U.S. patent application number 14/340686 was filed with the patent office on 2015-08-13 for polish cloth and method of manufacturing polish cloth.
This patent application is currently assigned to Kabushiki Kaisha Toshiba. The applicant listed for this patent is Kabushiki Kaisha Toshiba. Invention is credited to Tohru KAWAGUCHI.
Application Number | 20150224622 14/340686 |
Document ID | / |
Family ID | 53774129 |
Filed Date | 2015-08-13 |
United States Patent
Application |
20150224622 |
Kind Code |
A1 |
KAWAGUCHI; Tohru |
August 13, 2015 |
POLISH CLOTH AND METHOD OF MANUFACTURING POLISH CLOTH
Abstract
A polish cloth including a polish layer having a polish surface
configured to contact a polish object; a recess formed into the
polish surface; and a coating applied at least along a bottom
surface of the recess, the coating being made of a water repellant
and oil repellant material.
Inventors: |
KAWAGUCHI; Tohru;
(Higashiomi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Kabushiki Kaisha Toshiba |
Minato-ku |
|
JP |
|
|
Assignee: |
Kabushiki Kaisha Toshiba
Minato-ku
JP
|
Family ID: |
53774129 |
Appl. No.: |
14/340686 |
Filed: |
July 25, 2014 |
Current U.S.
Class: |
451/527 ;
427/402 |
Current CPC
Class: |
B24B 37/22 20130101;
B24B 37/24 20130101; B24B 37/26 20130101 |
International
Class: |
B24B 37/26 20060101
B24B037/26; B24B 37/22 20060101 B24B037/22 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 13, 2014 |
JP |
2014-025523 |
Claims
1. A polish cloth comprising: a polish layer having a polish
surface configured to contact a polish object; a recess formed into
the polish surface; and a coating applied at least along a bottom
surface of the recess, the coating being made of a water repellant
and oil repellant material.
2. The polish cloth according to claim 1, wherein the coating is
further applied along a side surface of the recess.
3. The polish cloth according to claim 1, wherein the polish
surface further includes an uncoated region, the uncoated region
occupying a region exclusive of the recess.
4. The polish cloth according to claim 1, wherein a fluid contact
angle in the recess ranges from 100 to 180 degrees.
5. The polish cloth according to claim 2, wherein a fluid contact
angle in the recess ranges from 100 to 180 degrees.
6. The polish cloth according to claim 3, wherein a fluid contact
angle in the recess ranges from 100 to 180 degrees.
7. The polish cloth according to claim 1, wherein the polish layer
further includes a foam hole.
8. The polish cloth according to claim 2, wherein the polish layer
further includes a foam hole.
9. The polish cloth according to claim 3, wherein the polish layer
further includes a foam hole.
10. The polish cloth according to claim 4, wherein the polish layer
further includes a foam hole.
11. A method of manufacturing a polish cloth, the method
comprising: forming a polish layer having a polish surface
configured to contact a polish object; forming a recess into the
polish surface; applying a coating entirely above the polish
surface including the recess, the coating being formed of a water
repellant and oil repellant material; and removing the coating
located in regions of the polish surface exclusive of the recess so
that the coating remains at least along a bottom surface of the
recess.
12. The method according to claim 11, wherein the removing leaves
the coating along a side surface of the recess.
13. The method according to claim 11, wherein the removing forms an
uncoated region in the polish surface, the uncoated region
occupying a region exclusive of the recess.
14. The method according to claim 11, wherein the applying
increases a fluid contact angle in the recess so as to range from
100 degrees to 180 degrees.
15. The method according to claim 12, wherein the removing
increases a fluid contact angle in the recess so as to range from
100 degrees to 180 degrees.
16. The method according to claim 13, wherein the removing
increases a fluid contact angle in the recess so as to range from
100 degrees to 180 degrees.
17. The method according to claim 11, wherein forming the polish
layer forms a foam hole in the polish layer.
18. The method according to claim 12, wherein forming the polish
layer forms a foam hole in the polish layer.
19. The method according to claim 13, wherein forming the polish
layer forms a foam hole in the polish layer.
20. The method according to claim 14, wherein forming the polish
layer forms a foam hole in the polish layer.
Description
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application is based upon and claims the benefit of
priority from Japanese Patent Application No. 2014-025523, filed
on, Feb. 13, 2014 the entire contents of which are incorporated
herein by reference.
FIELD
[0002] Embodiments disclosed herein generally relate to a polish
cloth and a method of manufacturing the polish cloth.
BACKGROUND
[0003] Chemical mechanical polishing (CMP) is frequently used in
semiconductor device manufacturing. A rotary CMP apparatus
typically polishes the polish object such as a wafer by placing the
polish object in contact with a polish cloth and supplying slurry
onto the polish cloth while rotating the polish head and the table
at the same time. The polish surface of the polish cloth is
provided with multiplicity of recesses such as holes and trenches.
Thus, wastes or foreign substances such as abrasive grains and
chemical components of the slurry, polish dust, and polish residue
accumulate in the recesses of the polish surface as increasing
number of wafers are polished. Such residual waste may stick to the
wafer or damage the wafer and possibly degrade the polish
performance of the wafer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1 is one example of a perspective view illustrating one
embodiment of a polish cloth.
[0005] FIG. 2 is one example of a partially-enlarged vertical
cross-sectional view illustrating one embodiment of the polish
cloth.
[0006] FIGS. 3A to 3C are examples of vertical cross-sectional
views illustrating the manufacturing process flow of one embodiment
of the polish cloth.
[0007] FIG. 4 is one example of a partially-enlarged vertical
cross-sectional view illustrating holes, trenches, and their
peripheral structures provided in one embodiment of the polish
cloth.
[0008] FIG. 5 is one example of a partially-enlarged vertical
cross-sectional view illustrating a foam hole formed in a polish
layer provided in one embodiment of the polish cloth.
DESCRIPTION
[0009] In one embodiment, a polish cloth includes a polish layer
having a polish surface configured to contact a polish object; a
recess formed into the polish surface; and a coating applied at
least along a bottom surface of the recess, the coating being made
of a water repellant material or an oil repellant material.
Embodiments
[0010] Embodiments are described hereinafter with references to the
accompanying drawings. Elements that are identical or similar
across the embodiments are identified with identical or similar
reference symbols and may not be re-described.
First Embodiment
[0011] A description will be given on one embodiment of a polish
cloth and a method of manufacturing the polish cloth with
references to the accompanying drawings. FIG. 1 illustrates one
example of polish cloth 10 configured for attachment to a rotary
CMP apparatus not shown. Polish cloth 10 is generally shaped like a
disc and includes polish layer 11 and sub-pad layer 12. Though not
described in detail, the CMP apparatus, as known in the art, is
provided with components such as a rotary table, a slurry
dispenser, and a dresser. The rotary table holds polish cloth 10.
The slurry dispenser supplies the slurry to polish surface 13 of
polish cloth 10. The dresser dresses polish surface 13 of polish
cloth 10.
[0012] Polish layer 11 of polish cloth 10 comprises a foamed resin
such as a foamed polyurethane. Thus, foam holes 11a are formed
inside polish layer 11 as well as on the surface of polish layer 11
as shown in FIG. 5. The upper surface of polish layer 11 serves as
polish surface 13. Polish surface 13 contacts the polish object,
one example of which is a wafer, during the polishing process of
the CMP apparatus. Multiplicity of holes 14 and trenches 15 are
formed in polish surface 13. Holes 14 and trenches 15 are examples
of a recess. During the polishing process of the CMP apparatus,
slurry is supplied onto polish surface 13 by the slurry dispenser
not shown. The slurry contains polish agents such as abrasive
grains and chemical components but is mostly made of water. Sub-pad
layer 12 is configured by an unwoven fabric for example and is in
intimate contact with the undersurface of polish layer 11 in the
opposite side of polish surface 13.
[0013] As shown in FIG. 2 for example, coating C is applied along
the inner surface of hole 14 or more specifically, along the bottom
surface and the side surface (or both side surfaces when viewed in
the cross section of FIG. 2) of hole 14. Coating C comprises a
water repellant and oil repellant material. Coating C is also
applied along the inner surface of trench 15 or more specifically,
along the bottom surface and the side surface of trench 15. In one
embodiment, the thickness of coating C ranges from tens of
nanometers (nm) to several micrometers (.mu.m). Various types of
organic resins may be employed as the water repellant and oil
repellent material. Among such resins, it is preferable to use a
fluorine-based resin. In the description given herein, a material
possessing water repellency and oil repellency is also referred to
as "water repellant and oil repellant material". Coating C
comprising water repellant and oil repellant material is applied
along holes 14 and trenches 15 of polish cloth 10. Thus, the
contact angle of fluid within holes 14 and trenches 15 is
increased. In one embodiment, the fluid is a slurry made mostly of
water.
[0014] The contact angle of the slurry in holes 14 and trenches 15
is preferably increased as much as possible and is preferably at
least 100 degrees or greater. In other words, coating C is
preferably made of a material that increases the contact angle of
the slurry in holes 14 and trenches 15. For example, coating C
maybe formed that provides a significantly high contact angle of
150 degrees or higher. In another example, coating C may be formed
that provides an exceptionally high contact angle of 180 degrees
substantially reaching the upper limit. Thus, in the present
embodiment, a "high contact angle" ranges from 100 degrees to 180
degrees, in other words, equal to or greater than 100 degrees and
equal to or less than 180 degrees. Further, applying coating C,
comprising water repellant and oil repellant material, to holes 14
and trenches 15 of polish cloth 10 reduces the friction coefficient
in holes 14 and trenches 15.
[0015] Further, applying coating C, comprising water repellant and
oil repellant material, to trenches 15 of polish cloth 10 improves
slurry discharge efficiency in trenches 15. Trenches 15 throw off
the slurry from polish cloth 10 with centrifugal force exerted by
the rotation of polish cloth 10 during the polishing process.
[0016] Next, a description will be given on one example of a
manufacturing process flow of polish cloth 10 with reference FIGS.
3A to 3C. In the present embodiment, the manufacturing process
includes a coating step and a dressing step.
[0017] In the coating step illustrated in FIG. 3A for example,
coating C comprising water repellant and oil repellant material is
formed entirely across polish surface 13 including holes 14 and
trenches 15. A film of coating C may be formed by dipping the
molded polish cloth 10 into a solution of the water repellant and
oil repellant material. Alternatively, a film of coating C may be
formed above the molded polish cloth 10 by gasifying the water
repellant and oil repellant material. Examples of methods for
forming a film of coating C above polish cloth 10 using gasified
water repellant and oil repellant material include PVD (Physical
Vapor Deposition), CVD (Chemical Vapor Deposition), or the like
known in the art.
[0018] Next, in the dressing step illustrated in FIG. 3B for
example, the dresser not shown is used to dress the regions of
polish surface 13 covered by coating C exclusive of holes 14 and
trenches 15. As a result, portions above the broken line indicated
in FIG. 3B for example are removed, consequently removing coating C
formed in regions of polish surface 13 exclusive of holes 14 and
trenches 15. Thus, as illustrated in FIG. 3C for example, the
foregoing manufacturing process flow produces polish cloth 10 in
which coating C, comprising water repellant and oil repellant
material, remain along the bottom surface and side surface of each
hole 14 and trench 15. The regions of polish surface 13 exclusive
of holes 14 and trenches 15, in other words, the regions dressed in
the dressing step are referred to as uncoated regions D which are
not coated with the water repellant and oil repellant material.
Uncoated regions D contact the wafer during the polishing process
and thus, contribute to the polishing of the wafer.
[0019] In polish cloth 10 manufactured in the above described
manner, slurry does not easily remain in holes 14 because of the
water repellant and oil repellant effect of coating C. In trenches
15, slurry is easily discharged from polish cloth 10 by the water
repellant and oil repellant effect of coating C and further by the
centrifugal force exerted by the rotation of polish cloth 10. Thus,
waste does not easily remain in holes 14 and trenches 15. Further,
waste remaining in holes 14 and trenches, if any, can be discharged
rapidly. As a result, it is possible to prevent the growth and
enlargement of waste remaining in holes 14 and trenches 15.
[0020] In the schematic example illustrated in FIG. 4, holes 14 and
trenches 15 are closed by wafer W during the polishing process. As
illustrated, coating C possessing water repellency and oil
repellency is applied along the bottom surfaces of holes 14 and
trenches 15. Thus, as indicated by arrow A for example, slurry
inside holes 14 and trenches 15 is restrained from moving downward
and thus is moved upward. Further, coating C possessing water
repellency and oil repellency is applied along the side surfaces of
holes 14 and trenches 15. Thus, as indicated by arrow B for
example, slurry inside holes 14 and trenches 15 is restrained from
moving outward and thus is moved inward. As a result, the
convective flow of slurry inside holes 14 and trenches 15 is
reinforced by the flow of slurry, such as those indicated by arrows
A and B, produced inside holes 14 and trenches 15. This increases
the contact percentage of slurry to wafer W and consequently
improves the polish rate.
[0021] In the present embodiment, coating C comprising water
repellant and oil repellant material is applied along the bottom
surfaces and side surfaces of holes 14 and trenches 15 formed into
polish surface 13 of polish cloth 10 contacting the wafer. Polish
cloth 10 configured in the above described manner does not allow
waste to easily remain in holes 14 and trenches 15 formed into
polish surface 13.
[0022] Further in the present embodiment, the regions of polish
surface 13 of polish cloth 10 exclusive of holes 14 and trenches 15
are referred to as uncoated regions D which are not coated with the
water repellant and oil repellant material. In other words, coating
C is not applied to the regions of polish cloth 10 that contact the
wafer during the polishing process and that contribute to wafer
polishing. As a result, the polish performance is not reduced by
coating C.
[0023] Still further in the present embodiment, multiplicity of
foam holes 11a are formed in polish layer 11 of polish cloth 10.
Thus, multiplicity of foam holes 11a also exist in the bottom
surfaces and side surfaces of holes 14 and trenches 15 formed in
polish layer 11. However coating C is applied along the bottom
surfaces and side surfaces of holes 14 and trenches 15 of polish
cloth 10, meaning that foam holes 11a existing in the surfaces of
holes 14 and trenches 15 are covered by coating C. Thus, it is
possible to inhibit accumulation of waste in foam holes 11a
existing in the surfaces of holes 14 and trenches 15.
[0024] As described above, the present embodiment provides a polish
cloth in which waste does not easily remain in the recesses formed
into the polish surface. The present embodiment further provides an
optimal manufacturing process flow for manufacturing of the polish
cloth.
[0025] While certain embodiments have been described, these
embodiments have been presented by way of example only, and are not
intended to limit the scope of the inventions. Indeed, the novel
embodiments described herein may be embodied in a variety of other
forms; furthermore, various omissions, substitutions and changes in
the form of the embodiments described herein may be made without
departing from the spirit of the inventions. The accompanying
claims and their equivalents are intended to cover such forms or
modifications as would fall within the scope and spirit of the
inventions.
[0026] For example, the polish cloth may be configured so that the
coating, possessing water repellant and oil repellant material, is
applied at least along the bottom surface of each recess formed
into the polish surface.
* * * * *