Title of Invention

CHEMICAL MECHANICAL POLISHING COMPOSITION

Abstract A chemical mechanical polishing composition has a pH value between 2 and 5, and comprises a mixture having following components : an aqueous medium, a abrasive, a corrosion inhibitor, a surfactant, a diacid compound, and a metal residue inhibitor. The metal residue inhibitor is selected from the group consisting of compounds represented by the following chemical formulas: (I), (II), (III), (IV), (V) and combinations thereof, wherein the structures of formulas (II) to (V) and the definition of each substituent group are as defined in the specification and claims. When the chemical mechanical polishing composition of the present invention is used to polish a surface of a semiconductor wafer, a good metal polishing rate can be obtained, metal dishing can be efficiently reduced, and metal residue on the wafer surface can be reduced.
Full Text CHEMICAL MECHANICAL POLISHING COMPOSITION
This application claims priority of Taiwanese
application no. 095108960, filed on March 16, 2006.
This invention relates to a chemical mechanical
polishing composition, more particularly to a chemical
mechanical polishing composition that can prevent
undesired metal residue and dishing effect on a wafer
surface.
Chemical mechanical polishing is a technique for
removing defects on a wafer surface so as to achieve
planarity of the surface, thereby eliminating focusing
problems during photolithography process. The chemical
mechanical polishing technique was originally used in
manufacturing micro devices having a size less than 0.5
micron. However, with the current trend of minimization
of devices, chemical mechanical polishing technique has
been widely employed in the industry.
In the process for manufacturing an integrated circuit,
a polishing process is employed to planarize an interlayer
(e.g., silicon oxide and silicon nitride), and a metal
wire used to connect active devices. The method for
polishing a metal wire, e.g., tungsten, copper, aluminum,
etc., includes the steps of disposing a semiconductor wafer
on a polishing stage provided with a polishing head, and
applying an abrasive particle-containing slurry to a
surface of the semiconductor wafer so as to improve
polishing efficiency. Two mechanisms can be chosen for

polishing the metal wire using the slurry composition.
In the first mechanism, components in the slurry
composition react with the metal wire to continuously form
an oxide layer on the metal surface, and the abrasive
particles in the slurry composition act to polish and to
remove the oxide layer. An oxidizing agent is generally
required in the first mechanism. In the second mechanism,
no protective oxide layer is formed. Instead, the
components in the slurry composition attack and dissolve
the metal, and the mechanical action of the abrasive
particles enhances the dissolution rate so as to reduce
the thickness of the metal wire. Because of the uneven
polishing problem in the CMP process, undesired dishing
effect and undesired metal residue on the wafer surface
tend to take place.
Since the components of the slurry composition for
CMPprocess have great effect on the polishing rate, dishing
degree, and metal residue on the wafer surface, there is
a need in the art to provide a composition that can eliminate
the problems of metal dishing and metal residue while
maintaining desired polishing rate.
Therefore, the object of the present invention is to
provide a chemical mechanical polishing composition that
can overcome at least one of the aforesaid drawbacks of
the prior art.
According to this invention, a chemical mechanical
polishing composition comprises: an abrasive component,

a corrosion inhibitor, a surfactant, a diacid compound,
a metal residue inhibitor, and water, the metal residue
inhibitor being selected from the group consisting of
compounds having the following formulas:

wherein R1, R2, R3, and R4 are independently selected
from the group consisting of: H, C1-C6 alkyl, C2-C6 alkenyl,
and C2-C6 alkylidyne; and R5, R6, R7, R8, R9, and R10 are
independently selected from the group consisting of: H
and C1-C6 alkyl.
The preferred embodiment of a chemical mechanical
polishing composition according to the present invention
includes an abrasive component, a corrosion inhibitor,
a surfactant, a diacid compound, a metal residue inhibitor,
and water. The metal residue inhibitor is selected from
the group consisting of compounds having the following
formulas:


wherein R1, R2, R3, and R4 are independently selected
from the group consisting of: H, C1-C6 alkyl, C2-C6 alkenyl,
and C2-C6 alkylidyne; and R5, R6, R7, R8, R9, and R10 are
independently selected from the group consisting of: H
and C1-C6 alkyl.
The abrasive component is present in an amount ranging
from 0.10 to 25.00wt%, the corrosion inhibitor is present
in an amount ranging from 0.01 to 1.00 wt%, the surfactant
is present in an amount ranging from 0.01 to 1.00 wt%,
the diacid compound is present in an amount ranging from
0.01 to 1.00 wt%, the metal residue inhibitor is present
in an amount ranging from 0 . 01 to 1. 00 wt%, and the remainder
is water.
Preferably, when the metal residue inhibitor is
selected from the group consisting of compound (I),
compound (II), compound (III), and compound (IV), the
content of each of the components is as follows : the abrasive
component is 0.50 to 10.00 wt%, the corrosion inhibitor

is 0.01 to 0.50 wt%, the surfactant is 0.01 to 0.50 wt%,
the diacid compound is 0.05 to 1.00 wt%, the metal residue
inhibitor is 0.01 to 0.50 wt%, and the remainder is water.
More preferably, the abrasive component is 0.50 to 5.00
wt%, the corrosion inhibitor is 0.01 to 0.20 wt%, the
surfactant is 0.01 to 0.30 wt%, the diacid compound is
0.10 to 1.00 wt%, the metal residue inhibitor is 0.01 to
0.30 wt%, and the remainder is water. In particular, when
the metal residue inhibitor is compound (I), the content
thereof ranges from 0.01 to 0.10 wt%.
Alternatively, when the metal residue inhibitor is
compound (V), the content of each of the components is
as follows: the abrasive component is 0.50 to 10.00 wt%,
the corrosion inhibitor is 0 . 01 to 0 . 50 wt%, the surfactant
is 0.01 to 0.50 wt%, the diacid compound is 0.05 to 1.00
wt%, the metal residue inhibitor is 0.05 to 1.00 wt%, and
the remainder is water. More preferably, the abrasive
component is 0.50 to 5.00 wt%, the corrosion inhibitor
is 0.01 to 0.20 wt%, the surfactant is 0.01 to 0.30 wt%,
the diacid compound is 0.10 to 1.00 wt%, the metal residue
inhibitor is 0.05 to 0.50 wt%, and the remainder is water.
It should be noted herein that the polishing rate can
be enhanced by increasing the amount of the diacid compound
if it is below 3000 A/min. The amount of the surfactant
can be increased to reduce the dishing degree, and the
amount of the metal residue inhibitor can be increased
to alleviate the metal residue problem.

Preferably, the composition has a pH value ranging
from 2 to 5, and more preferably, from 3 to 4.
Preferably, compound (II) is selected from the group
consisting of 2,2-dimethylsuccinic acid,
2-ethyl-2-methylsuccinic acid, 2,3-dimethylsuccinic
acid, and methylenesuccinic acid.
Compound (III) can be cis or trans. Preferably,
compound (III) is selected from the group consisting of
maleic acid, 2-methyl maleic acid, furmaric acid, and
2-methyl furmaric acid.
Preferably, compound (IV) is selected from the group
consisting of 2-hydroxy acetic acid, 2-methyl-2-hydroxy
acetic acid, 2-ethyl-2-hydroxy acetic acid,
2,2-diethyl-2-hydroxy acetic acid, and
2-ethyl-2-methyl-2-hydroxy acetic acid.
Preferably, compound (V) is selected from the group
consisting of acrylic acid, 2-methyl acrylic acid, 2-ethyl
acrylic acid, 3-methyl acrylic acid, and 2,3-dimethyl
acrylic acid.
The surfactant suitable for use in this invention
varies based on actual requirements. Preferably, the
surfactant is anionic type or nonionic type.
The abrasive component is a commercially available
product and varies based on actual requirements.
Preferably, the abrasive component is selected from the
group consisting of: SiO2, Al2O3, ZrO2, CeO2, SiC, TiO2,
Si3N4, and combinations thereof. Moreover, the particle

size varies based on actual requirements. Preferably, the
particle size ranges from 15 nm to 30 nm.
The corrosion inhibitor can be any commercially
available product that has been used in the semiconductor
field and that has corrosion inhibiting effect. Preferably,
the corrosion inhibitor is selected from the group
consisting of benzotriazole,
1,3,5-triazine-2,4,6,-triol, 1,2,3-triazole,
3-amino-1,2,4-triazole, . 3-nitro-l,2,4-triazole,
4-amino-3-hydrazino-l,2,4-triazole-5-thiol,
benzotriazole-5-carboxylic acid,
3-amino-1,2,4-triazole-5-carboxylic acid, 1-hydroxy
benzotriazole, nitrobenzotriazole, and combinations
thereof.
The diacid compound can be linear or branched.
Preferably, the diacid compound is selected from the group
consisting of: succinic acid, adipic acid, glutaric acid,
and combinations thereof.
The water used in this invention is preferably
deionized water.
The method for making the chemical mechanical
polishing composition includes the steps of mixing the
abrasive component, the surfactant, the corrosion
inhibitor, the diacid compound, the metal residue
inhibitor, and deionized water; and adjusting the pH value
of the mixture to a range within 2 and 5, preferably within
3 and 4, using a suitable acid or base. The suitable acid

or base is not limited. Preferably, the acid is hydrogen
chloride or nitric acid. The base can be ammonia or
tetramethylammonium hydroxide (TMAH).
Preferably, the CMP composition further includes an
oxidizing agent selected from the group consisting of
hydrogen peroxide, ferric nitrate, potassium iodate,
acetic hydroperoxide, and potassium permanganate. The
weight ratio of the oxidizing agent to the mixture of the
abrasive component, the corrosion inhibitor, the
surfactant, the diacid compound, the metal residue
inhibitor, and deionized water ranges from 1:9 to 1:30.
Preferably, the chemical mechanical polishing
composition further includes formic acid so as to increase
the polishing rate and to reduce the dishing effect on
the wafer surface . The amount of formic acid can be adjusted
according to actual requirements, and preferably ranges
from 0.01 to 1.00 wt%.
Examples
The following metal residue inhibitor compounds,
1,2,3,4-butanetetracarboxylic acid (which is hereinafter
referred as compound (I)), methylenesuccinic acid,
furmaric acid, 2-hydroxy acetic acid, and acrylic acid
(which are available from Aldrich Company) , were used for
preparing CMP compositions of Examples 1 to 9. Each of
the compounds was mixed with 2.00 wt% of colloidal silica,
0.05 wt% of benzotriazole, 0.4 wt% of adipic acid, 0.2
wt% anionic surfactant, optional formic acid, and water

so as to obtain a mixture. Hydrogen peroxide was mixed
into each of the mixtures at the weight ratio of 1:11,
followed by adjusting the pH value to range from 3 to 4
so as to form the CMP compositions of Examples 1 to 9.
The type and amount of the metal residue inhibitor and
the diacid compound, and the amount of formic acid used
in Examples 1 to 9 are shown in Table 1.
The CMP compositions of the comparative examples 1
to 4 were prepared by mixing 2.00 wt% of colloidal silica
with 0.05 wt% of benzotriazole, the diacid compound (0.4
wt% of adipic acid, a mixture 0.4 wt% of adipic acid and
0.1 wt% of glutaric acid, and a mixture of 0.4 wt% of adipic
acid and 0.2 wt% of glutaric acid were used for the
comparative examples 1 to 4) , 0.2 wt% anionic surfactant,
optional formic acid, and water. In the comparative
examples, there is no metal residue inhibitor.
The compositions in Examples 1 to 9 of this invention
and the compositions in the comparative examples 1 to 4
were used to polish a wafer having a copper metal layer
(made by Sematech Company, 0.18 µm line width) on a
polishing device (AMAT/Mirra, made by Applied Material,
INC. ) under conditions ofl.0tol.5psi membrane pressure,
1.8 psi retaining ring pressure, 70 rpm platen speed, 74
rpm carrier speed, 25 °C , and 200 mL/min slurry flow rate.
The polishing stage used in the examples is CUP 4410. The
polishing time was determined by End Point System
incorporated in the polishing device . After the polishing,

a further 20 % over-polishing was conducted. Wafer cleaning
using a cleaning device (Evergreen Model 10X, made by Solid
State Equipment Corp. ) , and nitrogen drying were conducted
subsequently.
The polishing rate was determined by the removed
thickness of the copper metal per minute. The removed
thickness of the copper metal was measured by KLA-Tencor
RS-75 made by KLA-TENCOR Company.
The dishing degree was determined by a Surface Profiler
(KLA-Tencor P-11, made by KLA-TENCOR Company) to measure
the dishing between a barrier layer and a copper line having
100 µm line width which is used as a measuring reference.
The metal residue was observed by naked eye.



It is noted from Table 1 that, in Examples 1 to 9 of
this invention, no metal residue was observed on the wafer
surface, the dishing degree was below 700 A, and the
polishing rate was kept above 4800 A/min. However, the
metal residue was observed in each comparative example.
In addition, it is noted from Examples 1 and 2, 3 and 4,
and 6 and 7, an increased amount of compound (I), a
combination of Compound (I) and methylenesuccinic acid,
and a combination of Compound (I) and 2-hydroxy acetic
acid also improve the polishing rate. Moreover, comparing
Example 9 with comparative example 1, addition of formic
acid improves polishing rate and reduces dishing degree
and metal residue phenomena.
With the inclusion of the metal residue inhibitor,
the surfactant, the corrosion inhibitor, and the diacid
compound in the CMP composition of this invention, the
CMP composition can not only reduce the dishing and metal
residue phenomena but also maintain the polishing rate
above 4 8 00 A/min.
While the present invention has been described in
connection with what is considered the most practical and
preferred embodiments, it is understood that this
invention is not limited to the disclosed embodiments but
is intended to cover various arrangements included within
the spirit and scope of the broadest interpretation and
equivalent arrangements.

WE CLAIM :
1. A chemical mechanical polishing composition,
characterized by : an abrasive component, a corrosion
inhibitor, a surfactant, a diacid compound, a metal residue
inhibitor, and water, said water residue inhibitor is :

2. The chemical mechanical polishing composition of claim 1,
characterized in that said abrasive component is present in an
amount ranging from 0.10 to 25.00 wt %, said corrosion
inhibitor is present in an amount ranging from 0.01 to 1.00 wt
%, said surfactant is present in an amount
ranging from 0.01 to 1.00 wt %, said diacid compound

is present in an amount ranging from 0.01 to 1.00 wt%,
said metal residue inhibitor is present in an amount ranging
from 0.01 to 1.00 wt%, and the remainder is water.
3. The chemical mechanical polishing composition of
claim 2, characterized in that said abrasive component
is present in an amount ranging from 0.50 to 10.00 wt%.
4. The chemical mechanical polishing composition of
claim 3, characterized in that said abrasive component
is present in an amount ranging from 0.50 to 5.00 wt%.
5. The chemical mechanical polishing composition of
claim 2, characterized in that said corrosion inhibitor
is present in an amount ranging from 0.01 to 0.50 wt%.
6. The chemical mechanical polishing composition of
claim 5, characterized in that said corrosion inhibitor
is present in an amount ranging from 0.01 to 0.20 wt%.
7. The chemical mechanical polishing composition of
claim 2, characterized in that said surfactant is present
in an amount ranging from 0.01 to 0.50 wt%.
8. The chemical mechanical polishing composition of
claim 7, characterized in that said surfactant is present
in an amount ranging from 0.10 to 0.30 wt%.
9. The chemical mechanical polishing composition of
claim 2, characterized in that said diacid compound is
present in an amount ranging from 0.05 to 1.00 wt%.
10. The chemical mechanical polishing composition of
claim 9, characterized in that said diacid compound is
present in an amount ranging from 0.10 to 1.00 wt%.

11. The chemical mechanical polishing composition of
claim 2, characterized in that said metal residue inhibitor
is present in an amount ranging from 0.01 to 0.50 wt% when
said metal residue inhibitor is selected from the group
consisting of compound (I) , compound (II), compound (III),
and compound (IV).
12. The chemical mechanical polishing composition of
claim 11, characterized in that said metal residue
inhibitor is present in an amount ranging from 0.01 to
0.30 wt%.
13. The chemical mechanical polishing composition of
claim 2, characterized in that said metal residue inhibitor
is compound (V) having an amount ranging from 0.05 to 1.00
wt%.
14. The chemical mechanical polishing composition of
claim 13, characterized in that said metal residue
inhibitor is present in an amount ranging from 0.05 to
0.50 wt%.
15. The chemical mechanical polishing composition of
claim 2, characterized in that said compound (II) is
selected from the group consisting of 2, 2-dimethyl succinic
acid, 2-ethyl-2-methylsuccinic acid,
2,3-dimethylsuccinic acid, and methylenesuccinic acid.
16. The chemical mechanical polishing composition of
claim 2, characterized in that said compound (III) is
selected from the group consisting of ma leic acid, 2-methyl
maleic acid, furmaric acid, and 2-methyl furmaric acid.

17. The chemical mechanical polishing composition of
claim 2, characterized in that said compound (IV) is
selected from the group consisting of 2-hydroxy acetic
acid, 2-methyl-2-hydroxy acetic acid, 2-ethyl-2-hydroxy
acetic acid, 2,2-diethyl-2-hydroxy acetic acid, and
2-ethyl-2-methyl-2-hydroxy acetic acid.
18. The chemical mechanical polishing composition of
claim2, characterized in that said compound (V) is selected
from the group consisting of acrylic acid, 2-methyl acrylic
acid, 2-ethyl acrylic acid, 3-methyl acrylic acid, and
2,3-dimethyl acrylic acid.
19. The chemical mechanical polishing composition of
claim 1, characterized in that said corrosion inhibitor
is selected from the group consisting of benzotriazole,
1,3,5-triazine-2,4,6,-triol, 1,2,3-triazole,
3-amino-1,2,4-triazole, 3-nitro-l,2,4-triazole,
4-amino-3-hydrazino-1,2,4-triazole-5-thiol,
benzotriazole-5-carboxylic acid,
3-amino-1,2,4-triazole-5-carboxylic acid, 1-hydroxy
benzotriazole, nitrobenzotriazole, and combinations
thereof.
20. The chemical mechanical polishing composition of
claim 1, characterized in that said surfactant is selected
from the group consisting of anionic type and nonionic
type.
21. The chemical mechanical polishing composition of
claim 1, characterized in that said diacid compound is

selected from the group consisting of : succinic acid, adipic
acid, glutaric acid, and combinations thereof.
22. The chemical mechanical polishing composition of claim 1,
characterized in that said composition has a pH value ranging
from 2 to 5.
23. The chemical mechanical polishing composition of claim
22, characterized in that said composition has a pH value
ranging from 3 to 4.
24. The chemical mechanical polishing composition of claim 1,
characterized in that said abrasive component is selected from
the group consisting of: SiO2, Al2O3, ZrO2, CeO2, Si3N4, and
combinations thereof.
25. The chemical mechanical polishing composition of claim 1,
further characterized in that the composition comprises an
oxidizing agent selected from the group consisting of hydrogen
peroxide, ferric nitrate, potassium iodate, acetic
hydroperoxide, and potassium permanganate.

26. The chemical mechanical polishing composition of claim
25, characterized in that the weight ratio of said oxidizing
agent to the mixture of said abrasive component, said
corrosion inhibitor, said surfactant, said diacid compound,
said metal residue inhibitor, and water ranges from 1:9 to
1:30.
27. The chemical mechanical polishing composition of claim 2,
further characterized in that the composition comprises 0.01
to 1.00 wt% formic acid receptively, to render the content
clearer.


A chemical mechanical polishing composition has a pH value between 2 and 5,
and comprises a mixture having following components : an aqueous medium, a
abrasive, a corrosion inhibitor, a surfactant, a diacid compound, and a metal residue
inhibitor. The metal residue inhibitor is selected from the group consisting of
compounds represented by the following chemical formulas: (I), (II), (III), (IV), (V)
and combinations thereof, wherein the structures of formulas (II) to (V) and the
definition of each substituent group are as defined in the specification and claims.
When the chemical mechanical polishing composition of the present invention is
used to polish a surface of a semiconductor wafer, a good metal polishing rate can be
obtained, metal dishing can be efficiently reduced, and metal residue on the wafer
surface can be reduced.

Documents:

00357-kol-2007 correspondence-1.1.pdf

00357-kol-2007 others.pdf

00357-kol-2007 priority document-1.1.pdf

00357-kol-2007-correspondence-1.2.pdf

00357-kol-2007-correspondence-1.3.pdf

00357-kol-2007-form-18.pdf

00357-kol-2007-p.a.pdf

0357-kol-2007 abstract.pdf

0357-kol-2007 claims.pdf

0357-kol-2007 correspondence others.pdf

0357-kol-2007 description(complete).pdf

0357-kol-2007 form-1.pdf

0357-kol-2007 form-2.pdf

0357-kol-2007 form-3.pdf

0357-kol-2007 form-5.pdf

0357-kol-2007 priority document.pdf

357-KOL-2007-AMANDED CLAIMS.pdf

357-KOL-2007-AMANDED PAGES OF SPECIFICATION.pdf

357-kol-2007-correspondence.pdf

357-KOL-2007-DESCRIPTION (COMPLETE).pdf

357-kol-2007-examination report.pdf

357-KOL-2007-FORM 1.pdf

357-kol-2007-form 18.pdf

357-KOL-2007-FORM 2.pdf

357-kol-2007-form 26.pdf

357-kol-2007-form 3-1.1.pdf

357-KOL-2007-FORM 3.pdf

357-kol-2007-form 5-1.1.pdf

357-KOL-2007-FORM 5.pdf

357-kol-2007-granted-abstract.pdf

357-kol-2007-granted-claims.pdf

357-kol-2007-granted-description (complete).pdf

357-kol-2007-granted-form 1.pdf

357-kol-2007-granted-form 2.pdf

357-kol-2007-granted-specification.pdf

357-KOL-2007-OTHERS.pdf

357-kol-2007-reply to examination report-1.1.pdf

357-KOL-2007-REPLY TO EXAMINATION REPORT.pdf

abstract-00357-kol-2007.jpg


Patent Number 246820
Indian Patent Application Number 357/KOL/2007
PG Journal Number 11/2011
Publication Date 18-Mar-2011
Grant Date 16-Mar-2011
Date of Filing 12-Mar-2007
Name of Patentee EPOCH MATERIAL CO., LTD
Applicant Address NO.2, LUKE 8TH ROAD, KAOHSIUNG SCIENCE PARK, KAOHSIUNG COUNTY, 82151, TAIWAN
Inventors:
# Inventor's Name Inventor's Address
1 HUI-FANG HOU NO.2, LUKE 8TH ROAD, KAOHSIUNG SCIENCE PARK, KAOHSIUNG COUNTY, 82151, TAIWAN
2 PAO-CHENG CHEN NO.2, LUKE 8TH ROAD, KAOHSIUNG SCIENCE PARK, KAOHSIUNG COUNTY, 82151, TAIWAN
3 YEN-LIANG CHEN NO.2, LUKE 8TH ROAD, KAOHSIUNG SCIENCE PARK, KAOHSIUNG COUNTY, 82151, TAIWAN
4 JUI-CHING CHEN NO.2, LUKE 8TH ROAD, KAOHSIUNG SCIENCE PARK, KAOHSIUNG COUNTY, 82151, TAIWAN
5 WEN-CHENG LTU NO.2, LUKE 8TH ROAD, KAOHSIUNG SCIENCE PARK, KAOHSIUNG COUNTY, 82151, TAIWAN
PCT International Classification Number H01L 21/321
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 095108960 2006-03-16 Taiwan