U.S. patent application number 11/143082 was filed with the patent office on 2005-12-15 for single component pad backer for polishing head of an orbital chemical mechanical polishing machine and method therefor.
Invention is credited to Pinder, Harvey.
Application Number | 20050277376 11/143082 |
Document ID | / |
Family ID | 35510298 |
Filed Date | 2005-12-15 |
United States Patent
Application |
20050277376 |
Kind Code |
A1 |
Pinder, Harvey |
December 15, 2005 |
Single component pad backer for polishing head of an orbital
chemical mechanical polishing machine and method therefor
Abstract
A pad backer for a polishing head of an orbital chemical
mechanical polishing (CMP) machine is formed of a flexible pad. A
plurality of holes are formed through the flexible pad. The holes
are used to accommodate tile flow of a polishing liquid from the
underside of the flexible pad. A plurality of grooves are formed on
a backside of the flexible pad for transferring a liquid during the
polishing process.
Inventors: |
Pinder, Harvey; (Mesa,
AZ) |
Correspondence
Address: |
WEISS & MOY PC
4204 NORTH BROWN AVENUE
SCOTTSDALE
AZ
85251
US
|
Family ID: |
35510298 |
Appl. No.: |
11/143082 |
Filed: |
June 2, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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60578987 |
Jun 11, 2004 |
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Current U.S.
Class: |
451/442 |
Current CPC
Class: |
B24B 37/105 20130101;
B24D 11/02 20130101; B24B 37/26 20130101; B24B 37/30 20130101 |
Class at
Publication: |
451/442 |
International
Class: |
B24B 021/18 |
Claims
What is claimed is:
1. A pad backer for a polishing head of an orbital chemical
mechanical polishing (CMP) machine comprising: a flexible pad; a
plurality of holes formed through the flexible pad to accommodate a
flow of a polishing liquid from the underside of the flexible pad;
and a plurality of grooves formed on a backside of the flexible pad
for transferring the polishing liquid to the plurality of
holes.
2. A pad backer for a polishing head of an orbital chemical
mechanical polishing (CMP) machine in accordance with claim 1
wherein the flexible pad is made of a urethane material.
3. A pad backer for a polishing head of an orbital chemical
mechanical polishing (CMP) machine in accordance with claim 1
wherein the flexible pad is a circular flexible pad.
4. A pad backer for a polishing head of an orbital chemical
mechanical polishing (CMP) machine in accordance with claim 1
wherein the holes are spaced around the pad backer to allow for a
fairly uniform flow of polishing liquid from an underside of the
pad backer to a top surface of the pad backer.
5. A pad backer for a polishing head of an orbital chemical
mechanical polishing (CMP) machine in accordance with claim 1
wherein the holes are formed in a plurality of rows and columns
around the pad backer to allow for a fairly uniform flow of
polishing liquid from an underside of the pad backer to a top
surface of the pad backer.
6. A pad backer for a polishing head of an orbital chemical
mechanical polishing (CMP) machine comprising: a flexible pad
member; a plurality of holes formed through the flexible pad to
accommodate a uniform flow of a polishing liquid from the underside
of the flexible pad across a top surface of the flexible pad; and a
plurality of grooves formed on a backside of the flexible pad for
transferring the polishing liquid to the plurality of holes.
7. A pad backer for a polishing head of an orbital chemical
mechanical polishing (CMP) machine in accordance with claim 6
wherein the flexible pad is made of a urethane material.
8. A pad backer for a polishing head of an orbital chemical
mechanical polishing (CMP) machine in accordance with claim 6
wherein the flexible pad is a circular flexible pad.
9. A pad backer for a polishing head of an orbital chemical
mechanical polishing (CMP) machine in accordance with claim 6
wherein the holes are formed in a plurality of rows and columns
around the pad backer to allow for a fairly uniform flow of
polishing liquid from an underside of the pad backer to a top
surface of the pad backer.
10. A pad backer for a polishing head of an orbital chemical
mechanical polishing (CMP) machine comprising: a flexible plate
member, wherein the flexible plate member improves upon achieving a
uniform surface layer of a semiconductor wafer being polished; a
plurality of holes formed through the flexible plate member to
accommodate flow of a polishing liquid from the underside of the
flexible plate member to a top surface of the flexible plate
member; and a plurality of grooves formed on a backside of the
flexible pad for transferring the polishing liquid to the plurality
of holes.
11. A pad backer for a polishing head of an orbital chemical
mechanical polishing (CMP) machine in accordance with claim 10
wherein the flexible plate member improves upon achieving a uniform
surface layer of a semiconductor wafer being polished by allowing
an inflatable air bladder mounted above the pad backer to contact
the entire top surface of the pad backer.
12. A pad backer for a polishing head of an orbital chemical
mechanical polishing (CMP) machine in accordance with claim 10
wherein the flexible plate member is made of a urethane
material.
12. A pad backer for a polishing head of an orbital chemical
mechanical polishing (CMP) machine in accordance with claim 10
wherein the flexible plate member is circular in shape.
13. A pad backer for a polishing head of an orbital chemical
mechanical polishing (CMP) machine in accordance with claim 10
wherein the holes are spaced around the pad backer to allow for a
fairly uniform flow of polishing liquid from an underside of the
pad backer to a top surface of the pad backer.
14. A pad backer for a polishing head of an orbital chemical
mechanical polishing (CMP) machine in accordance with claim 10
wherein the holes are formed in a plurality of rows and columns
around the pad backer to allow for a fairly uniform flow of
polishing liquid from an underside of the pad backer to a top
surface of the pad backer.
Description
RELATED APPLICATIONS
[0001] This patent application is claiming the benefit of the U.S.
Provisional Application having an application number of 60/578,987,
filed Jun. 11, 2004, in the name of Harvey Pinder, and entitled
"SINGLE COMPONENT PAD BACKER FOR POLISHING HEAD OF AN ORBITAL
CHEMICAL MECHANICAL POLISHING MACHINE".
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an orbital chemical
mechanical polishing machine, and more particularly, to a new
single component flexible pad backer for the polishing head of an
orbital chemical mechanical polishing machine.
[0004] 2. Description of the Prior Art
[0005] Chemical mechanical polishing is utilized in the fabrication
of a semiconductor wafer in order to planarize both dielectric and
metallization layers within the semiconductor wafer. The uniformity
or planarization of each layer is critical for several reasons. A
planar layer reduces the step height to facilitate the subsequent
photolithography process. Additionally, a planar layer reduces the
likelihood of accidental coupling of active conductive devices
between different metallization layers. For these reasons, chemical
mechanical polishing (CMP) has become the industry standard by
which to achieve the most uniform or planar surface of each layer
in the semiconductor fabrication process.
[0006] Chemical mechanical polishing (CMP) typically involves
mounting a wafer on a holder (carrier), facing down, and rotating
or, orbiting the wafer against a polishing pad mounted on a
rotating platen or orbiting pad backer. Slurry containing chemical
and abrasive components is applied to the polishing pad between the
pad surface and the face of the wafer. The slurry interacts with
the surface layer of the wafer and thereby physically removes a
portion of the surface layer in order to obtain a planar
surface.
[0007] In the design of an orbital CMP system, the pad backer is
mounted above an inflatable air bladder which is used to control
the amount of pressure applied during the polishing of the wafer.
Therefore, the flexibility of the pad backer becomes critical in
the ability of achieving the desired planer surface of the
semiconductor wafer.
[0008] As shown in FIG. 1, the conventional multi-component pad
backer (100) comprises of a flexible urethane type material (101)
physically mounted or attached to a metal plate (102) by gluing and
riveting (105) the urethane to the metal plate. Additionally, the
urethane portion of the pad backer has grooves (103) scribed into
the top surface to allow for expansion and contraction of the pad
backer during the polishing process. Holes (104) are drilled
through the entire assembly to allow the polishing liquid to pass
through the pad backer to the top surface of the polishing pad. The
backside of the pad backer's metal plate is smooth and therefor
requires a screen or mesh material to be placed between the air
bladder and the pad backer to accommodate the flow of liquid from
the bottom to the top of the pad backer and polishing pad. In FIG.
2, the backside of the conventional multi-component pad backer
(200) comprises of a metal plate (201) and rivets (202) utilized to
hold the metal plate to the urethane portion of the pad backer.
Also shown, are the holes (203) required for liquid transfer to the
topside of the pad backer.
[0009] The conventional multi-component pad backer design reduces
the flexibility of the pad backer through the use of the metal
plate that the urethane is portion of the pad backer is mounted to.
By reducing the flexibility of the pad backer, the planarization
efficiency or uniformity of the polished surface layer of the wafer
is affected.
[0010] A single component flexible packer design greatly increases
the flexibility of the pad backer and thereby improves the
resulting uniformity of the polished surface layer of the wafer to
a more desirable level. Additionally, by comprising the pad backer
of a single material other issues normally related to the usability
of the pad backer can be improved. In the conventional
multi-component pad backer, the usable life of the pad backer is
reduced due to the metal plate bending or deforming to the point
that a planar or uniform surface on the wafer cannot be achieved.
Furthermore, users of the conventional multi-component pad backer
have noted that the glue layer between the urethane and metal
portions of the pad backer breaks down during use and results in
delaminating of the pad backer. Either of these situations has a
negative impact of the planarization of the wafer surface and
renders the pad backer unusable.
[0011] For the previously mentioned reasons, a new single component
flexible urethane or similar material pad backer is invented. By
the use of single component the issues of deforming or delaminating
are eliminated and thereby extending the usable life of the pad
backer. Additionally, by utilizing only the urethane or similar
material for the pad backer, the flexibility of the pad backer is
greatly increased and results in a more planar or uniform polished
surface layer of the wafer. Furthermore, incorporating channels or
grooves for liquid transport into the backside of the pad backer
eliminates the need for a screen or mesh material to be placed
between the air bladder and pad backer.
SUMMARY OF THE INVENTION
[0012] In accordance with one embodiment of the present invention,
it is an object of the present invention to provide a new single
component flexible pad backer.
[0013] It is another object of the present invention to provide a
new single component flexible pad backer that overcomes the
problems associated with conventional multi-component pad
backer.
[0014] It is still another object of the present invention to
provide a single component flexible packer design that increases
the flexibility of the pad backer and thereby improves the
resulting uniformity of the polished surface layer of a wafer to a
more desirable level.
[0015] It is yet another object of the present invention to provide
a single component flexible packer design that increases the
useable life of the packer since in the conventional
multi-component pad backers, the usable life of the pad backer is
reduced due to the metal plate bending or deforming to the point
that a planar or uniform surface on the wafer cannot be
achieved.
[0016] It is still another object of the present invention to
provide a single component flexible packer design that increases
the useable life of the packer since in the conventional
multi-component pad backers, since users of the conventional
multi-component pad backer have noted that the glue layer between
the urethane and metal portions of the pad backer breaks down
during use and results in delaminating of the pad backer.
[0017] It is another object of the present invention to provide a
single component flexible packer design that incorporates channels
or grooves for liquid transport into the backside of the pad backer
thereby eliminating the need for a screen or mesh material to be
placed between the air bladder and pad backer.
BRIEF DESCRIPTION OF THE EMBODIMENTS
[0018] In accordance with one embodiment of the present invention a
pad backer for a polishing head of an orbital chemical mechanical
polishing (CMP) machine is disclosed. The pad backer comprises a
flexible pad member. A plurality of holes are formed through the
flexible pad member. The holes are used to accommodate a flow of a
polishing liquid from the underside of the flexible pad member. A
plurality of grooves are formed on a backside of the flexible pad.
The grooves are used for transferring the polishing liquid to the
plurality of holes.
[0019] In accordance with another embodiment of the present
invention a pad backer for a polishing head of an orbital chemical
mechanical polishing (CMP) machine is disclosed. The pad backer has
a flexible plate member. The flexible plate member improves upon
achieving a uniform surface layer of a semiconductor wafer being
polished. A plurality of holes formed through the flexible plate
member to accommodate flow of a polishing liquid from the underside
of the flexible plate member to a top surface of the flexible plate
member. A plurality of grooves are formed on a backside of the
flexible pad for transferring the polishing liquid to the plurality
of holes.
[0020] The foregoing and other objects, features, and advantages of
the invention will be apparent from the following, more particular,
description of the preferred embodiments of the invention, as
illustrated in the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The novel features believed characteristic of the invention
are set forth in the appended claims. The invention itself, as well
as a preferred mode of use, and advantages thereof, will best be
understood by reference to the following detailed description of
illustrated embodiments when read in conjunction with the
accompanying drawings.
[0022] FIG. 1 is a top view of a conventional multi-component pad
backer for an orbital chemical mechanical polishing machine.
[0023] FIG. 2 is a bottom view of a conventional multi-component
pad backer for an orbital chemical mechanical polishing
machine.
[0024] FIG. 3 is a top view of a single component flexible pad
backer for an orbital chemical mechanical polishing machine of the
present invention.
[0025] FIG. 4 is a bottom view of a single component flexible pad
backer for an orbital chemical mechanical polishing machine of the
present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0026] Referring to FIG. 1, a conventional multi-component pad
backer (100) is shown. The multi-component pad backer (100) is
comprised of a flexible type material (101) physically mounted and
attached to a metal plate (102). The flexible type material (101)
is generally mounted and attached to the metal plate (102) by
gluing and riveting (105) the flexible type material (101) to the
metal plate (102). The flexible type of material (101) of the
multi-component pad backer (100) has grooves (103) scribed into the
top surface of the flexible type of material (101). The grooves are
used to allow for expansion and contraction of the multi-component
pad backer (100) during the polishing process.
[0027] Holes (104) are drilled through the multi-component pad
backer (100). The holes are used to allow the polishing liquid to
pass through the multi-component pad backer (100) to the top
surface of the polishing pad. The backside of the pad backer's
metal plate (102) is smooth and therefor requires a screen or mesh
material to be placed between the air bladder and the pad backer
(100) to accommodate the flow of liquid from the bottom to the top
of the pad backer (100) and polishing pad.
[0028] In FIG. 2, the backside of the conventional multi-component
pad backer (100) is shown. As may be seen, the pad backer 100
comprises the metal plate (102) and rivets (105) utilized to hold
the metal plate to the urethane portion of the pad backer. Also
shown, are the holes (104) required for liquid transfer to the
topside of the pad backer.
[0029] The conventional multi-component pad backer disclosed above
reduces the flexibility of the pad backer since the metal plate is
mounted to the flexible urethane portion. By reducing the
flexibility of the pad backer, the planarization efficiency or
uniformity of the polished surface layer of the wafer is
affected.
[0030] Referring to FIGS. 3 and 4, a single component flexible pad
backer (300) for an orbital chemical mechanical polishing (CMP)
machine is shown. FIG. 3 is a top view of the single component
flexible pad backer (300) and FIG. 4 is a bottom view of the single
component flexible pad backer (300) for an orbital chemical
mechanical polishing (CMP) machine according to a preferred
embodiment of the present invention.
[0031] As shown in FIG. 3, a top view of a single component
flexible pad backer (300) is provided. The single component
flexible pad backer (300) comprises a molded urethane or similar
type flexible material. The single component flexible pad backer
(300) has a smooth surface. Holes (301) are formed through the pad
backer (300) to accommodate tile flow of the polishing liquid from
the underside of the pad backer (300) to the top surface of the
polishing pad that will be mounted to the top surface of the
described pad backer (300). The holes (301) are spaced around the
pad backer (300) to allow for a fairly uniform flow of polishing
liquid from the underside of the pad backer (300) to the top
surface of the pad backer (300). As seen in FIG. 3, the holes (301)
are formed in a plurality of rows and columns on the top surface of
the pad backer (300). However, this should not be seen as to limit
the scope of the present invention. The holes may be formed in any
pattern as long as the holes (301) are spaced around the pad backer
(300) to allow for a fairly uniform flow of polishing liquid from
the underside of the pad backer (300) to the top surface of the pad
backer (300).
[0032] As shown in FIG. 4, a bottom view of a single component
flexible pad backer (300) is shown. The molded urethane or similar
type flexible material has grooves or channels (302) formed into
the backside of the described pad backer (300). The grooves or
channels (302) are used to accommodate the flow of the polishing
liquid from the underside of the pad backer (300) through the holes
(301) without the use of a separate screen or mesh material that is
normally placed between the air bladder and the pad backer
(300).
[0033] The flexibility of the described single component flexible
pad backer is much greater than that of any prior art or
conventional multi-component pad backers presently used in the
orbital chemical mechanical polishing (CMP) machines. This
increased flexibility greatly improves upon achieving the desired
level of a planar or uniform surface layer of the semiconductor
wafer being polished since the pad backer is mounted above an
inflatable air bladder which is used to control the amount of
pressure applied during the polishing of the wafer. The flexible
pad backer allows for a more uniform pressure to be applied to the
entire surface of pad backer. Therefore, the flexibility of the pad
backer becomes critical in the ability of achieving the desired
planer surface of the semiconductor wafer.
[0034] Additionally, the single component design has fewer parts
prone to failure and thereby will provide a longer usable life of
the described pad backer.
[0035] While the invention has been particularly shown and
described with reference to preferred embodiments thereof, it will
be understood by those skilled in the art that the foregoing and
other changes in form and details may be made therein without
departing from the spirit and scope of the invention.
* * * * *