U.S. patent application number 11/374250 was filed with the patent office on 2007-09-13 for smart polishing media assembly for planarizing substrates.
This patent application is currently assigned to Applied Materials, Inc.. Invention is credited to Benjamin A. Bonner, Anand N. Iyer, Garlen C. Leung, Peter McReynolds, Gregory E. Menk, Gopalakrishna B. Prabhu, Erik S. Rondum.
Application Number | 20070212976 11/374250 |
Document ID | / |
Family ID | 38479545 |
Filed Date | 2007-09-13 |
United States Patent
Application |
20070212976 |
Kind Code |
A1 |
McReynolds; Peter ; et
al. |
September 13, 2007 |
Smart polishing media assembly for planarizing substrates
Abstract
A smart polishing media assembly is provided, along with a
polishing system and a method for using the same. In one
embodiment, the smart polishing media assembly includes a memory
device coupled to a polishing material. The polishing material may
be in pad, web or belt form. The memory device generally stores at
least one material information, historical use information, and/or
conditioning information of the polishing material.
Inventors: |
McReynolds; Peter; (San
Mateo, CA) ; Menk; Gregory E.; (Pleasanton, CA)
; Bonner; Benjamin A.; (San Jose, CA) ; Prabhu;
Gopalakrishna B.; (San Jose, CA) ; Rondum; Erik
S.; (San Ramon, CA) ; Leung; Garlen C.; (San
Jose, CA) ; Iyer; Anand N.; (Santa Clara,
CA) |
Correspondence
Address: |
PATTERSON & SHERIDAN, LLP
3040 POST OAK BOULEVARD, SUITE 1500
HOUSTON
TX
77056
US
|
Assignee: |
Applied Materials, Inc.
|
Family ID: |
38479545 |
Appl. No.: |
11/374250 |
Filed: |
March 13, 2006 |
Current U.S.
Class: |
451/5 ; 451/526;
451/8 |
Current CPC
Class: |
B24B 21/004 20130101;
B24B 37/20 20130101 |
Class at
Publication: |
451/005 ;
451/008; 451/526 |
International
Class: |
B24B 51/00 20060101
B24B051/00; B24B 49/00 20060101 B24B049/00; B24D 11/00 20060101
B24D011/00 |
Claims
1. A smart polishing media assembly, comprising: a polishing
material; and a memory device coupled to the polishing
material.
2. The apparatus of claim 1 further comprising: a core having the
polishing material wound thereon.
3. The apparatus of claim 2, wherein the memory device is coupled
to the core.
4. The apparatus of claim 1, wherein the memory device is coupled
to a leader of the polishing material.
5. The apparatus of claim 1, wherein the memory device is a
computer readable and writable device.
6. The apparatus of claim 1, wherein the memory device is coupled
to an exterior surface of the polishing material.
7. The apparatus of claim 1, wherein the memory device is embedded
in the polishing material.
8. The apparatus of claim 1, wherein the memory device includes
information relating to the polishing material, the information
comprising at least one of length, thickness, brand, material type,
sequence numbers or unique identification code stored thereon.
9. The apparatus of claim 1, wherein the memory device includes
historical use information associated with the polishing material
stored thereon.
10. The apparatus of claim 1, wherein the memory device includes
conditioning information stored thereon.
11. The apparatus of claim 1, wherein the polishing material is a
web or belt.
12. The apparatus of claim 1, wherein the polishing material is a
pad.
13. A polishing system, comprising: a polishing station; a
polishing material disposed in the polishing station; a memory
device coupled to the polishing material; and a computer based
controller adapted to communicate with the memory device.
14. The apparatus of claim 13, wherein the memory device is a
computer readable and writable device.
15. The apparatus of claim 13, wherein the memory device includes
information relating to the polishing material, the information
comprising at least one of length, thickness, brand, material type,
sequence numbers or unique identification code stored thereon.
16. The apparatus of claim 13, wherein the memory device includes
historical use information of the polishing material stored
thereon.
17. The apparatus of claim 13, wherein the memory includes
conditioning information relating to the polishing material stored
thereon.
18. The apparatus of claim 13, wherein the polishing material is a
web or belt.
19. The apparatus of claim 13, wherein the polishing material is a
pad.
20. The apparatus of claim 13 further comprising: a core having the
polishing material wound thereon, wherein the memory device is
coupled to the core.
21. A method for using a smart polishing media assembly in a
polishing system, comprising: reading information from a memory
device coupled to a polishing material disposed in a polishing
station; and polishing a substrate placed in contact with the
polishing material.
22. The method of claim 21, further comprising: writing information
to the memory device relating to historical use of the polishing
material.
23. The method of claim 22, wherein the information written to the
memory device is at least one of conditioning information, material
polished, fluids used on the polishing material, life of the
polishing material or remaining length of a web.
24. The method of claim 21, further comprising: analyzing the read
information; and determining if polishing should be commenced in
response to the read information.
25. The method of claim 21, wherein the step of reading information
from a memory device comprises: reading information indicative of
polishing material life.
26. The method of claim 21, wherein the step of reading information
from a memory device comprises: reading information indicative of
an unused length of the polishing material.
27. The method of claim 22, wherein the step of reading information
from a memory device comprises: reading information relating to
process fluids used on the polishing material.
28. The method of claim 22, wherein the step of reading information
from a memory device comprises: reading information relating to
materials polished on the polishing material.
Description
BACKGROUND OF THE DISCLOSURE
[0001] 1. Field of the Invention
[0002] Embodiments of the invention generally relate to a polishing
media assembly for use in a chemical mechanical polishing
system.
[0003] 2. Background of Invention
[0004] In semiconductor wafer processing, the use of chemical
mechanical planarization, or CMP, has gained favor due to the
enhanced ability to increase device density on a semiconductor
workpiece, or substrate, such as a wafer. As the demand for
planarization of layers formed on wafers in semiconductor
fabrication increases, the requirement for greater system (i.e.,
process tool) throughput with less wafer damage and enhanced wafer
planarization has also increased.
[0005] CMP systems generally include a polishing head and a
polishing material disposed on a platen. A substrate retained in
the polishing head is pressed against the polishing material and
moved relative to the polishing material in the presence of a
polishing fluid. Abrasives, typically contained in the polishing
fluid and/or polishing material, remove material from the surface
of the substrate synergistically with the chemical activity
provided by the polishing fluid.
[0006] Conventional polishing material is generally comprised of a
foamed polymer, such as polyurethane. Conventional polishing
materials are generally available in the form of circular pads or
in a linear form, such as a web or belt. The web or belt is
periodically advanced over the course of polishing a number of
substrates as the polishing surface of the web is consumed by the
polishing process. Alternatively, the web or belt may be
continuously advanced or moved back and forth during
processing.
[0007] Polishing materials generally wear during polishing, causing
the surface of the polishing material to lose the ability to
adequately retain polishing fluid during the polishing process,
resulting in a non-uniform distribution of polishing fluid across
the polishing material. A non-uniform distribution of polishing
fluid may result in variations of removal rates across the
substrate surface and inhibit uniform polishing of a substrate
surface. To maintain uniform polishing results, the polishing
material is periodically conditioned, cleaned, or advanced across
the platen after polishing one or more substrates, thereby
refreshing the portion of the polishing surface in contact with
substrate during processing to maintain good processing
results.
[0008] As the polishing material may be removed from the polishing
system before fully consumed, or reused after an interruption in
processing, it is critical to preserve the historical information
regarding the prior use of the polishing material in order to
prevent substrate damage and defect generation. For example, it may
be undesirable to utilize polishing material that was used to
polish one material, such as conductive material, for later used to
polish another material, such as an insulating material.
Furthermore, it may be undesirable to use different polishing
fluids on the same polishing material to prevent cross-talk between
polishing fluids, which may lead to undesired polishing results.
Additionally, information regarding the number of times that a
polishing material has been utilized and/or conditioned is critical
to prevent the start of a polishing process without enough material
life or length remaining to complete substrate polishing process.
Moreover, as the polishing material may be transferred between
tools, it would be advantageous for information associated with the
polishing material to remain with the polishing material.
[0009] Therefore, there is a need for polishing material which can
communicate with a processing system.
SUMMARY OF INVENTION
[0010] Embodiments of the invention generally include a smart
polishing media assembly having a memory device, a polishing system
in communication with the smart polishing media assembly, and
methods for using the same. In one embodiment, the smart polishing
media assembly includes a polishing material and a memory device
coupled to the polishing material.
[0011] In another embodiment, the apparatus includes a polishing
station, a polishing material disposed in the polishing station, a
memory device coupled to the polishing material, and a computer
based controller adapted to communicate with the memory device.
[0012] In yet another embodiment, the method for using a smart
polishing media assembly includes reading information from a memory
device coupled to a polishing media disposed in a polishing
station, and polishing a substrate placed in contact with the
polishing material. In other embodiment, historical processing
information may be written to the memory device.
BRIEF DESCRIPTION OF DRAWINGS
[0013] So that the manner in which the above recited features of
the present invention are attained and can be understood in detail,
a more particular description of the invention, briefly summarized
above, may be had by reference to the embodiments thereof 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.
[0014] FIG. 1 depicts a plan view of one embodiment of a chemical
mechanical planarization system of the invention;
[0015] FIG. 2 depicts a sectional view of one embodiment of a
polishing station;
[0016] FIG. 3A depicts an end view of one embodiment of a memory
device embedded in a core according to the present invention;
[0017] FIG. 3B depicts a side view of one embodiment of a memory
device embedded in a core according to the present invention;
[0018] FIG. 4 depicts a cross section view of another embodiment of
a memory device embedded in a polishing media assembly according to
the present invention; and
[0019] FIG. 5 depicts a cross section view of yet another
embodiment of a memory device embedded in a polishing media
assembly on a platen according to the present invention.
[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 embodiment may be beneficially incorporated in
other embodiments without further recitation.
[0021] It is to be noted, however, that the appended drawings
illustrate only exemplary 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.
DETAILED DESCRIPTION OF INVENTION
[0022] The invention will be described below in reference to a
planarizing process and a polishing material that can be performed
on a chemical mechanical polishing system, such as a REFLEXION.RTM.
CMP System available from Applied Materials, Inc., located in Santa
Clara, Calif. Although the polishing process and composition
described herein is illustrated utilizing the REFLEXION.RTM. CMP
System, any system enabling chemical mechanical polishing and/or
electrochemical mechanical processing using the methods or
polishing material described herein can be used to advantage.
[0023] FIG. 1 depicts a plan view of one embodiment of a chemical
mechanical planarization system 100 generally having a factory
interface 102, a loading robot 104, and one or more polishing
modules 106. Generally, the loading robot 104 is disposed proximate
the factory interface 102 and the polishing module 106 to
facilitate the transfer of substrates 122 therebetween. The
polishing module 106 generally includes at least one polishing
station 132 configured to planarize a substrate processed thereon.
Some examples of suitable polishing stations are described in U.S.
Pat. No. 6,244,935, U.S. Pat. No. 5,733,574, U.S. patent
application Ser. No. 10/941,060 filed on Sep. 14, 2004, among
others, all of which are hereby incorporated by reference.
[0024] A computer based controller 190 is connected to the
polishing system 100 for instructing the system to perform one or
more processing steps on the system, such as polishing a substrate
or transferring a substrate in the polishing system 100. In one
embodiment, the invention may be implemented as a computer
program-product for use with a computer system or computer based
controller 190. The programs defining the functions of an
embodiment can be provided to a computer via a variety of
signal-bearing media and/or computer readable media, which include
but are not limited to, (i) information permanently stored on
non-writable storage media (e.g., read-only memory devices within a
computer such as read only CD-ROM disks readable by a CD-ROM or DVD
drive; (ii) alterable information stored on a writable storage
media (e.g., floppy disks within diskette drive or hard-disk
drive); or (iii) information conveyed to a computer by
communications medium, such as through a computer or telephone
network, including wireless communication. Such signal-bearing
media, when carrying computer-readable instructions that direct the
functions of the invention, represent alternative embodiments of
the present invention.
[0025] The factory interface 102 generally includes a cleaning
module 116 and one or more substrate cassettes 118. An interface
robot 120 is employed to transfer substrates 122 between the
substrate cassettes 118, the cleaning module 116 and an input
module 124. The input module 124 is positioned to facilitate
transfer of substrates 122 between the polishing module 106 and the
factory interface 102 by the loading robot 104. For example,
unpolished substrates 122 retrieved from the cassettes 118 by the
interface robot 120 may be transferred to the input module 124
where the substrates 122 may be accessed by the loading robot 104
while polished substrates 122 returning from the polishing module
106 may be placed in the input module 124 by the loading robot 104.
Polished substrates 122 are typically passed from the input module
124 through the cleaning module 116 before the factory interface
robot 120 returns the cleaned substrates 122 to the cassettes 118.
An example of such a factory interface 102 that may be used to
advantage is disclosed in U.S. Pat. No. 6,361,422, issued Mar. 26,
2002, which is hereby incorporated by reference.
[0026] The loading robot 104 is generally positioned proximate the
factory interface 102 and the polishing module 106 such that the
range of motion provided by the robot 104 facilitates transfer of
the substrates 122 therebetween. An example of a loading robot 104
is a 4-Link robot, manufactured by Kensington Laboratories, Inc.,
located in Richmond, Calif.
[0027] The exemplary loading robot 104 has an articulated arm 126
having a rotary actuator 128 at its distal end. An edge contact
gripper 130 is coupled to the rotary actuator 128. The rotary
actuator 128 permits the substrate 122 secured by the gripper 130
to be oriented in either a vertical or a horizontal orientation
without contacting the feature side of the substrate 122 and
possibly causing scratching or damage to the exposed features.
Additionally, the edge contact gripper 130 securely holds the
substrate 122 during transfer, thus decreasing the probability that
the substrate 122 will become disengaged. Optionally, other types
of grippers, such as electrostatic grippers, vacuum grippers and
mechanical clamps, may be substituted.
[0028] The polishing module 106 may be any suitable device for
planarizing a substrate on a polishing material, including those
that use polishing pads, polishing belts, polishing webs, or a
combination thereof. Other systems that benefit from the systems
include moving a substrate relative a polishing surface in a
rotational, linearly or in other motion within a plane. As noted
above, the polishing modules may be utilized in an electrochemical
mechanical polishing system in which a substrate is processed by
electrochemical dissolution concurrently with mechanical polishing.
One such electrochemical mechanical process is described in U.S.
patent application Ser. No. 10/941,060 filed Sep. 14, 2004, which
is hereby incorporated by reference.
[0029] The exemplary polishing module 106 has a transfer station
136, a plurality of polishing stations 132 and a carousel 134
disposed on an upper or first side 138 of a machine base 140. In
one embodiment, the transfer station 136 comprises at least an
input buffer station 142, an output buffer station 144, a transfer
robot 146, and a load cup assembly 148. The loading robot 104
places the substrate 122 onto the input buffer station 142. The
transfer robot 146 has two gripper assemblies, each having
pneumatic gripper fingers that grab the substrate 122 by the
substrate's edge. The transfer robot 146 lifts the substrate 122
from the input buffer station 142 and rotates the gripper and
substrate 122 to position the substrate 122 over the load cup
assembly 148, then places the substrate 122 down onto the load cup
assembly 148. An example of a transfer station that may be used to
advantage is described in U.S. Pat. No. 6,156,124, issued Dec. 5,
2000, which is hereby incorporated by reference.
[0030] The carousel 134 is centrally disposed on the base 140. The
carousel 134 typically includes a plurality of arms 150, each
supporting a polishing head assembly 152. Two of the arms 150
depicted in FIG. 1 are shown in phantom such that a polishing
surface 131 of one of the polishing stations 132 and the transfer
station 136 may be seen. The carousel 134 is indexable such that
the polishing head assemblies 152 may be moved between the
polishing stations 132 and the transfer station 136. One embodiment
of a suitable carousel is generally described in the previously
incorporated U.S. Pat. No. 5,804,507.
[0031] Generally, a planarization process is performed at each
polishing station 132. The planarization process may be a chemical
mechanical planarization process, an electrochemical mechanical
planarization process or other planarization process employing a
pad or a web of polishing material to process a substrate thereon.
A conditioning device 182 is disposed on the base 140 adjacent each
polishing station 132. The conditioning device 182 periodically
conditions the polishing surface 131 to maintain uniform polishing
results.
[0032] FIG. 2 depicts a sectional view of the polishing head
assembly 152 supported above the polishing station 132. The
polishing head assembly 152 generally includes a drive system 202
coupled to a polishing head 204. The drive system 202 generally
provides rotational motion to the polishing head 204. The drive
system 202 is coupled to a carrier 208 that translates upon a rail
210 disposed in the arm 150 of the carousel 134. A ball screw or
other linear motion device 212 couples the carrier 208 to the
carousel 134 and positions the drive system 202 and polishing head
204 along the rail 210.
[0033] In one embodiment, the polishing head 204 includes a housing
214 having an extending lip 216 that defines a center recess 218 in
which is disposed a bladder 220. The bladder 220 may be comprised
of an elastomeric material or thermoplastic elastomer such as
ethylene propylene, silicone and HYTREL.TM. polymer. The bladder
220 is coupled to a fluid source (not shown) such that the bladder
220 may be controllably inflated or deflated. The bladder 220, when
in contact with the substrate 122, retains the substrate 122 within
the polishing head 204 by deflating, thus creating a vacuum between
the substrate 122 and the bladder 220. A retaining ring 224
circumscribes the polishing head 204 to retain the substrate 122
below the polishing head 204 while polishing. In another
embodiment, the polishing head 204 is a TITAN HEAD.TM. substrate
carrier manufactured by Applied Materials, Inc., Santa Clara,
Calif.
[0034] The polishing station 132 generally includes a platen 230
that supports a polishing material 252. The platen 230 is typically
comprised of aluminum. The platen 230 is supported above the base
140 by a bearing 238 so that the platen 230 may rotate in relation
to the base 140. An area of the base 140 circumscribed by the
bearing 238 is open and provides a conduit for the electrical,
mechanical, pneumatic, control signals and connections
communicating with the platen 230.
[0035] Conventional bearings, rotary unions and slip rings (not
shown) are provided such that electrical, mechanical, pneumatic,
control signals and connections may be coupled between the base 140
and the rotating platen 230. The platen 230 is typically coupled to
a motor 232 that provides the rotational motion to the platen
230.
[0036] A polishing material 252 is disposed on the platen 230 and
defines the polishing surface 131. The polishing material 252 may
be in the form of a pad, a belt or a web. The polishing surface 131
of the polishing material 252 may be a dielectric or conductive
material. The polishing material 252 may include grooves,
embossments, texturing and/or perforations. In the embodiment
depicted in FIG. 2, the polishing material is a web that may be
advanced across the platen 230.
[0037] The platen 230 has an upper portion 236 that supports the
polishing material 252. A top surface 260 of the platen 230
contains a center recess 276 extending into the top portion 236.
The top portion 236 may optionally include a plurality of passages
244 disposed adjacent to the recess 276. The passages 244 are
coupled to a fluid source (not shown). Fluid flowing through the
passages 244 may be used to control the temperature of the platen
230 and the polishing material 252 disposed thereon. The polishing
material 252 may be releasably fixed by adhesives, vacuum,
mechanical clamps or by other holding methods to the platen
230.
[0038] A process fluid delivery system 290 may be disposed adjacent
the platen 230. The process fluid delivery system 290 includes a
nozzle or outlet 286 coupled to an process fluid source 292. The
outlet 286 flows process fluid, such as electrolyte, from the
process fluid source 292 onto the surface of the polishing material
252. Alternatively, it is contemplated that the process fluid may
be delivered from other portion of the system, such as through the
platen 230 and the polishing material 252.
[0039] A sub-pad 278 and a sub-plate 280 are disposed in the center
recess 276. The sub-pad 278 is typically a polymeric material, such
as polycarbonate or foamed polyurethane. Generally, the hardness or
durometer of the sub-pad may be chosen to produce a particular
polishing result. The sub-pad 278 generally maintains the polishing
material 252 parallel to the plane of the substrate 122 held in the
polishing head 204 and promotes global planarization of the
substrate 122. The sub-plate 280 is positioned between the sub-pad
278 and the bottom of the recess 276 such that the upper surface of
the sub-pad 278 is coplanar with the top surface 260 of the platen
230.
[0040] Both the sub-pad 278 and the sub-plate 280 optionally
contain a plurality of apertures (not shown). A vacuum port 284 is
provided in the recess 276 and is coupled to an external pump 282.
When a vacuum is drawn through the vacuum port 284, the air removed
between the polishing material 252 and the sub-pad 278 causes the
polishing material 252 to be firmly secured to the sub-pad 278
during polishing. One example of such polishing material retention
system is disclosed in U.S. Pat. No. 6,491,570, which is hereby
incorporated by reference.
[0041] Optionally, to assist in releasing the polishing material
252 from the sub-pad 278 and platen 230 prior to advancing the
polishing material 252, surface tension caused by fluid that may be
disposed between the sub-pad 278 and the polishing material 252, a
blast of fluid may be provided through the vacuum port 284 or other
port (not shown) into the recess 276 by the pump 282 (or other
source). The fluid within the recess 276 moves through the
apertures (not shown) disposed in the sub-pad 278 and sub-plate 280
and lifts the polishing material 252 from the sub-pad 278 and the
top surface 260 of the platen 230. The polishing material 252 rides
upon the cushion of fluid such that it may be freely indexed across
the platen 230.
[0042] In one embodiment, the polishing material 252 is part of a
polishing media assembly 274. The polishing media assembly 274
includes a memory device 298 for providing information relating to
the polishing material 252. In the embodiment depicted in FIG. 2,
the polishing media assembly 274 is configured as a supply roll 240
that contains at least a portion of the polishing material 252
wound on a core 296. The polishing material 252 is fed from the
supply roll 240 over a roller 242 and across the top surface 260 of
the platen 230 to a roller 246. The polishing material 252 is fed
over the roller 246 to a take-up roll 248 disposed to the opposite
side of the platen 230.
[0043] The supply roll 240 is removably coupled to the platen 230
to facilitate loading another supply roll containing different
polishing material. The supply roll 240 may be replaced once the
polishing material 252 is consumed over the course of polishing a
number of substrates or for other reasons. The supply roll 240 is
coupled to a slip clutch 250 or similar device that prevents the
polishing material 252 from inadvertently unwinding from the supply
roll 240. After processing, the polishing material 252 may be
rewound on the supply roll 240 for removal from the polishing
station 132.
[0044] The memory device 298 is utilized to store information
relating to the polishing material 252. In one embodiment, the
memory device 298 is a read/writable chip. Information that may be
written to, and/or read from the memory device 298 includes
polishing material type, unused or remaining length, conditioning
information, historical use information, thickness, diameter,
unique identification code and the like. Conditioning information
may include the number of times the material has been conditioned,
which portions of the material has been conditioned, the type of
conditioner used (i.e., brush, diamond, etc.), conditioning
downforce, conditioner, RPM, conditioner sweep information,
conditioning and fluids used and among others. Historical use
information may include the numbers of substrate being polished,
the polishing fluid used thereon, type of materials polished on the
substrate, polishing recipes used (platen/head RPM), head sweep and
substrate downforce, and among others. In another embodiment, the
memory device 298 is a computer writeable and readable chip that
can be remotely read and/or written by a computer based controller,
such as the controller 190 described in FIG. 1.
[0045] The take-up roll 248 generally is removably coupled to the
platen 230 to facilitate removal of used polishing material 252
that is wound thereon. The take-up roll 248 is coupled to a
tensioning device 262 that keeps the polishing material 252 taunt
between the supply roll 240 and take-up roll 248.
[0046] The polishing material 252 is advanced between the supply
roll 240 and take-up roll 248 by a driver 266. In one embodiment,
the driver 266 comprises a drive roller 268 and an idler 270 that
pinches the polishing material 252 therebetween. The drive roller
268 generally is coupled to the platen 230. The drive roller 268 is
connected to a controlled motor such as a stepper and an encoder
294 (as shown in phantom). The encoder 294 detects a metric
indicative of the length of polishing material advanced across the
driver roller 268 that corresponds to an amount of linear
displacement of the polishing material across the platen 230. The
encoder 294 may be a rotary encoder, a proximity sensor, an optical
sensor, a linear displacement transducer or other sensor for
detecting a length of polishing material as the polishing material
252 advances. Alternatively, the encoder 294 may be positioned to
detect rotation of the rollers 242, 246 having a polishing material
running thereover to determine the amount of polishing material
advanced.
[0047] The driver 266 enables a predetermined length of polishing
material to be pulled off the supply roll 240 by drive roller 268
as the drive roller 256 is controllably rotated. The predetermined
length is usually about 1 inch or less, such as about 1/4 inch
indexing between substrates. A corresponding length of polishing
material is wound on the take-up roll 248 as the polishing material
252 is advanced across the platen 230. The roll of polishing
material 252 is about 100 feet in length, which allows for about
5000 or more substrates to be polished as compared to prior art
polishing pads which often have to be replaced after 600 to 1000
substrates are polished.
[0048] A sensor 288 for detecting the diameter of the polishing
material wound on the take-up roll 248 is typically coupled to the
platen 230. The sensor 288 detects the surface of the polishing
material such that as the polishing material advances, a chance in
the diameter of the polishing material disposed the take-up roll
248 may be detected. It is contemplated that other types of sensors
may be utilized to provide and detect different information as
needed. The sensor 288 may also provide surface texture
information, such as roughness, porosity, glazing, contamination,
compressibility, and hardness, among others.
[0049] In one embodiment, the sensors 288, 294 may provide the
controller 190 with signals that are resolved to indicate the
usage, the amount of linear displacement, and condition of the
polishing material 252 in the system, thereby allowing the
controller to dynamically write and update information in the
memory device 298. The updated and rewritten information in the
memory device 298 allows the controller 190 to obtain the latest
performance and condition of the polishing material 252, thus
enhancing the process control and consumable material management.
The signals between the controller 190 and memory device 298 may be
provided by radio frequency transmission, optical communication,
wireless transmission, hard wire or any other suitable means.
[0050] FIGS. 3A-B depict end and side views of one embodiment of
the supply roll 240 of the polishing media assembly 274. In the
embodiment depicted in FIG. 3B, the core 296 is a cylindrical body
310. The body 310 has an outer wall 302 and an inner wall 304 that
defines a hollow passage 308 through the center of the core 296. In
one embodiment, the body 310 includes a slot or a notch 306 that
receives the memory device 298. The slot 306 may be in the inner
wall 304, outer wall 302, or through the body 310. In another
embodiment, the memory device 298 may be clamped, adhered, secured
or fastened by other suitable materials to the core 296.
[0051] FIG. 4 depicts another embodiment of a memory device 298
coupled to a polishing media assembly 400. The polishing media
assembly 400 may include a leader 272 connected to the beginning
and/or end of the polishing material 252. In one embodiment, the
memory device 298 may be mounted on or embedded in the leader 272
of the polishing material 252, as shown by phantom position 402. In
another embodiment, the memory device 298 may be attached to or
embedded in a portion of the polishing material 252, as shown by
phantom position 404. It is contemplated that the ends of a
polishing material without a leader may be fastened together to
form a belt.
[0052] FIG. 5 depicts another embodiment of a polishing media
assembly 500 having a memory device 298. The polishing media
assembly 500 is in the form of a pad 502, for example, a circular
pad. The memory device 298 is coupled to or embedded in the pad
502. In one embodiment, the memory device 298 may be embedded in an
edge 506 of the polishing pad 502. In another embodiment, the
memory device 298 may be embedded in a top portion or a bottom
portion 508 of the polishing pad 502. In yet another embodiment,
the memory device 298 may be attached on a bottom 504 of the
polishing pad 502. In still another embodiment, the memory device
298 may be coupled to the exterior of the pad 502, for example, the
edge 510.
[0053] The memory device 298 provides information relating to the
polishing material 252 to the controller 190. As the memory device
298 being installed with the polishing media assembly 274 in the
polishing system 100, the computer based controller 190 may sense
the memory device 298 and read the information contained in the
memory device 298, thereby allowing the system 100 to determine
suitable parameters corresponding to the installed polishing media
assembly 274. In one embodiment, the controller 190 may remotely
detect and/or sense the memory device 298 by radio transmission,
optical communication, wireless transmission, or other suitable
methods. Alteratively, a connector may be provided on the platen
230 or polishing station 132 to facilitate communication with the
controller 190 through wires.
[0054] Thus, the present invention provides a memory device coupled
to a polishing material to provide information associated with the
polishing material. Moreover, the memory device advantageously
facilitates efficient management of the polishing material by
dynamically communicating with a computer based controller in a
polishing system, thereby enhancing a better control of the
polishing performance, polishing material maintenance and process
cost.
[0055] 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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