reduced as compared with Comparative Example 1,
but the effect thereof was insufficient. On the other hand, as
shows in in Examples 1 to 11 and Comparative Example 4 in which the
aluminum component content was 0.000006 weight % or greater, there
was almost no change in pH over time compared to Comparative
Examples 1 to 3. In addition, as shown in Table 3, as Comparative
Example 3 included an amount of 0.000004 weight % of the aluminum
component, the particle size was hardly changed but the effect of
suppressing the pH change was insufficient. Further as Examples 1
to 11 included an amount of about 0.000006 to 0.01 weight % of the
aluminum component, the particle size hardly changed over time
compared with Comparative Examples 1 and 2. However, when the
aluminum component content was 0.01 weight % or greater, the
particle size was rather increased as compared with Comparative
Example 1, as in Comparative Example 4. Therefore, change of pH in
the slurry composition with time was prevented by using an
appropriate amount of the aluminum component.
Experimental Example 2: Measuring Polishing Rate
[0040] Tungsten (W) film of 8 inches and insulating layer (PE-TEOS)
of 8 inches (blanket wafer) were loaded on Mirra 3400 of polisher
(Applied Materials, Inc.) on which IC-1010 of polishing pad (Rohm
& Haas Co. Ltd.) was mounted. Next, the tungsten film and the
insulating layer were polished for 60 seconds while supplying the
slurry compositions of the Examples 1 to 8 and the Comparative
Examples 1 to 4 to the wafer. In Examples 7 and 8 and Comparative
Example 2, 2 wt % of hydrogen peroxide was further mixed before the
slurry composition was injected. The polishing conditions were
listed on following Table 4. The hydrogen peroxide was mixed prior
to polishing, since hydrogen peroxide decomposes when used as an
oxidizing agent after mixing with the slurry composition. In the
following Table 4, IC pressure, RR pressure, EC pressure, UC
pressure each represents respectively Inter Chamber Pressure,
Retainer Ring Pressure, External Chamber Pressure, Upper Chamber
Pressure, which shows pressure condition in respective part of head
on which the wafer was mounted.
TABLE-US-00004 TABLE 4 Platen Head IC RR EC UC Slurry flow rate
rate pressure pressure pressure pressure rate 84 rpm 78 rpm 3.6 psi
10.4 psi 5.2 psi 5.2 psi 200 ml/min
[0041] Removal rate of tungsten film and insulating layer
(Angstrom(A)/min, hereinafter, referred to as R/R) was measured by
using a resistance measuring instrument (CMT-2000, 4-point probe,
Chang-min Tech Co., Ltd./Thermawave OP-2600, KLA TENCOR), and the
result thereof was shown in following Table 5 (SiO.sub.2 polishing
rate) and Table 6 (tungsten(W) polishing rate). Here, the polishing
rate was calculated by using "polishing rate=thickness before
CMP-thickness after CMP".
TABLE-US-00005 TABLE 5 SiO.sub.2 polishing rate (.ANG./min) Example
1 1,002 Example 2 1,006 Example 3 995 Example 4 1,031 Example 5
1,017 Example 6 1,023 Comparative Example 1 1,020 Comparative
Example 3 1,048 Comparative Example 4 969
TABLE-US-00006 TABLE 6 Tungsten polishing rate (.ANG./min) Example
7 3,300 Example 8 3,197 Comparative Example 2 3,250
[0042] As shown in Tables 5 and 6, it can be seen that when the
content of aluminum chloride was increased, the SiO.sub.2 polishing
rate was not influenced, and as shown in the Examples 7 and 8, that
the application of each 0.01 weight % of aluminum chloride,
aluminum potassium sulfate did not affect the polishing rate of
tungsten compared to Comparative Example 2.
Reference Examples 1 to 10: Measuring Scratch Inhibiting Effect of
Slurry Composition According to Number of Silanol Groups
[0043] A slurry composition was prepared including colloidal silica
5 weight % having the number of the silanol groups as shown in
Table 7 below, a pH adjusting agent (nitric acid or
tetramethylammonium hydroxide) to adjust the pH to 2.5 and the
remaining distilled water. The measurement of the number of the
silanol groups (p[number/nm.sup.2]) was carried out as follows
using titration. First, an appropriate amount (100 ml or less) of
the solution was prepared so that the total area of silica is 90
m.sup.2, and then a titration sample (X [ml]) was prepared. Next,
the pH of the slurry composition was adjusted to 3 using 0.1 M
HNO.sub.3 aqueous solution and stabilized sufficiently until the pH
change amount became 0.01 or less. Thereafter, the pH was titrated
to 10 with a 0.1 M NaOH aqueous solution at a rate of 0.5 mV/min or
less. The required amount of 0.1M NaOH (Y [mol]) for areas without
change in the number of H.sup.+ and OH.sup.- moles of the titrant
solution was determined. The required amount(Y) was divided by the
initial amount (X [ml]) of the titration sample to obtain
[OH.sup.-] (B [mol/L]) which was adsorbed on the silica particles
(B=Y/X). From the following Equation (2), the silanol group density
of the silica particles was calculated.
.rho. = ( B N A ) ( S BET Cp 10 18 ) [ Equation 2 ]
##EQU00001##
Wherein, N.sub.A[number/mol] represents Avogadro's number,
S.sub.BET[m.sup.2/g] represents specific surface area of silica
particles and Cp[g/L] represents concentration of silica
particles.
[0044] After polishing an insulating film (PE-TEOS) blanket wafer
for 60 seconds by using the slurry composition prepared, the number
of scratches formed on the wafer was measured using a Negevtech
defect inspection equipment. The polishing rate of the SiO.sub.2
insulating film of the slurry composition and the amount of pH
change before and after storage for 30 days at room temperature
were measured and are shown in Table 7 together.
TABLE-US-00007 TABLE 7 SiO.sub.2 Silica Number of polishing pH
content Silanol rate Scratch 0.sup.th 30.sup.th Change (weight %)
pH (number/nm.sup.2) (.ANG./min) (number) day day amount Reference
5 2.5 0.5 525 48 2.51 2.63 0.12 Example 1 Reference 5 2.5 0.8 536
52 2.5 2.61 0.11 Example 2 Reference 5 2.5 1.2 794 35 2.5 2.59 0.09
Example 3 Reference 5 2.5 1.6 812 37 2.5 2.62 0.12 Example 4
Reference 5 2.5 2.3 885 18 2.51 2.65 0.14 Example 5 Reference 5 2.5
3.8 1,002 20 2.49 2.67 0.18 Example 6 Reference 5 2.5 4.9 1,227 15
2.5 2.75 0.25 Example 7 Reference 5 2.5 9.7 1,374 7 2.5 2.88 0.38
Example 8 Reference 5 2.5 10.9 1,311 9 2.51 4.25 1.74 Example 9
Reference 5 2.5 11.8 1,297 10 2.5 3.99 1.49 Example 10
[0045] As shown in Table 7, as the number of the silanol groups
increased on the surface of the silica, the polishing rate of the
oxide increased while the scratch decreases. In addition, as the
number of the silanol groups on the abrasive surface increased, pH
was increased during storage at room temperature, and especially,
when the number of the silanol groups was more than 10/nm.sup.2,
the change amount in pH rapidly increased.
Examples 12-23, Comparative Examples 5-10: Long-Term Storage
Stability Measurement of Slurry Composition Depending on Number of
Silanol Groups and Aluminum Component Content
[0046] The slurry composition was prepared comprising 5 weight % of
colloidal silica having the number of the silanol groups as shown
in Table 8 below, various contents of aluminum sulfate, a pH
adjusting agent (nitric acid or tetramethylammonium hydroxide) to
adjust the pH to 2.5, and the remaining distilled water. The pH
change amount and the particle size change amount of the slurry
composition thus prepared were measured and shown in Table 9.
TABLE-US-00008 TABLE 8 Aluminum Aluminum Silica Number of sulfate
component content Silanol content content (weight %) pH
(number/nm.sup.2) (weight %) (weight %) (S*C)*100 Comparative 5 2.5
3.8 0 0 0 Example 5 Comparative 5 2.5 0.5 0.000032 0.000005 0.0003
Example 6 Comparative 5 2.5 0.5 0.000044 0.000007 0.0004 Example 7
Example 12 5 2.5 0.5 0.000063 0.00001 0.0005 Example 13 5 2.5 0.8
0.000038 0.000006 0.0005 Comparative 5 2.5 1.2 0.000019 0.000003
0.0004 Example 8 Example 14 5 2.5 1.2 0.00032 0.00005 0.006 Example
15 5 2.5 1.2 0.019 0.003 0.36 Example 16 5 2.5 1.6 0.019 0.003 0.48
Example 17 5 2.5 2.3 0.00004 0.000006 0.0014 Example 18 5 2.5 2.3
0.038 0.006 1.4 Example 19 5 2.5 3.8 0.025 0.004 1.5 Comparative 5
2.5 3.8 0.10 0.015 5.7 Example 9 Example 20 5 2.5 4.9 0.0013 0.0002
0.098 Example 21 5 2.5 4.9 0.057 0.009 4.41 Comparative 5 2.5 4.9
0.076 0.012 5.9 Example 10 Example 22 5 2.5 9.7 0.019 0.003 2.9
Example 23 5 2.5 9.7 0.044 0.007 6.8
TABLE-US-00009 TABLE 9 pH Particle size 0.sup.th 90.sup.th
180.sup.th 0.sup.th 90.sup.th 180.sup.th Change (S*C)*100 day day
day Change day day day amount Comparative 0 2.49 3.81 4.56 2.07 89
90 90 1 Example 5 Comparative 0.0003 2.50 2.73 3.55 1.05 89 89 89 0
Example 6 Comparative 0.0004 2.51 2.77 3.33 0.82 90 91 90 0 Example
7 Example 12 0.0005 2.50 2.52 2.54 0.04 89 90 90 1 Example 13
0.0005 2.50 2.50 2.56 0.06 90 90 90 0 Comparative 0.0004 2.51 3.74
4.02 1.51 90 89 91 1 Example 8 Example 14 0.006 2.51 2.50 2.53 0.02
91 91 92 1 Example 15 0.36 2.50 2.52 2.56 0.06 90 91 90 0 Example
16 0.48 2.50 2.51 2.57 0.07 90 91 91 1 Example 17 0.0014 2.49 2.52
2.58 0.09 89 90 91 2 Example 18 1.4 2.50 2.51 2.52 0.02 90 91 91 1
Example 19 1.5 2.50 2.50 2.51 0.01 90 89 91 1 Comparative 5.7 2.50
2.51 2.53 0.03 90 193 521 431 Example 9 Example 22 0.098 2.51 2.52
2.56 0.05 90 89 90 0 Example 21 4.41 2.51 2.50 2.50 0.01 91 91 91 0
Comparative 5.9 2.49 2.51 2.51 0.02 89 130 205 116 Example 10
Example 22 2.9 2.50 2.51 2.51 0.01 90 90 91 1 Example 23 6.8 2.50
2.49 2.52 0.02 90 121 158 68
[0047] As shown in Table 9, when the product of the number of the
silanol groups on the silica surface in the slurry and the content
of the aluminum component satisfied the condition of
0.0005.ltoreq.(S*C)*100.ltoreq.4.5, stabilization of the pH for a
long period at room temperature was established more efficiently.
As in Comparative Examples 9 and 10, when (S*C)*100 exceeded 4.5,
the pH was stabilized while the particle size increased sharply. As
in Comparative Examples 5 to 8, when the (S*C)*100 was less than
0.0005, the pH stabilizing effect was poor.
[0048] Therefore, the aforementioned embodiments are merely
illustrative but are construed as limiting the present invention.
The scope of the present invention is represented by the claims
below rather than the detailed description, and the meaning and
scope of the claims and all modifications or variations derived
from equivalents thereof are intended to be incorporated within the
scope of the present invention.
* * * * *