Title: Method and apparatus for executing plural processes on a microelectronic workpiece at a single processing station
Abstract: An apparatus for processing a microelectronic workpiece is set forth. The apparatus comprises a workpiece support adapted to hold the microelectronic workpiece and a processing container adapted to receive the microelectronic workpiece held by the workpiece support. A drive mechanism is connected to drive the processing container and the workpiece support relative to one another so that the microelectronic workpiece may be moved to a plurality of workpiece processing positions for processing using processing fluid that is provided by first and second chemical delivery systems. The apparatus also includes first and second chemical collector systems that are used to assist in at least partially removing spent processing fluid. In accordance with one embodiment, the apparatus is particularly adapted to execute an immersion process, such as electroplating, and a spraying process, such as an in-situ rinse.
Patent Number: 6,854,473 Issued on 02/15/2005 to Hanson, et al.
| Inventors:
|
Hanson; Kyle M. (Kalispell, MT);
Blackburn; Reed A. (Whitefish, MT)
|
| Assignee:
|
Semitool, Inc. (Kalispell, MT)
|
| Appl. No.:
|
836844 |
| Filed:
|
April 17, 2001 |
| Current U.S. Class: |
134/95.3; 134/58R; 134/94.1; 134/95.1; 134/95.2; 134/103.2; 134/198; 134/902; 422/292; 422/300 |
| Intern'l Class: |
B05B 012//02; B05B 003//00 |
| Field of Search: |
204/199,212,224 R,225,232,237,263,275.1,297.01,297.06,297.07,297.08
422/292,300
134/58 R,94.1,95.1,95.2,95.3,103.2,198,902
|
References Cited [Referenced By]
U.S. Patent Documents
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| 5169408 | Dec., 1992 | Biggerstaff et al. | 29/25.
|
| 5344491 | Sep., 1994 | Katou.
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| 5421987 | Jun., 1995 | Tzanavarat et al.
| |
| 5447615 | Sep., 1995 | Ishida.
| |
| 5871584 | Feb., 1999 | Tateyama et al. | 118/323.
|
| 5932077 | Aug., 1999 | Reynolds.
| |
| 6050275 | Apr., 2000 | Kamikawa et al. | 134/105.
|
| 6080291 | Jun., 2000 | Woodruff et al.
| |
| 6099702 | Aug., 2000 | Reid et al.
| |
| 6139703 | Oct., 2000 | Hanson et al.
| |
| 6156167 | Dec., 2000 | Patton et al. | 204/270.
|
| 6214193 | Apr., 2001 | Reid et al. | 205/122.
|
| 6280581 | Aug., 2001 | Cheng | 204/224.
|
| 6352623 | Mar., 2002 | Volodarsky et al. | 204/275.
|
| 6391166 | May., 2002 | Wang | 204/224.
|
| 6416647 | Jul., 2002 | Dordi et al. | 205/137.
|
| 2003/0079989 | May., 2003 | Klocke et al. | 204/471.
|
Primary Examiner: Nguyen; Nam
Assistant Examiner: Mutschler; Brian L.
Attorney, Agent or Firm: Perkins Coie LLP
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable
This application is a continuation of U.S. application Ser. No. 09/416,235
filed on Oct. 12, 1999, now abandoned.
Claims
What is claimed is:
1. An apparatus for processing a microelectronic workpiece, the apparatus
comprising:
a workpiece support configured to hold the microelectronic workpiece;
a processing container configured to receive the microelectronic workpiece
held by the workpiece support;
a drive mechanism connected to drive at least one of the processing
container and the workpiece support holding the microelectronic workpiece
relative to the other so that the microelectronic workpiece may be moved
to a plurality of workpiece processing positions;
a first chemical delivery system providing at least one processing fluid to
the processing container for application to the microelectronic workpiece
when the microelectronic workpiece is in a first one of the plurality of
workpiece processing positions;
a first chemical collector system configured to assist in at least
partially removing spent processing fluid provided by the first chemical
delivery system while the microelectronic workpiece is in the first one of
the plurality of workpiece processing positions;
a second chemical delivery system providing at least one processing fluid
to the processing container for application to the microelectronic
workpiece when the microelectronic workpiece is in a second one of the
plurality of microelectronic workpiece processing positions, the second
chemical delivery system directing a spray of processing fluid for initial
contact with the microelectronic workpiece at an initial radial position;
a second chemical collector system configured to assist in at least
partially removing spent processing fluid provided by the second chemical
delivery system from the processing container while the microelectronic
workpiece is in the second one of the plurality of microelectronic
workpiece processing positions; and
a control system operatively coupled to the second chemical delivery system
and the drive mechanism and being programmed with instructions that direct
the drive mechanism to move the workpiece support during application of
the spray from the second chemical delivery system so as to vary the
radial position of the initial contact between the spray and the
microelectronic workpiece.
2. The apparatus of claim 1, further comprising a rotor drive connected to
spin the workpiece support.
3. The apparatus of claim 1 wherein the first one of the plurality of
workpiece processing positions is at a first level within the processing
container and the second one of the plurality of workpiece processing
positions is at a second level within the processing container, the second
level being above the first level.
4. The apparatus of claim 1 wherein the first chemical collector system is
disposed at a level of the processing container corresponding to the first
one of the plurality of workplace processing positions and the second
chemical collector system is disposed at a different level of the
processing container that corresponds to the second one of the plurality
of workplace processing positions.
5. The apparatus of claim 1 wherein the second chemical collector system
collects spent processing fluid as the spent processing fluid is flung
from the microelectronic workpiece during spinning of the microelectronic
workpiece.
6. The apparatus of claim 1 wherein the second chemical collector system
comprises:
a splash wall extending about the interior periphery of the processing
container;
a further wall extending about the interior periphery of the processing
container;
the splash wall and further wall defining a collection channel therebetween
for collecting the spent processing fluid of the second chemical delivery
system.
7. The apparatus of claim 6, further comprising a fluid outlet proceeding
from the collection channel.
8. The apparatus of claim 1 wherein the second chemical delivery system is
configured to direct a spray of processing fluid that initially impinges
on less than an entire radius of the microelectronic workpiece.
9. The apparatus of claim 1 wherein the second chemical delivery system
directs a stream of the at least one processing fluid toward a fixed
location.
10. An apparatus for processing a microelectronic workpiece, the apparatus
comprising:
a workpiece support configured to hold the microelectronic workpiece;
a processing container configured to receive the microelectronic workpiece
held by the workpiece support;
an automated drive system connected to drive at least one of the processing
container and the workpiece support holding the microelectronic workpiece
relative to the other so that the microelectronic workpiece is moved
between an initial processing position and a secondary processing
position;
a chemical delivery system providing at least one stream of at least one
processing fluid to the processing container for application to at least
one surface of the microelectronic workpiece as the microelectronic
workpiece proceeds between the initial processing position and secondary
processing position, the at least one stream being directed toward a first
portion of the at least one surface of the microelectronic workpiece when
the microelectronic workpiece is in the initial processing position, the
at least one stream being directed toward a second portion of the at least
one surface of the microelectronic workpiece disposed radially outwardly
from the first portion, when the microelectronic workpiece is in the
secondary processing position; and
a control system operatively coupled to the chemical delivery system and
the automated drive system and programmed with instructions that direct
the drive system to move the workpiece support while the chemical delivery
system directs the at least one stream toward the microelectronic
workpiece.
11. The apparatus of claim 10 wherein the automated drive system includes a
linear actuator that drives at least one of the processing container and
the workpiece support relative to the other along a vertically oriented
drive path.
12. The apparatus of claim 10 wherein the automated drive system includes a
rotational actuator that drives at least one of the processing container
and the workpiece support relative to the other along an angular drive
path.
13. The apparatus of claim 10, further comprising a chemical collector
system configured to remove spent processing fluid provided by the
chemical delivery system as the microelectronic workpiece proceeds between
the initial processing position and the secondary processing position.
14. The apparatus of claim 13, further comprising:
a further chemical delivery system configured to provide at least one
processing fluid to the processing container for application to the
microelectronic workpiece when the microelectronic workpiece is in a
further processing position other than a position between the initial and
secondary processing positions; and
a further chemical collector system configured to assist in at least
partially removing spent processing fluid provided by the further chemical
delivery system from the processing container while the microelectronic
workpiece is in the further workpiece processing position.
15. The apparatus of claim 13 wherein the chemical collector system
comprises:
a splash wall extending about the interior periphery of the processing
container;
a further wall extending about the interior periphery of the processing
container;
the splash wall and further wall defining a collection channel therebetween
for collecting the spent processing fluid of the further chemical delivery
system.
16. The apparatus of claim 10, further comprising a rotor drive connected
to spin the workpiece support and corresponding microelectronic workpiece
as the microelectronic workpiece proceeds from the initial processing
position to the secondary processing position.
17. The apparatus of claim 10, wherein the chemical delivery system is
configured to direct a stream of processing fluid that initially impinges
on less than an entire radius of the microelectronic workpiece.
18. An apparatus for processing a microelectronic workpiece, the apparatus
comprising:
a workpiece support configured to hold the microelectronic workpiece;
a processing container configured to receive the microelectronic workpiece
held by the workpiece support, the processing container being configured
for immersion processing of at least one surface of the microelectronic
workpiece at a first processing portion of the processing container, and
configured for spray processing the at least one surface of the
microelectronic workpiece at a second processing portion of the processing
container;
a drive mechanism connected to drive at least one of the processing
container and the workpiece support holding the microelectronic workpiece
relative to the other so that the microelectronic workpiece may be moved
to a plurality of workpiece processing positions, the plurality of
workpiece processing positions including at least an immersion processing
position proximate the first portion of the processing container and a
spray processing position proximate the second portion of the processing
container;
a first chemical delivery system configured to provide at least one
processing fluid to the processing container for immersion processing of
the at least one surface of the microelectronic workpiece when the
microelectronic workpiece is at the immersion processing position;
a first chemical collector system configured to assist in at least
partially removing spent processing fluid provided by the first chemical
delivery system while the microelectronic workpiece is at the immersion
processing position;
a second chemical delivery system configured to provide at least one
processing fluid to the processing container for spray processing of the
at least one surface of the microelectronic workpiece when the
microelectronic workpiece is at the spray processing position, the second
chemical delivery system being positioned to direct a spray of processing
fluid for initial contact with the microelectronic workpiece at an initial
radial position;
a second chemical collector system configured to assist in at least
partially removing spent processing fluid provided by the second chemical
delivery system from the processing container while the microelectronic
workpiece is at the spray processing position; and
a control system operatively coupled to the second chemical delivery system
and the drive mechanism and programmed with instructions that direct the
drive mechanism to move the workpiece support during application of the
spray from the second chemical delivery system so as to vary the radial
position of the initial contact between the spray and the microelectronic
workpiece.
19. The apparatus of claim 18 wherein the first processing portion of the
processing container is below the second processing portion of the
processing container.
20. The apparatus of claim 18, further comprising a rotor drive connected
to spin the workpiece support.
21. The apparatus of claim 18 wherein the immersion processing position is
at a first level within the processing container and the spray processing
position is at a second level within the processing container, the second
level being above the first level.
22. The apparatus of claim 18 wherein the second chemical collector system
collects spent processing fluid as the spent processing fluid is flung
from the microelectronic workpiece during spinning of the microelectronic
workpiece.
23. The apparatus of claim 22 wherein the second chemical collector system
comprises:
a splash wall extending about the interior periphery of the processing
container;
a further wall extending about the interior periphery of the processing
container;
the splash wall and further wall defining a collection channel therebetween
for collecting the spent processing fluid of the second chemical delivery
system.
24. The apparatus of claim 23, further comprising a fluid outlet proceeding
from the collection channel.
25. The apparatus of claim 18 wherein the drive mechanism comprises a
linear actuator and wherein the control system directs the linear actuator
to drive the microelectronic workpiece along a vertically oriented linear
drive path between the immersion processing position and the spray
processing position.
26. The apparatus of claim 18 wherein the drive mechanism comprises a
rotational actuator and wherein the control system directs the rotational
actuator to rotate the microelectronic workpiece along an angular drive
path about a fixed rotation axis between the immersion processing position
and the spray processing position.
27. An apparatus for processing a microelectronic workpiece, comprising:
a workpiece support configured to hold a microelectronic workpiece;
a processing vessel configured to receive a microelectronic workpiece held
by the workpiece support;
a drive system coupled to the workpiece support to move the workpiece
support along a first axis relative to the processing vessel between a
first position and a second position, the drive system being configured to
tilt the workpiece support relative to the vessel about a second axis
generally transverse to the first axis;
a fluid delivery system positioned to direct at least one stream of
processing fluid toward the workpiece support to impinge on a
microelectronic workpiece while the workpiece support holds the
microelectronic workpiece; and
a control system operatively coupled to the drive system to direct the
drive system to move the workpiece support while the fluid delivery system
directs the at least one stream of processing fluid, wherein the control
system directs the drive system to drive the microelectronic workpiece
between the first position and the second position as the fluid delivery
system provides the at least one stream of processing fluid for contact
with at least one surface of the microelectronic workpiece, the at least
one stream being directed toward a first portion of the at least one
surface of the microelectronic workpiece when the microelectronic
workpiece is in the first position, the at least one stream being directed
toward a second portion of the at least one surface of the microelectronic
workpiece disposed radially outwardly from the first position, when the
microelectronic workpiece is in the second position.
28. The apparatus of claim 27, further comprising:
a fluid collector system; and
a rotor drive connected to spin the workpiece support and corresponding
microelectronic workpiece to thereby fling spent processing fluid into the
fluid collector system.
29. The apparatus of claim 27, further comprising a fluid collector system
that includes:
a splash wall extending about the interior periphery of the processing
vessel;
a further wall extending about the interior periphery of the processing
vessel;
the splash wall and further wall defining a collection channel therebetween
for collecting the spent processing fluid of the fluid delivery system.
30. The apparatus of claim 29, further comprising a fluid outlet proceeding
from the collection channel.
31. The apparatus of claim 27 wherein the drive system comprises a linear
actuator and wherein the control system directs the linear actuator to
drive the microelectronic workpiece along a vertically oriented linear
drive path between the first position and the second position.
32. An apparatus for processing a microelectronic workpiece, comprising:
a workpiece support configured to hold the microelectronic workpiece;
a processing container configured to receive the microelectronic workpiece
held by the workpiece support;
a drive mechanism connected to drive at least one of the processing
container and the workpiece support relative to the other to move the
microelectronic workpiece to at least one processing position;
a fluid delivery system positioned to direct a spray of a processing fluid
to the processing container for application to the microelectronic
workpiece when the microelectronic workpiece is in the at least one
workpiece processing position; and
a collector system positioned to receive at least a portion of the
processing fluid directed by the fluid delivery system, the collector
system including a first annular channel and a second annular channel
positioned at least proximate to the first annular channel, the first and
second annular channels being in fluid communication with each other via a
common outlet.
33. The apparatus of claim 32 wherein the first and second annular channels
are disposed concentrically about an axis, and wherein the workpiece
support is rotatable relative to the container about the axis.
34. The apparatus of claim 32 wherein at least one of the annular channels
is bounded by a first wall and a second wall, with at least part of the
second wall positioned radially outwardly from the first wall.
35. The apparatus of claim 32 wherein the first annular channel is bounded
by a first wall and a second wall, with at least part of the second wall
positioned radially outwardly from the first wall, and wherein the second
annular channel is bounded by the second wall and a third wall, with at
least part of the third wall positioned radially outwardly from the second
wall.
36. The apparatus of claim 32 wherein the second annular channel is
positioned above the first annular channel.
37. The apparatus of claim 32 wherein the first and second annular channels
are concentric about an axis and wherein the first annular channel has a
first axial position relative to the axis and the second annular channel
has a second axial position relative to the axis, the second axial
position being different than the first axial position.
38. The apparatus of claim 32, further comprising a control system
operatively coupled to the drive mechanism and programmed to direct the
drive mechanism to move the workpiece support during application of the
spray from the delivery system so as to vary the radial position of an
initial contact between the spray and the microelectronic workpiece.
39. The apparatus of claim 32 wherein the workpiece support is movable
relative to the container along an axis to a plurality of processing
positions, and wherein at least one of the annular channels is bounded by
a first wall and a second wall, with at least part of the second wall
disposed radially outwardly from the first wall, and wherein the first and
second walls are disposed obliquely relative to the axis.
40. An apparatus for processing a microelectronic workpiece, comprising:
a workpiece support configured to hold the microelectronic workpiece;
a processing container configured to receive the microelectronic workpiece
held by the workpiece support;
a drive mechanism connected to drive at least one of the processing
container and the workpiece support relative to the other to move the
microelectronic workpiece to a plurality of processing positions;
a first fluid delivery system positioned to provide at least one processing
fluid to the processing container for application to the microelectronic
workpiece when the microelectronic workpiece is in a first one of the
plurality of workpiece processing positions;
a first fluid collector system positioned to receive at least a portion of
the processing fluid provided by the first fluid delivery system while the
microelectronic workpiece is in the first one of the plurality of
workpiece processing positions;
a second fluid delivery system positioned to direct a spray of at least one
processing fluid to the processing container for application to the
microelectronic workpiece when the microelectronic workpiece is in a
second one of the plurality of microelectronic workpiece processing
positions;
a second fluid collector system positioned to receive at least a portion of
the processing fluid directed by the second fluid delivery system while
the microelectronic workpiece is in the second one of the plurality of
microelectronic workpiece processing positions, the second fluid collector
including a first annular channel and a second annular channel positioned
at least proximate to the first annular channel, the first and second
annular channels being in fluid communication with each other via a common
outlet.
41. The apparatus of claim 40 wherein the first and second annular channels
are disposed concentrically about an axis, and wherein the workpiece
support is rotatable relative to the container about the axis.
42. The apparatus of claim 40 wherein at least one of the annular channels
is bounded by a first wall and a second wall, with at least part of the
second wall positioned radially outwardly from the first wall.
43. The apparatus of claim 40 wherein the first annular channel is bounded
by a first wall and a second wall, with at least part of the second wall
positioned radially outwardly from the first wall, and wherein the second
annular channel is bounded by the second wall and a third wall, with at
least part of the third wall positioned radially outwardly from the second
wall.
44. The apparatus of claim 40 wherein the second annular channel is
positioned above the first channel.
45. The apparatus of claim 40 wherein the first and second annular channels
are concentric about an axis and wherein the first annular channel has a
first axial position relative to the axis and the second annular channel
has a second axial position relative to the axis, the second axial
position being different than the first axial position.
46. The apparatus of claim 40, further comprising a control system
operatively coupled to the drive mechanism and configured to direct the
drive mechanism to move the workpiece support during application of the
spray from the second delivery system so as to vary the radial position of
an initial contact between the spray and the microelectronic workpiece.
47. The apparatus of claim 40 wherein the workpiece support is movable
relative to the container along an axis to a plurality of processing
positions, and wherein at least one of the annular channels is bounded by
a first wall and a second wall, with at least part of the second wall
disposed radially outwardly from the first wall, and wherein the first and
second walls are disposed obliquely relative to the axis.
Description
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
BACKGROUND OF THE INVENTION
The fabrication of microelectronic components from a workpiece, such as a
semiconductor wafer substrate, polymer substrate, etc., involves a
substantial number of processes. There are a number of different
processing operations performed on the workpiece to fabricate the
microelectronic component(s). Such operations include, for example,
material deposition, patterning, doping, chemical mechanical polishing,
electropolishing, and heat treatment.
Material deposition processing involves depositing thin layers of
electronic material to the surface of the workpiece (hereinafter described
as, but not limited to, a semiconductor wafer). Patterning provides
removal of selected portions of these added layers. Doping of the
semiconductor wafer is the process of adding impurities known as "dopants"
to the selected portions of the wafer to after the electrical
characteristics of the substrate material. Heat treatment of the
semiconductor wafer involves heating and/or cooling the wafer to achieve
specific process results. Chemical mechanical polishing involves the
removal of material through a combined chemical/mechanical process while
electropolishing involves the removal of material from a workpiece surface
using electrochemical reactions.
Numerous processing devices, known as processing "tools", have been
developed to implement the foregoing processing operations. These tools
take on different configurations depending on the type of workpiece used
in the fabrication process and the process or processes executed by the
tool. One tool configuration, known as the Equinox(R) wet processing tool
and available from Semitool, Inc., of Kalispell, Mont., includes one or
more workpiece processing stations that utilize a workpiece holder and a
process bowl or container for implementing wet processing operations. Such
wet processing operations include electroplating, etching, cleaning,
electroless deposition, electropolishing, etc.
In accordance with one configuration of the foregoing Equinox(R) tool, the
workpiece holder and the process bowl are disposed proximate one another
and function to bring the semiconductor wafer held by the workpiece holder
into contact with a processing fluid disposed in the process bowl and
forming a processing chamber.
Conventional workpiece processors have utilized various techniques to bring
the processing fluid into contact with the surface of the workpiece in a
controlled manner. For example, the processing fluid may be brought into
contact with the surface of the workpiece using a controlled spray. In
other types of processes, such as in partial or full immersion processing,
the processing fluid resides in a bath and at least one surface of the
workpiece is brought into contact with or below the surface of the
processing fluid.
BRIEF SUMMARY OF THE INVENTION
An apparatus for processing a microelectronic workpiece is set forth. The
apparatus comprises a workpiece support adapted to hold the
microelectronic workpiece and a processing container adapted to receive
the microelectronic workpiece held by the workpiece support. A drive
mechanism is connected to drive the processing container and the workpiece
support holding the microelectronic workpiece relative to one another so
that the microelectronic workpiece may be moved to a plurality of
workpiece processing positions. At least two chemical delivery systems are
employed. A first chemical delivery system is used to provide at least one
processing fluid to the processing container for application to the
microelectronic workpiece when the microelectronic workpiece is in a first
one of the plurality of workpiece processing positions while a second
chemical delivery system is used to provide at least one processing fluid
to the processing container for application to the microelectronic
workpiece when the microelectronic workpiece is in a second one of the
plurality of microelectronic workpiece processing positions. The apparatus
also includes at least two chemical collector systems. A first chemical
collector system is used to assist in at least partially removing spent
processing fluid provided by the first chemical delivery system while the
microelectronic workpiece is in the first one of the plurality of
workpiece processing positions. Similarly, a second chemical collector
system is used to assist in at least partially removing spent processing
fluid provided by the second chemical delivery system from the processing
container while the microelectronic workpiece is in the second one of the
plurality of microelectronic workpiece processing positions. In accordance
with one embodiment, the apparatus is particularly adapted to execute an
immersion process, such as electroplating, and a spraying process, such as
an in-situ rinse.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a perspective view of a reactor constructed in accordance with
one embodiment of the present invention.
FIG. 2 is a cross-sectional view of the reactor illustrated in FIG. 1.
FIG. 3 is a further cross-sectional view of the reactor illustrated in FIG.
1.
FIGS. 4 and 5 illustrate the orientation of the processing head and
corresponding workpiece during a workpiece loading operation.
FIGS. 6-9 are cross-sectional views of the reactor of FIG. 1 illustrating
the microelectronic workpiece at various processing positions within the
processing container.
FIGS. 10 and 11 are cross-sectional views of the reactor of FIG. 1
illustrating the microelectronic workpiece at various angular positions
within the second processing portion of the processing container so as to
vary the position of initial contact of a stream of processing fluid with
a surface of the microelectronic workpiece.
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIGS. 1-3, there is shown a reactor assembly 20 for
processing a microelectronic workpiece, such as a semiconductor wafer 25
or the like. Generally stated, the reactor assembly 20 is comprised of a
reactor head, shown generally at 30, that includes one or more components
used to support the workpiece 25. Additionally, the reactor assembly 20
includes a corresponding reactor container, shown generally at 35, that
receives one or more processing fluids from one or more chemical delivery
systems.
The reactor head 30 of the reactor 20 is preferably comprised of a
stationary assembly 40 and, optionally, a rotor assembly 45 that is driven
by a corresponding rotor motor 47. Rotor assembly 45 may be configured to
receive and carry an associated wafer 25 or like workpiece, position the
workpiece in a process-side down orientation within reactor container 35,
and to rotate or spin the workpiece. The rotor assembly 45 and/or reactor
head 30 may also be used to elevate the workpiece after initial contact
with a processing liquid so that only a meniscus of the processing fluid
contacts the side of the workpiece that is to be processed. This also
falls within the ambit of an immersion process.
The reactor head 30 is mounted on a lift/rotate apparatus 50 which is
configured to rotate the reactor head 30 from an upwardly-facing
disposition in which it receives the wafer to be plated, to a downwardly
facing disposition in which the surface of the wafer to be processed is
positioned so that it may be brought into contact with a processing fluid,
such as an electroplating solution, in reactor container 35. A robotic arm
(not illustrated), which may include an end effector, is typically
employed for placing the workpiece 25 in position on the rotor assembly
45, and for removing the processed wafer from within the rotor assembly 45
after processing is complete.
Lift/rotate apparatus 50 is preferably capable of moving the workpiece 25
to a plurality of positions with respect to reactor container 35. More
particularly, the lift/rotate apparatus 50 may be capable of moving the
reactor head 30 and the corresponding workpiece 25 in a vertical fashion
toward and away from the reactor container 35. Such vertical motion may be
directed by a programmable control system 55 or the like. Programmable
control system 55 may also be used to adjust the spin rate of the rotor
motor 47.
Although lift/rotate apparatus 50 of the disclosed embodiment has the
ability to rotate reactor head 30 for presentation of the workpiece 25 by
a corresponding robot in a process-side up orientation, it will be
recognized that apparatus 50 need not have such rotation abilities.
Rather, the workpiece 25 may be presented to the reactor head 30 by the
corresponding robot in a process-side down orientation. In such instances,
rotation of the workpiece to the process-side down orientation may take
place on the corresponding robot or another apparatus within the overall
processing system.
The reactor container 35 includes a first processing portion, shown
generally at 60, that is configured to execute a first process in which
one or more processing fluids are delivered to treat at least one surface
of the workpiece 25. In the illustrated embodiment, for exemplary
purposes, first processing portion 60 of container 35 is configured to
execute an electroplating process. However, the first processing portion
60 of container 35 may be alternatively configured to execute any number
of different processes. Such processes include, but are not limited to,
immersion processes, vapor processes, spray processes, gaseous processes,
etc.
Pursuant to executing an electroplating process in the first processing
portion 60, container 35 is configured to provide a flow of an
electroplating solution to one or more surfaces of the workpiece 25. To
this end, container 35 includes an interior container 65 having an inlet
70 through which a flow of electroplating solution is provided. The
electroplating solution provided through inlet 70 flows through the
interior container 65 and overflows therefrom about an upper weir 75 into
an exterior overflow region 77. This type of reactor assembly is
particularly suited for effecting electroplating of semiconductor wafers
or like workpieces, in which an electrically conductive, thin-film layer
of the wafer is electroplated with a blanket or patterned metallic layer
while in a process-side down orientation.
Within the interior container 65 there is an anode assembly, shown
generally at 80, having one or more anodes 85 that is in the electrical
contact with the electroplating solution (although the illustrated
embodiment utilizes a single anode 85). The one or more anodes 85 are
electrically connected to a source of electroplating power (not shown)
through one or more electric conductive structures. The anode assembly 80
may be constructed in the manner set forth in PCT Application No.
PCT/US99/15430, entitled "REACTOR VESSEL HAVING IMPROVED CUP, ANODE AND
CONDUCTOR ASSEMBLY", filed Jul. 9, 1999, the teachings of which are hereby
incorporated by reference. An alternative reactor container suitable for
immersion processing is set forth in U.S. Ser. No. 60/143,769, entitled
"workpiece processor having improved processing chamber", filed Jul. 12,
1999.
In those instances in which the reactor is to be used in an electroplating
process, the rotor assembly 45 of head 30 may include one or more cathode
contacts that provide electroplating power to the surface of the wafer. In
the illustrated embodiment, a cathode contact assembly is shown generally
at 90. This cathode contact assembly may be constructed in accordance with
the teachings of PCT Application No. PCT/US99/15847, entitled "METHOD AND
APPARATUS FOR COPPER PLATING USING ELECTROLESS PLATING AND
ELECTROPLATING", filed Jul. 12, 1999. Although the various contact
configurations illustrated in that patent application provide
electroplating power directly to the side of the wafer that is to be
processed, it will be recognized that backside contact may be implemented
in lieu of front side contact when the substrate is conductive or other
means are provided to electrically connect the backside of the of the
workpiece with the process side thereof. The contact assembly 90 may be
operated between an open state that allows the wafer to be place don the
rotor assembly 45, and a closed state that secures the wafer to the rotor
assembly and brings the electrically conductive components of the contact
assembly 90 into electrical engagement with the surface of the wafer that
is to be plated.
Processing container 35 also includes a second processing portion, shown
generally at 95, that is adapted to execute a further process on one or
more surfaces of the microelectronic workpiece 25. In the illustrated
embodiment, the second processing portion 95 is adapted to execute a
process in which a processing fluid is provided at the downward facing
surface of the workpiece 25. To this end, one or more nozzles 100 are
provided in the second processing portion 95 and are directed toward the
workpiece 25.
It is often desirable to at least partially inhibit mixing of the
processing chemicals used in different processing steps. Reactor container
35 therefore includes separate collection systems for collecting spent
processing fluids (e.g., processing fluids that have contacted one or more
surfaces of the workpiece 25). With respect to the illustrated embodiment,
the processing fluids used in processes carried out in the first
processing portion 60 of reactor container 35 are liquids that overflow
the weir 75 of the interior container 65 and enter the overflow region 77.
After entering the overflow region 77, the processing chemicals are
removed through one or more outlets that are in fluid communication with
the overflow region 77. The fluid exiting from the reactor container 35
subsequently undergoes disposal, recycling, constituent dosing, etc.
In those instances in which the processing fluid used in the first
processing portion 60 is in a gaseous or vapor state, overflow region 77
may be connected to a vacuum source. Spent processing fluid may then be
removed as it overflows the weir 75. As above, process fluid exiting from
the reactor container 35 may subsequently undergo disposal, recycling,
constituent dosing, etc.
A further collection system is used for collecting spent processing fluids
employed in processes carried out in the second processing portion 95. The
further collection system, generally designated at 105, is provided in or
proximate the second processing portion 95. In the illustrated embodiment,
the first processing portion 60 of reactor container 35 is disposed
vertically below the second processing portion 95 and, further, is open to
the second processing portion 95. These factors complicate the collection
process as it is to be executed by the further collection system. For
example, if a liquid is used as the processing fluid in the second
processing portion 95 and delivered to a surface of the microelectronic
workpiece 25, liquid drops can readily enter and adversely effect the
first processing portion 60. Although small amounts of the liquid may be
tolerated in the first processing portion 60, the substantial amounts of
the liquid that are often introduced during spray processing or like can
and often will reduce the effectiveness of the processing that takes place
in the first processing portion 60.
To overcome the foregoing problems, the further collection system 105 is in
the form of one or more fluid channels, shown generally at 110, that are
disposed at the inner periphery of reactor container 35. As shown, the
fluid channels 110 are located in the second processing portion 95
proximate the position of the workpiece 25 as it undergoes processing in
the second processing portion 95. Each fluid channel, as illustrated in
FIGS. 2 and 3, may be defined by a splash wall 115 and a retainer wall
120. The splash wall 115 and retainer wall 120 may each be disposed at an
angle with respect to horizontal. The manner in which this further
collection system functions will become clearer in connection with the
operational description below.
In operation, the reactor head 30 is elevated and rotated by the
lift/rotate apparatus 50 to a loading position, illustrated in FIG. 4,
that is located above the reactor container 35. While in this position, a
workpiece 25 is placed upon rotor assembly 45 with the side of the
workpiece that is to be electroplated facing upward. The contact assembly
90 of the rotor assembly 45 is then actuated to grip the workpiece 25 and
secure it therewith. This actuation also causes the contact assembly 90 to
make electrical contact with the workpiece 25 to supply power for the
electroplating operation. As noted above, however, rotation of the reactor
head 30 need not take place in apparatus in which the workpiece 25 is
rotated to a process-side down position prior to introduction of the
workpiece 25 to the rotor assembly 45.
Once the workpiece 25 has been secured with the rotor assembly 45, the
lift/rotate apparatus 50 is directed by the control system 55 to rotate
the reactor head 30 so that the surface of the workpiece that is to be
processed is faced downward, as illustrated in FIG. 5. With the workpiece
25 in this state, the control system 55 directs the lift/rotate apparatus
50 to drive the rotor assembly 45 and the corresponding workpiece to a
first workpiece processing position within the reactor container 35. This
first workpiece processing position may be located in either the first
processing portion 60 or the second processing portion 95 of the reactor
container 35. For exemplary purposes, it will be assumed that processing
will first take place in the first processing portion 60. As such, the
lift/rotate apparatus 50 is directed by the control system 55 to take the
necessary steps to bring the workpiece 25 to the position illustrated in
FIG. 6. In this position, at least the lower surface of the workpiece 25
is brought into contact with a flow of electroplating solution provided at
the upper portion of interior container 65. Electroplating power is then
provided to both the workpiece 25 and the anode 85 to affect
electroplating of the surface. During the electroplating process, spent
processing fluid is collected within the overflow region 77 and removed
from the reactor container 35.
Once electroplating is completed in the first processing portion 60, the
control system 55 directs the lift/rotate apparatus 50 to move the
workpiece 25 to an intermediate position, designated generally at 57 of
FIG. 7. While at this position, the workpiece 25 is spun at a high
rotation rate to fling off a bulk portion of any excess electroplating
solution. This reduces drag out and waste of the electroplating solution.
After the bulk portion of the excess electroplating solution has been flung
off, the control system 55 directs the lift/rotate apparatus 50 to move
the workpiece 25 to a second processing position. Here, in the exemplary
process, the second processing position is located in the second
processing portion 95 of the reactor container 35. The lift/rotate
apparatus 50 thus drives the workpiece 25 to the position illustrated in
FIG. 7. In this position, one or more further processing chemicals are
provided from a chemical supply system to contact one or more surfaces of
the workpiece 25. With respect to the specific embodiment disclosed
herein, a liquid stream of a processing fluid, such as water that may or
may not include additives, is provided through the one or more nozzles 100
to contact the lower surface of the workpiece 25 that has been
electroplated. As the liquid stream is directed toward the workpiece
surface, the rotor assembly 45 and corresponding workpiece 25 are rotated
at a high rotation rate so that the liquid impinging on the workpiece
surface is flung radially outward therefrom under the influence of
centripetal acceleration. The liquid flung in this manner is collected by
the further collection system 105. More particularly, the liquid flung in
this manner contacts the splash wall 115 corresponding to the channel 110
that is immediately adjacent the lower surface of the workpiece 25, and
proceeds downward therealong into the corresponding channel 110. Retainer
wall 120, being disposed at an angle with respect to horizontal, assists
in retaining the accumulated liquid within the corresponding channel 110.
One or more outlets 125 are placed in fluid communication with the channel
110 to allow the spent processing liquid to be removed from the reactor
container 35. As such, the spent processing liquid used in the second
processing portion 95 is effectively removed from the reactor container 35
by the further collection system 105, thereby minimizing the amount of the
spent liquid that enters the first processing portion 60.
As can be seen in the FIGUREs, a plurality of collection channels 110 may
be used. In accordance with one embodiment of the present invention, all
of the plurality of collection channels 110 can be connected to a common
drain. Such a configuration is particularly useful in those instances in
which a single processing fluid is employed for processing the workpiece
when it is in the second processing portion 95. However, it may be
desirable to process the workpiece 25 using more than one type of
processing fluid in the second processing portion 95 while collecting the
processing fluids separately. To this end, programmable control system 55
directs the lift/rotate apparatus 50 to a plurality of positions within
the second processing portion 95. Here, those positions differ with
respect to their vertical position within the reactor container 35.
A unique manner of delivering a fluid stream to the surface of a workpiece
is illustrated in connection with FIGS. 7-9 As illustrated, the workpiece
25 is moved to a plurality of processing positions within the second
processing portion 95. With reference to FIG. 7, the reactor head 30 is
driven by the control system 55 to place the workpiece 25 at a first
processing position within the second processing portion 95. In this
position, nozzle 100 directs a stream of processing fluid 130 toward a
central portion of the lower surface of the workpiece 25 at an upward
angle. As the stream of processing fluid 130 is provided to the surface of
workpiece 25, the control system 55 directs the reactor head 30 to move
the workpiece 25 sequentially through the positions illustrated in FIGS. 7
through 9. Such movement through these positions can be executed in
accordance with a controlled continuous velocity, a controlled velocity
profile, or in discrete steps. As the workpiece 25 is moved to these
various processing positions, the stream of processing fluid 130 from
nozzle 100 is directed at a substantially fixed point in space. Since the
stream 130 is fixed at an acute angle as the workpiece 25 is moved, the
radial position at which the stream 130 contacts the workpiece 25 changes
and approaches the periphery of the surface of workpiece 25. This is
particularly useful when this apparatus configuration and method of
operation are used in connection with electroplating operations, since the
stream 130 may be comprised of deionized water and effectively "chase off"
electroplating solution from surface of microelectronic workpiece 25.
As can be seen in the foregoing figures, a plurality of channels 110 are
employed. Each channel 110 corresponds to one or more processing positions
assumed by the workpiece 25 as it is processed in the second processing
portion 95. In those instances in which a single processing fluid is used
in the second processing portion 95, the channels 110 may be connected
together and tied to a single outlet 135. However, it is also possible to
provide different processing fluids to the surface of the workpiece 25 at
different processing positions within the second processing portion 95. In
such operations, channels 110 may be used to separately collect each of
the processing fluids and provide them to separate outlets.
An alternative method (or additional method, if used in conjunction with
the method described above) of delivering a stream of processing fluid to
the downward facing surface of the workpiece 25 is illustrated in FIGS. 10
and 11. In accordance with this latter method, reactor head 30 is driven
to a fixed position within second processing portion 95 by the lift/rotate
apparatus 50 under the direction of control system 55. A stream of
processing fluid is provided through one or more nozzles 100. Control
system 55 directs lift/rotate apparatus 50 to rotate reactor head 30
through a plurality of angles so that the stream of processing fluid 130
makes initial contact with the lower surface of workpiece 25 at a
plurality of portions thereof sequentially as a function of time. Again,
workpiece 25 may be spun at a high rotation rate to fling off spent
processing fluid into the fluid channels 110 of the further collection
system 105 as the stream of processing fluid 130 is delivered to the
surface of workpiece 25. Rotation of the reactor head 30 and corresponding
workpiece 25 may be executed in accordance with a controlled motion
profile, such as a controlled continuous or variable rotation rate,
between the starting and ending angular positions. Alternatively, the
controlled motion profile may be in the form of discrete angular steps
between the starting and ending angular positions.
FIGS. 10 and 11 illustrate starting and ending angular positions that may
be employed, with FIG. 10 illustrating the starting angular position and
FIG. 11 illustrating the ending angular position. In this illustrated
embodiment, the stream of processing fluid 130 is initially directed to a
central portion of the workpiece 25 as in FIG. 10. Reactor head 30 and the
corresponding workpiece 25 are then rotated through one or more angular
positions to reach the ending angular position shown in FIG. 11 in which
the stream of processing fluid 130 is directed for initial contact with a
peripheral portion of the workpiece 25.
Although, as noted above, the present invention is suitable for use in a
wide range of microelectronic workpiece processes, it is particularly
well-suited for use in microelectronic workpiece electroplating. After
plating a wafer, the surface of the wafer that has been exposed to the
plating solution is wetted with plating solution. The contact assembly and
corresponding barrier seal are also wetted at the seal interface with the
wafer. This condition is difficult to solve due to conflicting
requirements. The wafer needs to remain wetted until the plating solution
can be neutralized by deionized water or another neutralizer. The contact
seal, on the other hand, needs the residual solution removed or dried to
prevent migration of the plating solution to the sealed area, and
ultimately behind it, during product removal. Simply drying this residual
plating solution is not an option to the corrosive/oxidizing effect drying
has on the plated film. Such problems are addressed by rinsing the wafer
and seal interface before the wafer is removed from then reactor. Also, it
has been found to be desirable to occasionally rinse the seal and
electrical contact in the absence of a wafer to assist in preventing a
buildup of copper salts.
Numerous modifications may be made to the foregoing system without
departing from the basic teachings thereof. Although the present invention
has been described in substantial detail with reference to one or more
specific embodiments, those of skill in the art will recognize that
changes may be made thereto without departing from the scope and spirit of
the invention as set forth in the appended claims.
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