U.S. patent application number 10/642929 was filed with the patent office on 2004-05-06 for polishing method and polishing composition used for polishing.
Invention is credited to Hirano, Tatsuhiko, Ina, Katsuyoshi, Kawamura, Atsunori, Matsuda, Tsuyoshi, Sakai, Kenji, Tamai, Kazusei.
Application Number | 20040084414 10/642929 |
Document ID | / |
Family ID | 32021964 |
Filed Date | 2004-05-06 |
United States Patent
Application |
20040084414 |
Kind Code |
A1 |
Sakai, Kenji ; et
al. |
May 6, 2004 |
Polishing method and polishing composition used for polishing
Abstract
A polishing method for reliably polishing a polishing target and
a polishing composition used for polishing are provided. The
polishing method of the present invention includes a first step in
which the polishing target is polished with a first polishing
composition, a second step in which the polishing target is
polished with a second polishing composition, and a third step in
which polishing target is polished with a third polishing
composition. The polishing target is a multilayer, which includes
an insulation layer, which has trenches on its surface, a barrier
layer located on the insulation layer, and a conductor layer
located on the barrier layer. In the first step, part of a portion
of the conductor layer located outside the trenches is removed. In
the second step, a remaining part of the portion of the conductor
layer located outside the trenches is removed. In the third step, a
portion of the barrier layer located outside the trenches is
removed.
Inventors: |
Sakai, Kenji; (Aichi,
JP) ; Tamai, Kazusei; (Aichi, JP) ; Kawamura,
Atsunori; (Aichi, JP) ; Matsuda, Tsuyoshi;
(Aichi, JP) ; Hirano, Tatsuhiko; (Aichi, JP)
; Ina, Katsuyoshi; (Aichi, JP) |
Correspondence
Address: |
MADSON & METCALF
GATEWAY TOWER WEST
SUITE 900
15 WEST SOUTH TEMPLE
SALT LAKE CITY
UT
84101
|
Family ID: |
32021964 |
Appl. No.: |
10/642929 |
Filed: |
August 18, 2003 |
Current U.S.
Class: |
216/88 ;
257/E21.304 |
Current CPC
Class: |
C09G 1/02 20130101; H01L
21/3212 20130101; C23F 3/00 20130101 |
Class at
Publication: |
216/088 |
International
Class: |
C23F 001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 19, 2002 |
JP |
2002-238596 |
Claims
1. A method for polishing a polishing target, wherein the polishing
target has an insulation layer, a barrier layer, and a conductor
layer, wherein the insulation layer has a surface, which includes a
trench, wherein the barrier layer is located on the insulation
layer, wherein the conductor layer is made of metal that includes
copper and is located on the barrier layer, and wherein each of the
barrier layer and the conductor layer has an inner portion located
inside the trench and an outer portion located outside the trench,
the method comprising: polishing the polishing target using a first
polishing composition to remove part of the outer portion of the
conductor layer; wherein the first polishing composition includes
abrasive, a polishing accelerator, hydrogen peroxide, and water;
wherein the abrasive includes at least one of silicon dioxide and
aluminum oxide; and wherein the polishing accelerator includes at
least one of glycine and .alpha.-alanine; polishing the polishing
target using a second polishing composition to remove a remaining
part of the outer portion of the conductor layer; and polishing the
polishing target using a third polishing composition to remove the
outer portion of the barrier layer.
2. A method for polishing a polishing target, wherein the polishing
target has an insulation layer, a barrier layer, and a conductor
layer; wherein the insulation layer has a surface, which includes a
trench; wherein the barrier layer is located on the insulation
layer; wherein the conductor layer is made of metal that includes
copper and is located on the barrier layer; and wherein each of the
barrier layer and the conductor layer has an inner portion located
inside the trench and an outer portion located outside the trench,
the method comprising: polishing the polishing target with a first
polishing composition to remove part of the outer portion of the
conductor layer; polishing the polishing target with a second
polishing composition to remove a remaining part of the outside
portion of the conductor layer; wherein the second polishing
composition includes abrasive, a polishing accelerator, an organic
compound, a corrosion inhibitor, hydrogen peroxide, and water;
wherein the abrasive includes at least one of silicon dioxide and
aluminum oxide; wherein the polishing accelerator includes at least
one of glycine and .alpha.-alanine; and wherein the organic
compound includes at least one compound selected from the group
consisting of polyethylene oxide, polypropylene oxide,
polyoxyethylene alkyl ether, polyoxypropylene alkyl ether,
polyoxyethylene polyoxypropylene alkyl ether, and an addition
polymer of polyoxyalkylene represented by the following chemical
formula (1), 8wherein each of R.sup.1 to R.sup.6 represents a
hydrogen atom or an alkyl group the carbon number of which is any
of integer numbers 1 to 10, wherein each of X and Y represents an
ethyleneoxy group or a propyleneoxy group, wherein each of m and n
represents any of integer numbers 1 to 20, and wherein the
corrosion inhibitor includes at least one of benzotriazole and a
derivative of benzotriazole; and polishing the polishing target
using a third polishing composition to remove the outer portion of
the barrier layer.
3. The method according to claim 2, wherein the first polishing
composition includes abrasive, which includes at least one of
silicon dioxide and aluminum oxide; a polishing accelerator, which
includes at least one of glycine and .alpha.-alanine; hydrogen
peroxide; and water.
4. The method according to claim 2, wherein the third polishing
composition includes abrasive, which includes at least one of
silicon dioxide and aluminum oxide; acid or alkali, a corrosion
inhibitor, which includes at least one of benzotriazole and a
derivative of benzotriazole, and water, wherein the acid includes
at least one acid selected from the group consisting of nitric
acid, hydrochloric acid, lactic acid, phosphoric acid, sulfuric
acid, acetic acid, oxalic acid, citric acid, tartaric acid, malonic
acid, succinic acid, maleic acid, and fumaric acid, and wherein the
alkali includes at least one alkali selected from the group
consisting of potassium hydroxide, ammonium hydroxide, and sodium
hydroxide.
5. A method for polishing a polishing target; wherein the polishing
target has an insulation layer, a barrier layer, and a conductor
layer; wherein the insulation layer has a surface, which includes a
trench; wherein the barrier layer is located on the insulation
layer; wherein the conductor layer is made of metal that includes
copper and is located on the barrier layer; and wherein each of the
barrier layer and the conductor layer has an inner portion located
inside the trench and an outer portion located outside the trench,
the method comprising: polishing the polishing target using a first
polishing composition to remove part of the outer portion of the
conductor layer; polishing the polishing target using a second
polishing composition to remove a remaining part of the outer
portion of the conductor layer; and polishing the polishing target
using a third polishing composition to remove the outer portion of
the barrier layer; wherein the third polishing composition includes
abrasive, acid or alkali, a corrosion inhibitor, and water; wherein
the abrasive includes at least one of silicon dioxide and aluminum
oxide; wherein the acid includes at least one acid selected from
the group consisting of nitric acid, hydrochloric acid, lactic
acid, phosphoric acid, sulfuric acid, acetic acid, oxalic acid,
citric acid, tartaric acid, malonic acid, succinic acid, maleic
acid, and fumaric acid; wherein the alkali includes at least one
alkali selected from the group consisting of potassium hydroxide,
ammonium hydroxide, and sodium hydroxide; and wherein the corrosion
inhibitor includes at least one of benzotriazole and a derivative
of benzotriazole.
6. The method according to claim 5, wherein the first polishing
composition includes abrasive, which includes at least one of
silicon dioxide and aluminum oxide; a polishing. accelerator;
hydrogen peroxide; and water; and wherein the polishing accelerator
includes at least one of glycine and .alpha.-alanine.
7. A method for polishing a polishing target, wherein the polishing
target has an insulation layer, a barrier layer, and a conductor
layer; wherein the insulation layer has a surface, which includes a
trench; wherein the barrier layer is located on the insulation
layer; wherein the conductor layer is made of metal that includes
copper and is located on the barrier layer; and wherein each of the
barrier layer and the conductor layer has an inner portion located
inside the trench and an outer portion located outside the trench,
the method comprising: polishing the polishing target using a first
polishing composition to remove part of the outer portion of the
conductor layer; wherein the first polishing composition includes
abrasive, a polishing accelerator, hydrogen peroxide, and water;
polishing the polishing target using a second polishing composition
to remove a remaining part of the outer portion of the conductor
layer; wherein the second polishing composition includes abrasive,
a polishing accelerator, an organic compound, a corrosion
inhibitor, hydrogen peroxide, and water; and polishing the
polishing target using a third polishing composition to remove the
outer portion of the barrier layer; wherein the third polishing
composition includes abrasive, acid or alkali, a corrosion
inhibitor, and water; wherein each abrasive includes at least one
of silicon dioxide and aluminum oxide; wherein each polishing
accelerator includes at least one of glycine and .alpha.-alanine;
wherein the organic compound includes at least one compound
selected from the group consisting of polyethylene oxide,
polypropylene oxide, polyoxyethylene alkyl ether, polyoxypropylene
alkyl ether, polyoxyethylene polyoxypropylene alkyl ether, and an
addition polymer of polyoxyalkylene represented by the following
chemical formula (1), and 9wherein each of R.sup.1 to R.sup.6
represents a hydrogen atom or an alkyl group the carbon number of
which is any of integer numbers 1 to 10; wherein each of X and Y
represents an ethyleneoxy group or a propyleneoxy group, wherein
each of m and n represents any of integer numbers 1 to 20; wherein
the acid includes at least one acid selected from the group
consisting of nitric acid, hydrochloric acid, lactic acid,
phosphoric acid, sulfuric acid, acetic acid, oxalic acid, citric
acid, tartaric acid, malonic acid, succinic acid, maleic acid, and
fumaric acid; wherein the alkali includes at least one alkali
selected from the group consisting of potassium hydroxide, ammonium
hydroxide, and sodium hydroxide; and wherein each corrosion
inhibitor includes at least one of benzotriazole and a derivative
of benzotriazole.
8. The method according to claim 7, wherein the third polishing
composition further includes a polishing accelerator, which
includes at least one of glycine and .alpha.-alanine.
9. The method according to claim 8, wherein a main composition, a
first sub-composition, and a second sub-composition are prepared
before polishing the polishing target, wherein the main composition
includes abrasive, a polishing accelerator, and water; wherein the
abrasive includes at least one of silicon dioxide and aluminum
oxide; wherein the polishing accelerator includes glycine and
.alpha.-alanine; wherein the first sub-composition includes an
organic compound, a first corrosion inhibitor, and water; and
wherein the organic compound includes at least one compound
selected from the group consisting of polyethylene oxide,
polypropylene oxide, polyoxyethylene alkyl ether, polyoxypropylene
alkyl ether, polyoxyethylene polyoxypropylene alkyl ether, and an
addition polymer of polyoxyalkylene represented by the following
chemical formula (1), 10wherein each of R.sup.1 to R.sup.6
represents a hydrogen atom or an alkyl group the carbon number of
which is any of integer numbers 1 to 10 ; wherein each of X and Y
represents an ethyleneoxy group or a propyleneoxy group; wherein
each of m and n represents any of integer numbers 1 to 20; wherein
the first corrosion inhibitor includes at least one of
benzotriazole and a derivative of benzotriazole; wherein the second
sub-composition includes acid or alkali, a second corrosion
inhibitor, and water; wherein the acid includes at least one acid
selected from the group consisting of nitric acid, hydrochloric
acid, lactic acid, phosphoric acid, sulfuric acid, acetic acid,
oxalic acid, citric acid, tartaric acid, malonic acid, succinic
acid, maleic acid, and fumaric acid; wherein the alkali includes at
least one alkali selected from the group consisting of potassium
hydroxide, ammonium hydroxide, and sodium hydroxide; and wherein
the second corrosion inhibitor includes at least one of
benzotriazole and a derivative of benzotriazole; and wherein the
first polishing composition is prepared by mixing the main
composition and hydrogen peroxide when using the first polishing
composition; wherein the second polishing composition is prepared
by mixing the main composition, the first sub-composition, and
hydrogen peroxide when using the second polishing composition; and
wherein the third polishing composition is prepared by mixing the
main composition and the second sub-composition when using the
third polishing composition.
10. The method according to claim 7, wherein the third polishing
composition further includes hydrogen peroxide.
11. A polishing composition used for polishing a polishing target;
wherein the polishing target has an insulation layer, a barrier
layer, and a conductor layer; wherein the insulation layer has a
surface, which includes a trench; wherein the barrier layer is
located on the insulation layer; wherein the conductor layer is
made of metal that includes copper and is located on the barrier
layer; and wherein each of the barrier layer and the conductor
layer has an inner portion located inside the trench and an outer
portion located outside the trench; wherein the polishing
composition is used to polish the polishing target to remove part
of the outer portion of the conductor layer; wherein the polishing
composition includes abrasive, a polishing accelerator, hydrogen
peroxide, and water; wherein the abrasive includes at least one of
silicon dioxide and aluminum oxide; and wherein the polishing
accelerator includes at least one of glycine and
.alpha.-alanine.
12. The polishing composition according to claim 11, wherein the
polishing composition is prepared by mixing a mixture of the
abrasive, the polishing accelerator, and the water with the
hydrogen peroxide when using the polishing composition.
13. The polishing composition according to claim 11, wherein the
polishing composition is prepared by mixing a mixture of the
abrasive, the polishing accelerator, and part of the water with the
hydrogen peroxide when using the polishing composition; and further
diluting the polishing composition with remaining water.
14. A polishing composition used for polishing a polishing target;
wherein the polishing target has an insulation layer, a barrier
layer, and a conductor layer; wherein the insulation layer has a
surface, which includes a trench; wherein the barrier layer is
located on the insulation layer; wherein the conductor layer is
made of metal that includes copper and is located on the barrier
layer; and wherein each of the barrier layer and the conductor
layer has an inner portion located inside the trench and an outer
portion located outside the trench, wherein the polishing
composition is used to polish the polishing target from which part
of the outer portion of the conductor layer is removed by
prepolishing to remove a remaining part of the outer portion of the
conductor layer; wherein the polishing composition includes
abrasive, a polishing accelerator, a organic compound, a corrosion
inhibitor, hydrogen peroxide, and water; wherein the abrasive
includes at least one of silicon dioxide and aluminum oxide;
wherein the polishing accelerator includes at least one of glycine
and .alpha.-alanine; and wherein the organic compound includes at
least one compound selected from the group consisting of
polyethylene oxide, polypropylene oxide, polyoxyethylene alkyl
ether, polyoxypropylene alkyl ether, polyoxyethylene
polyoxypropylene alkyl ether, and an addition polymer of
polyoxyalkylene represented by the following chemical formula (1),
and 11wherein each of R.sup.1 to R.sup.6 represents a hydrogen atom
or an alkyl group the carbon number of which is any of integer
numbers 1 to 10; wherein each of X and Y represents an ethyleneoxy
group or a propyleneoxy group; wherein each of m and n represents
any of integer numbers 1 to 20; and wherein the corrosion inhibitor
includes at least one of benzotriazole and a derivative of
benzotriazole.
15. The polishing composition according to claim 14, wherein the
polishing composition is prepared by mixing a first mixture, which
includes the abrasive, the polishing accelerator, and part of the
water; a second mixture, which includes the organic compound, the
corrosion inhibitor, and a remaining part of the water; and the
hydrogen peroxide when using the polishing composition.
16. The polishing composition according to claim 14, wherein the
polishing composition is prepared by mixing a first mixture, which
includes the abrasive, the polishing accelerator, and part of the
water; a second mixture, which includes the organic compound, the
corrosion inhibitor, and another part of the water; and the
hydrogen peroxide when using the polishing composition; and further
diluting the polishing composition with a remaining part of the
water.
17. A polishing composition used for polishing a polishing target;
wherein the polishing target has an insulation layer, a barrier
layer, and a conductor layer; wherein the insulation layer has a
surface, which includes a trench; wherein the barrier layer is
located on the insulation layer; wherein the conductor layer is
made of metal that includes copper and is located on the barrier
layer; and wherein each of the barrier layer and the conductor
layer has an inner portion located inside the trench and an outer
portion located outside the trench, wherein the polishing
composition is used to polish the polishing target from which the
outer portion of the conductor layer is removed by prepolishing to
remove the outer portion of the barrier layer; wherein the
polishing composition includes abrasive, acid or alkali, a
corrosion inhibitor, and water; wherein the abrasive includes at
least one of silicon dioxide and aluminum oxide; wherein the acid
includes at least one acid selected from the group consisting of
nitric acid, hydrochloric acid, lactic acid, phosphoric acid,
sulfuric acid, acetic acid, oxalic acid, citric acid, tartaric
acid, malonic acid, succinic acid, maleic acid, and fumaric acid;
wherein the alkali includes at least one alkali selected from the
group consisting of potassium hydroxide, ammonium hydroxide, and
sodium hydroxide; and wherein the corrosion inhibitor includes at
least one of benzotriazole and a derivative of benzotriazole.
18. The polishing composition according to claim 17, further
comprising a polishing accelerator, wherein the polishing
accelerator includes at least one of glycine and
.alpha.-alanine.
19. The polishing composition according to claim 18, wherein the
polishing composition is prepared by mixing a first mixture, which
includes the abrasive, the polishing accelerator, and part of the
water; and a second mixture, which includes the acid or alkali, the
corrosion inhibitor, and a remaining part of the water when using
the polishing composition.
20. The polishing composition according to claim 18, wherein the
polishing composition is prepared by mixing a first mixture, which
includes the abrasive, the polishing accelerator, and part of the
water; and a second mixture, which includes the acid or alkali, the
corrosion inhibitor, and another part of the water when using the
polishing composition; and further diluting the polishing
composition with a remaining part of the water.
21. The polishing composition according to claim 17, further
comprising hydrogen peroxide.
22. The polishing composition according to claim 18, further
comprising hydrogen peroxide.
23. The polishing composition according to claim 22, wherein the
polishing composition is prepared by mixing a first mixture, which
includes the abrasive, the polishing accelerator, and part of the
water; a second mixture, which includes the acid or alkali, the
corrosion inhibitor, and a remaining part of the water; and
hydrogen peroxide when using the polishing composition.
24. The polishing composition according to claim 22, wherein the
polishing composition is prepared by mixing a first mixture, which
includes the abrasive, the polishing accelerator, and part of the
water; a second mixture, which includes the acid or alkali, the
corrosion inhibitor, and another part of the water; and hydrogen
peroxide when using the polishing composition; and further diluting
the polishing composition with a remaining part of the water.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a polishing method used
when, for example, forming a wiring structure of a semiconductor
device, and to a polishing composition used for polishing.
[0002] A wiring structure of a semiconductor device can be formed
by using a chemical mechanical polishing (CMP) method. When forming
a wiring structure using the CMP method, a multilayer is prepared
as a polishing target. As shown in FIG. 1(a), the multilayer
includes an insulation layer 11, a barrier layer 14, which is
located on the insulation layer 11; and a conductor layer 13, which
is located on the barrier layer 14. The insulation layer 11 has
trenches 12 on its surface. Each of the barrier layer 14 and the
conductor layer 13 has an inner portion located inside the trenches
12 and an outer portion located outside the trenches 12.
[0003] The multilayer is polished to remove the outer portion of
the conductor layer 13 and the outer portion of the barrier layer
14. As a result, a wiring portion 17 (see FIG. 1(d)), which is made
of the inner portion of the conductor layer 13, is formed in the
trenches 12.
[0004] The following first and second methods have been proposed as
methods for polishing a multilayer.
[0005] In the first method, a multilayer is polished using a
polishing composition that efficiently polishes the conductor layer
13 to remove the outer portion of the conductor layer 13. Then, the
multilayer is polished using a different polishing composition that
efficiently polishes the barrier layer 14 to remove the outer
portion of the barrier layer 14.
[0006] In the second method, a multilayer is polished using a
polishing composition that efficiently polishes the conductor layer
13 to remove part of the outer portion of the conductor layer 13.
Then, the multilayer is polished using a different polishing
composition that efficiently polishes the conductor layer 13 and
the barrier layer 14 to remove a remaining part of the outer
portion of the conductor layer 13 and the outer portion of the
barrier layer 14.
[0007] However, in the first method, a considerable amount of the
inner portion of the conductor layer 13 is removed with the outer
portion of the conductor layer 13 in the first polishing step. In
the second method, a considerable amount of the inner portion of
the conductor layer 13 is removed with the remaining part of the
outer portion of the conductor layer 13 and the outer portion of
the barrier layer 14 in the second polishing step.
SUMMARY OF THE INVENTION
[0008] Accordingly, it is an objective of the present invention to
provide a polishing method that reliably polishes a polishing
target and a polishing composition used for polishing.
[0009] To achieve the above objective, the present invention
provides a method for polishing a polishing target. The polishing
target has an insulation layer, a barrier layer, and a conductor
layer. The insulation layer has a surface, which includes a trench.
The barrier layer is located on the insulation layer. The conductor
layer is made of metal that includes copper and is located on the
barrier layer. Each of the barrier layer and the conductor layer
has an inner portion located inside the trench and an outer portion
located outside the trench. The method includes: polishing the
polishing target using a first polishing composition to remove part
of the outer portion of the conductor layer; wherein the first
polishing composition includes abrasive, a polishing accelerator,
hydrogen peroxide, and water; wherein the abrasive includes at
least one of silicon dioxide and aluminum oxide; and wherein the
polishing accelerator includes at least one of glycine and
.alpha.-alanine; polishing the polishing target using a second
polishing composition to remove a remaining part of the outer
portion of the conductor layer; and polishing the polishing target
using a third polishing composition to remove the outer portion of
the barrier layer.
[0010] The present invention also provides a method for polishing a
polishing target. The polishing target has an insulation layer, a
barrier layer, and a conductor layer. The insulation layer has a
surface, which includes a trench. The barrier layer is located on
the insulation layer. The conductor layer is made of metal that
includes copper and is located on the barrier layer. Each of the
barrier layer and the conductor layer has an inner portion located
inside the trench and an outer portion located outside the trench.
The method includes: polishing the polishing target with a first
polishing composition to remove part of the outer portion of the
conductor layer; polishing the polishing target with a second
polishing composition to remove a remaining part of the outside
portion of the conductor layer; wherein the second polishing
composition includes abrasive, a polishing accelerator, an organic
compound, a corrosion inhibitor, hydrogen peroxide, and water;
wherein the abrasive includes at least one of silicon dioxide and
aluminum oxide; wherein the polishing accelerator includes at least
one of glycine and .alpha.-alanine; and wherein the organic
compound includes at least one compound selected from the group
consisting of polyethylene oxide, polypropylene oxide,
polyoxyethylene alkyl ether, polyoxypropylene alkyl ether,
polyoxyethylene polyoxypropylene alkyl ether, and an addition
polymer of polyoxyalkylene represented by the following chemical
formula (1), 1
[0011] wherein each of R.sup.1 to R.sup.6 represents a hydrogen
atom or an alkyl group the carbon number of which is any of integer
numbers 1 to 10, wherein each of X and Y represents an ethyleneoxy
group or a propyleneoxy group, wherein each of m and n represents
any of integer numbers 1 to 20, and wherein the corrosion inhibitor
includes at least one of benzotriazole and a derivative of
benzotriazole; and polishing the polishing target using a third
polishing composition to remove the outer portion of the barrier
layer.
[0012] A further aspect of the present invention is a method for
polishing a polishing target. The polishing target has an
insulation layer, a barrier layer, and a conductor layer. The
insulation layer has a surface, which includes a trench. The
barrier layer is located on the insulation layer. The conductor
layer is made of metal that includes copper and is located on the
barrier layer. Each of the barrier layer and the conductor layer
has an inner portion located inside the trench and an outer portion
located outside the trench. The method includes: polishing the
polishing target using a first polishing composition to remove part
of the outer portion of the conductor layer; polishing the
polishing target using a second polishing composition to remove a
remaining part of the outer portion of the conductor layer; and
polishing the polishing target using a third polishing composition
to remove the outer portion of the barrier layer; wherein the third
polishing composition includes abrasive, acid or alkali, a
corrosion inhibitor, and water; wherein the abrasive includes at
least one of silicon dioxide and aluminum oxide; wherein the acid
includes at least one acid selected from the group consisting of
nitric acid, hydrochloric acid, lactic acid, phosphoric acid,
sulfuric acid, acetic acid, oxalic acid, citric acid, tartaric
acid, malonic acid, succinic acid, maleic acid, and fumaric acid;
wherein the alkali includes at least one alkali selected from the
group consisting of potassium hydroxide, ammonium hydroxide, and
sodium hydroxide; and wherein the corrosion inhibitor includes at
least one of benzotriazole and a derivative of benzotriazole.
[0013] The present invention may also be embodied in a method for
polishing a polishing target. The polishing target has an
insulation layer, a barrier layer, and a conductor layer. The
insulation layer has a surface, which includes a trench. The
barrier layer is located on the insulation layer. The conductor
layer is made of metal that includes copper and is located on the
barrier layer. Each of the barrier layer and the conductor layer
has an inner portion located inside the trench and an outer portion
located outside the trench. The method includes: polishing the
polishing target using a first polishing composition to remove part
of the outer portion of the conductor layer; wherein the first
polishing composition includes abrasive, a polishing accelerator,
hydrogen peroxide, and water; polishing the polishing target using
a second polishing composition to remove a remaining part of the
outer portion of the conductor layer; wherein the second polishing
composition includes abrasive, a polishing accelerator, an organic
compound, a corrosion inhibitor, hydrogen peroxide, and water; and
polishing the polishing target using a third polishing composition
to remove the outer portion of the barrier layer; wherein the third
polishing composition includes abrasive, acid or alkali, a
corrosion inhibitor, and water. Each abrasive includes at least one
of silicon dioxide and aluminum oxide. Each polishing accelerator
includes at least one of glycine and .alpha.-alanine. The organic
compound includes at least one compound selected from the group
consisting of polyethylene oxide, polypropylene oxide,
polyoxyethylene alkyl ether, polyoxypropylene alkyl ether,
polyoxyethylene polyoxypropylene alkyl ether, and an addition
polymer of polyoxyalkylene represented by the following chemical
formula (1). 2
[0014] Each of R.sup.1 to R.sup.6 represents a hydrogen atom or an
alkyl group the carbon number of which is any of integer numbers 1
to 10. Each of X and Y represents an ethyleneoxy group or a
propyleneoxy group. Each of m and n represents any of integer
numbers 1 to 20. The acid includes at least one acid selected from
the group consisting of nitric acid, hydrochloric acid, lactic
acid, phosphoric acid, sulfuric acid, acetic acid, oxalic acid,
citric acid, tartaric acid, malonic acid, succinic acid, maleic
acid, and fumaric acid. The alkali includes at least one alkali
selected from the group consisting of potassium hydroxide, ammonium
hydroxide, and sodium hydroxide. Each corrosion inhibitor includes
at least one of benzotriazole and a derivative of
benzotriazole.
[0015] The present invention provides a polishing composition used
for polishing a polishing target. The polishing target has an
insulation layer, a barrier layer, and a conductor layer. The
insulation layer has a surface, which includes a trench. The
barrier layer is located on the insulation layer. The conductor
layer is made of metal that includes copper and is located on the
barrier layer. Each of the barrier layer and the conductor layer
has an inner portion located inside the trench and an outer portion
located outside the trench. The polishing composition is used to
polish the polishing target to remove part of the outer portion of
the conductor layer. The polishing composition includes abrasive, a
polishing accelerator, hydrogen peroxide, and water. The abrasive
includes at least one of silicon dioxide and aluminum oxide. The
polishing accelerator includes at least one of glycine and
.alpha.-alanine.
[0016] The present invention also provides a polishing composition
used for polishing a polishing target. The polishing target has an
insulation layer, a barrier layer, and a conductor layer. The
insulation layer has a surface, which includes a trench. The
barrier layer is located on the insulation layer. The conductor
layer is made of metal that includes copper and is located on the
barrier layer. Each of the barrier layer and the conductor layer
has an inner portion located inside the trench and an outer portion
located outside the trench. The polishing composition is used to
polish the polishing target from which part of the outer portion of
the conductor layer is removed by prepolishing to remove a
remaining part of the outer portion of the conductor layer. The
polishing composition includes abrasive, a polishing accelerator,
an organic compound, a corrosion inhibitor, hydrogen peroxide, and
water. The abrasive includes at least one of silicon dioxide and
aluminum oxide. The polishing accelerator includes at least one of
glycine and .alpha.-alanine. The organic compound includes at least
one compound selected from the group consisting of polyethylene
oxide, polypropylene oxide, polyoxyethylene alkyl ether,
polyoxypropylene alkyl ether, polyoxyethylene polyoxypropylene
alkyl ether, and an addition polymer of polyoxyalkylene represented
by the following chemical formula (1). 3
[0017] Each of R.sup.1 to R.sup.6 represents a hydrogen atom or an
alkyl group the carbon number of which is any of integer numbers 1
to 10. Each of X and Y represents an ethyleneoxy group or a
propyleneoxy group. Each of m and n represents any of integer
numbers 1 to 20. The corrosion inhibitor includes at least one of
benzotriazole and a derivative of benzotriazole.
[0018] A further aspect of the present invention is a polishing
composition used for polishing a polishing target. The polishing
target has an insulation layer, a barrier layer, and a conductor
layer. The insulation layer has a surface, which includes a trench.
The barrier layer is located on the insulation layer. The conductor
layer is made of metal that includes copper and is located on the
barrier layer. Each of the barrier layer and the conductor layer
has an inner portion located inside the trench and an outer portion
located outside the trench. The polishing composition is used to
polish the polishing target from which the outer portion of the
conductor layer is removed by prepolishing to remove the outer
portion of the barrier layer. The polishing composition includes
abrasive, acid or alkali, a corrosion inhibitor, and water. The
abrasive includes at least one of silicon dioxide and aluminum
oxide. The acid includes at least one acid selected from the group
consisting of nitric acid, hydrochloric acid, lactic acid,
phosphoric acid, sulfuric acid, acetic acid, oxalic acid, citric
acid, tartaric acid, malonic acid, succinic acid, maleic acid, and
fumaric acid. The alkali includes at least one alkali selected from
the group consisting of potassium hydroxide, ammonium hydroxide,
and sodium hydroxide. The corrosion inhibitor includes at least one
of benzotriazole and a derivative of benzotriazole.
[0019] Other aspects and advantages of the invention will become
apparent from the following description, taken in conjunction with
the accompanying drawings, illustrating by way of example the
principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The invention, together with objects and advantages thereof,
may best be understood by reference to the following description of
the presently preferred embodiments together with the accompanying
drawings in which:
[0021] FIGS. 1(a) to 1(d) are cross-sectional views illustrating
part of a multilayer to explain a polishing method according to a
preferred embodiment of the present invention;
[0022] FIG. 2(a) is an enlarged partial cross-sectional view
illustrating a portion of the multilayer shown in FIG. 1(c) where
dishing occurred;
[0023] FIG. 2(b) is an enlarged partial cross-sectional view
illustrating a portion of the multilayer shown in FIG. 1(c) where
erosion occurred;
[0024] FIG. 3(a) is an enlarged partial cross-sectional view
illustrating a portion of the multilayer shown in FIG. 1(d) where
dishing occurred; and
[0025] FIG. 3(b) is an enlarged partial cross-sectional view
illustrating a portion of the multilayer shown in FIG. 1(d) where
erosion occurred.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] A preferred embodiment of the present invention will now be
described with reference to FIGS. 1(a) to 3(b).
[0027] A polishing method and a polishing composition according to
the preferred embodiment are used when forming a wiring structure
of a semiconductor device. A method for manufacturing a multilayer
that is prepared for forming a wiring structure of a semiconductor
device will be described first. A multilayer is generally
manufactured in the following manner.
[0028] As shown in FIG. 1(a), an insulation layer 11 is formed on a
base plate (not shown). The insulation layer 11 is, for example, a
Sio.sub.2 film, a SiOF film, or a SiOC film; and is formed by a
chemical vapor deposition (CVD) method, which uses
tetraethoxysilane (TEOS) The surface of the insulation layer 11 is
preferably flat.
[0029] Then, trenches 12 are formed on the surface of the
insulation layer 11. The trenches 12 are formed by known
lithography or etching, and have a predetermined pattern based on a
circuit design.
[0030] Then, a barrier layer 14 is formed on the insulation layer
11. The barrier layer 14 is formed by a spattering method. The
barrier layer 14 is formed of a simple substance of tantalum or a
compound that includes tantalum, such as tantalum nitride. The
barrier layer 14 prevents copper in a conductor layer 13, which
will be described later, from being scattered to the insulation
layer 11. The barrier layer 14 has a predetermined thickness and
has an inner portion located inside the trenches 12 and an outer
portion located outside the trenches 12.
[0031] Consequently, the conductor layer 13 is formed on the
barrier layer 14. The conductor layer 13 is formed of metal that
includes copper, such as a simple substance of copper, an alloy of
copper and aluminum, and an alloy of copper and titanium. The
conductor layer 13 completely fills the trenches 12. The conductor
layer 13 has an inner portion located inside the trenches 12 and an
outer portion located outside the trenches 12. Hollows 15 are
formed due to the trenches 12 at the portions of the surface of the
conductor layer 13 that correspond to the trenches 12. The depth of
the hollows 15 is referred to as a step height.
[0032] The multilayer manufactured as mentioned above is then
polished to remove the outer portion of the conductor layer 13 and
the outer portion of the barrier layer 14. As a result, a wiring
portion 17 (see FIG. 1(d)), which is made by the inner portion of
the conductor layer 13, is formed in the trenches 12.
[0033] The multilayer is polished in the following manner in the
preferred embodiment.
[0034] In a first step, the multilayer is polished using a first
polishing composition to remove part of the outer portion of the
conductor layer 13 (see FIG. 1(b)). After polishing with the first
polishing composition, the hollows 15 are preferably removed almost
completely. The depth of the hollows 15 after polishing is
preferably less than or equal to 500 .ANG., and more preferably,
less than or equal to 200 .ANG..
[0035] In a second step, the multilayer is polished using a second
polishing composition to remove a remaining part of the outer
portion of the conductor layer 13 (see FIG. 1(c)).
[0036] The dimension represented by d1 in FIG. 2(a) is a dishing
amount measured after polishing with the second polishing
composition at a portion of the multilayer that corresponds to the
trench 12 the width of which is relatively large, for example, a
portion of the multilayer that corresponds to the trench 12 the
width of which is 10 .mu.m. The dishing amount dl is preferably
less than or equal to 500 .ANG., and more preferably, less than or
equal to 300 .ANG.. The dishing is a phenomenon where part of the
inner portion of the conductor layer 13 is removed, and the surface
of the inner portion of the conductor layer 13 becomes hollow.
[0037] The dimension represented by e1 in FIG. 2(b) is an erosion
amount measured after polishing with the second polishing
composition at a portion of the multilayer where the trenches 12
are densely arranged, such as where the trenches 12 the width of
which is 9 .mu.m are located at intervals of 1 .mu.m. The erosion
amount e1 is preferably less than or equal to 500 .ANG., and more
preferably, less than or equal to 300 .ANG.. The erosion is a
phenomenon where part of the insulation layer 11 between the
adjacent trenches 12 is removed, and the surface of the portion of
the multilayer where the trenches 12 are arranged densely becomes
hollow. The portion of the multilayer where the proportion of the
trenches 12 to the entire multilayer is 90%, such as the portion of
the multilayer where the trenches 12 the width of which is 9 .mu.m
are located at intervals of 1 .mu.m, is referred to as a 90% high
density wiring area.
[0038] Finally, in a third step, the multilayer is polished using a
third polishing composition to remove the outer portion of the
barrier layer 14 (see FIG. 1(d)).
[0039] The dimension represented by d2 shown in FIG. 3(a) is a
dishing amount measured after polishing with the third polishing
composition at a portion of the multilayer that corresponds to the
trench 12, the width of which is relatively large, for example, a
portion of the multilayer that corresponds to the trench 12 the
width of which is 10 .mu.m. The dimension represented by e2 shown
in FIG. 3(b) is an erosion amount measured after polishing with the
third polishing composition at a portion of the multilayer where
the trenches 12 are densely arranged, such as where the trenches
12, the width of which is 9 .mu.m, are located at intervals of 1
.mu.m.
[0040] The polishing time taken in each of the first to third steps
is preferably the same as the polishing time of the other two
steps. This improves the efficiency in forming the wiring
structure.
[0041] The first polishing composition includes abrasive, a
polishing accelerator, hydrogen peroxide, and water. The second
polishing composition includes abrasive, a polishing accelerator, a
nonionic organic compound, a corrosion inhibitor, hydrogen
peroxide, and water. The third polishing composition includes
abrasive, acid or alkali, a corrosion inhibitor, and water, and
further includes a polishing accelerator and hydrogen peroxide as
required. If part of the outer portion of the conductor layer 13
remains after polishing with the second polishing composition, the
third polishing composition preferably includes hydrogen
peroxide.
[0042] The abrasive serves to mechanically polish the polishing
target. Each of the first to third polishing compositions includes
at least one of silicon dioxide and aluminum oxide. Silicon
dioxide, such as colloidal silica and fumed silica, is preferably
used as abrasive. Colloidal silica is particularly preferable for
abrasive. This is because silicon dioxide is highly stable and
colloidal silica does not easily form scratches on the polishing
target.
[0043] The average particle size of the abrasive obtained from the
surface area of the abrasive measured by a BET method is preferably
3 to 100 nm, more preferably 5 to 60 nm, and most preferably 10 to
50 nm. If the average particle size of the abrasive is less than 3
nm, the polishing performance of the polishing composition
deteriorates. If the average particle size of the abrasive exceeds
100 nm, the polishing composition often forms scratches on the
polishing target.
[0044] The content of abrasive in each of the first to third
polishing compositions is preferably 1 to 100 g/L, more preferably
2 to 50 g/L. If the content of abrasive is less than 1 g/L, the
polishing performance of the polishing composition decreases. If
the content exceeds 100 g/L, the abrasive easily cohere with each
other in the polishing composition and the polishing composition
often forms scratches on the polishing target.
[0045] The polishing accelerator causes a chelate bond with copper
in the conductor layer 13 to accelerate polishing of the conductor
layer 13. Each of the first and second polishing compositions
includes at least one of glycine and .alpha.-alanine as the
polishing accelerator. A preferable polishing accelerator is
.alpha.-alanine since the polishing composition that includes
.alpha.-alanine reliably polishes the polishing target.
[0046] The content of the polishing accelerator in the first
polishing composition is preferably 2 to 30 g/L, more preferably 5
to 20 g/L. If the content of the polishing accelerator is less than
2 g/L, the polishing performance of the first polishing composition
deteriorates, and if the content of the polishing accelerator
exceeds 30 g/L, the polishing performance of the first polishing
composition excessively increases. The content of the polishing
accelerator in the second polishing composition is preferably 2 to
20 g/L, more preferably 5 to 20 g/L. If the content of the
polishing accelerator is less than 2 g/L, the polishing performance
of the second polishing composition deteriorates, and if the
content of the polishing accelerator exceeds 20 g/L, the polishing
performance of the second polishing composition excessively
increases.
[0047] The nonionic organic compound serves to suppress generation
of dishing and erosion. The second polishing composition includes
at least one of polyethylene oxide, polypropylene oxide,
polyoxyethylene alkyl ether, polyoxypropylene alkyl ether,
polyoxyethylene polyoxypropylene alkyl ether, and an addition
polymer of polyoxyalkylene represented by the following chemical
formula (1). In the chemical formula (1), each of R.sup.1 to
R.sup.6 represents a hydrogen atom or an alkyl group the carbon
number of which is any of integer numbers 1 to 10, each of X and Y
represents an ethyleneoxy group or a propyleneoxy group, and each
of m and n represents any of integer numbers 1 to 20. 4
[0048] The second polishing composition preferably includes dialkyl
dimethyl butynediol polyoxyethylene glycol ether represented by the
following chemical formula (2). The second polishing composition
more preferably includes the dialkyl dimethyl butynediol
polyoxyethylene glycol ether and the polyoxyethylene
polyoxypropylene alkyl ether. The dialkyl dimethyl butynediol
polyoxyethylene glycol ether is kind of the addition polymer of
polyoxyalkylene and strongly suppresses the inner portion of the
conductor layer 13 from being removed by chemical etching. In the
chemical formula (2), each of R.sup.5 and R.sup.6 represents a
hydrogen atom or an alkyl group the carbon number of which is any
of integer numbers 1 to 10, and each of m and n represents any of
integer numbers 1 to 20. 5
[0049] The polyethylene oxide is also referred to as polyethylene
glycol and is represented by the following chemical formula (3).
The polypropylene oxide is also referred to as polypropylene glycol
and is represented by the following chemical formula (4). The
average molecular weight of the polyethylene oxide and the
polypropylene oxide is preferably 100 to 10000, more preferably 200
to 1000. If the average molecular weight is less than 100,
occurrence of dishing and erosion is not effectively suppressed. If
the average molecular weight exceeds 10000, the solubility in water
is decreased. A character n in the chemical formula (3) represents
the number average degree of polymerization of ethylene glycol, and
a character m in the chemical formula (4) represents the number
average degree of polymerization of propylene glycol.
H--(OCH.sub.2CH.sub.2).sub.n--OH (3)
H--(OCH (CH.sub.3)CH.sub.2).sub.m--OH (4)
[0050] The polyoxyethylene alkyl ether is combined by addition
polymerization of ethylene oxide with straight chain or branched
higher alcohol. The polyoxyethylene alkyl ether is represented by
the following chemical formula (5). The polyoxypropylene alkyl
ether is combined by addition polymerization of propylene oxide
with straight chain or branched higher alcohol. The
polyoxypropylene alkyl ether is represented by the following
chemical formula (6). In chemical formulas (5) and (6), R
represents an alkyl group, n represents the number average degree
of polymerization of ethylene glycol, and m represents the number
average degree of polymerization of propylene glycol.
R--O--(CH.sub.2CH.sub.2O).sub.n--H (5)
R--O--(CH.sub.2CH(CH.sub.3)O).sub.m (6)
[0051] The polyoxyethylene polyoxypropylene alkyl ether is combined
by addition polymerization of propylene oxide and ethylene oxide
with straight chain or branched higher alcohol. The polyoxyethylene
polyoxypropylene alkyl ether is represented by the following
chemical formula (7). In the chemical formula (7), R represents an
alkyl group, n represents the number average degree of
polymerization of ethylene glycol, and m represents the number
average degree of polymerization of propylene glycol.
R--O--(CH.sub.2CH(CH.sub.3)O).sub.m--(CH.sub.2CH.sub.2O).sub.n--H
(7)
[0052] The proportion of hydrophilic group, or ethylene oxide, in
the molecules of each of the polyoxyethylene alkyl ether, the
polyoxypropylene alkyl ether, the polyoxyethylene polyoxypropylene
alkyl ether, and the addition polymer of polyoxyalkylene is
preferably 10 to 80%. If the proportion is less than 10% or greater
than 80%, occurrence of dishing and erosion is not effectively
suppressed.
[0053] The average molecular weight of each of the polyoxyethylene
alkyl ether, the polyoxypropylene alkyl ether, the polyoxyethylene
polyoxypropylene alkyl ether, and the addition polymer of
polyoxyalkylene is preferably 1000 to 30000, more preferably 2000
to 20000. If the average molecular weight is less than 1000,
occurrence of dishing and erosion is not effectively suppressed. If
the average molecular weight exceeds 30000, the solubility in water
is decreased.
[0054] The content of nonionic organic compound in the second
polishing composition is preferably 2 to 30 g/L, more preferably 4
to 20 g/L. If the content of the nonionic organic compound is less
than 2 g/L, occurrence of dishing and erosion is not effectively
suppressed. If the content of the nonionic organic compound exceeds
30 g/L, the polishing performance of the second polishing
composition deteriorates.
[0055] When the polishing target, which includes the conductor
layer 13 including copper and the barrier layer 14 including
tantalum, is polished with the conventional polishing composition,
an electrochemical reaction occurs between copper and tantalum. As
a result, the conductor layer 13 is selectively removed and dishing
is caused. This is because the conventional polishing composition
functions as an electrolyte during polishing. In contrast, the
second polishing composition according to the preferred embodiment
does not function as an electrolyte during polishing. Therefore,
when polishing with the second polishing composition, occurrence of
dishing due to electrochemical reaction is prevented. The second
polishing composition does not function as an electrolyte during
polishing because the nonionic organic compound included in the
second polishing composition decreases the electric conductivity of
the second polishing composition.
[0056] The corrosion inhibitor serves to suppress corrosion of the
conductor layer 13 during and after polishing, and to suppress
occurrence of dishing and erosion. Each of the second and third
polishing compositions includes at least one of benzotriazole and a
derivative of benzotriazole as the corrosion inhibitor. The
preferable corrosion inhibitor is benzotriazole since the
benzotriazole more reliably prevent corrosion of the conductor
layer 13.
[0057] The benzotriazole and a derivative of benzotriazole are
represented by the following chemical formula (8). In the chemical
formula (8), each of R.sup.7 to R.sup.11 represents a hydrogen atom
or an alkyl group. When R.sup.11 represents an alkyl group, the
alkyl group may include hydroxyl group or carboxyl group. Fourth,
fifth, sixth, and seventh carbon atoms in the chemical formula (8)
may be replaced with nitrogen atoms. A third nitrogen atom may be
replaced with a carbon atom. 6
[0058] Examples of a derivative of benzotriazole are
1-(2,3dihydroxypropyl) benzotriazole, 1-[N, N-Bis (hydroxyethyl)
aminomethyl] benzotriazole, 1-(hydroxymethyl) benzotriazole, and
1-(1,2-dicarboxyethyl) benzotriazole.
[0059] The content of the corrosion inhibitor in each of the second
and third polishing compositions is preferably 0.01 to 0.1 g/L,
more preferably 0.02 to 0.06 g/L. If the content of the corrosion
inhibitor is less than 0.01 g/L, occurrence of dishing and erosion
is not effectively suppressed. If the content of the corrosion
inhibitor exceeds 0.1 g/L, the polishing performance of the
polishing composition deteriorates.
[0060] The acid and alkali serves to accelerate polishing of the
barrier layer 14. The third polishing composition includes at least
one acid selected from the group consisting of nitric acid,
hydrochloric acid, lactic acid, phosphoric acid, sulfuric acid,
acetic acid, oxalic acid, citric acid, tartaric acid, malonic acid,
succinic acid, maleic acid, and fumaric acid, or at least one
alkali selected from the group consisting of potassium hydroxide,
ammonium hydroxide, and sodium hydroxide. The preferable acid is
lactic acid and nitric acid. The preferable alkali is potassium
hydroxide. This is because the lactic acid, nitric acid, and
potassium hydroxide strongly accelerate polishing of the barrier
layer 14.
[0061] The content of acid and the content of alkali in the third
polishing composition are preferably 1 to 20 g/L, more preferably 2
to 10 g/L. If the content of acid or the content of alkali is less
than 1 g/L, polishing of the barrier layer 14 is not effectively
accelerated. If the content of acid or the content of alkali
exceeds 20 g/L, handling of the third polishing composition becomes
difficult.
[0062] When the third polishing composition includes acid, the pH
of the third polishing composition is preferably 2 to 4. If the pH
is less than 2, handling of the third polishing composition becomes
difficult. If the pH exceeds 4, polishing of the barrier layer 14
is not effectively accelerated. When the third polishing
composition includes alkali, the pH of the third polishing
composition is preferably 9 to 11. If the pH exceeds 11, handling
of the third polishing composition becomes difficult. If the pH is
less than 9, polishing of the barrier layer 14 is not effectively
accelerated.
[0063] The hydrogen peroxide serves as an oxidant to accelerate
polishing of the conductor layer 13. The content of the hydrogen
peroxide in the first polishing composition is preferably 1 to 20
g/L, more preferably 3 to 10 g/L. If the content of the hydrogen
peroxide is less than 1 g/L or if the content of the hydrogen
peroxide is greater than 20 g/L, polishing of the conductor layer
13 is not effectively accelerated. The content of the hydrogen
peroxide in the second polishing composition is preferably 1 to 15
g/L, more preferably 2 to 10 g/L. If the content of the hydrogen
peroxide is less than 1 g/L or if the content of the hydrogen
peroxide exceeds 15 g/L, polishing of the conductor layer 13 is not
effectively accelerated. When the third polishing composition
includes the hydrogen peroxide, the content of the hydrogen
peroxide in the third polishing composition is preferably 0.5 to 20
g/L, more preferably 1 to 10 g/L. If the content of the hydrogen
peroxide is less than 0.5 g/L, polishing of the conductor layer 13
is not effectively accelerated. If the content of the hydrogen
peroxide exceeds 20 g/L, dishing and erosion are often caused.
[0064] The water serves as a medium for dispersing and dissolving
components other than water included in each of the first to third
polishing compositions. The water preferably does not include
impurities. The preferable water is filtered ion exchanged water
and distilled water.
[0065] The rate that the first polishing composition polishes the
conductor layer 13 is preferably 5000 to 100000 .ANG./min., more
preferably 7000 to 9000 .ANG./min. If the rate is less than 5000
.ANG./min., the polishing time is increased. If the rate exceeds
10000 .ANG./min., the polishing rate is not easily maintained in a
stable manner.
[0066] The rate that the second polishing composition polishes the
conductor layer 13 is preferably 1000 to 4000 .ANG./min., more
preferably 2000 to 3000 .ANG./min. If the rate is less than 10000
.ANG./min., the polishing time is increased. If the rate exceeds
4000 .ANG./min., dishing and erosion are often caused.
[0067] The rate that the second polishing composition polishes the
conductor layer 13 is preferably 100 to 10000 times the rate that
the second polishing composition polishes the barrier layer 14.
More preferably, the rate that the second polishing composition
polishes the conductor layer 13 is 200 to 800 times the rate that
the second polishing composition polishes the barrier layer 14. If
the rate of polishing the conductor layer 13 is less than 100 times
the rate of polishing the barrier layer 14, the barrier layer 14 is
excessively polished. It is difficult to prepare the second
polishing composition that polishes the conductor layer 13 at the
polishing rate that exceeds 10000 times the rate of polishing the
barrier layer 14.
[0068] The rate that the third polishing composition polishes the
barrier layer 14 is preferably 500 to 1500 .ANG./min., more
preferably 700 to 1000 .ANG./min. If the rate is less than 500
.ANG./min., the polishing time increases. If the rate exceeds 1500
.ANG./min., the polishing speed is not easily maintained in a
stable manner.
[0069] The rate that the third polishing composition polishes the
insulation layer 11 is preferably less than 100 .ANG./min., more
preferably less than 50 .ANG./min. If the rate exceeds 100
.ANG./min., the insulation layer 11 is excessively polished.
[0070] The rate that the third polishing composition that does not
include hydrogen peroxide polishes the conductor layer 13 is
preferably less than 100 .ANG./min., more preferably less than 50
.ANG./min. If the rate exceeds 100 .ANG./min., dishing and erosion
are often caused. The rate that the third polishing composition
that includes hydrogen peroxide polishes the conductor layer 13 is
preferably 100 to 300 .ANG./min., more preferably 150 to 250
.ANG./min. If the rate is less than 100 .ANG./min., the polishing
time increases. If the rate exceeds 300 .ANG./min., dishing and
erosion are often caused.
[0071] It should be apparent to those skilled in the art that the
present invention may be embodied in many other specific forms
without departing from the spirit or scope of the invention.
Particularly, it should be understood that the invention may be
embodied in the following forms.
[0072] Each of the first to third polishing compositions may be
formed by mixing agents that are prepared separately when using the
first, second, or third polishing composition. For example, the
first polishing composition may be prepared by mixing a mixture of
abrasive, a polishing accelerator, and water with hydrogen peroxide
when using the first polishing composition. The second polishing
composition may be prepared by mixing a mixture of abrasive, a
polishing accelerator, a nonionic organic compound, a corrosion
inhibitor, and water with hydrogen peroxide when using the second
polishing composition. The third polishing composition may be
prepared by mixing a mixture of abrasive, acid or alkali, a
corrosion inhibitor, and water with hydrogen peroxide when using
the third polishing composition.
[0073] Alternatively, a main composition, which includes abrasive,
a polishing accelerator, and water; a first sub-composition, which
includes a nonionic organic compound, a corrosion inhibitor, and
water; a second sub-composition, which includes acid or alkali, a
corrosion inhibitor, and water; and hydrogen peroxide may be
prepared in advance. In this case, the first polishing composition
is prepared by mixing the main composition and the hydrogen
peroxide, the second polishing composition is prepared by mixing
the main composition, the first sub-composition, and the hydrogen
peroxide, and the third polishing composition is prepared by mixing
the main composition, the second sub-composition, and hydrogen
peroxide as required.
[0074] In general, liquid that includes abrasive is difficult to
preserve. Therefore, a complicated maintenance is required to
preserve the first to third polishing compositions in a good
condition for a long time. However, as mentioned above, in the case
where each of the first to third polishing compositions is formed
by mixing agents that are separately prepared when using the first,
second, or third polishing composition, only the main composition
includes abrasive during preservation, which reduces the
maintenance process.
[0075] Each of the main composition, the first sub-composition, and
the second sub-composition preferably includes components other
than water at a relatively high density to reduce the transport
cost of the compositions. More specifically, it is preferable that
the main composition is reliably used as the first polishing
composition by diluting the main composition with water that is 2
to 20 times the volume of the main composition and adding hydrogen
peroxide. It is more preferable that the main composition is
reliably used as the first polishing composition by diluting the
main composition with water that is 5 to 15 times the volume of the
main composition and adding hydrogen peroxide. It is preferable
that a mixture of the main composition and the first
sub-composition that is 1 to 9 times the volume of the main
composition is reliably used as the second polishing composition by
diluting the mixture with water that is 1 to 10 times the volume of
the main composition and adding hydrogen peroxide. It is preferable
that a mixture of the main composition and the second
sub-composition that is 1 to 7 times the volume of the main
composition is reliably used as the third polishing composition by
diluting the mixture with water that is 1 to 16 times the volume of
the main composition and adding hydrogen peroxide as required.
[0076] The first polishing composition may further include the
corrosion inhibitor. In this case, when the multilayer is exposed
to the first polishing composition for a long time in the first
step, the conductor layer 13 is prevented from being polished
excessively.
[0077] The present invention will further be described with
examples and comparison examples.
EXAMPLES 1 TO 11 AND COMPARISON EXAMPLES 1 TO 3
[0078] Several main compositions were prepared by mixing abrasive,
which is colloidal silica the average particle size of which is 35
nm; a polishing accelerator, which is .alpha.-alanine or glycine; a
corrosion inhibitor, which is benzotriazole; and water. In the
examples 1 to 8 and the comparison examples 1 to 3, .alpha.-alanine
was used as the polishing accelerator. In the examples 9 to 11,
glycine was used as the polishing accelerator. Several first
polishing compositions were prepared by adding 30% aqueous solution
of hydrogen peroxide and water to the main composition.
[0079] A copper blanket wafer was polished with each first
polishing composition under the following polishing conditions (1)
for one minute. The thickness of each copper blanket wafer was
measured before and after polishing using a sheet resistor"IVR-120"
manufactured by Kokusai Electric System Service Co., Ltd. The
polishing speed was calculated from the difference between the
thicknesses before and after polishing. The result is shown in
Table 1. The copper blanket wafer is manufactured by forming a
copper film on a surface of a silicon wafer by electrolytic
plating.
[0080] The copper pattern wafer, which is 854 mask pattern
manufactured by SEMATECH, Inc., was polished with each first
polishing composition under the following polishing conditions (1).
The copper pattern wafer is manufactured by depositing a barrier
layer, which is formed of tantalum and has the thickness of 250
.ANG., and a conductor layer, which is formed of copper and has the
thickness of 10000 .ANG., on an insulation layer having trenches.
Hollows the depths of which are 8000 .ANG. are formed on portions
of the surface of the conductor layer that correspond to the
trenches. The polishing was terminated when the thickness of the
conductor layer of the copper pattern wafer becomes 2000 .ANG.. The
step height was measured at the 90% high density wiring area of the
copper pattern wafer using a profiler "HRP340" manufactured by
KLA-Tencor Corporation. The result is shown in Table 1.
[0081] Polishing Conditions (1)
[0082] Polishing Machine: Polishing machine "Mirra" for
single-sided
[0083] CMP manufactured by Applied Materials Inc.
[0084] Polishing Pad: Polyurethane polishing pad "IC-1000/Suba400"
manufactured by Rodel Corporation
[0085] Polishing Pressure: 2.5 psi (approx. 17.3 kPa)
[0086] Rotational Speed Of Surface Plate: 90 rpm
[0087] Supply Speed Of First Polishing Composition: 200 ml/min.
[0088] Rotational Speed Of Carrier: 90 rpm
1 TABLE 1 Main Composition First Polishing (g/L) Main Composition
(g/L) Polishing Step Polishing Corrosion Composition:Water
Polishing Corrosion Hydrogen Speed Height Abrasive Accelerator
Inhibitor (Volume Ratio) Abrasive Accelerator Inhibitor Peroxide
(.ANG./min.) (.ANG.) Ex. 1 20 100 0.1 1:9 2 10 0.01 3 6000 150 Ex.
2 150 100 0.1 1:9 15 10 0.01 3 7410 150 Ex. 3 150 25 0.03 1:2 50
8.3 0.01 3 7680 150 Ex. 4 200 100 0.1 1:19 10 5 0.005 3 4420 150
Ex. 5 150 200 0.1 1:9 15 20 0.01 3 8090 210 Ex. 6 150 100 0.1 1:9
15 10 0.01 1 4430 150 Ex. 7 150 100 0.1 1:9 15 10 0.01 10 6990 150
Ex. 8 150 100 0 1:9 15 10 0 3 7920 200 Ex. 9 150 100 0.4 1:9 15 10
0.04 5 4920 150 Ex. 10 150 100 0.4 1:9 15 10 0.04 10 7970 150 Ex.
11 150 100 0.4 1:9 15 10 0.04 20 6980 150 C. Ex. 1 0 100 0.1 1:9 0
10 0.01 3 3010 -- C. Ex. 2 150 0 0.1 1:9 15 0 0.01 3 1510 -- C. Ex.
3 150 100 0.1 1:9 15 10 0.01 0 800 --
[0089] shown in Table 1, the polishing speeds when the first
polishing compositions of the examples 1 to 11 were used were
significantly greater than the polishing speeds when the first
polishing compositions of the comparison examples 1 to 3 were used.
In addition, the maximum step height measured after polishing with
the first polishing compositions of the examples 1 to 11 was as
small as 210 .ANG.. On the other hand, the step height was
incapable of measurement in the comparison examples 1 to 3. This is
because when the first polishing compositions of the comparison
examples 1 to 3 are used, the copper pattern wafer cannot be.
polished till the thickness of the conductor layer becomes 2000
.ANG..
EXAMPLES 12 TO 23 AND COMPARISON EXAMPLES 4 TO 6
[0090] Several main compositions were prepared by mixing colloidal
silica the average particle size of which is 35 nm,
.alpha.-alanine, benzotriazole, and water. Several first
sub-compositions were prepared by mixing nonionic organic compound,
benzotriazole, and water. Several second polishing compositions
were prepared by mixing the main composition, the first
sub-composition, 30% aqueous solution of hydrogen peroxide, and
water. The nonionic organic compound is a mixture of diisobutyl
dimethyl butynediol polyoxyethylene glycol ether represented by the
following chemical formula (8) and polyoxyethylene polyoxypropylene
alkyl ether the molecular weight of which is 8000 in the weight
proportion of 2:1. 7
[0091] The copper blanket wafer, a tantalum blanket wafer, and a
silicon dioxide blanket wafer were polished with each second
polishing composition under the following polishing conditions (2)
for one minute. The thickness of each blanket wafer was measured
before and after polishing. The polishing speed was calculated from
the difference between the thicknesses measured before and after
polishing. The result is shown in Table 2. The thicknesses of the
copper blanket wafer and the tantalum blanket wafer were measured
by the sheet resistor "VR-120." The thickness of the silicon
dioxide blanket wafer was measured by an optical film thickness
gauge "VM-2030" manufactured by Dainippon Screen Mfg. Co., Ltd. The
tantalum blanket wafer is made by forming a tantalum film on the
surface of a silicon wafer by a spattering method. The silicon
dioxide blanket wafer is made by forming a silicon dioxide film on
the surface of a silicon wafer by a CVD method.
[0092] The prepolished copper pattern wafer was polished with each
second polishing composition under the following polishing
conditions (2). The dishing amount at a portion of the copper
pattern wafer that corresponds to the trench the width of which is
10 .mu.m was measured with the profiler "HRP340." The erosion
amount was measured at the 90% high density wiring area of the
copper pattern wafer. The result is shown in Table 2. The
prepolished copper pattern wafer refers to the copper pattern wafer
that is polished with any of the first polishing compositions of
examples 1 to 5 and 8 till the thickness of the conductor layer
becomes 2000 .ANG..
[0093] Polishing Conditions (2)
[0094] Polishing Machine: "Mirra"
[0095] Polishing Pad: Polyurethane polishing pad "IC-1400"
manufactured by Rodel Corporation
[0096] Polishing Pressure: 2 psi (approx. 13.8 kPa)
[0097] Polishing Time: Time required for removing portion of the
conductor layer outside the trenches and half that time.
[0098] Rotational Speed Of Surface Plate: 90 rpm
[0099] Supply Speed Of Second Polishing Composition: 200
ml/min.
[0100] Rotational Speed Of Carrier: 90 rpm
2 TABLE 2 Main Composition First Sub- (g/L) Composition (g/L) Main
Composition: Polishing Corrosion Organic Corrosion First
Sub-Composition:Water Abrasive Accelerator Inhibitor Compound
Inhibitor (Volume Ratio) Ex. 12 20 100 0.1 23 0.06 1:3:6 Ex. 13 150
100 0.1 35 0.1 1:3:11 Ex. 14 150 25 0.03 21 0.05 1:1:1 Ex. 15 200
100 0.1 46 0.16 1:5:27 Ex. 16 150 200 0.1 46 0.15 1:3:16 Ex. 17 150
100 0.1 20 0.1 1:3:11 Ex. 18 150 100 0.1 44.5 0.05 1:9:10 Ex. 19
150 100 0.1 35 0.069 1:3:11 Ex. 20 150 100 0.1 35 0.265 1:3:11 Ex.
21 150 100 0 35 0.14 1:3:11 Ex. 22 150 100 0.1 35 0.1 1:3:11 Ex. 23
150 100 0.1 35 0.1 1:3:11 C. Ex. 4 150 100 0.1 0 0.1 1:3:11 C. Ex.
5 150 100 0 35 0 1:3:11 C. Ex. 6 150 100 0.1 35 0.1 1:3:11 Second
Polishing First Polishing Polishing Speed Composition (g/L)
Composition (.ANG./min.) Dishing Erosion Polishing Organic
Corrosion Hydrogen Used In Silicon Amount Amount Abrasive
Accelerator Compound Inhibitor Peroxide Prepolishing Copper
Tantalum Dioxide (.ANG.) (.ANG.) Ex. 12 2.0 10.0 6.9 0.028 3 Ex. 1
2000 2 2 240 250 Ex. 13 10.0 6.7 7.0 0.027 3 Ex. 2 3540 5 4 240 250
Ex. 14 50.0 8.3 7.0 0.027 3 Ex. 3 3680 15 10 260 310 Ex. 15 6.1 3.0
7.0 0.027 3 Ex. 4 2230 4 3 250 250 Ex. 16 7.5 10.0 6.9 0.028 3 Ex.
5 4050 4 3 300 310 Ex. 17 10.0 6.7 4.0 0.027 3 Ex. 2 3630 5 4 290
290 Ex. 18 7.5 5.0 20.0 0.028 3 Ex. 2 3140 2 1 200 190 Ex. 19 10.0
6.7 7.0 0.020 3 Ex. 2 3930 5 4 310 310 Ex. 20 10.0 6.7 7.0 0.060 3
Ex. 2 2030 5 4 250 240 Ex. 21 10.0 6.7 7.0 0.028 3 Ex. 8 2960 5 4
260 250 Ex. 22 10.0 6.7 7.0 0.027 1 Ex. 2 2020 5 4 260 250 Ex. 23
10.0 6.7 7.0 0.027 10 Ex. 2 2510 5 4 240 260 C. Ex. 4 10.0 6.7 0
0.027 3 Ex. 2 3780 5 4 600 630 C. Ex. 5 10.0 6.7 7.0 0 3 Ex. 8 6620
5 4 820 910 C. Ex. 6 10.0 6.7 7.0 0.027 0 Ex. 2 600 5 4 -- --
[0101] As shown in Table 2, the polishing speeds when the second
polishing compositions of the examples 12 to 23 were used were
fine. In addition, the maximum dishing amount and the maximum
erosion amount measured after polishing with the second polishing
compositions of the examples 12 to 23 were as small as 310 .ANG..
On the other hand, the dishing amount and the erosion amount
measured after polishing with the second polishing compositions of
the comparison examples 4 and 5 were as large as greater than or
equal to 600 .ANG.. The dishing amount and the erosion amount were
incapable of measurement in the comparison example 6. This is
because the copper pattern wafer cannot be polished when the second
polishing composition of the comparison example 6 is used.
EXAMPLES 24 TO 45 AND COMPARISON EXAMPLES 7 TO 10
[0102] Several main compositions were prepared by mixing colloidal
silica the average particle size of which is 35 nm,
.alpha.-alanine, benzotriazole, and water. Several second
sub-compositions were prepared by mixing acid, which is lactic
acid, or alkali, which is potassium hydroxide, benzotriazole, and
water. Several third polishing compositions were prepared by mixing
the main composition, the second sub-composition, water, and 30%
aqueous solution of hydrogen peroxide as required.
[0103] The copper blanket wafer, the tantalum blanket wafer, and
the silicon dioxide blanket wafer were polished with each third
polishing composition under the following polishing conditions (3)
for one minute. The thickness of each blanket wafer was measured
before and after polishing. The polishing speed was calculated from
the difference between the thicknesses measured before and after
polishing. The result is shown in Table 3.
[0104] The copper pattern wafer that is polished in advance was
polished with each third polishing composition under the following
polishing conditions (3). The dishing amount at a portion of the
copper pattern wafer that corresponds to the trench the width of
which is 10 .mu.m was measured using the profiler "HRP340." The
erosion amount was measured at the 90% high density wiring area of
the copper pattern wafer. The result is shown in Table 3. The
copper pattern wafer that is polished in advance is the copper
pattern wafer that is polished with any of the first polishing
compositions of examples 1 to 5 and 8 till the thickness of the
conductor layer becomes 2000 .ANG. and further polished with any of
the second polishing composition of examples 12 to 16 and 21 until
all the portion of the conductor layer outside the trenches is
removed.
[0105] Polishing Conditions (3)
[0106] Polishing Machine: "Mirra"
[0107] Polishing Pad: "IC-1000/Suba400"
[0108] Polishing Pressure: 2.5 psi
[0109] Polishing Time: Twice the time required for removing portion
of the barrier layer outside the trenches.
[0110] Rotational Speed Of Surface Plate: 90 rpm
[0111] Supply Speed Of Third Polishing Composition: 200 ml/min.
[0112] Rotational Speed Of Carrier: 90 rpm
3 TABLE 3 Main Composition Second Sub- Main Composition: (g/L)
Composition (g/L) Second Sub- Polishing Corrosion Corrosion
Composition:Water Abrasive Accelerator Inhibitor Acid Alkali
Inhibitor (Volume Ratio) Ex. 24 20 100 0.1 17 -- 5.3 1:3:6 Ex. 25
150 100 0.1 25 -- 8 1:3:11 Ex. 26 150 25 0.03 15 -- 4.8 1:1:1 Ex.
27 200 100 0.1 33 -- 10.6 1:3:16 Ex. 28 150 200 0.1 25 -- 8 1:3:11
Ex. 29 150 100 0.1 10 -- 8 1:3:11 Ex. 30 150 100 0.1 50 -- 8 1:3:11
Ex. 31 150 100 0.1 25 -- 2.49 1:3:11 Ex. 32 150 100 0.1 11 -- 10.7
1:7:7 Ex. 33 150 100 0.1 25 -- 8 1:3:11 Ex. 34 150 100 0.1 25 -- 8
1:3:11 Ex. 35 20 100 0.1 -- 17 5.3 1:3:6 Ex. 36 150 100 0.1 -- 25 8
1:3:11 Ex. 37 150 25 0.03 -- 15 4.8 1:1:1 Ex. 38 200 100 0.1 -- 33
10.6 1:3:16 Ex. 39 150 200 0.1 -- 25 8 1:3:11 Ex. 40 150 100 0.1 --
10 8 1:3:11 Ex. 41 150 100 0.1 -- 50 8 1:3:11 Ex. 42 150 100 0.1 --
25 2.49 1:3:11 Ex. 43 150 100 0.1 -- 11 10.7 1:7:7 Ex. 44 150 100
0.1 -- 25 8 1:3:11 Ex. 45 150 100 0.1 -- 25 8 1:3:11 C. Ex. 7 150
100 0.1 0 -- 8 1:3:11 C. Ex. 8 150 100 0.1 -- 0 8 1:3:11 C. Ex. 9
150 100 0 25 -- 0 1:3:11 C. Ex. 10 150 100 0 -- 25 0 1:3:11 Third
Polishing Composition (g/L) Polishing Corrosion Hydrogen Abrasive
Accelerator Acid Alkali Inhibitor Peroxide Ex. 24 2.0 10.0 5.1 --
1.60 0 Ex. 25 10.0 6.7 5.0 -- 1.61 0 Ex. 26 50.0 8.3 5.0 -- 1.61 0
Ex. 27 10.0 5.0 5.0 -- 1.60 0 Ex. 28 10.0 13.3 5.0 -- 1.61 0 Ex. 29
10.0 6.7 2.0 -- 1.61 0 Ex. 30 10.0 6.7 10.0 -- 1.61 0 Ex. 31 10.0
6.7 5.0 -- 0.50 0 Ex. 32 10.0 6.7 5.1 -- 5.00 0 Ex. 33 10.0 6.7 5.0
-- 1.61 1 Ex. 34 10.0 6.7 5.0 -- 1.61 10 Ex. 35 2.0 10.0 -- 5.1
1.60 0 Ex. 36 10.0 6.7 -- 5.0 1.61 0 Ex. 37 50.0 8.3 -- 5.0 1.61 0
Ex. 38 10.0 5.0 -- 5.0 1.60 0 Ex. 39 10.0 13.3 -- 5.0 1.61 0 Ex. 40
10.0 6.7 -- 2.0 1.61 0 Ex. 41 10.0 6.7 -- 10.0 1.61 0 Ex. 42 10.0
6.7 -- 5.0 0.50 0 Ex. 43 10.0 6.7 -- 5.1 5.00 0 Ex. 44 10.0 6.7 --
5.0 1.61 1 Ex. 45 10.0 6.7 -- 5.0 1.61 10 C. Ex. 7 10.0 6.7 0 --
1.61 0 C. Ex. 8 10.0 6.7 -- 0 1.61 0 C. Ex. 9 10.0 6.7 5.0 -- 0 0
C. Ex. 10 10.0 6.7 -- 5.0 0 0 First Second Polishing Polishing
Polishing Speed Composition Composition (.ANG./min.) Dishing
Erosion Used In Used In Silicon Amount Amount Prepolishing
Prepolishing Copper Tantalum Dioxide (.ANG.) (.ANG.) Ex. 24 Ex. 1
Ex. 12 30 710 20 140 260 Ex. 25 Ex. 2 Ex. 13 50 690 30 140 240 Ex.
26 Ex. 3 Ex. 14 80 690 100 150 300 Ex. 27 Ex. 4 Ex. 15 50 700 30
140 260 Ex. 28 Ex. 5 Ex. 16 50 710 30 140 250 Ex. 29 Ex. 2 Ex. 13
50 510 30 150 260 Ex. 30 Ex. 2 Ex. 13 50 710 30 150 260 Ex. 31 Ex.
2 Ex. 13 100 690 30 250 300 Ex. 32 Ex. 2 Ex. 13 20 700 30 160 190
Ex. 33 Ex. 2 Ex. 13 200 710 30 210 240 Ex. 34 Ex. 2 Ex. 13 300 690
30 310 290 Ex. 35 Ex. 1 Ex. 12 30 710 20 150 250 Ex. 36 Ex. 2 Ex.
13 50 700 30 160 240 Ex. 37 Ex. 3 Ex. 14 80 700 100 160 300 Ex. 38
Ex. 4 Ex. 15 50 700 30 140 250 Ex. 39 Ex. 5 Ex. 16 50 710 30 150
240 Ex. 40 Ex. 2 Ex. 13 50 510 30 150 250 Ex. 41 Ex. 2 Ex. 13 50
700 30 150 260 Ex. 42 Ex. 2 Ex. 13 100 690 30 250 300 Ex. 43 Ex. 2
Ex. 13 20 690 30 140 200 Ex. 44 Ex. 2 Ex. 13 200 690 30 190 260 Ex.
45 Ex. 2 Ex. 13 300 690 30 300 300 C. Ex. 7 Ex. 2 Ex. 13 50 2 30 --
-- C. Ex. 8 Ex. 2 Ex. 13 50 2 30 -- -- C. Ex. 9 Ex. 8 Ex. 21 990
700 30 820 880 C. Ex. 10 Ex. 8 Ex. 21 1000 690 30 800 870
[0113] As shown in Table 3, the polishing speeds when the third
polishing compositions of the examples 24 to 45 were used were
fine. In addition, the maximum dishing amount and the maximum
erosion amount measured after polishing with the third polishing
compositions of the examples 24 to 45 were as small as 310 .ANG..
On the other hand, the dishing amount and the erosion amount were
incapable of measurement in the comparison examples 7 and 8. This
is because the copper pattern wafer cannot be polished when the
third polishing compositions of the comparison example 7 and 8 are
used. The dishing amount and the erosion amount measured after
polishing with the third polishing compositions of comparison
examples 9 and 10 were as large as greater than or equal to 800
.ANG..
COMPARISON EXAMPLE 11
[0114] The copper pattern wafer was polished with the first
polishing composition of the example 2 under the following
polishing conditions (4). The dishing amount at a portion of the
copper pattern wafer that corresponds to the trench the width of
which is 10 .mu.m was measured using the profiler "HRP340." The
erosion amount was measured at the 90% high density wiring area of
the copper pattern wafer. As a result, the dishing amount and the
erosion amount were as large as 650.ANG..
[0115] Polishing Conditions (4)
[0116] Polishing Machine: "Mirra"
[0117] Polishing Pad: "IC-1400"
[0118] Polishing Pressure: 2 psi
[0119] Polishing Time: Time required for removing portion of the
conductor layer outside the trenches and half that time.
[0120] Rotational Speed Of Surface Plate: 90 rpm
[0121] Supply Speed Of First Polishing Composition: 200 ml/min.
[0122] Rotational Speed Of Carrier: 90 rpm
[0123] The present examples and embodiments are to be considered as
illustrative and not restrictive and the invention is not to be
limited to the details given herein, but may be modified within the
scope and equivalence of the appended claims.
* * * * *