U.S. patent application number 13/163227 was filed with the patent office on 2012-12-20 for apparatus for chemical mechanical polishing.
This patent application is currently assigned to APPLIED MATERIALS, INC.. Invention is credited to Jagan Rangarajan, Alpay Yilmaz.
Application Number | 20120322345 13/163227 |
Document ID | / |
Family ID | 47354032 |
Filed Date | 2012-12-20 |
United States Patent
Application |
20120322345 |
Kind Code |
A1 |
Rangarajan; Jagan ; et
al. |
December 20, 2012 |
APPARATUS FOR CHEMICAL MECHANICAL POLISHING
Abstract
Embodiments of the invention generally relate to systems and
methods to CMP substrates. The systems generally include a
polishing system that has a polishing module and cleaning module.
Each of the polishing module and the cleaning module can be
partitioned into independently operable sections. Each section of
the polishing module includes a platen, at least one load cup, and
at least one polishing head. Each section of the cleaning module
includes a cleaning station and one or more robots adapted to
advance substrates through the cleaning station. The methods
generally include polishing a plurality of substrates in a
polishing system having independently operable sections. During the
polishing of the substrates in one section, a second of the
independently operable stations may be maintained or cleaned.
Inventors: |
Rangarajan; Jagan; (Fremont,
CA) ; Yilmaz; Alpay; (San Jose, CA) |
Assignee: |
APPLIED MATERIALS, INC.
Santa Clara
CA
|
Family ID: |
47354032 |
Appl. No.: |
13/163227 |
Filed: |
June 17, 2011 |
Current U.S.
Class: |
451/28 ;
451/67 |
Current CPC
Class: |
B24B 37/04 20130101 |
Class at
Publication: |
451/28 ;
451/67 |
International
Class: |
B24B 1/00 20060101
B24B001/00 |
Claims
1. An apparatus, comprising: a polishing module having a first
polishing station and a second polishing station; a partition
including a housing and an actuatable door located within the
polishing module between the first polishing station and the second
polishing station, the actuatable door adapted to be positioned to
environmentally isolate the first polishing station from the second
polishing station; and an overhead track disposed above the first
polishing station and the second polishing station.
2. The apparatus of claim 1, wherein the at least two polishing
stations are independently operable when separated by the
partition.
3. The apparatus of claim 1, wherein the overhead track includes a
movable seal coupled thereto, the movable seal adapted to be
engaged by the actuatable door.
4. The apparatus of claim 1, wherein the actuatable door is adapted
to be positioned within the housing and extend therefrom.
5. The apparatus of claim 4, wherein the actuatable door is
positioned on a track.
6. The apparatus of claim 5, wherein the actuatable door, when
extended from the housing, forms a substantially air-tight seal
separating the first polishing station from the second polishing
station.
7. The apparatus of claim 1, further comprising a cleaning module
coupled to the polishing module, the cleaning module having a first
cleaning station, and second cleaning station, and a central
transfer area disposed therebetween.
8. The apparatus of claim 7, further comprising a trough having at
least two shuttles therein, the trough in operable communication
with the first cleaning station, the second cleaning station, and
the central transfer area.
9. The apparatus of claim 8, wherein the trough further comprises a
plurality of partitions actuatable to selectively partition
portions of the trough.
10. The apparatus of claim 9, wherein actuation of at least one the
plurality of trough partitions isolates the first cleaning station
from the central transfer region and the second cleaning
station.
11. An apparatus, comprising: a polishing module, the polishing
module comprising: a first polishing station; a second polishing
station a partition including a housing and an actuatable door
located within the polishing module between the first polishing
station and the second polishing station, the actuatable door
adapted to be positioned to environmentally isolate the first
polishing station from the second polishing station; and a curved
overhead track disposed above the first polishing station and the
second polishing station; a cleaning module adjacent to and in
operable communication with the polishing module, the cleaning
module comprising: a first cleaning station; a second cleaning
station; a central transfer region positioned between the first
cleaning station and the second cleaning station; and a trough
disposed at one end of the cleaning module, the trough in operable
communication with the first cleaning station, the second cleaning
station, and the central transfer region.
12. The apparatus of claim 11, wherein the actuatable door is
adapted to be positioned within and extend from the housing.
13. The apparatus of claim 14, further comprising a movable seal
coupled to the curved track, wherein the movable seal includes a
slot adapted to be engaged by the actuatable door of the
partition.
14. The apparatus of claim 12, wherein the trough comprises a
plurality of actuatable partitions therein.
15. A method of processing substrates in a polishing system having
a polishing module and a cleaning module, comprising: partitioning
at least one of the cleaning module and the polishing module into a
first section and a second section; and performing at least one of
cleaning or maintenance on the first section while processing a
plurality of substrates in the second section.
16. The method of claim 15, wherein partitioning at least one of
the cleaning module and the polishing module comprises partitioning
the polishing module, and wherein performing at least one of
cleaning or maintenance comprises cleaning or maintaining the first
section of the polishing module while processing a plurality of
substrates in the second section of the polishing module and in the
cleaning module.
17. The method of claim 16, wherein partitioning the polishing
module comprises actuating a door across the polishing module to
separate a first polishing station from a second polishing
station.
18. The method of claim 15, wherein partitioning at least one of
the cleaning module and the polishing module comprises partitioning
the cleaning module, and wherein performing at least one of
cleaning or maintenance comprises cleaning or maintaining the first
section of the cleaning module while processing a plurality of
substrates in the second section of the cleaning module and in the
polishing module.
19. The method of claim 18, wherein partitioning the cleaning
module comprises actuating a partition located within a trough of
the cleaning module.
20. The method of claim 15, wherein partitioning at least one of
the cleaning module and the polishing module comprises partitioning
both the cleaning module and the polishing module.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] Embodiments of the present invention generally relate to
methods and apparatus for chemical mechanical polishing (CMP) of
substrates.
[0003] 2. Description of the Related Art
[0004] CMP is a known process used to planarize one or more
surfaces of a substrate. Although many commercially available CMP
systems have demonstrated robust polishing performance, the move to
smaller line widths requiring more precise fabrication techniques,
along with a continued need for increased throughput, drives an
ongoing effort for polishing system improvements. Current
commercially available systems polish substrates in a serial
fashion through sequential stations on a polishing system. Down
time due to maintenance or cleaning at one polishing station halts
throughput of substrates on the entire polishing system, thus
stopping production and increasing the cost to manufacture
substrates.
[0005] Therefore, there is a need for a modular CMP system.
SUMMARY OF THE INVENTION
[0006] Embodiments of the invention generally relate to systems and
methods to CMP substrates. The systems generally include a
polishing system that has a polishing module and cleaning module.
Each of the polishing module and the cleaning module can be
partitioned into independently operable sections. Each section of
the polishing module includes a platen, at least one load cup, and
at least one polishing head. Each section of the cleaning module
includes a cleaning station and one or more robots adapted to
advance substrates through the cleaning station. The methods
generally include polishing a plurality of substrates in a
polishing system having independently operable sections. During the
polishing of the substrates in one section, a second of the
independently operable stations may be maintained or cleaned.
[0007] In one embodiment, an apparatus comprises a polishing module
having a first polishing station and a second polishing station. A
partition including a housing and an actuatable door is located
within the polishing module between the first polishing station and
the second polishing station. The actuatable door is adapted to be
positioned to environmentally isolate the first polishing station
from the second polishing station. An overhead track is disposed
above the first polishing station and the second polishing
station.
[0008] In another embodiment, an apparatus comprises a polishing
module. The polishing module comprises a first polishing station, a
second polishing station, and a partition. The partition includes a
housing and an actuatable door located within the polishing module
between the first polishing station and the second polishing
station. The actuatable door is adapted to be positioned to
environmentally isolate the first polishing station from the second
polishing station. The polishing module also includes a curved
overhead track disposed above the first polishing station and the
second polishing station. The apparatus also comprises a cleaning
module adjacent to and in operable communication with the polishing
module. The cleaning module comprises a first cleaning station, a
second cleaning station, and a central transfer region positioned
between the first cleaning station and the second cleaning station.
A trough is disposed at one end of the cleaning module in operable
communication with the first cleaning station, the second cleaning
station, and the central transfer region.
[0009] In another embodiment, a method of processing substrates in
a polishing system having a polishing module and a cleaning module
comprises partitioning at least one of the cleaning module and the
polishing module into a first section and a second section. The
method further comprises performing at least one of cleaning or
maintenance on the first section while processing a plurality of
substrates in the second section.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] So that the manner in which the above recited features of
the present invention can be understood in detail, a more
particular description of the invention, briefly summarized above,
may be had by reference to embodiments, some of which are
illustrated in the appended drawings. It is to be noted, however,
that the appended drawings illustrate only typical embodiments of
this invention and are therefore not to be considered limiting of
its scope, for the invention may admit to other equally effective
embodiments.
[0011] FIGS. 1A and 1B are top plan views of a polishing system
according to one embodiment of the invention.
[0012] FIG. 2 is a perspective view of a polishing station
according to one embodiment of the invention.
[0013] FIGS. 3A and 3B are respective bottom and top isometric
views of a polishing module lid.
[0014] FIG. 4 is an isometric view of a partition according to one
embodiment of the invention.
[0015] FIG. 5 is a sectional view of a shuttle trough and shuttles
according to one embodiment of the invention.
[0016] FIG. 6 is an isometric view of cleaning robots according to
one embodiment of the invention.
DETAILED DESCRIPTION
[0017] Embodiments of the invention generally relate to systems and
methods to CMP substrates. The systems generally include a
polishing system that has a polishing module and cleaning module.
Each of the polishing module and the cleaning module can be
partitioned into independently operable sections. Each section of
the polishing module includes a platen, at least one load cup, and
at least one polishing head. Each section of the cleaning module
includes a cleaning station and one or more robots adapted to
advance substrates through the cleaning station. The methods
generally include polishing a plurality of substrates in a
polishing system having independently operable sections. During the
polishing of the substrates in one section, a second of the
independently operable stations may be maintained or cleaned.
[0018] FIGS. 1A and 1B are top plan views of a polishing system 100
according to one embodiment of the invention. The polishing system
100 includes a polishing module 101, a cleaning module 102, and a
factory interface 103. The factory interface 103 includes a robot
104 disposed on a track 105. The robot 104 is adapted to remove a
substrate 106 from one of the substrate storage cassettes 107 and
transfer the substrate 106 to transfer platforms 180, through a
port 110, such as a slit valve. The robot 104 is also configured to
receive substrates from each cleaning station 109A, 109B through
ports 111 subsequent to a cleaning process and return the cleaned
substrates to the substrate storage cassettes 107. The ports 111
are shown as having an "L" shape; however, other shapes, such as
linear, are contemplated. Although the robot 104 is shown as only
supporting one substrate 106, it is contemplated that the robot 104
may simultaneously support more than one substrate 106.
[0019] The factory interface 103 is positioned adjacent to and in
operable communication with the cleaning module 102. The cleaning
module 102 includes two cleaning stations 109A, 109B, a central
transfer area 112 located therebetween, and a shuttle trough 113
positioned at one end of the cleaning module 102 opposite the
factory interface 103. The cleaning stations 109A, 109B are
separated from the central transfer area by walls 117, which also
extend over the upper surface of the shuttle trough 113. The
cleaning stations 109A, 109B and the central transfer area 112 are
in communication with one another only through the shuttle trough
113 during system operation. Each cleaning station 109A, 109B
includes a plurality of cleaning units 115 and a dryer 120, each of
which generally includes an opening formed in the upper portion
thereof for accepting substrates therein. The cleaning units 115
may be one or more of brush boxes, rinsing stations, spray jet
units, megasonic cleaners, or combinations of two or more thereof.
Robots 116 are each connected to a track (not shown in FIG. 1A)
disposed in each of the cleaning stations 109A, 109B and coupled to
a surface of the walls 117. The robots 116 are adapted to move a
substrate received from the shuttle trough 113 through each of the
cleaning units 115 to the dryer 120. The dryer 120 has an output
station (not shown) through which the substrate is presented for
transfer to the robot 104, which then stores the substrate in the
substrate storage cassettes 107. For example, a first robot 116 may
be adapted to move substrates through a first set of cleaning units
115, such as the first two cleaning units 115, while a second robot
116 may be adapted to move the substrate through a second set of
cleaning units 115 and the dryer 120.
[0020] The central transfer area 112 of the cleaning module 102 is
in communication with the factory interface 103 and the polishing
module 101 through ports 110 and 118, respectively, each of which
may be selectively and independently opened and closed. The central
transfer area 112 includes two transfer platforms 180, two buffer
stations 108A, 108B and a robot 119 adapted to transfer two
substrates simultaneously from the transfer platforms 180 to the
interior of the polishing module 101 through one of the ports 118.
One or more substrates may optionally be vertically positioned in
the buffer stations 108A, 108B, which contain a solution such as
deionized water, to maximize throughput. In such an embodiment, the
robot 119 may remove substrates from the buffer stations 108A,
108B. The robot 119 includes a linkage assembly 124 coupled to an
overhead track or linkage (not shown), a robot body 127 coupled to
the linkage assembly 124, and two end effectors 126 coupled to the
robot body 127. The robot 119 is adapted to remove substrates from
the transfer platforms 180 and transfer the substrates into the
polishing module 101 to load cups 121A and 121B, or 122A and 122B
through a respective port 118. The robot 119 is also adapted to
remove substrates from the load cups 121A and 121B, or 122A and
122B after a polishing process, and dispose the substrates in the
shuttle trough 113 through openings 125 located in the upper
surface of the shuttle trough 113. The end effectors 126 each
generally include at least one gripping device, such as a
mechanical clamp or suction device in order to secure substrates
thereto.
[0021] The shuttle trough 113 accepts substrates in a vertical
orientation for placement on a shuttle located therein, as will be
explained in further detail with reference to FIG. 5, and transfer
the substrates to a location proximate the cleaning stations 109A,
109B (i.e., adjacent to openings 137) to facilitate transfer to the
robots 116. The robot 119 is adapted to pivot at the connection
between the robot body 127 and the linkage assembly 124 to allow
the end effectors 126 to assume a vertical orientation for transfer
of polished substrates through the openings 125 located in the
shuttle trough 113.
[0022] The polishing module 101 includes a plurality of polishing
stations 128 on which substrates are polished on polishing pads 135
while retained in polishing heads 131A, 131B, 132A, and 132B. The
polishing stations 128 are sized to interface with at least one
polishing head so that at least one substrate may be polished in
the polishing station 128. In the embodiment depicted in FIGS.
1A-1B, the polishing stations are sized to interface with at least
two polishing heads simultaneously so that polishing of multiple
substrates at the same polishing station 128 may occur at the same
time. Each polishing station 128 includes one or more pad
conditioners 134 for conditioning an upper surface of the polishing
pad 135, and one or more fluid delivery arms 136 for delivering a
polishing fluid, such as a polishing slurry or rinse fluid, to the
upper surface of the polishing pad 135. In the embodiment depicted
in FIGS. 1A-1B, each polishing station 128 includes at least two
pad conditioners 134 and at least 2 fluid delivery arms 136.
[0023] The polishing heads 131A, 131B, 132A, and 132B are coupled
to carriages that are mounted to an overhead track 130 (shown in
phantom). The overhead track 130 allows the polishing heads 131A,
131B, 132A, and 132B to be selectively positioned around the
polishing module 101 including over the polishing pads 135 disposed
in the polishing stations 128 and load cups 121A, 121B, 122A, and
122B. Thus, the polishing heads 131A, 131B, 132A, and 132B are
movable along the track 130 to a position over the load cups 121A,
121B, 122A, and 122B where substrates can be engaged and retained
by the polishing heads 131A, 131B, 132A, and 132B. The polishing
heads 131A, 131B, 132A, and 132B can then return to a position over
a selected one of the polishing stations 128 via movement along the
track 130 for polishing of the substrates on the polishing pads
135. The track 130 shown in FIG. 1A has a curved shape. Ends 190A
and 190B of the track 130 define an opening 191 on a side of the
polishing module 101 opposite the cleaning module 102. The opening
191 of the track 130 provides a space to accommodate the partition
129 which extends inwardly from one wall of the polishing module
101. It is contemplated that the track 130 may have other shapes,
including linear, elliptical, circular or other shape. It is
further contemplated that the track 130 may not have the opening
191, and thus, have a completely circular shape, as long as the
track 130 can still accommodate the partition 129.
[0024] The above description describes the structure of the
polishing system 100; and now the movement of substrates through
the polishing system 100 will be described. The robot 104 unloads
substrates 106 from the substrate storage cassettes 107 and
transfers the substrates to the transfer platforms 180 through the
port 110. The robot 119 then engages and lifts one substrate from
each of the transfer platforms 180 simultaneously. The robot
rotates approximately 180 degrees and enters the polishing module
101 to position the substrates on the load cups 121A, 1216 through
the respective port 118 closest to load cups 121A, 121B. The robot
119 is then retracted from the polishing module 101.
[0025] The polishing heads 131A, 131B travel along the track 130 to
a position above the load cups 121A, 121B. The polishing heads
131A, 131B actuate downward to engage and secure a substrate from
one of the load cups 121A, 121B, respectively. The polishing heads
131A, 131B then lift upward to provide sufficient clearance of the
load cups 122A, 122B and return to a position above the polishing
station 128. During the movement of the polishing heads 131A, 131B,
the robot 119 disposes two additional substrates from the transfer
platforms 180 on to the load cups 122A, 122B, respectively, through
the respective port 118. After the polishing heads 131A, 131B are
clear of the load cups 121A, 121B, the polishing heads 132A, 132B
move along the track 130 to a position above the load cups 122A,
122B, and secure substrates from the load cups 122A, 122B. The
polishing heads 132A, 132B then return to the other polishing
station 128 to polish the substrates.
[0026] While polishing heads 132A, 132B are engaging substrates
from load cups 122A, 122B, the robot 119 is reloading load cups
121A, 121B. Simultaneously, after completion of the polishing of
the substrates located in polishing heads 131A, 131B, the polishing
heads 131A, 131B rotate along the track to a position over the
unoccupied load cups 122A, 122B, respectively, and dispose the
polished substrates in the load cups 122A, 1226. The polishing
heads 131A, 131B then continue along the track to the load cups
121A, 121B to engage two new substrates, and the polishing process
is repeated. While the polishing heads 131A, 131B return to the
polishing station 128, the robot 119 removes the polished
substrates from the load cups 122A, 122B and disposes the polished
substrates in the openings 125 of the shuttle trough 113. Each of
the polished substrates is disposed on a shuttle (shown in FIG. 5)
located within the shuttle trough 113, and transferred via a
shuttle to one of the cleaning stations 109A, 109B. The shuttles
are independently operable to allow a first shuttle to carry a
first substrate to the cleaning station 109A, and to allow a second
shuttle to carry a second substrate in an opposite direction to
cleaning station 109B.
[0027] The polished substrates are then removed from the shuttle
trough 113 through openings 137 by respective robots 116 located in
each of the cleaning stations 109A, 109B. A first robot 116 in each
of the cleaning stations 109A, 109B advance the polished substrate
through a first set of the cleaning units 115, such as the first
two cleaning units 115. A second robot 116 in each of the cleaning
stations 109A, 109B removes the substrate from the last cleaning
unit 115 of the first set of cleaning units 115, and then advances
the substrate through the remainder of the cleaning units 115 and
the dryer 120. The cleaned substrates are then removed from the
cleaning stations 109A, 109B by the robot 104 and stored in the
substrate storage cassettes 107.
[0028] FIG. 1B is a top plan view of the polishing system 100
having the partition 129 positioned to separate and form a seal,
for example an air tight seal, between sections of the polishing
module 101. The partition 129 includes a housing 140 and an
actuatable door 141 which extends from the housing 140 to form a
substantially environmentally-isolating seal (in conjunction with
the closed ports 118) across the polishing module 101 to separate
the polishing stations 128 from one another. Thus, the polishing
module,101 is divided into two independently operable sections 101A
and 101B, wherein each section includes at least one load cup and
one polishing station. The partition 129 separates the sections
101A and 1018 from one another thus providing isolation
therebetween. In such a configuration, one of the sections 101A or
101B can be shut down for maintenance or cleaning, while the other
section 101A or 1018 can continue to operate uninterrupted and
unaffected by the shut down section. Therefore, throughput of the
polishing system 100 is reduced only by about 50 percent, instead
of completely shutting down, when maintenance or cleaning within
the polishing module is necessary. The partition 129 allows each
section 101A or 101B to be safely maintained by providing a barrier
between each of the sections 101A, 1018. Additionally, the
partition 129 forms an environmentally-isolating seal across the
polishing module 101 isolating section 101A from section 101B,
which reduces the probability of particulate contamination between
the adjacent section 101A or 101B due to cleaning or maintenance of
the other section 101A or 101B. Furthermore, the
environmentally-isolating seal formed by the partition 129 reduces
variations in air flow within the section 101A or 1018 during a
polishing process, which ensures uniform polishing from substrate
to substrate.
[0029] When one of the sections 101A, 101 B is shut down for
maintenance or cleaning, substrate movement through the system is
slightly different with the partition 129 closed than when the
entire polishing system 100 is operational. Specifically, the
polishing heads 131A and 131B, or 132A and 1326 use only the load
cups positioned adjacent thereto in the same section 101A or 101B
as the respective polishing heads. The polishing heads 131A, 131B,
132A, 132B are unable to access the load cups on the opposite side
of the polishing module 101 due to extension of the actuatable door
141. Furthermore, the port 118 on the respective side of the
section 101A, 101B generally remains closed during the maintenance
or cleaning of section 101A, 101B to maintain environmental
isolation.
[0030] Not only can the polishing module 101 be partitioned into
independently operable sections, but the cleaning module 102 can
also be partitioned into independently operable sections. For
example, either of the cleaning stations 109A and 109B can be shut
down for cleaning or maintenance, while the other cleaning station
109A or 109B continues to process substrates. As discussed above,
the cleaning stations 109A, 109B and the central transfer area 112
are separated by walls 117, and are in operable communication only
through the shuttle trough 113. Thus, partitioning of the shuttle
trough 113 adjacent to the walls 117 isolates a respective cleaning
station 109A or 109B from the remainder of the cleaning module 102,
allowing for cleaning or maintenance of the respective partitioned
cleaning station 109A or 109B. The shuttle trough 113 can be
partitioned via actuatable trough partitions 138, which are shown
in phantom in FIG. 1B and further described with reference to FIG.
5.
[0031] When the cleaning module 102 is partitioned for cleaning or
maintenance of one of the cleaning stations 109A, 109B, the
transfer of substrates from the polishing module to the operable
cleaning station is different than when the entire cleaning module
102 is operable. When one of the cleaning stations 109A or 109B is
shutdown, for example cleaning station 109B, the robot 119 removes
one polished substrate at a time from either of the first set of
load cups 121A or 121B, or the second set of load cups 122A and
122B. For example, if polished substrates are located on load cups
122A and 122B, the robot removes a polished substrate from the load
cup 122A, retracts the polished substrate into the cleaning module
102 while rotating 180 degrees, and places the substrate in the
shuttle trough through opening 125 closest to the cleaning station
109A. A shuttle 570 (shown in FIG. 5) then transports the substrate
through the shuttle trough 113 to a location adjacent to opening
137, where the substrate is picked up by a first robot 116 and
transported through the cleaning station 109A. The shuttle 570 then
returns to a position beneath the other opening 125 farthest from
the cleaning station 109A. The robot 119 then removes a polished
substrate from the other load cup 122B, and positions the substrate
on the shuttle 570 through the other opening 125. The shuttle then
transports the substrate to the opening 137 proximate to the
cleaning station 109A, where the substrate is picked up by a robot
116 and transported through the cleaning station 109A. Thus, when
one of the cleaning stations 109A or 109B is partitioned off for
cleaning or maintenance, substrates are transferred to the operable
cleaning station one at a time. Transferring the substrates one at
a time using a single shuttle 570 allows a second shuttle 570 to be
maintained simultaneously with one of the cleaning stations 109A or
109B.
[0032] It is to be noted that the polishing module 101, the
cleaning module 102, or both may be simultaneously partitioned. In
an embodiment where both the polishing module 101 and the cleaning
module 102 are partitioned, it is not necessary to shut down a
cleaning station 109A or 109B and a polishing section 101A or 101B
on the same side of the polishing system 100. For example, the
polishing module 101 may be partitioned for cleaning of section
101A, while the cleaning module 102 is partitioned for cleaning of
the cleaning station 109B. The ability to partition either or both
of the polishing module 101 and the cleaning module 102 assists in
cleaning, maintenance, engineering evaluation, or particle
apportionment in the polishing system 100.
[0033] FIGS. 1A and 1B illustrate one embodiment of a polishing
system 100; however, additional embodiments are also contemplated.
For example, it is contemplated that the polishing module 101 may
include more than two polishing stations 128, such as three
polishing stations 128 or four polishing stations 128. It is also
contemplated that polishing pads 135 on the polishing stations 128
may be a polyurethane pad or a fixed abrasive pad. It is further
contemplated that polishing stations 128 may be adapted to polish
200 millimeter, 300 millimeter, and/or 450 millimeter substrates,
or that the polishing stations 128 may be adapted to polish a
single substrate at a time. It is also contemplated that the
polishing module 101 may be utilized in conjunction with cleaning
modules other than the cleaning module 102.
[0034] Additionally, it is contemplated that the independently
operable sections 101A and 101B need not contain identical
polishing components. For example, it is contemplated that one of
the independently operable sections 101A or 101B could contain a
platen with load cups, as illustrated, while the other
independently operable section contains bevel polishing components
or other course polishing/grinding stations. Furthermore, it is
contemplated that the actuatable door 141 may be positioned to
actuate vertically, rather than horizontally from the housing
140.
[0035] FIG. 2 is a perspective view of a polishing station 128
according to one embodiment of the invention. The polishing station
128 includes a platen 242 having a shaft 243 coupled to a motor 244
which is adapted to rotate the shaft 243 and the platen 242 coupled
thereto. The polishing pad 135 is disposed on the upper surface of
the platen 242 and acts as a polishing surface during a chemical
mechanical polishing process. A substrate is retained against the
upper surface of the polishing pad 135 during polishing by each
polishing head 132A, 132B. The polishing heads 132A, 132B are
coupled to carriages 245 by rotatable and vertically actuatable
shafts 246. The carriages 245 are coupled to the track 130
supported above the platen 242 and below a polishing module lid
247. The carriages 245 can be selectively positioned along the
track 130 within the polishing module. The carriages 245 are moved
along the track 130 using an actuator (not shown), such as a
magnetic actuator, a gear motor, a servo motor, a linear motor or
other motion control device suitable for positioning the carriages
245 along the track 130. The carriages 245 are used to position the
polishing heads 132A, 132B over the load cups, to sweep the
polishing heads 132A, 132B over the polishing pad 135, or to
position the polishing heads 132A, 132B clear of the load cups or
polishing pad 135 for maintenance.
[0036] Rotatable fluid delivery arms 136 are positioned on opposite
sides of the platen 242 and are adapted to apply one or more fluids
to the upper surface of the polishing pad 135. For example, the
fluid delivery arms 136 may apply one or more of a polishing
slurry, a rinsing solution, or a conditioning solution to the upper
surface of the polishing pad 135. Rotatable pad conditioners 134
are positioned adjacent to each of the fluid delivery arms 136. The
pad conditioners 134 are adapted to contact and sweep across the
polishing pad 135 to condition the upper surface thereof.
[0037] FIGS. 3A and 3B are respective bottom and top isometric
views of a polishing module lid 247. The polishing module lid 247
is adapted to be positioned over the polishing module 101 (shown in
FIG. 1A) and supports a track 130 on the bottom surface thereof.
The track 130 includes an outer edge 350, an inner edge 351, and a
stator 352 disposed therebetween. The outer edge 350 and the inner
edge 351 define the curved track 130. The track has ends 190A and
190B which define an opening 191 in one portion of the track 130.
The opening 191 is positioned to accommodate the housing 140 of the
partition 129 (shown in FIG. 1B). An encoder scale 354 is coupled
to the polishing module lid 247 and is adapted to detect the
position of carriages 245.
[0038] The track 130 is shown has having four carriages 245 coupled
thereto; however, it is contemplated that more or less than four
carriages 245 may be coupled to the track 130. The carriages 245
are independently movable along the track 130 to selectively
position the carriages 245 and the polishing heads coupled thereto
about the track 130. For example, each carriage 245 may include a
coil that interfaces with the stator 352 of the track 130. In such
an example, the stator 352 includes magnets arranged in alternating
polarity so that each carriage 245 may be moved independently of
the other carriages 245 coupled to the track 130 by controlling the
magnetic field generated by the coil.
[0039] A movable seal 356 is also coupled to the track 130. The
movable seal 356 includes a slit 357 therein which is adapted to be
engaged by the actuatable door 141 of the partition 129 (shown in
FIG. 1B) to form a wall across the polishing module. The slit 357
may include a rubber seal or lining therein to increase the sealing
ability of the movable seal 356. When the movable seal is engaged
by the actuatable door 141, pins 358 may be disposed through the
polishing module lid 247 to engage and secure the movable seal 356
in place. The pins 358 are shown in the top isometric view of the
polishing module lid 247 shown in FIG. 3B. The pins 358 may engage
the movable seal 356, for example, via pneumatic actuation.
[0040] Returning to FIG. 3A, when the actuatable door 141 is not
engaged with the movable seal 356, for example, during normal
operation of the polishing module 101, the movable seal 356 travels
along the track 130. Movement of the movable seal 356 along the
track 130 allows the carriages 245 to be positioned over both sets
of load cups in the polishing module. Since the range of motion of
each carriage 245 is at least approximately 135 degrees (from one
polishing station to an oppositely positioned set of load cups),
the movable seal 356 travels along the track in the same direction
of movement as each set of carriages 245 to accommodate the
movement of the carriages 245. Thus, during polishing, the movable
seal 356 continuously shifts in a clockwise and then
counter-clockwise direction synchronized with the movement of the
carriages 245. In order to effect movement of the movable seal 356,
the movable seal 356 may include a linear motor similar to the
carriages 245. The movable seal 356 may additionally include one or
more metrology devices integrated therewith for monitoring
conditions within the polishing module. For example, the movable
seal 356 may include a pad metrology unit, a substrate defect
mapping device, a camera or video device, or a laser.
[0041] FIG. 4 is an isometric view of the partition 129 according
to one embodiment of the invention. The partition 129 includes a
housing 140 having an opening 460 which receives the actuatable
door 141. The actuatable door 141 is actuated along a track 461 via
an actuator 465, such as a motor, and engages a seal 462 located on
the wall 463. The wall 463 separates the polishing module 101 from
the cleaning module 102 (as shown in FIG. 1A) and includes ports
118 therethrough. The upper edge 464 of the of the actuatable door
141 is adapted to engage the slit 357 in the movable seal 356 (as
shown in FIG. 3A) to form a seal when partitioning the cleaning
module into independently operable sections. The upper surface 466
of the housing 140 is in contact with the lower surface of the
polishing module lid 247. The upper surface 466 has an opening 468
therein adapted to engage the encoder scale 354 (shown in FIG. 3A).
The partition 129 is generally formed from a polymer or a metal
material, such as stainless steel, or another material which does
not introduce undesired contamination into the polishing
module.
[0042] FIG. 5 is a sectional view of the shuttle trough 113 and
shuttles 570 according to one embodiment of the invention. The
shuttles 570 are used to move substrates 106 returning from the
polishing module (entering the shuttle trough 113 through openings
125) to a load position beneath openings 137 where the substrates
106 can be picked up by a cleaning station robot and moved through
a respective cleaning station. Although two shuttles 570 are shown,
it is contemplated that more or less shuttles may be utilized. The
shuttle trough 113 includes a trough body 571 adapted to hold a
fluid 572, such as a rinsing solution, therein. A track 576 is
disposed within the trough body 571 to which the shuttles 570 are
coupled to facilitate transfer of the substrates 106 within the
shuttle trough 113. Alternatively, it is contemplated that the
track may be disposed outside the shuttle trough 113, and connected
to the shuttles 570 via a slit through the back surface of the
shuttle trough 113. The shuttles 570 include substrate support 577,
such as a clamp, gripper, or grooved wafer holder, a track mount
578, and a stem 579 coupled therebetween. Each track mount 578
generally includes an actuator to facilitate movement of the
shuttles 570 along the track 576 and to provide independent
actuation to each of the shuttles 570.
[0043] The trough body 571 includes a roof portion 573 through
which openings 125 and 137 are disposed. The partitions 138 are
pivotally connected to the lower surface of the roof portion 573 by
hinges 574. The hinges 574 are adapted to pneumatically or
mechanically actuate the partitions 138. The partitions 138 are
adapted to pivot into a vertical position, as shown in phantom, to
isolate one portion of the shuttle trough 113 from the remainder of
the shuttle trough 113. One of the partitions 138 is generally
actuated on a respective side of the shuttle trough 113 adjacent to
a cleaning station during cleaning or maintenance of the cleaning
station. The vertically-positioned partition 138 isolates the
shutdown cleaning station from the remainder of the cleaning
module. One of the shuttles 570 may be located behind the partition
138 adjacent to the partitioned cleaning station to allow access to
the shuttle 570 for cleaning or maintenance at the same time as
cleaning or maintenance of the shutdown cleaning station. Drains
580 are disposed through the lower surface of the trough body 571
near the outer edges of the shuttle trough 113 for draining the
fluid 572 in the partitioned section of the shuttle trough 113 to
facilitate access to the shuttle 570 located therein.
[0044] FIG. 6 is an isometric view of cleaning robots 116 according
to one embodiment of the invention. The cleaning robots 116 are
adapted to remove polished substrates from the shuttle trough 113
through opening 137 (shown in FIG. 5) and transfer substrates
through a cleaning station. The robots 116 are disposed on a track
682 and are adapted to be positioned above a cleaning station. The
robots 116 are coupled to the track 682 by mounts 683. The mounts
683 include motors for independently moving the robots 116 along
the track 682. The mounts 683 additionally include actuators to
effect vertical movement of the robot 116 relative to the track
682. The vertical movement of the robots 116 facilitates movement
of substrates into and out of the cleaning units 115 and the dryers
120 (shown in FIG. 1A).
[0045] The robots 116 further include horizontal arms 684 for
positioning clamps 685 above the cleaning units 115 and the dryers
120. The clamps 685 are adapted contact the edges of substrate 106
to hold the substrate 106 therein as shown in phantom. The clamps
685 are coupled to the horizontal arms 684 by movable bases 686
which are actuatable along the horizontal arms 684. Actuation of
the clamps 685 allows for increased alignment precision of the
clamps 685 with the openings within the cleaning units 115 and the
dryers 120.
[0046] Benefits of the present invention include a modular
polishing system which can be partitioned into independently
operable sections. Some of the partitioned independently operable
sections can then be maintained while the remainder of the sections
simultaneously process substrates. Thus, system throughput is not
halted due to maintenance at one location on the system.
Additionally, throughput of the system is higher when all stations
of the system are operational, especially compared to two
independent polishing modules having the same total amount of
platens, due to modular polishing system's ability to share modules
while the system is in full production mode. Furthermore, the
footprint of the modular polishing system is smaller than two
separate polishing systems.
[0047] While the foregoing is directed to embodiments of the
present invention, other and further embodiments of the invention
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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