U.S. patent application number 16/037783 was filed with the patent office on 2019-01-31 for method of identifying and tracking roll to roll polishing pad materials during processing.
The applicant listed for this patent is Applied Materials, Inc.. Invention is credited to Jay GURUSAMY, Wai- Ming KAN, David J. LISCHKA, Jeonghoon OH, Steven M. REEDY, Erik RONDUM, Robert D. TOLLES, Steven M. ZUNIGA.
Application Number | 20190030677 16/037783 |
Document ID | / |
Family ID | 65040754 |
Filed Date | 2019-01-31 |
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United States Patent
Application |
20190030677 |
Kind Code |
A1 |
OH; Jeonghoon ; et
al. |
January 31, 2019 |
METHOD OF IDENTIFYING AND TRACKING ROLL TO ROLL POLISHING PAD
MATERIALS DURING PROCESSING
Abstract
Implementations described herein generally relate to methods and
apparatus for polishing substrates, more particularly, to methods
and apparatus for identifying and/or tracking polishing material in
a roll-to-roll polishing system. In one implementation, a method of
polishing a substrate is provided. The method comprises advancing a
polishing material across a surface of a platen. The polishing
material has a polishing surface and an opposing backside surface
and the backside surface has a pattern of identifying features
formed thereon. The method further comprises sensing the movement
of the pattern of identifying features past a detector assembly.
The method further comprises controlling a position of the
polishing material relative to the platen based on data received
from the sensed movement of the pattern of identifying
features.
Inventors: |
OH; Jeonghoon; (Saratoga,
CA) ; LISCHKA; David J.; (Austin, TX) ;
RONDUM; Erik; (San Ramon, CA) ; GURUSAMY; Jay;
(Santa Clara, CA) ; TOLLES; Robert D.; (San Jose,
CA) ; ZUNIGA; Steven M.; (Soquel, CA) ; REEDY;
Steven M.; (San Ramon, CA) ; KAN; Wai- Ming;
(San Ramon, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Applied Materials, Inc. |
Santa Clara |
CA |
US |
|
|
Family ID: |
65040754 |
Appl. No.: |
16/037783 |
Filed: |
July 17, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62538300 |
Jul 28, 2017 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B24B 37/16 20130101;
B24B 49/105 20130101; B24B 37/24 20130101; B24B 37/26 20130101;
B24B 21/004 20130101; B24B 27/0023 20130101; B24B 49/12 20130101;
B24B 37/005 20130101; B24B 21/20 20130101; B24B 21/008
20130101 |
International
Class: |
B24B 37/24 20060101
B24B037/24; B24B 37/005 20060101 B24B037/005 |
Claims
1. An apparatus for polishing a substrate, comprising: a polishing
module, comprising: a platen for supporting a polishing material
having a polishing surface and an opposing backside surface,
wherein the backside surface has a plurality of identifying
features formed thereon; a supply assembly adapted to provide the
polishing material to the platen; and a take-up assembly adapted to
receive the polishing material transferred across at least a
portion of the platen from the supply assembly; one or more
detector assemblies disposed adjacent to the backside surface of
the polishing material, wherein the one or more detector assemblies
are positioned to sense a change in position of the plurality of
identifying features formed on the backside surface as the
polishing material is transferred between the supply assembly and
the take-up assembly; and a system controller adapted to receive a
signal from the one or more detector assemblies and control the
position of the polishing material relative to the platen using an
actuator coupled to at least one of the supply assembly and the
take-up assembly.
2. The apparatus of claim 1, wherein each of the one or more
detector assemblies further comprise: an electromagnetic radiation
source mounted proximate to the backside surface of the polishing
material and adapted to emit electromagnetic radiation; and a
detector mounted proximate to the backside surface of the polishing
material and adapted to detect the variation of intensity of the
electromagnetic radiation delivered from the electromagnetic
radiation source after interacting with the plurality of
identifying features formed on the backside surface.
3. The apparatus of claim 1, wherein each of the one or more
detector assemblies further comprise: an electromagnetic radiation
source mounted proximate to the backside surface of the polishing
material and adapted to emit electromagnetic radiation; and a
detector mounted proximate to the polishing surface of the
polishing material opposite the electromagnetic radiation source
and adapted to detect the variation of intensity of the
electromagnetic radiation delivered from the electromagnetic
radiation source after interacting with the plurality of
identifying features formed on the backside surface.
4. The apparatus for claim 1, wherein the polishing material is a
continuous sheet of material that has one end coupled with the
supply assembly and a second end coupled with the take-up
assembly.
5. The apparatus of claim 1, wherein the plurality of identifying
features includes regularly spaced regions of deposited material or
holes within the polishing material.
6. The apparatus of claim 1, wherein the plurality of identifying
features includes a first start of line feature, which identifies a
start of a first polishing region of polishing material, and a
second start of line feature, which identifies an end of the first
polishing region and a start of a second polishing region of
polishing material.
7. The apparatus of claim 6, wherein the first polishing region of
polishing material and the second polishing region of polishing
material have similar or substantially similar patterns of
polishing features.
8. The apparatus of claim 1, wherein each of the one or more
detector assemblies comprise a capacitive type sensor, an optical
measurement sensor, or an eddy current measurement sensor.
9. The apparatus of claim 1, wherein the polishing material,
comprises a polymeric sheet.
10. The apparatus of claim 9, wherein the polishing material has: a
plurality of discrete elements formed in the polishing surface and
extending upward from the polishing surface; and a plurality of
grooves extending from the polishing surface toward the backside
surface.
11. The apparatus of claim 10, wherein the grooves define a
repeating pattern in the polishing surface.
12. A method of polishing a substrate, comprising: advancing a
polishing material across a surface of a platen, wherein the
polishing material has a polishing surface and an opposing backside
surface, wherein the backside surface has a pattern of identifying
features formed thereon; sensing the movement of the pattern of
identifying features past a detector assembly; and controlling a
position of the polishing material relative to the platen based on
data received from the sensed movement of the pattern of
identifying features.
13. The method of claim 12, further comprising: halting the
polishing material traveling across the surface of the platen when
the detector assembly senses identifying features that indicate the
start of a first region of polishing material having a desired
pattern of polishing features; urging a substrate toward the
polishing material on the platen; rotating the platen; removing
material from a surface of the substrate; and advancing the
polishing material relative to the platen after removing material
from the surface of the substrate.
14. The method of claim 13, further comprising: halting the
polishing material across the surface of the platen when the
detector assembly senses identifying features that indicate the
start of a second region of polishing material having the desired
pattern of polishing features.
15. The method of claim 14, wherein the polishing features are
selected from at least one of a plurality of discrete elements
formed in the polishing surface and extending upward from the
polishing surface and a plurality of grooves extending from the
polishing surface toward the backside surface.
Description
BACKGROUND
Field
[0001] Implementations described herein generally relate to methods
and apparatus for polishing substrates, more particularly, to
methods and apparatus for identifying and/or tracking movement of a
polishing material in a roll-to-roll polishing system during
processing.
Description of the Related Art
[0002] Chemical mechanical polishing (CMP) is a conventional
process used in many different industries to planarize surfaces of
substrates. In the semiconductor industry, uniformity of polishing
and planarization has become increasingly important as device
feature sizes continue to decrease. During a CMP process, a
substrate, such as a silicon wafer, is mounted on a carrier head
with the device surface placed against a moving polishing pad. The
carrier head provides a controllable load on the substrate to push
the device surface of the substrate against the moving polishing
pad. A polishing slurry, including an abrasive and at least one
chemically reactive agent, is typically supplied to the moving
polishing pad to provide an abrasive chemical solution at the
interface between the pad and the substrate. The polishing pad and
the carrier head apply mechanical energy to the substrate, while
the pad also helps to control the transport of slurry, which
interacts with the substrate during the polishing process.
[0003] An effective CMP process not only provides a high polishing
rate, but also provides a substrate surface which lacks small-scale
roughness, contains minimal defects and is flat, i.e., lacks large
scale topography. In addition, an effective CMP process also
provides consistent polishing results or "repeatability" between
substrates in a batch (e.g., 25 substrates). Polishing a substrate
with uncontrolled, misaligned or improperly positioned polishing
material relative to the carrier head and substrate can adversely
affect the process results and process repeatability between
substrates within a batch, which affects device yield.
[0004] Issues with the proper positioning of a desirable portion of
a polishing pad relative to each processed substrate is
increasingly important when the pad is not fixed, and is indexable,
relative to the platen that the pad is positioned over, such as
found in roll-to-roll polishing pad configurations. Moreover, the
accuracy of placement of the polishing material relative to the
substrate and the carrier head can affect the cost to produce
semiconductor devices and the cost of ownership of a semiconductor
device production line.
[0005] Therefore, there is a need for an improved apparatus and
methods for identifying and/or tracking movement of a polishing
material in a roll-to-roll polishing system that address some of
the aforementioned concerns.
SUMMARY
[0006] Implementations described herein generally relate to methods
and apparatus for polishing substrates, more particularly, to
methods and apparatus for identifying and/or tracking polishing
material in a roll-to-roll polishing system. In one implementation,
an apparatus for polishing a substrate is provided. The apparatus
comprises a polishing module. The polishing module comprises a
platen for supporting a polishing material having a polishing
surface and an opposing backside surface, wherein the backside
surface has a plurality of identifying features formed thereon. The
polishing module further comprises a supply assembly that is
adapted to provide the polishing material to the platen and a
take-up assembly that is adapted to receive the polishing material
transferred across at least a portion of the platen from the supply
assembly. The apparatus further comprises one or more detector
assemblies disposed adjacent to the backside surface of the
polishing material. The one or more detector assemblies are
positioned to sense a change in position of the plurality of
identifying features formed on the backside surface as the
polishing material is transferred between the supply assembly and
the take-up assembly. The apparatus further comprises a system
controller adapted to receive a signal from the one or more
detector assemblies and control the position of the polishing
material relative to the platen using an actuator coupled to at
least one of the supply assembly and the take-up assembly.
[0007] In another implementation, a method of polishing a substrate
is provided. The method comprises advancing a polishing material
across a surface of a platen. The polishing material has a
polishing surface and an opposing backside surface and the backside
surface has a pattern of identifying features formed thereon. The
method further comprises sensing the movement of the pattern of
identifying features past a detector assembly. The method further
comprises controlling a position of the polishing material relative
to the platen based on data received from the sensed movement of
the pattern of identifying features.
[0008] In yet another implementation, a polishing article is
provided. The polishing article comprises a linear polymeric sheet
having a length that extends in a first direction. The linear
polymeric sheet has a backside surface having a plurality of
identifying features formed in an array extending in the first
direction thereon. The linear polymeric sheet has an opposing
polishing surface having a plurality of polishing features selected
from at least one of a plurality of discrete elements formed in the
polishing surface and extending upward from the polishing surface
and a plurality of grooves extending from the polishing surface
toward the backside surface. At least one of the plurality of
identifying features is positioned a first distance in the first
direction from at least one of the plurality of polishing features,
and the plurality of identifying features are each configured to
interact with electromagnetic radiation provided from a source.
[0009] In yet another implementation, an apparatus for polishing a
substrate is provided. The apparatus comprises a polishing module.
The polishing module comprises a polishing material having a
polishing surface and an opposing backside surface. The backside
surface has a plurality of identifying features formed thereon. The
polishing module further includes a platen for supporting the
polishing material, a supply assembly that is adapted to provide
the polishing material to the platen, and a take-up assembly that
is adapted to receive the polishing material transferred across at
least a portion of the platen from the supply assembly. The
apparatus further comprises one or more detector assemblies
disposed adjacent to the backside surface of the polishing
material. The one or more detector assemblies are positioned to
sense a change in position of the plurality of identifying features
formed on the backside surface as the polishing material is
transferred between the supply assembly and the take-up assembly.
The apparatus further comprises a system controller adapted to
receive a signal from the one or more detector assemblies and
control the position of the polishing material relative to the
platen using an actuator coupled to at least one of the supply
assembly and the take-up assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] So that the manner in which the above-recited features of
the present disclosure can be understood in detail, a more
particular description of the implementations, briefly summarized
above, may be had by reference to implementations, some of which
are illustrated in the appended drawings. It is to be noted,
however, that the appended drawings illustrate only typical
implementations of this disclosure and are therefore not to be
considered limiting of its scope, for the disclosure may admit to
other equally effective implementations.
[0011] FIG. 1 is a plan view of one example of a chemical
mechanical polishing module according to one or more
implementations disclosed herein;
[0012] FIG. 2 is a schematic sectional view of one example
processing station of the module of FIG. 1 taken along line 2-2,
according to one or more implementations disclosed herein;
[0013] FIG. 3 is an enlarged schematic side view of one
implementation of a portion of an advanced polishing article having
identifying feature(s), according to one or more implementations of
the present disclosure;
[0014] FIG. 4 is a schematic top view of a portion of a
roll-to-roll type of an advanced polishing article having a
polishing surface with grooves formed therein, according to one or
more implementations of the present disclosure;
[0015] FIG. 5 is a close up isometric view of a portion of a
backside surface of an advanced polishing article having an
identifying feature(s) formed thereon according to one or more
implementations of the present disclosure;
[0016] FIG. 6A is a schematic sectional view of the processing
station of FIG. 2 having one implementation of a detector assembly
positioned therein, according to one or more implementations
disclosed herein; and
[0017] FIG. 6B is a schematic sectional view of the processing
station of FIG. 2 having another implementation of a detector
assembly positioned therein, according to one or more
implementations disclosed herein;
[0018] FIG. 7 is a flow chart depicting one example of a method of
polishing with an advanced polishing article having identifying
feature(s) according to one or more implementations described
herein; and
[0019] FIG. 8 is a flow chart depicting another example of a method
of polishing with an advanced polishing article having identifying
feature(s) according to one or more implementations described
herein.
[0020] To facilitate understanding, identical reference numerals
have been used, where possible, to designate identical elements
that are common to the figures. It is contemplated that elements
and features of one implementation may be beneficially incorporated
in other implementations without further recitation.
DETAILED DESCRIPTION
[0021] The following disclosure describes methods and apparatus for
identifying and/or tracking movement of a polishing material in a
roll-to-roll polishing system. Certain details are set forth in the
following description and in FIGS. 1-8 to provide a thorough
understanding of various implementations of the disclosure. Other
details describing well-known structures and systems often
associated with polishing processes and roll-to-roll systems are
not set forth in the following disclosure to avoid unnecessarily
obscuring the description of the various implementations.
[0022] Many of the details, dimensions, angles and other features
shown in the Figures are merely illustrative of particular
implementations. Accordingly, other implementations can have other
details, components, dimensions, angles and features without
departing from the spirit or scope of the present disclosure. In
addition, further implementations of the disclosure can be
practiced without several of the details described below.
[0023] As described herein, roll-to-roll polishing systems may be
used to polish a surface of a substrate. Typically, the polishing
material is wound around spools. As further described herein, in
some implementations, polishing pad material is supplied by a
supply roll and routed to a take-up roll. The polishing pad
material is typically tensioned between the supply roll and the
take-up roll, which may provide a tension force to polish the
substrate. In some implementations, after polishing one or more
substrates, the polishing pad material is advanced to expose an
unused or fresh portion of the polishing pad material, which is
used to polish additional substrates. As described herein, in some
implementations, polishing pad material has a pattern of precisely
formed polishing features for removing material from the surface of
the polished substrate. These features may include, for example, at
least one of grooves formed in the polishing surface and discrete
features (e.g., embossed regions, reliefs, pillars, etc.) that
extend above or upward from a lower portion of the polishing
surface. Since effective CMP processes provide consistent polishing
results or "repeatability" between substrates in a lot or batch it
is desirable to expose each substrate to polishing material having
similar or substantially similar pattern of polishing features to
produce similar or substantially similar polishing results.
Therefore, it is desirable to know the precise position of the
polishing material, and more particularly the precise positioning
of the features formed in the polishing material relative to each
of the substrates to be polished as the polishing pad position,
relative to the polishing platen that it is disposed over, is
adjusted during processing.
[0024] One potential solution for tracking polishing material in a
roll-to-roll system involves the use of a motor encoder to track
advancement of the polishing pad. However, use of a motor encoder
adds mechanical complexity to the polishing system, which can lead
to particle generation within the system. Additionally, the motor's
rotational position sensed by the motor encoder is difficult to
correlate to the position of the features formed on the polishing
pad, since the amount of linear movement of the polishing pad
relative to the platen changes as the diameter of the feed and
take-up rolls change as the polishing pad is adjusted during
processing. The polishing pad will typically stretch when a desired
tension is applied to the polishing pad during a polishing process,
and the motor is typically not directly coupled to the pad material
so that relative motion (e.g., slippage) can occur between the pad
material and the output of the motor. In addition, CMP is performed
in a wet environment meaning that the motor encoder must be
protected from polishing fluids, which adds additional complexity
to the polishing system. Further, in a motor encoder-based tracking
system if contact with the polishing material is lost (e.g.,
slippage), the position of the polishing material relative to the
platen and the carrier head is lost. Polishing a substrate with
misaligned or improperly positioned polishing material can
adversely affect repeatability between substrates, which affects
device yield. Moreover, the accuracy of placement of the polishing
material relative to the substrate can affect the cost to produce
semiconductor devices and the cost of ownership of a semiconductor
device production line.
[0025] In some implementations, the present disclosure provides
apparatus and methods to more efficiently track movement of a
polishing material in a roll-to-roll polishing system. In some
implementations, the present disclosure provides a polishing
material having a plurality of identifying feature(s) formed on a
backside surface of the polishing material that can be detected by
a sensor. In some implementations, the identifying feature(s) allow
the position of the polishing material to be determined. In some
implementations, the identifying feature(s) are associated with a
pattern of polishing features on the polishing surface of the
polishing material, thus allowing the user to position the
polishing material such that a substrate to be polished is exposed
to a desired pattern of polishing features of the polishing
material. The identifying feature(s) may extend along the length of
the polishing material. The identifying feature(s) may include a
first start of line feature, which identifies a start of a first
polishing region of polishing material, and a second start of line
feature, which identifies an end of the first polishing region and
a start of a second polishing region of polishing material. The
first polishing region of polishing material and the second
polishing region of polishing material may define similar or
substantially similar patterns of polishing material, which allows
the user to expose subsequently polished substrate to the same
pattern of features as previously polished substrates. In some
implementations, the identifying feature(s) are used as an
authentication mechanism. For example, different types of polishing
material may be associated with different polishing recipes and due
to the precise nature of polishing features on each type of pad
material, it is desirable to identify that the proper type of
polishing material is used for the desired polishing recipe. The
identifying feature(s) may include, for example, an optical
contrast or color marking compared to the unmarked polishing
material, laser marking or cutouts in the polishing material, a bar
code, or any other suitably identifiable feature.
[0026] In some implementations, the apparatus and methods described
herein increase the accuracy and placement of the polishing
material relative to the substrate, which decreases the cost to
produce semiconductor devices and the cost of ownership of a
semiconductor device production line.
CMP Hardware Implementation Examples
[0027] FIG. 1 depicts a plan view of a polishing module 106
according to one or more implementations disclosed herein. The
polishing module 106 may be a portion of a REFLEXION.RTM. Chemical
Mechanical Polisher, such as the REFLEXION.RTM. WEBB.TM. system,
the REFLEXION.RTM. LK CMP system, the REFLEXION.RTM. LK PRIME.TM.
CMP system, all of which are manufactured by Applied Materials,
Inc., located in Santa Clara, Calif. One or more of the
implementations described herein may be used on these polishing
systems. However, one skilled in the art may advantageously adapt
implementations as taught and described herein to be employed on
other types of polishing devices produced by other manufacturers
that utilize polishing articles, and particularly polishing
articles in a roll-to-roll polishing article format. The apparatus
description described herein is illustrative and should not be
construed or interpreted as limiting the scope of the
implementations described herein.
[0028] The polishing module 106 generally comprises a loading robot
104, a system controller 108, a transfer station 136, a plurality
of processing or polishing stations, such as a platen assembly 132,
a base 140 and a carousel 134 that supports a plurality of
polishing or carrier heads 152 (only one is shown in FIG. 1).
Generally, the loading robot 104 is disposed proximate the
polishing module 106 and a factory interface (not shown) to
facilitate the transfer of substrate(s) 122 therebetween.
[0029] The transfer station 136 generally includes a transfer robot
146, an input buffer station 142, an output buffer station 144 and
a load cup assembly 148. The input buffer station 142 receives a
substrate 122 from the loading robot 104. The transfer robot 146
moves the substrate 122 from the input buffer station 142 to the
load cup assembly 148 where the substrate 122 may be transferred to
the carrier head 152.
[0030] To facilitate control of the polishing module 106 as
described above, the system controller 108 comprises a central
processing unit (CPU) 110, support circuits 114 and memory 112. The
CPU 110 may be one of any form of computer processor that can be
used in an industrial setting for controlling various polishers,
drives, robots and sub-processors. The memory 112 is coupled to the
CPU 110. The memory 112, or computer-readable medium, may be one or
more of readily available memory such as random access memory
(RAM), read only memory (ROM), floppy disk, hard disk, or any other
form of digital storage, local or remote. The support circuits 114
are coupled to the CPU 110 for supporting the processor in a
conventional manner. These circuits include cache, power supplies,
clock circuits, input/output circuitry, subsystems, and the
like.
[0031] Generally, the carousel 134 has a plurality of arms 150 that
each support one of the carrier heads 152. Two of the arms 150
depicted in FIG. 1 are shown in phantom such that the transfer
station and an advanced polishing article 123 disposed on or over
one of the platen assemblies 132 may be seen. The carousel 134 is
indexable such that the carrier heads 152 may be moved between the
platen assemblies 132 and the transfer station 136. In another
implementation (not shown herein), the carousel 134 is replaced by
a circular track and the carrier heads 152 and movable along the
circular track. Typically, a chemical mechanical polishing process
is performed at each platen assembly 132 by moving the substrate
122 retained in the carrier head 152 relative to the advanced
polishing article 123 supported on the platen assembly 132.
[0032] In some implementations, the advanced polishing article 123
may be positioned across the platen assembly 132 and between a
supply assembly 156 and a take-up assembly 158 so that a polishing
process can be performed on surface of the advanced polishing
article 123 on the platen assembly 132. The supply assembly 156 and
the take-up assembly 158 may provide an opposing bias to the
advanced polishing article 123 in order to tighten and/or stretch
an exposed portion of the advanced polishing article 123 disposed
therebetween. The supply assembly 156 and the take-up assembly 158
are capable of an intermittent motion actuated in a controlled
manner for the necessary time; this motion enables the advanced
polishing article 123 to be advanced step-by-step in a controlled
manner.
[0033] In some implementations, the advanced polishing article 123
may have a flat or planar surface topology when stretched between
the supply assembly 156 and the take-up assembly 158. Additionally,
the advanced polishing article 123 may be advanced across and/or be
releasably fixed to the platen assembly 132 such that a new or
unused area of the advanced polishing article 123 may be released
from the supply assembly 156. Typically, the advanced polishing
article 123 is releasably fixed by a vacuum pressure applied to a
backside surface of the advanced polishing article 123, mechanical
clamps, or by other holding methods to the platen assembly 132
while a substrate is being polished.
[0034] As discussed herein, a polishing article, such as the
advanced polishing article 123 may include at least one of a raised
surface texture (e.g., embossed texture) formed on a polishing
surface and a plurality of grooves extending from the polishing
surface toward a backside surface, such as the discrete extended
elements and grooves, as, for example, illustrated in FIG. 3. The
advanced polishing article 123 further includes a pattern of
identifying feature(s), as shown in FIG. 4, formed on a backside
surface of the polishing material that may be detected by a sensor.
The pattern of identifying feature(s) may be used to identify the
position of the advanced polishing article 123 relative to a platen
and/or the substrate 122 to be polished. The pattern of identifying
feature(s) may also be used as an authentication mechanism. An
identifying feature may include a desired physical or optically
significant feature or pattern that is formed within, formed on, or
formed by removing or altering a portion of a surface of the
polishing pad.
[0035] The polishing process may utilize a slurry containing
abrasive particles delivered to the polishing article's surface by
the fluid nozzles 154 to aid in polishing the substrate 122.
Alternatively, the fluid nozzles 154 may deliver de-ionized water
(DIW) alone, or in combination with polishing chemicals. The fluid
nozzles 154 may rotate in the direction shown to a position clear
of the platen assemblies 132 as shown, to a position over each of
the platen assemblies 132. In one implementation, the fluid nozzles
154 track with the seeping motion of the carrier head 152 so the
slurry is deposited adjacent to the carrier head 152.
[0036] FIG. 2 depicts a side view of the platen assembly 132 and
one implementation of the supply assembly 156 and the take-up
assembly 158, illustrating the position of the advanced polishing
article 123 across a platen 230. Generally, the supply assembly 156
includes the supply roll 254, an upper guide member 204 and a lower
guide member 205 that are disposed between sidewalls 203 of the
platen assembly 132. Generally, the take-up assembly 158 includes a
take-up roll 252, an upper guide member 214 and a lower guide
member 216 that are all disposed between the sidewalls 203. The
take-up roll 252 generally contains a used portion of the advanced
polishing article 123 and is configured to be easily replaced
during a maintenance activity with an empty take-up roll once the
take-up roll 252 is filled with used advanced polishing article
123. The upper guide member 214 is positioned to lead the advanced
polishing article 123 from the platen 230 to the lower guide member
216. The lower guide member 216 leads the advanced polishing
article 123 onto the take-up roll 252. The advanced polishing
article 123 generally follows the path "A" shown in FIG. 2.
[0037] The platen assembly 132 may also include a detection system
220 that is adapted to transmit and receive output signals for
detecting the precise position of the advanced polishing article
123. Although the detection system 220 is positioned internal to
the platen assembly 132 it should be understood that in some
implementations, the detection system 220 may be positioned
external to the platen assembly 132. The detection system 220 may
be positioned to detect the pattern of identifying feature(s)
positioned on the backside surface of the advanced polishing
article 123. The detection system 220 is positioned a known
distance from the platen 230. The detection system 220 may be able
to detect contrast between different colors, textures, thickness,
or cutouts, for example, of the identifying feature(s) compared to
the advanced polishing article 123. The location data of the
advanced polishing article 123 can be used by the system controller
108 to position the advanced polishing article 123 relative to the
platen assembly 132 to improve the repeatability of polishing
between substrates. In some implementations, if the identifying
feature(s) indicate that the advanced polishing article 123 is
misaligned, the advanced polishing article 123 is advanced or
"indexed" until the optical sensing device identifies a suitable
position to polish a substrate. In some implementations, the
advanced polishing article 123 is advanced or "indexed" until the
optical sensing device identifies a start of line identifying
feature, which indicates that the advanced polishing article 123 is
in the proper position to polish a substrate.
[0038] In some implementations, the pattern of identifying
feature(s) function as an authentication feature. The detection
system 220 may be positioned to detect and/or identify the
identifying feature(s). Since different types of polishing material
may be associated with different polishing recipes and due to the
precise nature of polishing features on each type of polishing
material, it is desirable to identify that the proper type of
polishing material is used for the desired polishing recipe. If the
detection system 220 authenticates the identifying feature, then
the advanced polishing article 123 is allowed to operate on the
platen assembly 132. However, if the detection system does not
authenticate the identifying feature, then the advanced polishing
article 123 will not operate on the platen assembly 132.
[0039] In some implementations, the detection system 220 includes
an optical sensing device, such as a laser, that is adapted to
transmit and receive optical signals for detecting the identifying
feature(s) positioned on the backside surface of the advanced
polishing article 123. In some implementations, the detection
system 220 includes an optical sensing device that projects
radiation through the advanced polishing article 123 and receives
at a detector (not shown) any radiation reflected from the surface
of the substrate that passes back through the advanced polishing
article 123. In some implementations of the present disclosure the
polymeric material of the advanced polishing article 123 is
optically transparent, so that a "through beam" type (see FIG. 6A)
can optically monitor the identifying feature(s) during polishing
using the detection system 220.
[0040] In a "through beam" type detection configuration, at least a
portion of the advanced polishing article 123 may be formed from a
material that has an optical clarity that is at least about 25%
(e.g., at least about 50%, at least about 80%, at least about 90%,
at least about 95%) for light transmission over the wavelength
range of the light provided from and collected by the detection
system 220. Typical detection wavelength ranges can include the
visible spectrum (e.g., from about 400 nm to about 800 nm), the
ultraviolet (UV) spectrum (e.g., from about 300 nm to about 400
nm), and/or the infrared spectrum (e.g., from about 800 nm to about
1550 nm), such as wavelength ranges between about 200 nm and about
1600 nm. In one implementation, at least a portion of the advanced
polishing article 123 (e.g., identifying feature(s) 520) is formed
from a material that has a transmittance of >35% at wavelengths
between 280-399 nm, and a transmittance of >70% at wavelengths
between 400-800 nm. Conversely, in a "reflective" type of sensing
configuration (see FIG. 6B), at least a portion of the advanced
polishing article 123 (e.g., identifying feature(s) 520) may be
formed from a material that has an ability to reflect at least a
portion of the detection wavelength ranges described above, such as
between about 200 nm and about 1600 nm. In one example, the portion
of the advanced polishing article 123 is configured to reflect
>35% at wavelengths between 280-399 nm, and reflect >70% at
wavelengths between 400-800 nm.
[0041] The supply roll 254 generally contains an unused portion of
the advanced polishing article 123 and is configured so that it may
easily be replaced with another supply roll 254 containing a new
advanced polishing article 123 once the advanced polishing article
123 disposed on the supply roll 254 has been consumed by the
polishing or planarizing process. In general, the total length of
the advanced polishing article 123 includes an amount of polishing
material disposed on the supply roll 254, an amount disposed on the
take-up roll 252, and an amount that extends between the supply
roll 254 and the take-up roll 252. The total length is typically
larger than the size of the polished surface of multiple substrates
122 (FIG. 1), and may be for example several meters to several tens
of meters long.
[0042] The advanced polishing article 123 is generally configured
to controllably advance the advanced polishing article 123 in the
X-direction across a backing pad assembly 226. The advanced
polishing article 123 is generally moved in relation to the platen
230 by balancing the forces between a motor 222 coupled to the
supply assembly 156 and a motor 224 coupled to the take-up assembly
158. Ratchet mechanisms and/or braking systems (not shown) may be
coupled to one or both of the supply assembly 156 and the take-up
assembly 158 to fix the advanced polishing article 123 relative to
the backing pad assembly 226. The platen 230 may be operably
coupled to a rotary actuator 228 that rotates the platen assembly
132 and the advanced polishing article 123 about a rotational axis
235 generally orthogonal to the X and/or Y directions. In some
implementations, all of the elements shown in FIG. 2 rotate about
the rotational axis 235.
[0043] A vacuum system 232 may be coupled between the rotary
actuator 228 and the backing pad assembly 226. The vacuum system
232 may be used to fix the position of the advanced polishing
article 123 onto the platen 230. The vacuum system 232 may include
channels 234 formed in a plate 236 disposed below the backing pad
assembly 226. In one implementation, the backing pad assembly 226
may include a subpad 240 and a subplate 238, each having openings
242 formed therethrough that are in fluid communication with the
channels 234 and a vacuum source (not shown). In other
implementations, an integral subpad 250 (shown in dashed lines) may
be formed on a lower surface of the advanced polishing article 123.
In one implementation of the platen assembly 132, a subpad 240 and
an integral subpad 250 of the advanced polishing article 123 are
used in combination during a polishing process. In some
implementations, the subpad 240 and/or the integral subpad 250 is
typically formed from a polymeric, elastomeric, woven fiber or
plastic material, such as polypropylene, polycarbonate or
polyurethane. In one implementation, the subpad 240 and/or the
integral subpad 250 is formed from woven fiber polypropylene. In
some implementations, portions of plate 236 and the backing pad
assembly 226 have optical clarity sufficient to accommodate the
detection beam of the detection system 220.
[0044] Generally, the hardness, thickness and durometer of the
subpad 240 and/or the integral subpad 250 may be chosen to produce
a particular polishing result. The subpad 240 and/or the integral
subpad 250 generally maintains an upper surface 221 of the advanced
polishing article 123 in a plane that is parallel to the plane of a
substrate (not shown) in order to promote global planarization of
the substrate. In some implementations, the subplate 238 may be
positioned below the subpad 240, as shown. The subpad 240 and/or
the integral subpad 250 may be hydrophilic or hydrophobic. If the
subpad 240 and/or the integral subpad 250 is hydrophilic, the
subpad 240 and/or the integral subpad 250 should be configured to
absorb in a uniform manner.
[0045] The advanced polishing article 123 as described herein may
alleviate the need to condition the polishing article and thus
maximize polisher availability and polisher performance. For
example, the advanced polishing article 123 may be incrementally
advanced a distance smaller than the size (e.g., diameter) of the
substrate to present a portion of fresh polishing material in lieu
of the need to perform abrasive conditioning. The incremental
advancement of the advanced polishing article 123 may be performed
before, during or after a substrate is polished thereon by use of
one or more actuators coupled to the take-up roll 252 or supply
roll 254 (FIG. 2). In one implementation, the advanced polishing
article 123 is incrementally advanced from about 0.1 millimeters
per wafer to about 10 millimeters per wafer (e.g., 1 millimeter per
wafer to about 5 millimeters per wafer).
[0046] FIG. 3 is an enlarged schematic side view of one
implementation of the advanced polishing article 123, according to
one or more implementations of the present disclosure. The advanced
polishing article 123 includes a top pad 310 having a polishing
surface 312 and an opposing backside surface 314 that define a pad
body 330. The backside surface 314 has identifying feature(s) 520A,
520B (collectively 520) formed thereon as described herein. In one
implementation, as depicted in FIG. 3, the polishing surface 312 is
textured and includes a plurality of micro-features or discrete
extended elements 340 extending from the polishing surface 312 of
the advanced polishing article 123. In one implementation, the
texture is formed by embossing or other methods of forming a raised
surface texture on the polishing surface 312 the top pad 310. In
one implementation, the discrete extended elements 340 of the
polishing surface 312 have an average height "h" from about 1
micron to about 50 microns (e.g., from about 5 microns to about 30
microns, from about 10 microns to about 20 microns; or from about 5
to 10 microns). In one implementation, the texture formed by the
raised surface texture is spatially uniform or substantially
spatially uniform in a plane that is parallel to the polishing
surface of the top pad 310.
[0047] The top pad 310 is typically formed from synthetic
materials. Non-limiting examples of suitable synthetic materials
include films, such as polymeric or thermoplastic films, webs
comprising sustainable polymers, and the like. Suitable precursor
webs further include laminates or blends of these materials. In one
implementation, the top pad 310 is a polymeric sheet or film. In
some implementations, the top pad 310 includes a non-porous
polymeric material. Suitable polymeric films include thermoplastic
films composed of polymeric materials such as polyethylene (PE),
polypropylene (PP), polystyrene, polyethylene terephthalate (PET),
poly(methyl methacrylate) (PMMA), polyvinyl alcohol (PVA),
polytetrafluoroethylene (PTFE) (e.g., TEFLON), polyamides (e.g.,
nylon), polyurethane, or combinations thereof. Suitable polymeric
films can include blends or mixtures of polymers. In one
implementation, the top pad 310 is a polypropylene-based sheet.
[0048] The advanced polishing article 123 as described herein
includes a thickness that is generally less than a conventional CMP
polishing pad, which allows a longer length of the polishing
article material to be disposed on the same sized supply roll. The
polishing article's thickness is generally measured in a direction
that is parallel to the direction that the force is applied to the
advanced polishing article 123 by the substrate when it is being
polished. In some implementations, the advanced polishing article
123 has a thickness in a range from about 0.001 inches to about
0.025 inches.
[0049] In some implementations, the plurality of discrete extended
elements 340 are formed as protruded extensions of the top pad 310,
generally on the polishing surface 312 thereof. The number, size,
and distribution of the discrete extended elements 340 on the
polishing surface 312 can be predetermined based on the desired
polishing characteristics of the top pad 310. For most polishing
applications, it can be desired that the plurality of the discrete
extended elements 340 protrude only from one surface (e.g., the top
surface) of the top pad 310. In some implementations, the top pad
310 does not contain macro-features (e.g., grooves, channels or
other identifiable surface structure), but includes a random,
semi-random, or uniform (e.g., long range repeating) texture of
micro-features (e.g., discrete extended elements 340) having
varying heights and lateral spacing.
[0050] Referring to FIG. 3, in some implementations, the discrete
extended elements 340 can be described as protruding from the
polishing surface 312 of the pad body 330. As such, the discrete
extended elements 340 can be described as being integral with the
pad body 330, and formed by permanent local plastic deformation of
the pad body 330.
[0051] In some implementations, the top pad 310 further includes a
plurality of macro-features or groove(s) 342 formed in the
polishing surface 312. The groove(s) 342 formed in the top pad 310
can function as local reservoirs for the polishing slurry during a
polishing process. The groove(s) 342 may be formed in the top pad
310 using any suitable groove forming methods (e.g., laser cutting,
water jet cutting, die cutting, stamping, punch press, etc.). A
bottom portion 350 of the top pad 310 is contiguous and prevents
liquids such as polishing slurry or water from penetrating the top
pad 310. In this configuration, the groove(s) 342 formed through
the top pad 310 become local reservoirs for the polishing slurry,
since the slurry is retained in the formed grooves and the
polishing slurry will generally not penetrate the bottom portion
350 of the top pad 310. For multiple reasons including holding down
the pad during polishing and polisher cleanliness, it is
undesirable for the slurry to penetrate the top pad 310 through the
groove(s) 342 in the top pad 310.
[0052] In one implementation, the groove(s) 342 has a width between
about 0.05 inches and about 0.50 inches (e.g., between about 0.10
inches to about 0.40 inches, between about 0.15 inches to about
0.20 inches, or between about 0.18 inches to about 0.20 inches). In
one implementation, the spacing between adjacent grooves 342 is
between about 0.5 inches and about 2.5 inches (e.g., between about
1 inch to about 2 inches, between about 1 inch to about 2 inches,
or between about 1 inch to about 1.5 inches).
[0053] In some implementations, at least one identifying feature of
the pattern of identifying features is positioned a fixed distance
from at least one polishing feature. Positioning the at least one
identifying feature a fixed distance from the at least one
polishing feature makes it so the at least one identifying feature
can be used to identify the position of the polishing feature. For
example, as depicted in FIG. 3, identifying feature 520B is
positioned a fixed distance 701 from groove 342. Positioning
identifying feature 520B the fixed distance 701 from groove 342
allows for the position of groove 342 to be identified by
identifying feature 520B. In addition, since the detection system
220 is positioned a known distance from the platen 230, the
position of the platen 230 relative to the position of the
polishing features may be determined using the identifying
feature(s).
[0054] FIG. 4 is a schematic top view of a portion of a
roll-to-roll type of an advanced polishing article 400 having a
polishing surface 412 with grooves 432 formed therein, according to
one or more implementations of the present disclosure. In one
implementation, the advanced polishing article 400 may form part of
or be used in place of the advanced polishing article 123. The
polishing surface 412 may be textured as described herein. The
texture of the polishing surface 412 may be similar to the texture
of the polishing surface 312. The grooves 432 formed may be similar
to groove(s) 342 of advanced polishing article 123. The pattern of
grooves 432 of the advanced polishing article 123 includes a
sawtooth pattern of grooves 432 that are aligned relative to the
index axis 440 and or the axis of movement 450 along path "A."
[0055] FIG. 5 is a close up isometric view of a portion of a
backside surface 514 of an advanced polishing article 500 having a
pattern of identifying feature(s) 520 formed thereon according to
one or more implementations of the present disclosure. The pattern
of identifying feature(s) 520 may include, for example, an optical
contrast or color marking compared to the unmarked polishing
material, laser marking or cutouts in the polishing material, a bar
code, or any other suitably identifiable feature. In one
implementation, the advanced polishing article 500 may form part of
or be used in place of the advanced polishing article 123. The
backside surface 514 of the advanced polishing article 500 is
positioned adjacent to the detection system 220. The detection
system 220 is used to monitor and feedback the polishing material
of the advanced polishing article 500 movement and position data to
the system controller 108.
[0056] In general, the movement and position of the advanced
polishing article 500 can be monitored by use of a sensor assembly
260 in the detection system 220 that is positioned to view one or
more regions of the backside surface 514 of the advanced polishing
article 500 that has identifying feature(s) 520 formed thereon. The
sensor assembly 260 is typically a non-contact sensor. The
identifying feature(s) 520 of formed elements may include a regular
pattern of deposited material or formed features that can be
detected by the sensor assembly 260, so that a processor (e.g., CPU
110) in the system controller 108 can then analyze the detected
signal, as it passes through a detection region 530 of the sensor
assembly 260. In one implementation, the identifying feature(s) 520
are a regular array of printed ink lines that are deposited on the
backside surface 514 of the advanced polishing article 500. In
another implementation, the identifying feature(s) 520 is an array
of embossed features in the backside surface 514 of the advanced
polishing article 500. In yet another implementation, the
identifying feature(s) 520 is an array of regions of removed
polishing material, such as holes. The term holes as used herein
may include but is not limited to round holes, oval holes, polygon
shaped holes, slots, grooves, cuts or other similar feature that
are formed in the polishing material.
[0057] In one implementation, as depicted in FIG. 5, the
identifying feature(s) 520 comprises an array of equally spaced
features (e.g., lines) that are disposed on or formed in the
backside surface 514 of the advanced polishing article 500 that
passes through and are sensed by the components in the sensor
assembly 260.
[0058] The sensor assembly 260 generally contains one or more
components that are able monitor the movement of the identifying
feature(s) 520 as it is moved by the components in the supply
assembly 156 and the take-up assembly 158, and regularly or
continually deliver a detection signal to the system controller 108
based on the monitored movement. The sensor assembly 260 may
utilize optical monitoring techniques, capacitive measurement
technique, eddy current measurement techniques, or other similar
suitable technique that is able to detect the motion of the
identifying feature(s) 520 as it passes by the sensor assembly 260.
As noted above, the sensor assembly 260 will include a light source
610 and a detector 620 that are in communication with the system
controller 108. Typically, the light source 610 generally contains
a source of some form of electromagnetic energy, such as light
delivered from an LED or a laser that is emitted and directed at
the backside surface 514 of the advanced polishing article 500.
Typically, the detector 620 is conventional optical detector, such
as a photoconductive sensor, thermoelectric detector, AC type
optical sensor, DC type optical sensor, or other similar device
that is adapted to detect the variation in intensity of the energy
delivered by the light source 610 due to the interaction of the
energy with the identifying feature(s) 520.
[0059] In one implementation, each platen assembly 132 contains two
or more sensor assemblies 260 that are each positioned to detect
the motion of the identifying feature(s) 520, and are used in
combination with the system controller 108 to determine the actual
motion of the advanced polishing article 500. In one
implementation, the two or more sensor assemblies 260 are
positioned to monitor different portions of the identifying
feature(s) 520 so that the actual position can be determined.
[0060] In one implementation, the shape or one or more materials in
the formed identifying feature(s) 520 preferentially absorbs or
reflects one or more wavelengths of light delivered from the light
source 610 that is sensed by the detector 620. In one
implementation, an array of equally spaced lines of an ink material
are deposited on the backside surface 514 of the advanced polishing
article 500 which is seen as a series of signal intensity peaks and
valleys by the detector 620 and the system controller 108 as the
identifying feature(s) 520 is moved past the sensor assembly 260.
The system controller 108 may use the intensity peaks and valley
information to determine how much the advanced polishing article
500 has been moved past the sensor assembly 260 or determine the
actual position of a portion of the advanced polishing article 500
(e.g., position of the identifying feature(s) relative to the
position of polishing feature(s) on the pad material; position of
identifying features relative to the substrate to be polished;
position of the identifying feature(s) relative to the platen; or
position of the polishing features relative to the platen). In some
implementations, the shape of the features within the identifying
feature(s) 520 (e.g., length of bar shaped features in one
direction) may change from one region of the roll of the advanced
polishing article 500 to another (i.e., start of a roll of
polishing material to the end of the roll of polishing region),
thus providing some information about the actual position of a
region of the advanced polishing article 500 on the roll. In some
implementations, the shape of the features within the identifying
feature(s) 520 may change from one polishing region of the roll of
the advanced polishing article 500 to another polishing region
(i.e., start of the repeating pattern of the polishing surface to
the end of the repeating pattern), thus indicating where a new
region of polishing material begins such that subsequent substrates
are exposed to new polishing material with the same polishing
pattern as previously polished substrates.
[0061] One skilled in the art will appreciate that any known shaped
or spaced identifying feature(s) 520 could be used to provide
information to the system controller 108 about the movement of the
advanced polishing article 500 without deviating from the basic
scope of the disclosure described herein. In one example, the
identifying feature(s) 520 includes a distinct analog or digitally
encoded pattern that the detector and system controller are able to
analyze using a pattern recognition and/or signal processing
technique.
[0062] FIG. 6A is a schematic sectional view of the processing
station of FIG. 2 having one implementation of the sensor assembly
260 positioned therein, according to one or more implementations
disclosed herein. The sensor assembly 260 depicted in FIG. 6A uses
a through-beam sensor configuration to monitor the movement of the
advanced polishing article 500. In this implementation, the sensor
assembly 260 generally includes a light source 610 that is
positioned to provide electromagnetic radiation (e.g., light) to a
detector 620 that is disposed on the opposite side of the advanced
polishing article 500. Therefore, the detector 620 receives the
interference or interaction of the energy delivered by the light
source 610 with the identifying feature 520 so that the movement
and/or position of the material can be controlled. In one
implementation, the electromagnetic energy delivered by the light
source 610 is passed through an array of holes or thinned regions
formed in the in the advanced polishing article 500, and thus the
presence or absence of the advanced polishing article 500 in the
identifying feature(s) 520 is used to monitor the movement and/or
position of the advanced polishing article 500. In another
implementation, the electromagnetic energy delivered by the light
source 610 primarily passes through the advanced polishing article
500, and thus the presence of a material in the identifying
feature(s) 520 (e.g., ink) is used to alter the energy received by
the detector 620 to help provide information about the movement of
the advanced supporting article. In one implementation, the light
source 610 delivers light through a hole 630 formed in the plate
236 and hole 640 formed in the subpad 240. In some implementations,
at least one of the hole 630 and the hole 640 have a window
positioned therein.
[0063] FIG. 6B is a schematic sectional view of the processing
station of FIG. 2 having another implementation of the sensor
assembly 260 positioned therein, according to one or more
implementations disclosed herein. The sensor assembly 260 uses
reflected energy to monitor the movement of the advanced polishing
article 500. In this implementation, the sensor assembly 260
generally includes a light source 610 that illuminates "B1" the
detection region 530 (FIG. 5) on the advanced polishing article 500
containing the identifying feature(s) 520 and receives an amount of
reflected light "B2" at the detector 620 that is altered by the
interference or interaction with the identifying feature(s) 520.
The altered energy received by the detector 620 due to the
interaction with the identifying feature(s) 520 is fed back to the
system controller 108 so that the movement and/or position of the
advanced polishing article 500 can be controlled. In one
implementation, the electromagnetic energy delivered by the light
source 610 is designed to preferentially reflect from the backside
surface 514 of the advanced polishing article 500 or the material
from which that the identifying feature(s) 520 is formed, so that
the movement of the identifying feature(s) 520 can be monitored by
the system controller 108.
Polishing Process Examples
[0064] FIG. 7 is a flow chart depicting one example of a method 700
of polishing with an advanced polishing article having identifying
feature(s) according to one or more implementations described
herein. The advanced polishing article may be, for example, any of
the advanced polishing articles described herein (e.g., advanced
polishing article 123, advanced polishing article 400, or advanced
polishing article 500). The method may be performed, for example,
with any of the polishing modules depicted herein using any of the
aforementioned advanced polishing articles.
[0065] At operation 710, the advanced polishing article is advanced
using the supply roll 254 and the take-up roll 252. In some
implementations, the advanced polishing article is advanced
relative to the platen before and/or during removing material from
the substrate 122 by use of an actuator coupled to the supply roll
and/or an actuator coupled to the take-up roll. In one
implementation, the advancing comprises advancing the polymeric
sheet between about 1 mm and about 5 mm relative to the platen. In
one implementation, the advanced polishing article is a polymeric
sheet. As discussed herein, the advanced polishing article has a
textured polishing surface (e.g., polishing surface 312 or 412 is
textured) including, at least one of a microtexture (e.g.,
plurality of discrete elements) formed from the pad material and
extending upward from the polishing surface and a plurality of
macro-features (e.g., grooves) formed in the polishing surface. The
speed with which the advanced polishing article is advanced may be
based on a process recipe, for example, or other processing
parameters such as an optimized polishing speed.
[0066] At operation 720, the detection system 220 may detect and/or
sense the movement of an identifying feature (e.g., identifying
feature(s) 520) on the backside surface of the advanced polishing
article. The one or more detector assemblies may be selected from,
for example, a capacitive type sensor, an optical measurement
sensor, or an eddy current measurement sensor. In some
implementations, the identifying feature is associated with (e.g.,
positioned a known distance from) a specific polishing feature on
the polishing surface of the polishing article. For example, as
depicted in FIG. 3, identifying feature 520B is positioned a fixed
distance 701 from groove 342. Positioning identifying feature 520B
the fixed distance 701 from groove 342 allows for the position of
groove 342 to be identified by identifying feature 520B. In
addition, since the detection system 220 is positioned a known
distance from the platen 230, the position of the platen 230
relative to the position of the polishing features may be
determined using the identifying feature(s).
[0067] The polishing features may include, for example, at least
one of grooves formed in the polishing surface and a plurality of
discrete features that extend upward from the polishing surface. In
some implementations, the identifying feature is associated with a
fixed groove pattern that has a fixed pitch. Associating the
identifying feature with a specific polishing feature or
characteristic of a polishing feature allows the precise
positioning of the polishing material, and more particularly the
precise positioning of the polishing features formed in the
polishing material relative to the substrate to be polished to be
determined. In addition, associating the polishing feature with a
specific identifying feature allows for determining the position of
the polishing feature relative to hardware (e.g., position of the
identifying feature(s) relative to the platen; or position of the
polishing features relative to the platen.) The detection system
220 may send a signal to the system controller 108 regarding the
identifying feature. For example, the detection system 220 emits
electromagnetic radiation onto the backside surface of the advanced
polishing article, wherein the emitted radiation interacts with the
identifying features of the pattern of identifying features formed
on the backside surface. The detection system 220 then receives an
intensity of the electromagnetic radiation after at least a portion
of the electromagnetic radiation has interacted with the
identifying features.
[0068] At operation 730, the system controller associates the
identifying feature(s) with a specific location on the polishing
pad. For example, the system controller monitors the intensity of
the received electromagnetic radiation to determine the position of
the polishing material relative to the platen. In some
implementations, the identifying feature(s) is a start of line
feature. The start of line feature identifies a start of a
polishing region of polishing material where the substrate is
polished. In some implementations, the start of line feature(s)
includes a first start of line feature, which identifies a start of
a first polishing region of polishing material, and a second start
of line feature, which identifies an end of the first polishing
region and a start of a second polishing region of polishing
material. In some implementations, the first polishing region of
polishing material and the second polishing region of polishing
material have similar or substantially similar patterns of
polishing features. For example, with reference to FIG. 3, if the
system controller identifies feature 520A as a start of line
feature, advancement of the polishing article may be ended at
operation 740. If the identifying feature(s) is not a start of line
feature, the system controller 108 using the identifying feature(s)
to determine the current position of the polishing article. The
system controller 108 can determine the distance between the
identifying feature(s) and the next start of line feature and
advance the polishing article until the next start of line feature
is reached. In addition, since the detection system 220 is
positioned a known distance from the platen 230, the position of
the platen 230 relative to the start of line feature may be
determined using the identifying feature(s).
[0069] At operation 740, in some implementations, advancement of
the polishing article is ended. For example, the polishing material
traveling across the surface of the platen is halted when the
detector assembly senses identifying features that indicate the
start of a first region of polishing material having a desired
pattern of polishing features. In some implementations, the
advanced polishing article continues to move during the polishing
process.
[0070] At operation 750, a substrate is urged toward the advanced
polishing article. In one implementation, the substrate is
substrate 122, which is disposed in a carrier head (e.g., carrier
head 152). In some implementations, the advanced polishing article
is disposed on a platen (e.g., platen 230 of platen assembly
132).
[0071] The substrate 122 may be a silicon-based material or any
suitable insulating materials or conductive materials as needed. In
one implementation, the substrate 122 may be a material such as
crystalline silicon (e.g., Si<100> or Si<111>), silicon
oxide, strained silicon, silicon germanium, doped or undoped
polysilicon, doped or undoped silicon wafers and patterned or
non-patterned wafers silicon on insulator (SOI), carbon doped
silicon oxides, silicon nitride, doped silicon, germanium, gallium
arsenide, glass, sapphire. The substrate 122 may have various
dimensions, such as 200 mm, 300 mm, and 450 mm or other diameter
wafers, as well as, rectangular or square panels. Unless otherwise
noted, implementations and examples described herein are conducted
on substrates with a 200 mm diameter, a 300 mm diameter, a 450 mm
diameter substrate.
[0072] A polishing slurry is delivered to the polishing surface of
the advanced polishing article. Any suitable polishing slurry
compatible with the materials polished may be used. In one
implementation, the polishing slurry includes at least one of
oxidizers, passivation agents, pH buffers, metal complexing agents,
surfactants and abrasives. In one implementation, the polishing
slurry is delivered to the textured polishing surface via a fluid
nozzle (e.g., fluid nozzle(s) 154). In some implementations, the
substrate 122 contacts the textured polishing surface after
delivery of the polishing slurry. In some implementations, the
substrate 122 contacts the textured polishing surface prior to
delivery of the polishing slurry. In some implementations, the
substrate 122 contacts the textured polishing surface during
delivery of the polishing slurry.
[0073] The substrate 122 may be urged against the textured
polishing surface with a force of less than about 10 pounds per
square inch (psi) (e.g., less than about 9 psi; less than about 7
psi; less than about 5 psi; or less than about 2.5 psi). In one
implementation, the force is between about 1 psi and 2 psi, for
example, about 1.8 psi.
[0074] At operation 760, relative motion is provided between the
substrate 122 and the polishing surface. In one implementation, the
carrier head is rotated at between about 50-100 revolutions per
minute, for example, between about 30-60 revolutions per minute,
while the platen positioned below the polishing surface is rotated
at between about 50-100 revolutions per minute, for example,
between about 7-35 revolutions per minute. In some implementation,
the advanced polishing article remains stationary while the carrier
head and platen rotate. In some implementations, the carrier head,
the platen, the supply roll and the take-up roll are rotated
relative to the substrate 122.
[0075] During operation 760, material is removed from the surface
of the substrate 122 by applying a pressure to a surface of the
substrate 122, such that the substrate 122 is urged against the
polishing surface. The material may be a conductive material (e.g.,
copper), a dielectric material (e.g., oxide or nitride containing),
or both a conductive material and dielectric material. The advanced
polishing articles described herein have demonstrated little impact
on polishing performance when slurry flow rates are below 100
ml/min, versus conventional polyurethane polishing articles that
typically have slurry flow rate that range from 100-300 ml/min with
150 ml/min being very common value.
[0076] At operation 770, after polishing is completed, the method
700 returns to operation 710 where additional substrates may be
polished. In some implementations, the advanced polishing article
is advanced relative to the platen before, during and/or after
removing material from the substrate 122 by use of an actuator
coupled to the supply roll and/or an actuator coupled to the
take-up roll. The polishing article can be advanced until a desired
identifying feature(s) is identified. For example, the desired
identifying feature (s) may be the next start of line feature,
which identifies a fresh region of polishing material. In one
implementation, the advancing comprises advancing the polymeric
sheet between about 1 mm and about 5 mm relative to the platen.
[0077] FIG. 8 is a flow chart depicting another example of a method
800 of polishing with an advanced polishing article having
identifying feature(s) used for authentication according to one or
more implementations described herein. The advanced polishing
article may be, for example, any of the advanced polishing articles
described herein (e.g., advanced polishing article 123, advanced
polishing article 400, or advanced polishing article 500). The
method may be performed, for example, with any of the polishing
modules depicted herein using any of the aforementioned advanced
polishing articles.
[0078] In some implementations, the plurality of identifying
feature(s) function as a coded authentication feature. The coded
authentication mechanism is capable of being identified by a system
controller (e.g., system controller 108). Since different types of
polishing material may be associated with different polishing
recipes and due to the precise nature of polishing features on each
type of pad material, this authentication mechanism allows for
verification that the proper type of polishing material is used on
the proper platen assembly for the desired polishing recipe. In
some implementations, the coded authentication mechanism allows the
settings of the platen assembly to be pre-set for a desired
polishing recipe.
[0079] At operation 810, the advanced polishing article is
installed on a platen assembly.
[0080] At operation 820, the identifying feature is detected on the
backside surface of the advanced polishing article. The detection
system 220 may detect the identifying feature on the backside
surface of the advanced polishing article. The detection system 220
may be positioned to authenticate the identifying feature.
[0081] At operation 830, a system controller (e.g., system
controller 108) is used to verify whether the identifying feature
is valid. If the system controller authenticates the identifying
feature, then the advanced polishing article 123 is allowed to
operate on the platen assembly 132. However, if the detection
system does not authenticate the identifying feature, then the
advanced polishing article 123 is not allowed to operate on the
platen assembly 132. For example, in implementations, where the
identifying feature(s) identifies the polishing article as a
polishing article designed for polishing dielectric materials,
polishing recipes and polishing fluids used for polishing metals
may be locked out.
[0082] At operation 840, if the advanced polishing article is
authenticated, a substrate may be polished using the advanced
polishing article using, for example, the method 700.
[0083] In summary, some benefits of some of the implementations
described herein provide apparatus and methods that increase the
accuracy and placement of polishing material relative to a
substrate, which decreases the cost to produce semiconductor
devices and the cost of ownership of a semiconductor device
production line. In some implementations, the advanced polishing
pads described herein include identifying feature(s) that are
associated with a pattern of polishing features on the polishing
surface of the polishing material, thus allowing the user to
position the polishing material such that a substrate to be
polished is exposed to a desired pattern of polishing features of
the polishing material. In some implementations, the identifying
feature(s) may include a first start of line feature, which
identifies a start of a first polishing region of polishing
material, and a second start of line feature, which identifies an
end of the first polishing region and a start of a second polishing
region of polishing material. The first polishing region of
polishing material and the second polishing region of polishing
material may define similar or substantially similar patterns of
polishing material, which allows the user to expose subsequently
polished substrate to the same pattern of features as previously
polished substrates.
[0084] When introducing elements of the present disclosure or
examples of aspects or implementation(s) thereof, the articles "a,"
"an," "the" and "said" are intended to mean that there are one or
more of the elements.
[0085] The terms "comprising," "including" and "having" are
intended to be inclusive and mean that there may be additional
elements other than the listed elements.
[0086] While the foregoing is directed to implementations of the
present disclosure, other and further implementations of the
disclosure may be devised without departing from the basic scope
thereof, and the scope thereof is determined by the claims that
follow.
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