U.S. patent application number 10/828017 was filed with the patent office on 2004-10-21 for planarizing machines and methods for dispensing planarizing solutions in the processing of microelectronic workpieces.
Invention is credited to Joslyn, Michael J..
Application Number | 20040209548 10/828017 |
Document ID | / |
Family ID | 27613892 |
Filed Date | 2004-10-21 |
United States Patent
Application |
20040209548 |
Kind Code |
A1 |
Joslyn, Michael J. |
October 21, 2004 |
Planarizing machines and methods for dispensing planarizing
solutions in the processing of microelectronic workpieces
Abstract
Machines with solution dispensers and methods of using such
machines for chemical-mechanical planarization and/or
electrochemical--mechanical planarization/deposition of
microelectronic workpieces. One embodiment of such a machine
includes a table having a support surface, a processing pad on the
support surface, and a carrier assembly having a head configured to
hold a microelectronic workpiece. The carrier assembly can further
include a drive assembly that manipulates the head. The machine can
also include a solution dispenser separate from the head. The
solution dispenser can include a support extending over the pad and
a fluid discharge unit or distributor carried by the support. The
fluid discharge unit is configured to discharge a planarizing
solution onto a plurality of separate locations across the pad.
Inventors: |
Joslyn, Michael J.; (Boise,
ID) |
Correspondence
Address: |
PERKINS COIE LLP
PATENT-SEA
P.O. BOX 1247
SEATTLE
WA
98111-1247
US
|
Family ID: |
27613892 |
Appl. No.: |
10/828017 |
Filed: |
April 20, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10828017 |
Apr 20, 2004 |
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09939430 |
Aug 24, 2001 |
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6722943 |
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Current U.S.
Class: |
451/5 ; 451/41;
451/6; 451/8 |
Current CPC
Class: |
B24B 37/04 20130101;
B24B 57/02 20130101 |
Class at
Publication: |
451/005 ;
451/006; 451/008; 451/041 |
International
Class: |
B24B 049/00; B24B
051/00; B24B 001/00 |
Claims
1-8. (Canceled)
9. A planarizing machine, comprising: a table having a support
surface; a processing pad on the support surface; a carrier
assembly having a head configured to hold a microelectronic
workpiece and a drive assembly carrying the head relative to the
support surface; a solution dispenser separate from the head, the
solution dispenser being configured to discharge a planarizing
solution onto a Plurality of locations on the Dad; a temperature
sensor to sense a temperature of a contact surface of the
processing pad; a valve coupled to the flow of the planarizing
solution; and a controller coupled to the temperature sensor and
the valve, wherein the controller causes the valve to adjust the
flow rate of the planarizing solution through the dispenser
according to the temperature sensed by the temperature sensor.
10. A planarizing machine, comprising: a table having a support
surface; a processing pad on the support surface; a carrier
assembly having a head configured to hold a microelectronic
workpiece and a drive assembly carrying the head relative to the
support surface; a solution dispenser separate from the head, the
solution dispenser being configured to discharge a planarizing
solution onto a plurality of locations on the pad; a pressure
sensor to sense a pressure between the workpiece and a contact
surface of the processing pad; a valve coupled to the flow of the
planarizing solution; and a controller coupled to the pressure
sensor and the valve, wherein the controller causes the valve to
adjust the flow rate of the planarizing solution through the
dispenser according to the pressure sensed by the pressure
sensor.
11. A planarizing machine, comprising: a table having a support
surface; a processing pad on the support surface; a carrier
assembly having a head configured to hold a microelectronic
workpiece and a drive assembly carrying the head relative to the
support surface; a solution dispenser separate from the head, the
solution dispenser being configured to discharge a planarizing
solution onto a plurality of locations on the pad; a drag sensor to
sense a drag force between the workpiece and a contact surface of
the processing pad; a valve coupled to the flow of the planarizing
solution; and a controller coupled to the drag sensor and the
valve, wherein the controller causes the valve to adjust the flow
rate of the planarizing solution through the dispenser according to
the drag force sensed by the drag sensor.
12-37. (Canceled)
38. A method of processing a microelectronic workpiece, comprising:
removing material from the workpiece by pressing the workpiece
against a contact surface of a processing pad and imparting
relative motion between the workpiece and the contact surface;
depositing a first flow of a planarizing solution from a dispenser
directly onto a first region of the contact surface; depositing a
second flow of the planarizing solution from the dispenser directly
onto a second region of the contact surface separate from the first
region; sensing a planarizing parameter while removing material
from the workpiece; and controlling the first and second flows
according to the sensed planarizing parameter.
39. A method of processing a microelectronic workpiece, comprising:
removing material from the workpiece by pressing the workpiece
against a contact surface of a processing pad and imparting
relative motion between the workpiece and the contact surface;
depositing a first flow of a planarizing solution from a dispenser
directly onto a first region of the contact surface; depositing a
second flow of the planarizing solution from the dispenser directly
onto a second region of the contact surface separate from the first
region, wherein depositing the flow of the planarizing solution
comprises discharging planarizing solution through a first
discharge unit and a second discharge unit, the first discharge
unit discharging the first flow and the second discharge unit
discharging the second flow; sensing a planarizing parameter
associated with removing material from the workpiece; and
controlling the first and second flows according to the sensed
planarizing parameter.
40. The method of claim 39 wherein sensing a planarizing parameter
comprises measuring a plurality of temperatures at points across
the processing pad.
41. The method of claim 39 wherein sensing a planarizing parameter
comprises measuring a plurality of pressures at points across the
processing pad.
42. The method of claim 39 wherein sensing a planarizing parameter
comprises measuring drag force between the processing pad and the
workpiece.
43-54. (Canceled)
55. A method of processing a microelectronic workpiece, comprising:
removing material from the workpiece by pressing the workpiece
against a contact surface of a processing pad and imparting
relative motion between the workpiece and the contact surface;
discharging a planarizing solution directly onto a first region of
the contact surface and a second region of the contact surface
separate from the first region; sensing a parameter of removing
material from the workpiece; and controlling a first volume of
planarizing solution discharged onto the first region independently
from a second volume of planarizing solution discharged onto a
second region.
56. A planarizing machine, comprising: a table having a support
surface; a processing pad on the support surface; a carrier
assembly having a head configured to hold a microelectronic
workpiece and a drive assembly carrying the head relative to the
support surface; a solution dispenser separate from the head, the
solution dispenser being configured to discharge a planarizing
solution onto a plurality of locations on the pad; a sensor to
sense a parameter relative to areas of the processing pad; a valve
coupled to the flow of the planarizing solution; and a controller
coupled to the sensor and the valve, wherein the controller
includes a computer operable medium containing instructions that
cause the valve to adjust the flow rate of the planarizing solution
through the solution dispenser according to the parameter sensed by
the sensor.
57. The planarizing machine of claim 56 wherein the sensor is a
temperature sensor.
58. The planarizing machine of claim 56 wherein the sensor is a
pressure sensor.
59. The planarizing machine of claim 56 wherein the sensor is a
drag force sensor.
Description
TECHNICAL FIELD
[0001] The present invention relates to planarizing machines and
methods for dispensing planarizing solutions onto a plurality of
locations of a processing pad in the fabrication of microelectronic
devices.
BACKGROUND
[0002] Mechanical and chemical-mechanical planarizing processes
(collectively "CMP") remove material from the surface of
semiconductor wafers, field emission displays, read/write heads or
other microelectronic workpieces in the production of
microelectronic devices and other products. FIG. 1 schematically
illustrates a CMP machine 10 with a platen 20, a carrier assembly
30, and a planarizing pad 40. The CMP machine 10 may also have an
under-pad 25 attached to an upper surface 22 of the platen 20 and
the lower surface of the planarizing pad 40. A drive assembly 26
rotates the platen 20 (indicated by arrow F), or it reciprocates
the platen 20 back and forth (indicated by arrow G). Since the
planarizing pad 40 is attached to the under-pad 25, the planarizing
pad 40 moves with the platen 20 during planarization.
[0003] The carrier assembly 30 has a head 32 to which a workpiece
12 may be attached, or the workpiece 12 may be attached to a
resilient pad 34 in the head 32. The head 32 may be a free-floating
wafer carrier, or an actuator assembly 36 may be coupled to the
head 32 to impart axial and/or rotational motion to the workpiece
12 (indicated by arrows H and 1, respectively).
[0004] The planarizing pad 40 and a planarizing solution 44 on the
pad 40 collectively define a planarizing medium that mechanically
and/or chemically-mechanically removes material from the surface of
the workpiece 12. The planarizing pad 40 can be a soft pad or a
hard pad. The planarizing pad 40 can also be a fixed-abrasive
planarizing pad in which abrasive particles are fixedly bonded to a
suspension material. In fixed-abrasive applications, the
planarizing solution 44 is typically a non-abrasive "clean
solution" without abrasive particles. In other applications, the
planarizing pad 40 can be a non-abrasive pad composed of a
polymeric material (e.g., polyurethane), resin, felt or other
suitable materials. The planarizing solutions 44 used with the
non-abrasive planarizing pads are typically abrasive slurries with
abrasive particles suspended in a liquid.
[0005] To planarize the workpiece 12 with the CMP machine 10, the
carrier assembly 30 presses the workpiece 12 face-downward against
the polishing medium. More specifically, the carrier assembly 30
generally presses the workpiece 12 against the planarizing liquid
44 on a planarizing surface 42 of the planarizing pad 40, and the
platen 20 and/or the carrier assembly 30 move to rub the workpiece
12 against the planarizing surface 42. As the workpiece 12 rubs
against the planarizing surface 42, material is removed from the
face of the workpiece 12.
[0006] CMP processes should consistently and accurately produce a
uniformly planar surface on the workpiece to enable precise
fabrication of circuits and photo-patterns. During the construction
of transistors, contacts, interconnects and other features, many
workpieces develop large "step heights" that create highly
topographic surfaces. Such highly topographical surfaces can impair
the accuracy of subsequent photolithographic procedures and other
processes that are necessary for forming sub-micron features. For
example, it is difficult to accurately focus photo patterns to
within tolerances approaching 0.1 micron on topographic surfaces
because sub-micron photolithographic equipment generally has a very
limited depth of field. Thus, CMP processes are often used to
transform a topographical surface into a highly uniform, planar
surface at various stages of manufacturing microelectronic devices
on a workpiece.
[0007] In the highly competitive semiconductor industry, it is also
desirable to maximize the throughput of CMP processing by producing
a planar surface on a workpiece as quickly as possible. The
throughput of CMP processing is a function, at least in part, of
the polishing rate of the planarizing cycle and the ability to
accurately stop CMP processing at a desired endpoint. Therefore, it
is generally desirable for CMP processes to provide (a) a desired
polishing rate gradient across the face of a substrate to enhance
the planarity of the finished surface, and (b) a reasonably
consistent polishing rate during a planarizing cycle to enhance the
accuracy of determining the endpoint of a planarizing cycle.
[0008] Conventional planarizing machines may not provide consistent
polishing rates because of nonuniformities in (a) the distribution
of the slurry across the processing pad, (b) the wear of the
processing pad, and/or (c) the temperature of the processing pad.
The distribution of the planarizing solution across the surface of
the processing pad may not be uniform because conventional
planarizing machines typically discharge the planarizing solution
onto a single point at the center of the pad. This causes a thicker
layer of planarizing solution to be at the center of the pad than
at the perimeter, which may result in different polishing rates
across the pad. Additionally, the nonuniform distribution of the
planarizing solution may cause the center region of the pad to
behave differently than the perimeter region because many low PH
solutions used during planarizing cycles are similar to cleaning
solutions for removing stains and waste matter from the pads when
polishing metallic surfaces. Such low PH planarizing solutions
dispersed locally accordingly may change the physical
characteristics differently at the center of the pad than at the
perimeter. The nonuniform distribution of planarizing solution also
causes a nonuniform temperature distribution across the pad because
the planarizing solution is typically at a different temperature
than the processing pads. For example, when the planarizing
solution is at a lower temperature than the pad, the temperature
near the single dispensing point of the planarizing solution is
typically lower than other areas of the processing pad.
[0009] One concern of manufacturing microelectronic workpieces is
that the distribution of the planarizing solution can cause
variances in the planarized surface of the workpieces. For example,
an inconsistent distribution of planarizing solution between the
workpiece and the pad can cause certain areas of the workpiece to
planarize faster than other areas. Nonuniform pad wear and
nonuniform temperature distributions across the processing pad can
also cause inconsistent planarizing results that (a) reduce the
planarity and uniformity of the planarized surface on the
workpieces, and (b) reduce the accuracy of endpointing the
planarizing cycles. Therefore, it would be desirable to develop
more consistent planarizing procedures and machines to provide more
accurate planarization of microelectronic workpieces.
SUMMARY OF THE INVENTION
[0010] The present invention describes machines with solution
dispensers for use in chemical-mechanical planarization and/or
electrochemical-mechanical planarization/deposition of
microelectronic workpieces. One embodiment of such a machine
includes a table having a support surface, a processing pad on the
support surface, and a carrier assembly having a head configured to
hold a microelectronic workpiece. The carrier assembly can further
include a drive assembly that carries the head. The machine can
also include a solution dispenser separate from the head. The
solution dispenser can include a support extending over the pad and
a fluid discharge unit or distributor carried by the support. The
fluid discharge unit is configured to simultaneously discharge a
planarizing solution onto a plurality of separate locations across
the pad.
[0011] In one particular embodiment, the solution dispenser
comprises an elongated support extending over the pad at a location
spaced apart from a travel path of the head, a fluid passageway
carried by the support through which the planarizing solution can
flow, and a plurality of nozzles carried by the support. The
nozzles are in fluid communication with the fluid passageway to
create a plurality of flows of planarizing solution that are
discharged onto separate locations across the processing pad. An
alternate embodiment of a machine in accordance with the invention
includes a solution dispenser comprising an elongated support
extending over the pad at a location spaced apart from the travel
path of the head, a fluid passageway carried by the support through
which a planarizing solution can flow, and an elongated slot
extending along at least a portion of the support. The elongated
slot is in fluid communication with the fluid passageway to create
an elongated flow of planarizing solution. Another alternative
embodiment includes an elongated support having a channel extending
along at least a portion of the support through which the
planarizing solution can flow and a lip along at least a portion of
the channel over which the planarizing solution can flow. The lip
accordingly defines a weir for depositing an elongated flow of
planarizing solution across a portion of the pad.
[0012] Other embodiments of solution dispensers for the planarizing
machine comprise an elongated support extending over the pad at a
location spaced apart from the travel path of the head, a fluid
passageway carried by the support, a first fluid discharge unit,
and a second fluid discharge unit. The elongated support of these
embodiments can include a first section and a second section. The
first fluid discharge unit can be carried at the first section of
the support to discharge a first flow of the planarizing solution
onto a first location of the pad. The second fluid discharge unit
can be carried by the second section of the support to discharge a
second flow of the planarizing solution onto a second location of
the pad. The first and second fluid discharge units can be
independently controllable from one another so that the first flow
of planarizing solution discharged onto the first location of the
pad is different than the second flow of planarizing solution
discharged onto the second location of the pad.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a cross-sectional view of a planarizing machine in
accordance with the prior art in which selected components are
shown schematically.
[0014] FIG. 2 is a side elevation view of a planarizing system
including a planarizing solution dispenser in accordance with an
embodiment of the invention with selected components shown in
cross-section or schematically.
[0015] FIGS. 3A-3C are cross-sectional views showing an embodiment
of a planarizing solution dispenser in accordance with the
invention.
[0016] FIG. 4 is a side elevation view of a planarizing system
including a planarizing solution dispenser in accordance with
another embodiment of the invention with selected components shown
in cross-section or schematically.
[0017] FIG. 5 is a top plan view of the planarizing system of FIG.
4.
[0018] FIG. 6 is a side elevation view of a planarizing system
including a planarizing solution dispenser in accordance with an
embodiment of the invention with selected components shown in
cross-section or schematically.
[0019] FIG. 7 is a front cross-sectional view of a portion of the
planarizing solution dispenser of FIG. 6.
[0020] FIG. 8 is a side elevation view of a planarizing system
including a planarizing solution dispenser in accordance with an
embodiment of the invention with selected components shown in
cross-section or schematically.
[0021] FIG. 9 is a side elevation view of an embodiment of a
planarizing solution dispenser in accordance with the embodiment of
FIG. 8.
[0022] FIG. 10 is a side elevation view of a planarizing system
including a planarizing solution dispenser in accordance with an
embodiment of the invention with selected components shown in
cross-section or schematically.
[0023] FIG. 11 is a side elevation view of a planarizing system
including a planarizing solution dispenser in accordance with an
embodiment of the invention with selected components shown in
cross-section or schematically.
DETAILED DESCRIPTION
[0024] The following disclosure describes planarizing machines with
planarizing solution dispensers and methods for planarizing
microelectronic workpieces. The microelectronic workpieces can be
semiconductor wafers, field emission displays, read/write media,
and many other workpieces that have microelectronic devices with
miniature components (e.g., integrated circuits). Many of the
details of the invention are described below with reference to
rotary planarizing applications to provide a thorough understanding
of such embodiments. The present invention, however, can also be
practiced using web-format planarizing machines and
electrochemical-mechanical planarizing/deposition machines.
Suitable web-format planarizing machines that can be adapted for
use with the present invention include U.S. patent application Ser.
Nos. 09/595,727 and 09/565,639, which are herein incorporated by
reference. A suitable electrochemical-mechanical
planarizing/deposition machine that can be adapted for use is shown
in U.S. Pat. No. 6,176,992, which is also herein incorporated by
reference. A person skilled in the art will thus understand that
the invention may have additional embodiments, or that the
invention may be practiced without several of the details described
below.
[0025] FIG. 2 is a cross-sectional view of a planarizing system 100
having a planarizing solution dispenser 160 that discharges a
planarizing solution 150 in accordance with an embodiment of the
invention. The planarizing machine 100 has a table 114 with a top
panel 116. The top panel 116 is generally a rigid plate to provide
a flat, solid surface for supporting a processing pad. In this
embodiment, the table 114 is a rotating platen that is driven by a
drive assembly 118.
[0026] The planarizing machine 100 also includes a workpiece
carrier assembly 130 that controls and protects a microelectronic
workpiece 131 during planarization or electrochemical-mechanical
planarization/deposition processes. The carrier assembly 130 can
include a workpiece holder 132 to pick up, hold and release the
workpiece 131 at appropriate stages of a planarizing cycle and/or a
conditioning cycle. The workpiece carrier assembly 130 also
generally has a backing member 134 contacting the backside of the
workpiece 131 and an actuator assembly 136 coupled to the workpiece
holder 132. The actuator assembly 136 can move the workpiece holder
132 vertically (arrow H), rotate the workpiece holder 132 (arrow
1), and/or translate the workpiece holder 132 laterally. In a
typical operation, the actuator assembly 136 moves the workpiece
holder 132 to press the workpiece 131 against a processing pad
140.
[0027] The processing pad 140 shown in FIG. 2 has a planarizing
medium 142 and a contact surface 144 for selectively removing
material from the surface of the workpiece 131. The planarizing
medium 142 can have a binder 145 and a plurality of abrasive
particles 146 distributed throughout at least a portion of the
binder 145. The binder 145 is generally a resin or another suitable
material, and the abrasive particles 146 are generally alumina,
ceria, titania, silica or other suitable abrasive particles. At
least some of the abrasive particles 146 are partially exposed at
the contact surface 144 of the processing pad 140. Suitable
fixed-abrasive planarizing pads are disclosed in U.S. Pat. Nos.
5,645,471; 5,879,222; 5,624,303; and U.S. patent application Ser.
Nos. 09-164,916 and 09-001,333; all of which are herein
incorporated by reference. In other embodiments the processing pad
140 can be a non-abrasive pad without abrasive particles, such as a
Rodel OXB 3000 "Sycamore" polishing pad manufactured by Rodel
Corporation. The Sycamore pad is a hard pad with trenches for
macro-scale slurry transportation underneath the workpiece 131. The
contact surface 144 can be a flat surface, or it can have a pattern
of micro-features, trenches, and/or other features.
[0028] Referring still to FIG. 2, the dispenser 160 is configured
to discharge the planarizing solution 150 onto a plurality of
separate locations of the pad 140. In this embodiment, the
dispenser 160 includes a support 162 extending over a portion of
the pad 140 and a fluid discharge unit or distributor 164 (shown
schematically) carried by the support 162. The support 162 can be
an elongated arm that is attached to an actuator 166 that moves the
support 162 relative to the pad 140. The distributor 164 can
discharge a flow of the planarizing solution 150 onto the contact
surface 144 of the pad 140. The distributor 164, for example, can
be an elongated slot or a plurality of other openings extending
along a bottom portion of the support 162. In this embodiment, the
distributor 164 creates an elongated flow of planarizing solution
150 that simultaneously contacts an elongated portion of the
contact surface 144 of the pad 140. The dispenser 160 accordingly
discharges the planarizing solution onto a plurality of separate
points or areas of the contact surface 144.
[0029] FIG. 3A is a top cross-sectional view showing the embodiment
of the dispenser 160 of FIG. 2 along line 3A-3A. In this
embodiment, the support 162 has a fluid passageway 168 for
receiving the planarizing solution from a reservoir (not shown in
FIG. 3A). The fluid passageway 168 can have a proximal section 167a
through which the planarizing solution flows into the support and a
distal section 167b defining a cavity over the processing pad 140.
The distributor 164 in this embodiment can have an elongated slot
169 along the bottom of the support 162 and a valve 170 within the
distal section 167b of the fluid passageway 168. The valve 170 has
a cavity 172, and the planarizing fluid can flow through the
proximal section 167a and into the cavity 172 of the valve 170. The
valve 170 operates to open and close the elongated slot 169 for
controlling the flow of planarizing solution onto the contact
surface 144.
[0030] FIGS. 3B and 3C are cross-sectional views of the dispenser
160 taken along line 3B-3B shown in FIG. 3A. Referring to FIG. 3B,
the valve 170 can fit within the distal section 167b so that an
outer wall of the valve 170 engages or otherwise faces an inner
wall of the distal section 167b. The valve 170 can have an
elongated slot 174 or a plurality of holes extending along a
portion of the valve. FIG. 3B illustrates the valve 170 in an open
position in which the slot 174 in the valve 170 is at least
partially aligned with the elongated slot 169 in the support 162 so
that a fluid F can flow through the slot 169. FIG. 3C illustrates
the valve 170 in a closed position in which the slot 174 is not
aligned with the elongated slot 169 so that the valve 170 prevents
the planarizing solution from flowing through the distributor 164.
In operation, a motor or other actuator (not shown) can rotate the
valve 170 within the arm 162 to open and close the slot 169.
[0031] Several embodiments of the planarizing machine 100 shown in
FIG. 2 are expected to provide better planarizing results because
the dispenser 160 is expected to provide a uniform coating of
planarizing solution 150 across the contact surface 144 of the pad
140. By discharging the planarizing solution 150 along an elongated
line across the pad 140, the planarizing solution 150 is deposited
onto a plurality of separate areas of the contact surface 144. As
the pad 140 rotates, the centrifugal force drives planarizing
solution 150 off the perimeter of the pad. The wide coverage of the
discharge area for the planarizing solution 150 and the spinning
motion of the pad 140 act together to provide a distribution of
planarizing solution across the pad 140 that is expected to have a
uniform thickness. As a result, several embodiments of the
planarizing machine 100 are expected to provide more uniform pad
wear and temperature distribution across the contact surface 144 of
the pad 140. Therefore, several embodiments of the planarizing
machine 100 are expected to provide consistent planarizing results
by reducing variances in planarizing parameters caused by a
nonuniform distribution of planarizing solution.
[0032] FIGS. 4 and 5 illustrate the planarizing machine 200 having
a solution dispenser 260 in accordance with another embodiment of
the invention. The table 114, the drive assembly 118 and the
carrier assembly 130 can be similar to those described above with
reference to FIG. 2, and thus like reference numbers refer to like
components in FIGS. 2-5. In this embodiment, the dispenser 260
includes a support 262 and a plurality of nozzles 264 carried by
the support 262. The nozzles 264 are in fluid communication with a
fluid passageway 268 that is also carried by the support 262. The
nozzles 264 can be configured to produce gentle, low-velocity flows
of planarizing solution 250. In operation, the planarizing solution
250 is pumped through the fluid passageway 268 and through the
nozzles 264. The nozzles 264 accordingly define a distributor that
discharges the planarizing solution 250 onto a plurality of
locations of the pad 140. The planarizing machine 200 is expected
to have several of the same advantages as the planarizing machine
100 described above.
[0033] FIGS. 6 and 7 show a dispenser 360 in accordance with
another embodiment of the invention for use with a planarizing
machine 300. Referring to FIG. 6, the dispenser 360 has a support
362 with a fluid passageway 368 that extends into a weir 370. FIG.
7 is a cross-sectional view of the support 362 taken along line 7-7
of FIG. 6. Referring to FIG. 7, the weir 370 includes a channel or
trough 372 that is in fluid communication with the fluid passageway
368 and a lip 374 at the top of the trough 372. In operation, a
planarizing fluid 350 flows through the fluid passageway 368 and
fills the trough 372 until the planarizing solution 350 flows over
the lip 374. As shown in FIG. 6, the dispenser 360 discharges the
planarizing solution 350 onto a plurality of separate locations of
the contact surface 144. Several embodiments of the dispenser 360
are expected to operate in a manner similar to the dispensers 160
and 260 explained above.
[0034] FIG. 8 shows a planarizing machine 400 having a distributor
460 in accordance with another embodiment of the invention. In this
embodiment, the distributor 460 includes a support 462, a first
fluid discharge unit 464a carried by a first section of the support
462, and a second fluid discharge unit 464b carried by a second
section of the support 462. The dispenser 460 can further include a
fluid passageway 468 coupled to each of the first and second
discharge units 464a and 464b. The dispenser 460 also includes a
controller 480 coupled to the fluid passageway 468 and/or each of
the first and second fluid discharge units 464a and 464b.
[0035] In operation, the controller 480 independently controls the
flow of the planarizing solution to the first and second fluid
discharge units 464a and 464b.
[0036] The first fluid discharge unit 464a can accordingly
discharge a first flow of planarizing fluid 450a, and the second
fluid discharge unit 464b can discharge a second flow of
planarizing fluid 450b. The controller 480 can vary the first and
second flows 450a and 450b of planarizing solution so that the
planarizing solution is discharged onto the contact surface 144 in
a manner that provides a desired distribution of the planarizing
solution across the pad 140. For example, if the temperature at the
perimeter portion of the processing pad 140 is greater than the
central portion, then the first fluid flow 450a can be increased
and/or the second fluid flow 450b can be decreased so that more
planarizing solution is deposited onto the perimeter portion of the
processing pad 140 relative to the central portion to dissipate
more heat from perimeter portion of the pad 140. The controller 480
can be a computer, and each of the fluid discharge units 464a and
464b can be separate nozzles, slots, weirs, or other structures
that can independently discharge separate fluid flows onto the pad
140.
[0037] Several embodiments of the planarizing machine 400 are
expected to provide good control of planarizing parameters. By
independently discharging separate fluid flows onto the pad 140,
the distributor 460 and the controller 480 can be manipulated to
change the distribution of the planarizing solution across the
surface of the pad according to the actual planarizing results or
parameters that are measured during a planarizing cycle. As such,
the planarizing machine can create a desired nonuniform
distribution of planarizing solution across the pad 140 to
compensate for variances in other planarizing parameters.
Therefore, several embodiments of the planarizing machine 400 are
expected to provide additional control of the planarizing
parameters to consistently produce high-quality planarized
surfaces.
[0038] FIG. 9 illustrates a dispenser 560 in accordance with
another embodiment of the invention that can be used with the
controller 480 of FIG. 8. In this embodiment, the dispenser 560
includes a support 562 extending over the pad 140 and a plurality
of nozzles 564 (identified individually be reference numbers
564a-c) carried by the support 562. The support 562 can be an arm
that is attached to an actuator or a fixed support relative to the
pad 140. The nozzles 564 can include at least a first nozzle 564a
defining a first fluid discharge unit and a second nozzle 564b
defining a second fluid discharge unit. The nozzles 564 can also
include a third nozzle 564c defining a third fluid discharge unit
or any other suitable number of nozzles. The dispenser 560 also
includes a fluid passageway 568 and a plurality of control valves
570 (identified individually by reference numbers 570a-c) coupled
between the fluid passageway 568 and the nozzles 564. In this
embodiment, the control valves include a first control valve 570a
coupled to the first nozzle 564a, a second control valve 570b
coupled to the second nozzle 564b, and a third control valve 570c
coupled to the third nozzle 564c. The control valves 570 can be
solenoid valves that are operatively coupled to the controller (not
shown in FIG. 9) by signal lines 572a-c.
[0039] In operation, a planarizing solution flows through the fluid
passageway 568 to the control valves 570, and the controller
adjusts the control valves 570 to provide a plurality of separate
planarizing solution flows 574a-c from the nozzles 564a-c. The
controller can adjust the control valves according to real-time
input from sensors during the planarizing cycles of the workpieces
and/or from data based upon previous planarizing cycles. This
allows the nozzles 564a-c to independently discharge the
planarizing solution flows 574a-c onto separate regions
R.sub.1-R.sub.3 across the pad 140 to compensate for
nonuniformities in planarizing parameters across the pad 140. For
example, if region R.sub.1 requires less planarizing solution than
region R.sub.2, then the controller can send a signal to the first
control valve 570a to reduce the first planarizing solution flow
574a from the first nozzle 564a. This is only an example, and it
will be appreciated that many different combinations of flows can
be configured by selecting the desired flow rates through the
control valves 570.
[0040] FIG. 10 shows a planarizing machine 600 in accordance with
another embodiment of the invention. The planarizing machine 600
can have several components that are similar to the planarizing
machine 400 shown in FIG. 8, and thus like reference numbers refer
to like components in FIGS. 8 and 10. Additionally, the dispenser
460 in FIG. 10 can be similar to the dispenser 560 of FIG. 9. The
planarizing machine 600 also includes a sensor assembly 610 that
senses a planarizing parameter relative to areas or regions on the
contact surface 144 of the pad 140. The sensor assembly. 610 can be
embedded in the pad 140, between the pad 140 and the support
surface 116, and/or embedded in the support surface 116 of the
table 114. The sensor assembly 610 can include temperature sensors
that sense the temperature at the contact surface 144, pressure
sensors that sense localized forces exerted against the contact
surface 144, and/or drag force sensors between the workpiece 131
and the contact surface 144. Suitable sensor assemblies are
disclosed in U.S. Pat. Nos. 6,207,764; 6,046,111; 5,036,015; and
5,069,602; and U.S. application Ser. Nos. 09/386,648 and
09/387,309, all of which are herein incorporated by reference. In
an alternate embodiment, the sensor assembly can be a sensor 612
positioned above the pad 140. The sensor 612 can be an infrared
sensor to measure the temperature gradient across the contact
surface, or the sensor 612 can be an optical sensor for sensing
another type of parameter. The sensor assembly 610 and the sensor
612 can be coupled to the controller 480 to provide feedback
signals of the sensed planarizing parameter.
[0041] In the operation of the planarizing machine 600, the sensor
assembly 610 senses the planarizing parameter (i.e., temperature,
pressure and/or drag force) and sends a corresponding signal to the
controller 480. The sensor assembly 610, for example, can sense the
differences in the planarizing parameter across the contact surface
144 and send signals to the controller 480 corresponding to a
distribution of the planarizing parameter across the contact
surface 144. The controller 480 then sends command signals to the
fluid discharge units 464a and 464b according to the sensed
planarizing parameters to independently adjust the flow rates of
the planarizing solution flows 450a and 450b in a manner that
brings or maintains the planarizing parameter within a desired
range.
[0042] FIG. 11 shows a planarizing machine 700 having a distributor
760 and a controller 780 coupled to the distributor 760 in
accordance with another embodiment of the present invention. In
this embodiment, the distributor 760 includes a support 762 and a
fluid discharge unit 764 moveably coupled to the support 762. The
fluid discharge unit 764 can be slidably coupled to the support 762
to translate along the length of the support 762 (indicated by
arrow T). In an alternate embodiment, the fluid discharge unit 764
can be rotatably carried by the support 762 (arrow R). The
dispenser 760 can further include an actuator 767 coupled to the
fluid discharge unit 764, and the support 762 can be a track along
which the fluid discharge unit 764 can translate. The actuator 767
can be a servomotor or a linear actuator that drives the fluid
discharge unit 764 along the support 762. The actuator 767 can also
rotate the fluid discharge unit 764 relative to the support 762 in
lieu of, or in addition to, translating the fluid discharge unit
764 along the support 762. The dispenser 760 can also include a
fluid passageway 768 coupled to the fluid discharge unit 764. The
fluid passageway 768 can be a flexible hose that coils up or
elongates according to the movement of the fluid discharge unit 764
along the support 762.
[0043] The controller 780 is coupled to the actuator 767 to control
the motion of the fluid discharge unit 764 relative to the support
762. The controller 780 can send command signals to the actuator
767 to increase or decrease the velocity of the relative motion
between the fluid discharge unit 764 and the arm 762 to adjust the
volume of planarizing solution deposited onto different areas of
the contact surface 144 of the pad 140. This embodiment allows a
single flow of planarizing solution 750 to have different flow
characteristics according to the desired distribution of
planarizing solution across the contact surface 144.
[0044] From the foregoing, it will be appreciated that specific
embodiments of the invention have been described herein for
purposes of illustration, but that various modifications may be
made without deviating from the spirit and scope of the invention.
Accordingly, the invention is not limited except as by the appended
claims.
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