U.S. patent application number 11/838453 was filed with the patent office on 2008-05-15 for microelectronic workpiece processing tool including a processing reactor having a paddle assembly for agitation of a processing fluid proximate to the workpiece.
This patent application is currently assigned to Semitool, Inc.. Invention is credited to Kyle M. Hanson, Thomas H. Oberlitner.
Application Number | 20080110751 11/838453 |
Document ID | / |
Family ID | 23892214 |
Filed Date | 2008-05-15 |
United States Patent
Application |
20080110751 |
Kind Code |
A1 |
Oberlitner; Thomas H. ; et
al. |
May 15, 2008 |
Microelectronic Workpiece Processing Tool Including A Processing
Reactor Having A Paddle Assembly for Agitation of a Processing
Fluid Proximate to the Workpiece
Abstract
An integrated tool is provided including at least one workpiece
processing station having a paddle assembly. In accordance with
another independent aspect of the present invention, the workpiece
processing station is adapted for adjusting the level of the
processing fluid relative to a workpiece, wherein the portion of
the workpiece to be processed and possibly the paddle is
selectively immersed within the processing fluid. In accordance
with a further independent aspect of the present invention, a
paddle is provided for use proximate to a workpiece in a workpiece
processing station. The paddle includes a one or more sets of
delivery ports and one or more sets of fluid recovery ports. In at
least one embodiment, the paddle provides for agitation of a
processing fluid proximate to the surface of the workpiece. In at
least another embodiment, the paddle provides for the delivery
and/or recovery of one or more fluids to the portion of the
workpiece to be processed. One aspect of the present invention
enables the fluids supplied to the workpiece by the paddle to be
limited to the space located between the workpiece and the paddle,
thus avoiding mixing of these fluids with the processing fluid
located within the bowl assembly not supplied by the paddle.
Inventors: |
Oberlitner; Thomas H.;
(Kalispell, MT) ; Hanson; Kyle M.; (Kalispell,
MT) |
Correspondence
Address: |
PERKINS COIE LLP
P.O. BOX 1247, PATENT-SEA
SEATTLE
WA
98111-1247
US
|
Assignee: |
Semitool, Inc.
Kalispell
MT
|
Family ID: |
23892214 |
Appl. No.: |
11/838453 |
Filed: |
August 14, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10367100 |
Feb 14, 2003 |
7294244 |
|
|
11838453 |
|
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|
09476526 |
Jan 3, 2000 |
6547937 |
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10367100 |
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Current U.S.
Class: |
204/273 |
Current CPC
Class: |
H01L 21/67005 20130101;
C25D 17/001 20130101; H01L 21/67023 20130101; C25D 5/08 20130101;
C25D 21/10 20130101; C25D 17/007 20130101; H01L 21/67086 20130101;
H01L 21/6723 20130101; H01L 21/67057 20130101; C25D 7/123
20130101 |
Class at
Publication: |
204/273 |
International
Class: |
C25B 9/00 20060101
C25B009/00 |
Claims
1-57. (canceled)
58. An apparatus for processing a microelectronic workpiece,
comprising: a head assembly configured to support a microelectronic
workpiece for processing at a process location; and a paddle
assembly having a paddle positioned to move relative to the process
location, the paddle having a first fluid aperture in fluid
communication with a first fluid channel internal to the paddle,
the paddle further having a second fluid aperture in fluid
communication with a second fluid channel internal to the paddle,
the first and second fluid channels being sealably separated from
each other in the paddle assembly.
59. The apparatus of claim 58 wherein the first fluid aperture is
configured to deliver fluid to the process location and wherein the
second fluid aperture is configured to retrieve fluid from the
process location.
60. The apparatus of claim 58 wherein the head assembly includes a
first electrode positioned to contact the microelectronic workpiece
when the head assembly carries the microelectronic workpiece, the
first electrode being coupleable to an electrical potential at a
first polarity, and wherein the apparatus further comprises a
second electrode spaced apart from the first electrode and the
paddle assembly, the second electrode being coupleable to an
electrical potential at a second polarity opposite the first
polarity.
61. The apparatus of claim 58, further comprising: an input/output
station configured to receive a plurality of microelectronic
workpieces; and a robot positioned between the input/output station
and the head assembly to move microelectronic workpieces between
the input/output station and the head assembly.
62. The apparatus of claim 58 wherein the paddle is an elongated
paddle having a first end and a second end, and wherein the paddle
assembly includes: a first paddle support to carry the paddle
positioned toward the first end of the paddle; a second paddle
support to carry the paddle positioned toward the second end of the
paddle; and a drive unit operatively coupled to the paddle to move
the paddle relative to the process location.
63. The apparatus of claim 62 wherein the first paddle support
includes a first generally cylindrical guide rod and wherein the
second paddle support includes a second generally cylindrical guide
rod.
64. The apparatus of claim 62 wherein the drive unit includes a
first powered portion coupled toward the first end of the paddle,
and wherein the drive unit includes a second powered portion
coupled toward the second end of the paddle.
65. The apparatus of claim 62 wherein the first paddle support
includes a first generally cylindrical guide rod and wherein the
second paddle support includes a second generally cylindrical guide
rod, and wherein the paddle is slideably carried by the first and
second guide rods.
66. The apparatus of claim 62 wherein the first support member
includes a first travel guide and the second support member
includes a second travel guide.
67. The apparatus of claim 62 wherein the first support member
includes a first travel guide that is slideably received in an
aperture of a first connecting assembly connected toward the first
end of the paddle, and wherein the second support member includes a
second travel guide that is slideably received in an aperture of a
second connecting assembly connected toward the second end of the
paddle.
68. The apparatus of claim 58, further comprising a drive unit
configured to drive the paddle linearly back and forth relative to
the process location.
69. The apparatus of claim 68, further comprising a programmable
control system operatively coupled to the drive unit to direct
operation of the drive unit.
70. The apparatus of claim 68 wherein the drive unit includes a
motor and a belt operatively coupled between the motor and the
paddle.
71. The apparatus of claim 58, further comprising an electrode
carried by the head assembly and configured to contact the
microelectronic workpiece when the microelectronic workpiece is
supported by the head assembly, the electrode being coupleable to
an electrical potential.
72. The apparatus of claim 58 wherein the head assembly is
configured to carry a microelectronic workpiece in a generally
horizontal orientation for processing and wherein the paddle is
positioned below the head assembly.
73. The apparatus of claim 58, further comprising a vessel, and
wherein the vessel includes a weir over which the processing liquid
flows, the weir defining an exposed surface of the processing
liquid in the vessel, the exposed surface having a first width, and
wherein the head assembly is positioned over the weir and is
movable toward and away from the weir to position the
microelectronic workpiece in contact with the exposed liquid
surface, the head assembly and the microelectronic workpiece having
a second width at the exposed surface that is no greater than the
first width.
74. The apparatus of claim 73, further comprising a wall extending
upwardly from a position above the weir, the wall having a third
width that is no greater than the first width, the head assembly
being movable alongside the wall to contact the microelectronic
workpiece with the processing liquid.
75. The apparatus of claim 73, further comprising a current thief
positioned proximate to the head assembly and the weir to redirect
plating material from an outer edge of the microelectronic
workpiece.
76. The apparatus of claim 58, further comprising a current thief
positioned proximate to the head assembly to redirect plating
material from an outer edge of the microelectronic workpiece.
77. An apparatus for processing a microelectronic workpiece,
comprising: a head assembly configured to carry a microelectronic
workpiece for processing at a process location; an elongated paddle
having a first end and a second end and being positioned to move
relative to the process location, wherein the paddle has at least
one fluid delivery port oriented toward the microelectronic
workpiece when the microelectronic workpiece is carried by the head
assembly, and wherein the paddle further includes at least one
fluid recovery port; a first paddle support to carry the paddle
positioned toward the first end of the paddle; a second paddle
support to carry the paddle positioned toward the second end of the
paddle; and a drive unit operatively coupled to the paddle to move
the paddle relative to the process location.
78. The apparatus of claim 77, further comprising: an input/output
station configured to receive a plurality of microelectronic
workpieces; and a robot positioned between the input/output station
and the head assembly to move microelectronic workpieces between
the input/output station and the head assembly.
79. An apparatus for processing a microelectronic workpiece,
comprising: a head assembly configured to carry a microelectronic
workpiece in a generally horizontal orientation for processing at a
process location; a paddle assembly having a paddle positioned to
move relative to the process location, wherein the paddle has at
least one fluid delivery port oriented toward the microelectronic
workpiece when the microelectronic workpiece is carried by the head
assembly, and wherein the paddle further includes at least one
fluid recovery port; and a drive unit operatively coupled to the
paddle to move the paddle relative to the process location.
80. The apparatus of claim 79, further comprising: an input/output
station configured to receive a plurality of microelectronic
workpieces; and a robot positioned between the input/output station
and the head assembly to move microelectronic workpieces between
the input/output station and the head assembly.
81. The apparatus of claim 79 wherein the paddle has a first end
and a second end, and wherein the apparatus further comprises: a
first paddle support to carry the paddle positioned toward the
first end of the paddle, the first paddle support including a first
generally cylindrical guide rod; and a second paddle support to
carry the paddle positioned toward the second end of the paddle,
the second paddle support including a second generally cylindrical
guide rod.
82. The apparatus of claim 79 wherein the drive unit includes a
first powered portion coupled toward a first end of the paddle, and
wherein the drive unit includes a second powered portion coupled
toward a second end of the paddle.
83. The apparatus of claim 79 wherein the drive unit is configured
to drive the paddle linearly back and forth relative to the process
location.
84. The apparatus of claim 79, further comprising an electrode
carried by the head assembly and configured to contact the
microelectronic workpiece when the microelectronic workpiece is
supported by the head assembly, the electrode being coupleable to
an electrical potential.
85. The apparatus of claim 79, further comprising a programmable
control system operatively coupled to the drive unit to direct
operation of the drive unit.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
BACKGROUND OF THE INVENTION
[0003] The present invention generally relates to an apparatus for
processing a microelectronic workpiece. More particularly, the
present invention is directed to a microelectronic workpiece
processing tool having a reactor that includes a paddle assembly,
which moves relative to the workpiece for facilitating the
processing of a microelectronic workpiece. For purposes of the
present application, a microelectronic workpiece is defined to
include a substrate upon which microelectronic circuits or
components, data storage elements or layers, and/or
micro-mechanical elements are formed.
[0004] During the processing of a workpiece, the portion of the
workpiece to be processed is often exposed to a processing fluid
designed to bring about a desired alteration of the surface of the
workpiece. In many instances, the alteration of the surface of the
workpiece involves a particular chemical reaction that takes place
at the surface. As the reaction takes place at the surface, the
reactants from the processing fluid are consumed and/or chemical
byproducts are released into the fluid. In order to maintain the
desired forward reaction at the workpiece surface at optimal
levels, it is often necessary to continuously replenish the
processing fluid proximate the workpiece surface that is
processed.
[0005] One known technique for replenishing the processing fluid
proximate the workpiece surface includes spinning the workpiece to
agitate the processing fluid near the surface of the workpiece. In
this way, relatively fresh processing fluid whose chemical
concentrations have not yet been significantly affected by the
localized reactions taking place at the surface of the workpiece
will continuously replace the spent processing fluid.
[0006] There are instances, however, in which spinning a workpiece
relative to the processing fluid is undesirable. For example,
rotation of the workpiece may be undesirable when electroplating
certain materials onto a workpiece where the deposited material
must be uniformly aligned in a particular magnetically polarized
direction. Such processes are used in the formation of certain
read/write heads. In such processes, an external magnetic field is
applied to the processing area, which magnetically aligns the
material to be plated prior to the material being deposited. If the
workpiece within the magnetic field were to be spun, the
orientation of the magnetic field with respect to the workpiece
would be continuously changing. A continuously changing orientation
of the magnetic field would disrupt the formation of the desired
magnetically uniform deposition.
[0007] In view of the foregoing, other methods for agitating the
processing fluid have been developed for insuring the continuous
replenishment of the processing fluid proximate the workpiece
surface under process. Namely, a paddle is used that physically
moves through the processing fluid relative to and proximate to the
workpiece surface to thereby agitate the processing fluid near the
surface. Such agitation has the effect of replenishing the
processing fluid proximate the workpiece surface.
[0008] In addition to agitating the processing fluid, the paddle
motion has been separately developed to limit processing to a
portion of the area of the workpiece surface that is to be
processed. In essence, this provides localized control of the
processing of the workpiece, including localized control of the
application of processing fluids. To this end, the paddle is
directed to move across the workpiece in a predefined manner,
selectively applying chemistry and/or processing power at any one
time to only a portion of the total area to be processed.
Techniques which provide both linear and spiral movement of the
paddle relative to the workpiece have been previously
developed.
[0009] In these instances, concurrent processing of the entire
portion of the workpiece to be processed can produce undesirable or
incomplete results. In at least one instance a paddle has been used
to produce a controlled linear flow of the processing across the
area to be processed. The paddle is used to selectively supply
processing fluid to only a portion of the surface at any one time.
The direction of the processing is similarly controlled. The
direction of the processing is controlled in processes where the
specific order in which the separate portions of the surface are
processed is important.
[0010] One example of where the application of processing fluid for
processing a workpiece in a controlled fashion has been used is in
the electroetching or removal of a material from the surface of the
workpiece. In such instances, the material being removed provides
the conductive path for supplying a necessary portion of the
processing power. As a result, the removal of material must be
performed in a generally controlled manner, since global removal of
the entire conductive surface of the workpiece to be processed
would result in the etching away of portions of the conductive
layer located proximate to the source of processing power prior to
those areas located remote from the processing power source. This
would result in electrical isolation of such remote areas from the
processing power prior to the completion of the electroetch in
those areas. By selectively applying the etching process and
beginning with the areas furthest from the processing power source,
the likelihood of electrically isolating a region prior to
completing the electroetching in that region is reduced.
[0011] In addition to supplying processing fluid to the surface of
the workpiece, previous paddles have been similarly equipped with a
conductive surface coupled to a power source. Accordingly,
processing power can be supplied to the paddle for the purpose of
acting as an electrode in an electrochemical process.
[0012] However, in known systems, the processing fluid supplied by
the paddle has been allowed to run off of the workpiece and the
paddle into the processing chamber. Effectively the processing
fluid associated with the electroetch process is then unavoidably
present throughout the processing chamber. The presence of
processing fluid throughout the processing chamber may preclude the
use of the same processing chamber for use in a subsequent
processing step, especially where a different processing fluid is
used. The processing fluid present from the preceding step may
provide a source of chemical contamination or may result in the
mixing of chemicals, which may produce undesirable results.
Accordingly, under these circumstances, it may be very difficult to
use the same processing chamber for other processing steps. As
such, further processing reactors must be incorporated into the
processing tool in order to execute the further processing steps.
This results in an increased cost for the tool as well as an
increase in the required tool footprint.
[0013] In view of the cross-contamination issues noted above, the
development of paddles for providing localized processing of the
surface of the workpiece has proceeded independent of the
development of paddles for agitating a processing fluid proximate
to the workpiece. The risk of cross contamination of the
chemistries between each of the steps renders the co-development of
these differing approaches counter-intuitive. As a result, the use
of a paddle assembly within a given processing chamber has been
effectively limited to a single processing step or purpose. The
present inventors, however, have ignored such conventional wisdom
and have developed a reactor for processing a microelectronic
workpiece that employs a multi-purpose paddle assembly design that
effectively reduces and/or eliminates many of the
cross-contamination issues. In addition to the unique paddle
assembly design, the reactor further incorporates unique features
that enable it to be used to affect multiple processes at a single
processing station. Still further, novel microelectronic workpiece
processes and processing sequences naturally evolve from the unique
reactor and/or paddle assembly design.
BRIEF SUMMARY OF THE INVENTION
[0014] In accordance with one independent aspect of the present
invention an integrated tool for processing a workpiece is set
forth including at least one processing station. The processing
station comprises a bowl assembly, and a head assembly for
receiving a workpiece and orienting the workpiece within the bowl
assembly. The processing station further includes a paddle
assembly, which includes a paddle adapted for movement relative to
the workpiece when the workpiece is disposed on the head assembly
within the bowl assembly. The processing station further comprises
a fluid inlet for supplying processing fluid to the bowl assembly,
and at least one fluid path for adjusting the position of the level
of the processing fluid relative to the workpiece between a first
position and a second position wherein when in a first position at
least the portion of the workpiece to be processed is immersed
within the processing fluid, and wherein when in the second
position the portion of the workpiece to be processed is no longer
immersed within the processing fluid. The position of the level of
the processing fluid relative to the workpiece between a first
position and a second position is controlled by a fluid level
control mechanism. The fluid level control mechanism selectively
controls the relative level of the processing fluid with respect to
the workpiece by controlling the at least one fluid path.
[0015] In accordance with another independent aspect of the present
invention a processing station is set forth for processing a
workpiece. The processing station comprises a bowl assembly, and a
head assembly for receiving a workpiece and orienting the workpiece
within the bowl assembly. The processing station further includes a
paddle assembly, which includes a paddle adapted for movement
relative to the workpiece when the workpiece is disposed on the
head assembly within the bowl assembly. The processing station
further comprises a fluid inlet for supplying processing fluid to
the bowl assembly, and at least one fluid path for adjusting the
position of the level of the processing fluid relative to the
workpiece between a first position and a second position wherein
when in a first position at least the portion of the workpiece to
be processed is immersed within the processing fluid, and wherein
when in the second position the portion of the workpiece to be
processed and possibly the paddle is no longer immersed within the
processing fluid. The position of the level of the processing fluid
relative to the workpiece to between a first position and a second
position is controlled by a fluid level control mechanism. The
fluid level control mechanism selectively controls the relative
level of the processing fluid with respect to the workpiece by
controlling the at least one fluid path.
[0016] In accordance with one embodiment of the processing station,
the paddle supplies a fluid to the space between the paddle and the
workpiece and recovers the fluid. The supplied fluid is confined to
the space between the paddle and the workpiece prior to the fluid
being recovered by the paddle.
[0017] In accordance with yet another independent aspect of the
present invention a paddle for use proximate to a workpiece in a
workpiece processing station is set forth. The paddle includes a
surface, which faces the workpiece and comprises one or more sets
of fluid delivery ports, and one or more sets of fluid recovery
ports.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0018] FIG. 1 is an isometric view of an integrated processing tool
in accordance with one embodiment of the present invention in which
the tool is shown with several panels removed.
[0019] FIG. 2 is a further isometric view of the integrated
processing tool shown in FIG. 1.
[0020] FIG. 3 is a top plan view of the tool deck of the embodiment
of the integrated processing tool shown in FIGS. 1 and 2.
[0021] FIG. 4 is an isometric view of one embodiment of a
processing station suitable for use in the embodiment of the tool
shown in FIGS. 1-3, wherein the processing station incorporates one
embodiment of a paddle assembly constructed in accordance with one
aspect of the present invention.
[0022] FIG. 5 is a front sectional view of the embodiment of the
processing station shown in FIG. 4.
[0023] FIG. 6 is a side sectional view of the embodiment of the
processing station shown in FIGS. 4 and 5.
[0024] FIG. 7 is a side, cross-sectional view of one embodiment of
a bowl assembly that is suitable for use in the processing station
shown in FIGS. 4-6.
[0025] FIG. 8 is an isometric view of the embodiment of the bowl
assembly shown in FIG. 7.
[0026] FIG. 9 is a top isometric view of one embodiment of an anode
assembly suitable for use in the bowl assembly shown in FIGS. 7 and
8.
[0027] FIG. 10 is a bottom isometric view of the anode assembly
shown in FIG. 9.
[0028] FIG. 11 is a top isometric view of the anode assembly shown
in FIGS. 9 and 10, wherein the anode assembly includes a square
anode.
[0029] FIG. 12 is an exploded isometric view of the embodiment of
the paddle assembly used the processing station shown in FIGS.
4-6.
[0030] FIG. 13 is an exploded isometric view of one embodiment of a
chassis sub-assembly suitable for use in the paddle assembly shown
in FIG. 12.
[0031] FIG. 14 is an exploded isometric view of one embodiment of a
spring float assembly upon which the chassis sub-assembly shown in
FIG. 13 rests.
[0032] FIG. 15 is a side, cross-sectional view of the spring float
assembly shown in FIG. 14.
[0033] FIG. 16 is an isometric view of one embodiment of a paddle
actuation sub-assembly that may be used in the paddle assembly
shown in FIG. 12, with a silhouette of a circular workpiece shown
for reference purposes.
[0034] FIG. 17 is a partial isometric view of the paddle actuation
sub-assembly shown in FIG. 16.
[0035] FIG. 18 is a top plan view of one embodiment of a paddle for
use in the paddle assembly shown in FIG. 12.
[0036] FIG. 19 is a cross-sectional side view of the embodiment of
the paddle shown in FIG. 18.
[0037] FIG. 20 is an enlarged cross-sectional end view of the
embodiment of the paddle shown in FIGS. 18 and 19.
[0038] FIG. 21 is an isometric view of one embodiment of a head
assembly suitable for use in the processing station shown in FIGS.
4-6.
[0039] FIG. 22 is a side, cross-sectional view of the head assembly
shown in FIG. 21.
[0040] FIG. 23 is an exploded isometric view of one embodiment of a
workpiece engagement mechanism for use in the head assembly shown
in FIGS. 21 and 22.
[0041] FIG. 24 is a cross-sectional side view of the workpiece
engagement mechanism shown in FIG. 23.
[0042] FIG. 25 is an isometric top view of one embodiment of a
current thief assembly suitable for use in connection with the head
assembly shown in FIGS. 21 and 22.
[0043] FIG. 26 is an isometric/cut-away view of the embodiment of
the head assembly, shown in FIGS. 21 and 22, with the embodiment of
the current thief assembly, shown in FIG. 25, attached thereto.
[0044] FIG. 27 is a cross-sectional side view of a workpiece in
contact with the embodiment of the current thief assembly shown in
FIG. 26, and the embodiment of the workpiece engagement mechanism,
shown in FIGS. 23 and 24.
[0045] FIG. 28 is an isometric view of the embodiment of the
processing station shown in, FIGS. 4-6, wherein the portion of the
paddle actuation sub-assembly corresponding to FIG. 17 has been
removed and placed upon the head assembly, shown in FIGS. 21 and
22, and where the head assembly has been oriented in a first
position for receiving a workpiece.
[0046] FIG. 29 is a partial, cross-sectional side view of the
embodiment of the paddle, shown in FIGS. 18-20, and a corresponding
workpiece, in which the paddle is supplying a fluid to the
workpiece.
DETAILED DESCRIPTION OF THE INVENTION
[0047] FIGS. 1 and 2 illustrate corresponding isometric views of an
integrated processing tool 10, shown with several panels removed.
The integrated processing tool 10 incorporates multiple processing
stations 12. Workpieces are generally received within the
integrated processing tool 10, via cassettes containing one or more
workpieces. The cassettes containing the workpieces enter and exit
the integrated processing tool 10, via a door in the side of the
integrated processing tool 10, where the cassettes are received by
a pair of lift/tilt mechanisms 14. The lift/tilt mechanisms 14
position and orient the cassettes to provide access to the
individual workpieces contained therein. A linear conveyor system
16 receives the individual workpieces and relays them to the
various processing stations 12.
[0048] Additional details in connection with the lift/tilt
mechanism 14 and the linear conveyor system 16 are provided in
connection with U.S. patent application Ser. No. 08/990,107,
entitled "Semiconductor Processing Apparatus having Linear Conveyor
System", the disclosure of which is incorporated herein by
reference.
[0049] In accordance with one embodiment, the linear conveyor
system includes two wafer transport units 18 or robot arms, which
move independently with respect to one another. One of the wafer
transport units 18 handles dry workpieces, while the other wafer
transport unit 18 handles wet workpieces.
[0050] The illustrated integrated processing tool 10 further
includes a pre-aligner 20, which establishes the alignment of the
workpiece with respect to the integrated processing tool 10 by
referencing a known registration notch on each of the workpieces.
Prior to forwarding the workpiece to any of the other processing
stations, the wafer is placed within the pre-aligner 20 and the
registration notch is located. After the pre-aligner 20 locates the
registration notch, the pre-aligner 20 then makes any necessary
adjustments of the orientation and alignment of the workpiece for
facilitating proper subsequent handling. The integrated processing
tool 10 can incorporate any one of several known pre-aligners
commonly available. An example of one such suitable pre-aligner for
use in the integrated processing tool 10, as presently configured,
includes a prealigner manufactured and sold by PRI Automation,
Equipe Division, under the model number PRE-201-CE.
[0051] The integrated processing tool 10 can further include
various combinations and arrangements of individual processing
stations. One such configuration which is consistent with the
features of the present invention is illustrated in FIG. 3. In
connection with FIG. 3, a description of an example of a
corresponding process suitable for handling a workpiece pursuant to
the illustrated configuration is similarly discussed. Specifically,
FIG. 3 illustrates a top plan view of the tool deck 22 of the
integrated processing tool 10, shown in FIGS. 1 and 2, including
multiple individual processing stations 12.
[0052] As previously noted, the integrated processing tool 10
includes a pair of lift/tilt mechanisms 14, a linear conveyor
system 16 including two independent wafer transport units 18, and a
pre-aligner 20. The integrated processing tool 10 further includes
a pair of SRD modules 24 (Spin, Rinse, Dry), a pair of pre-plate
modules 26, a pair of magnetic processing stations 28, and one
non-magnetic processing station 30.
[0053] The pre-plate modules 26 generally initially prepare the
surface of the workpiece for further processing by spraying a mild
acid or de-ionized water for wetting the surface of the workpiece
and removing the oxides. The SRD modules 24 generally clean the
workpiece by separately rinsing and drying the workpiece, after the
workpiece has been processed. The non-magnetic processing station
30 is similar to the magnetic processing station 28, with the
exception that the non-magnetic station 30 does not include a
permanent magnet positioned around the processing station for
encompassing the workpiece in a magnetic field during processing.
Both types of processing stations 28 and 30 will be described in
greater detail below in connection with the magnetic processing
station 28.
[0054] It is important to note that the illustrated configuration
represents one possible configuration, which is suitable for
practicing the present invention, many other configurations would
similarly be suitable.
[0055] As presently configured the integrated processing tool 10 is
well suited to performing a process for producing read/write heads,
which includes the following steps: [0056] 1. receiving a workpiece
from a cassette and forwarding the workpiece to the pre-aligner 20;
[0057] 2. receiving the pre-aligned workpiece from the pre-aligner
20 and forwarding the workpiece to a pre-plate processing module
26, wherein the workpiece is wet using a mild acid; [0058] 3.
without drying the workpiece, forwarding the workpiece to one of
the magnetic or non-magnetic processing stations 28 or 30, wherein
within each of the processing stations the workpiece is subjected
to a plating step wherein the processed surface of the workpiece is
immersed within a plating fluid and wherein during the plating step
the processing fluid is agitated by a paddle assembly; [0059] 4.
without removing the workpiece from the magnetic or non-magnetic
processing station 28 or 30, providing an in-situ rinse wherein the
relative position of the workpiece with respect to the plating
fluid is altered so as to no longer be immersed within the plating
fluid, and using the paddle assembly for simultaneously applying a
rinse solution and recovering the same; [0060] 5. repeating as
often as necessary steps 3 and 4 by moving the workpiece directly
between any one of the three magnetic or non-magnetic processing
stations 28 or 30, for building up the desired multiple laminate
layers; [0061] 6. after the last plating/in-situ rinse phase is
performed, forwarding the workpiece to the SRD module 24 dedicated
to rinsing; [0062] 7. after rinsing the workpiece, forwarding the
workpiece to the SRD module 24 dedicated to drying; and [0063] 8
after drying the workpiece, returning the workpiece to the
corresponding workpiece cassette at one of the lift/tilt mechanisms
14.
[0064] In connection with producing read/write heads the two
magnetic processing stations 28, typically include chemistry for
plating a nickel-iron alloy, wherein each of the stations 28
includes a solution of nickel and iron ions of differing
concentrations. The non-magnetic processing station 30 typically
includes chemistry for plating one of palladium-nickel,
cobalt-nickel, or copper.
[0065] By plating the nickel-iron alloy in a magnetic processing
station 28, a metallized layer, which is magnetically uniform, is
produced. The details in connection with the magnetic processing
station 28 are provided below. As previously noted producing a
layer of material having a uniform magnetic layer precludes
spinning the wafer within the magnetic field. Consequently, an
approach for agitating the plating fluid using a paddle agitator
has been developed and is described in greater detail below. The
specific approach developed is additionally capable of providing
for a rinse step within the same processing station 12, which does
not adversely affect the processing fluid similarly located within
the processing station 12, in this case a processing station 28 or
30. Furthermore the rinse phase within the same processing station
12 enables the workpiece to be forwarded directly to the next
appropriate processing station 12 without first performing a
separate rinse phase.
[0066] The below noted paddle design is not limited to being used
in connection with a combination plating phase/rinsing phase, but
could alternatively incorporate various other combinations of
processing steps, including combinations, which include more than
two unique steps.
[0067] FIG. 4 illustrates an isometric view of a magnetic
processing station 28, shown in FIG. 3, in accordance with the
present invention. As previously noted the non-magnetic processing
station 30 is identical to the magnetic processing station 28 with
the exception that the permanent magnet producing the magnetic
field for magnetically aligning the plated material in the magnetic
processing station 28 would not be present.
[0068] The magnetic processing station 28 includes a bowl assembly
32, within which a processing fluid is retained. Located around
three sides of the bowl assembly is a `U`-shaped permanent magnet
34. The permanent magnet 34 includes two sections comprised of a
suitably strong rare earth magnet 36. The two sections are located
at opposite legs of the "U"-shaped magnet. In at least one
embodiment, the rare earth magnet sections 36 are each comprised of
a neodymium-iron-boron magnet (NdFeB). The two rare earth sections
36 are coupled together via a magnet section 38 comprising a 1018
ferrous material. The magnet section 38, comprising the 1018
ferrous material, provides a return path for the magnetic field
produced between the rare earth magnetic sections 36.
[0069] Magnets made from other types of materials may also be
suitable. Furthermore, while the disclosed embodiment uses a
permanent magnet, an electro-magnet could also alternatively be
used.
[0070] Resting within the bowl assembly 32 is a paddle assembly 40,
which is discussed below in greater detail beginning with FIG. 12.
Additionally, extending into the bowl assembly 32 is a head
assembly 42, similarly discussed below in greater detail beginning
with FIG. 21. The head assembly 42 receives a workpiece and
reorients and/or repositions the workpiece relative to the bowl
assembly 32. The movement of the head assembly is facilitated by a
lift and rotate assembly 44. An example of a lift and rotate
assembly is described in greater detail in connection with U.S.
patent application Ser. No. 09/351,980, entitled "Lift and Rotate
Assembly for Use in a Workpiece Processing Station and a Method of
Attaching the Same", the disclosure of which is incorporated herein
by reference. In accordance with one embodiment the lift and rotate
assembly 44 reorients the head assembly 42, so as to orient the
side of the workpiece to be processed process side down in the
processing fluid. Furthermore the level of the workpiece is raised
and lowered by the lift and rotate assembly 44 with respect to the
level of the processing fluid.
[0071] FIG. 5 illustrates a front sectional view of the processing
station 28, shown in FIG. 4. In addition to the features noted
above in connection with FIG. 4, the front sectional view further
illustrates an array of diffuser holes 46 through which the
processing fluid enters the bowl assembly 32. In accordance with
the disclosed embodiment the processing fluid enters the bowl
assembly 32 via a pump coupled to a fluid reservoir (not
shown).
[0072] Additionally shown is an anode 48 located near the base of
the bowl assembly. In connection with plating a nickel-iron alloy
identified in the example process described above, and in
accordance with at least one embodiment, the anode 48 is a
consumable nickel anode. During processing, nickel ions are
replenished into the processing fluid from the consumable anode.
Iron ions are replenished by adding ferrous chloride to the
recirculated processing fluid.
[0073] Furthermore in accordance with one embodiment of the present
invention the lift and rotate assembly 44 includes a variable lift
controller, wherein the lift and rotate assembly 44 can further
adjust the degree of lift dependent upon the actual or determined
location of the top surface of the consumable anode 48. As more of
the anode 48 dissolves into the processing fluid, the lift and
rotate assembly 44 adjusts the relative level of the workpiece to
maintain a nearly constant distance between the anode 48 and the
workpiece. Specifically, the lift and rotate assembly 44 could
lower the workpiece an amount equivalent to the change in height of
the consumable anode 48. In this way the field strength, which is
related to the distance between the anode 48 and the workpiece, can
be maintained at a relatively constant level.
[0074] In accordance with the disclosed embodiment, the anode 48
receives processing power via a conductive path 50 and an
electrical connection 52 extending through the bottom of the bowl
assembly 32 and coupling to the bottom of the anode 48.
[0075] Furthermore additional diffuser holes 46 are located behind
the anode 48, through which the processing fluid enters the bowl
assembly 32, and which can not be seen in the figures shown.
[0076] FIG. 6 illustrates a side sectional view of the magnetic
processing station 28, shown in FIGS. 4 and 5. In addition to the
features previously discussed in connection with FIGS. 4 and 5,
FIG. 6 further illustrates the flow path 54 of the processing fluid
entering the bowl assembly 32 via the diffuser holes 46 (FIG. 5),
and the flow path 56 of the processing fluid exiting the bowl
assembly 32. The processing fluid enters the bowl assembly 32 via a
fluid inlet 57. The processing fluid exits the bowl assembly via a
drainage path 58. The fluid flow paths can be seen even more
clearly in connection with FIGS. 7 and 8, which separately
illustrates the bowl assembly 32.
[0077] FIGS. 7 and 8 illustrates the bowl assembly 32, shown in
FIGS. 4-6. As noted above, the fluid flow paths 54 and 56 are
similarly shown. As further illustrated in FIG. 7 the flow path 56
exiting via the drainage path 58, exits the bowl assembly 32 over a
weir 60. The weir 60 helps establish the height of the processing
fluid as any fluid which is higher than the weir 60 will travel
toward the weir 60 and exit the drainage path 58. As can be seen
from FIG. 6 the level of the weir 60 is such that when the weir 60
provides the only drainage path 58 for the processing fluid, the
fluid level will rise to a level higher than the bottom surface of
the head assembly 42, when in a lowered position and any workpiece
coupled thereto.
[0078] The bowl assembly 32 additionally provides for a further
exit flow path 62 through an opening 64 in tube 66, which can be
selectively opened, and which is lower then the flow path over the
weir 60. The further exit flow path 62 is coupled to a further
drainage path 68 and subsequently to a switch valve (not shown).
Once opened the further exit flow path 62 will influence the level
of the processing fluid in the bowl assembly 32 to a level
consistent with the height of tube 66 and the opening 64. In this
way the relative level of the processing fluid with respect to the
bottom of the head assembly 42 and a workpiece coupled thereto can
be adjusted so that the workpiece is no longer immersed in the
processing fluid, without raising the head assembly 42.
[0079] When the workpiece is maintained at a level wherein the
workpiece is immersed within the processing fluid, a processing
step can occur, which includes the exposure of the workpiece to the
processing fluid. When the fluid level of the processing fluid is
adjusted relative to the workpiece so as to no longer immerse the
workpiece within the processing fluid, a processing step can occur,
which is independent of the processing fluid located within the
bowl assembly 32.
[0080] Further shown in connection with FIG. 7, is a portion of a
hinge assembly 70 coupled to the anode 48, and a latch 72 coupled
to the anode 48 at the opposite end of the hinge assembly 70. In
accordance with one embodiment, the hinge assembly 70 comprises a
pair of approximately C-shaped connectors 74 coupled to an anode
carrier 76 (more clearly shown in connection with FIGS. 9-11). The
pair of approximately C-shaped connectors 74 separately engage a
pair of rods 78 extending from opposite sides 80 of the bowl
assembly 32.
[0081] The hinge assembly 70 helps to restrict the angle of
movement of the anode 48 during installation and removal. This can
be beneficial in view of the strong magnetic forces a nickel anode
or an anode formed from another magnetically conductive material
will be subject to from the magnet 34 located around the bowl
assembly 32. During installation and the removal of the anode 48, a
handle mechanism is temporarily attached to the anode 48 for
facilitating greater control of the anode 48 while moving the anode
48 within the magnetic field.
[0082] FIGS. 9-11 illustrate an anode assembly 80 for use in
connection with the bowl assembly 32, shown in FIGS. 7 and 8. The
anode assembly 80 includes an anode carrier 76, which is sized and
shaped to receive either a square anode or a circular anode. In
accordance with one embodiment, the magnetic processing station 28
and non-magnetic processing station 30 are configured to receive
either an approximately 4.5 inch square workpiece or an
approximately 6 inch round workpiece. The square anode would be
used in connection with a square workpiece, and a circular anode
would be used in connection with a circular workpiece.
[0083] The anode 48 is coupled to the anode carrier 76 via one or
more fasteners 82 connected through the bottom of the anode carrier
76. The anode carrier 76 further includes an opening 84 through
which an electrical connection 52 can be made to the bottom of the
anode 48 for supplying processing power thereto. The anode carrier
76 still further includes a latch platform 86 upon which a latch
can be hooked.
[0084] FIG. 12 illustrates an exploded isometric view of a paddle
assembly 40 for use in connection with the magnetic or non-magnetic
processing station 28 or 30, shown in FIGS. 4-6. The paddle
assembly includes a chassis sub-assembly 88, a paddle actuation
sub-assembly 90 which rests within the chassis sub-assembly 88, and
a shroud 92 for enclosing the paddle actuation sub-assembly 90. A
more detailed discussion concerning each of the noted
sub-assemblies are provided below in connection with FIGS.
13-20.
[0085] FIG. 13 illustrates an exploded isometric view of the
chassis sub-assembly 88 for the paddle assembly 40, shown in FIG.
12. As illustrated in FIG. 13, the exploded view of the chassis
sub-assembly 88 illustrates pulley rods 94 and various mounting
hardware 96 for attaching the pulley rods 94 to the chassis
sub-assembly 88. The pulley rods 94 provide a point of connection
for attaching corresponding pulleys 96 (FIGS. 12 and 17), which
will be discussed in greater detail in connection with FIG. 17.
Additionally coupled to the chassis sub-assembly 88 is mounting
hardware 98 for attaching a position sensor 100, shown in FIG.
12.
[0086] The chassis sub-assembly 88 further provides for mounting
pins 102, located at each corner of the chassis sub-assembly 88.
Each of the mounting pins 102 rest upon a corresponding spring
float assembly 104, shown in FIGS. 14 and 15, which is positioned
between the chassis sub-assembly 88 of the paddle assembly 40 and
the bowl assembly 32. The spring float assemblies 104 provide a
degree of float or self adjustment for positioning the paddle
assembly 40 with respect to the bowl assembly 32.
[0087] The spring float assembly 104 is shown in FIGS. 14 and 15.
FIG. 14 illustrates the spring float assembly 104 in an exploded
isometric view. FIG. 15 illustrates a cross sectional view of the
spring float assembly 104.
[0088] The spring float assembly 104 provides for a housing 106
having a central passageway 107, within which a spring float shaft
108 is received. At one end of the spring float shaft 108, the
shaft includes a portion 110, which is wider thereby restricting
motion of the shaft 108 past a specific point 112, illustrated in
FIG. 15, within the shaft having a narrower diameter. The shaft 108
is biased toward this point 112 by a spring 114 similarly located
within the central passageway 107 of the housing 106. The end of
the spring 114 opposite the point of contact with the shaft 108 is
fixed with respect to the housing 106 by a retainer 116.
[0089] The retainer 116 is held in place by a snap ring 118. The
snap ring 118 is a discontinuous circular ring, which may be
squeezed so as to deform the ring so as have a smaller deformed
diameter. When deformed, the snap ring 118 can slide into the
bottom opening 120 of the housing 106 past the more restrictive
shaft diameter, and expand and fit within a groove 122 located in
the wall of the central passageway 107 having a larger diameter,
which is proximate to the opening 120.
[0090] While the spring float assembly 104 can be a separate
assembly, as illustrated in connection with FIGS. 14 and 15, the
spring float assembly 104 can also be integrated as part of the
paddle assembly 40 or the bowl assembly 32.
[0091] A paddle actuation sub-assembly 90 and/or portions thereof
are illustrated in connection with FIGS. 16 and 17. As shown in
connection with FIG. 16, the paddle actuation sub-assembly 90
includes pulleys 96, which ride upon corresponding pulley rods 94,
also shown in connection with FIG. 13. The pulleys 96 and
corresponding pulley rods 94 are located at three of the four
corners of the paddle actuation sub-assembly 90. At the fourth
corner of the paddle actuation sub-assembly 90 is a motor 124.
[0092] The adjacent pulleys 96, and one of the pulleys adjacent to
the motor 124 and the motor 124 are attached to one another via
corresponding drive belts 126. In accordance with one embodiment,
the gear ratios of the pulleys are one to one, such that the rates
of movement of the drive belts 126 are substantially equivalent.
The pulleys 96 and the drive belts 126 enable the force supplied by
the motor 124 at one side of the paddle actuation sub-assembly 90
to be similarly supplied to the opposite side of the paddle
actuation sub-assembly 90.
[0093] Attached to the drive belts 126 on each of the opposite
sides is an engagement mechanism 128. The engagement mechanisms 128
each attach to a corresponding area of engagement 130 associated
with a paddle 132 for transferring the relative movement of the
drive belts 126 to the paddle 132. While only a single engagement
mechanism 128, associated with a single area of engagement 130 is
necessary for moving the paddle 132, in the disclosed embodiment a
pair of engagement mechanisms 128 are used. Driving the paddle 132
from both ends of the paddle 132 enables a more uniform or even
movement to be achieved. The drive belt 126 associated with the
adjoining side is coupled to a moveable portion of the position
sensor 100 (FIG. 12).
[0094] The areas of engagement 130 are coupled to the paddle 132
via corresponding connecting assemblies 134. As a result, as the
drive belts 126 move, so does the paddle 132. The speed at which
the paddle 132 moves is related to the drive speed of the motor
124. Consequently, the speed of the paddle 132, with respect to the
workpiece, can be controlled by controlling the speed of the motor
124.
[0095] The connecting assemblies 134 include an opening through
which a pair of corresponding travel guides 136 are received, and
upon which the connecting assemblies 134 travel. The travel guides
136 guide the movement of the paddle 132 laterally through a
relatively uniform motion. The travel guides 136 additionally help
maintain a consistent relative spacing between the surface of a
paddle and a nearby workpiece. A silhouette 138 of a workpiece is
shown for reference purposes.
[0096] The travel guide 136 additionally helps to maintain relative
spacing between the paddle 132 and the workpiece 138 via
positioning points 140, located on a travel guide cross member 142.
The positioning points 140 mate with corresponding sockets 144
located on the head assembly 42. The sockets 144 will be discussed
in greater detail below in connection with FIGS. 21 and 28.
[0097] The positioning points 140 of the travel guide 136 are set
with respect to the sockets 144 of the head assembly 42, so as to
provide a relative distance between the paddle 132 and a
corresponding workpiece 138. In accordance with one embodiment, the
relative distance is between approximately 40 thousandths of an
inch and 80 thousandths of an inch.
[0098] An additional set of ball assemblies 141, coupled to the
travel guide cross member 142 and oriented in the opposite
direction of positioning points 140, are provided for coupling the
paddle actuation sub-assembly 90 to corresponding sockets 143 (FIG.
13), which are integrated as part of the chassis sub-assembly
88.
[0099] FIGS. 18-20 illustrate various plan views of a paddle 132
for use in connection with the paddle assembly 40, shown in FIG.
12. FIG. 20 is shown enlarged with respect to the other two views
to enable easier viewing of the corresponding details associated
therewith. In accordance with one embodiment, the paddle 132 is an
elongated member having an approximately rectangular surface 146,
which faces the workpiece 138, as illustrated in FIG. 19. In
accordance with the same or similar embodiment, the paddle 132 has
a generally triangular cross-section 148, as illustrated in FIG.
20. The triangular cross-section helps to facilitate the desired
degree of fluid agitation, when used in connection with the
processing of the workpiece 138, when the workpiece 138 is immersed
in the processing fluid. However some degree of fluid agitation
will be achieved regardless of the cross-sectional shape of the
paddle. Accordingly the use of other cross-sectional shapes for the
paddle 132 are possible.
[0100] The approximately rectangular surface 146 of the paddle 132
includes one or more sets of fluid delivery ports 150 and one or
more sets of fluid recovery ports 152. In accordance with one
embodiment, the paddle 132 includes a single set of fluid delivery
ports 150, which are generally aligned in a row down the center of
the surface 146 of the paddle 132. The fluid delivery ports 150 are
coupled to a common supply channel 154, which runs the approximate
length of the paddle 132. The common supply channel 154 facilitates
fluid delivery to the surface of the paddle through the
corresponding set of fluid delivery ports 150.
[0101] In at least one embodiment, the common supply channel 154 is
located below the fluid delivery ports 150. The fluid delivery
ports 150 are coupled to the common supply channel 154 by drilling
down from the surface 146 of the paddle 132 to the common supply
channel 154. The common supply channel 154 is open at one end 156
for receiving the fluid to be delivered, via a fluid source couple
thereto.
[0102] The size of each of the fluid delivery ports 150 can be
varied so as to insure the desired amount of fluid is delivered at
each point along the length of the paddle 132. In accordance with
at least one embodiment, the size of the fluid delivery ports 150
generally increase as the distance between the fluid delivery port
150 and the open end 156 of the common supply channel 154
increases. One exception being proximate the closed end of the
common supply channel 154, where instead of the size of the fluid
delivery ports 150 further increasing, the size of the fluid
delivery ports begin to decrease.
[0103] The fluid source is coupled to the common supply channel 154
via a regulator, which controls the rate of fluid flow, and a
switch valve, which enables or disables the fluid flow. In addition
to providing the mechanism for supplying a fluid to the surface 146
of the paddle 132, the set of fluid delivery ports 150 could
additionally provide a source for additional fluid agitation.
[0104] The surface 146 of the paddle 132 includes two sets of fluid
recovery ports 152, one set located on each side of the single set
of fluid delivery ports 150. The fluid recovery ports 152 are
coupled to a corresponding common return channel 158, which
similarly runs the approximate length of the paddle 132. Each set
of fluid recovery ports 152 facilitates providing a negative
pressure with respect to the surface 146 of the paddle 132. Because
a set of fluid recovery ports 152 is provided on each side of the
set of fluid delivery ports 150, the fluid can readily be recovered
regardless of the present direction of travel of the paddle
132.
[0105] In addition to being offset widthwise with respect to the
fluid delivery ports 150, each set of fluid recovery ports 152 are
offset lengthwise with respect to one another. By offsetting
lengthwise each set of the fluid recovery ports 152, with respect
to one another, both sets can be coupled to the same corresponding
common return channel 158, while minimizing their effects with
respect to one another.
[0106] In at least one embodiment, the common return channel 158 is
located below the common supply channel 154. The fluid recovery
ports 152 are coupled to the common return channel 154 by drilling
down from the surface 146 of the paddle 132 at an angle to the
common return channel 158.
[0107] The common return channel 158 similarly has an open end 160
at one end of the paddle 132. The negative pressure is created by a
vacuum, which is supplied to the set of fluid recovery ports 152
via a pump coupled to the open end 160 of the common return channel
158. The pump is coupled to the common return channel 158 via a
separator in series with a valve. The separator separates the
fluids and gases received via the fluid recovery ports 152. The
rate of negative pressure at the surface 146 of the paddle 132 is
controlled by controlling the speed of the pump.
[0108] As noted previously above, the speed of the paddle 132, with
respect to the workpiece, can be controlled by controlling the
speed of the motor 124. This enables the rate of movement of the
paddle 132 to be altered. By altering the rate of movement of the
paddle 132 the rate of agitation of the processing fluid, or the
rate and/or time of exposure of a corresponding portion of the
workpiece to processing conditions, when the paddle 132 is used to
deliver and/or recover fluids with respect to the workpiece may
similarly be altered.
[0109] Furthermore the velocity of the paddle can be altered as a
function of time. The specific velocity can additionally be varied
based on one or more of a variety of processing parameters. One
such example includes altering the velocity of the paddle based on
amp-minutes of processing power supplied. Such an alteration could
account or compensate for predicted changes in chemical
concentrations within the processing fluid. Other such processing
parameters could additionally be used as a basis of altering the
velocity of the paddle 132.
[0110] In accordance with one embodiment, the paddle 132 is formed
from a non-magnetic high strength engineering plastic. In addition
to plastic, the paddle 132 could alternatively be formed from
titanium. Titanium readily forms a layer of titanium oxide, which
resists plating and provides good electrical isolation.
[0111] In at least one embodiment, one or more conductor segments
could be provided at the surface 146 of the paddle 132 for
supplying processing power thereto, so as to act as a cathode or an
anode dependent upon the polarity of the power supplied with
respect to the corresponding electrode.
[0112] Additionally the paddle 132 could incorporate additional
sets of fluid delivery ports 150 and fluid recovery ports 152, and
additional corresponding common supply channels 154 and common
return channels 158. In this way sets of fluid delivery ports 150
and fluid recovery ports 152 having varying supply and recovery
rates can be provided. Alternatively the additional fluid delivery
ports 150 and fluid recovery ports 152 could be used to supply and
recover different types of chemicals, either simultaneously or
alternatively. Alternative sizes and shapes for the paddle 132
could also be used.
[0113] FIGS. 21 and 22 illustrate the head assembly 42 for
receiving a workpiece. As noted previously the head assembly
reorients and/or repositions the workpiece relative to the bowl
assembly 32. The movement of the head assembly 42 is facilitated by
a lift and rotate assembly 44. The head assembly 42 is coupled to
the lift and rotate assembly 44 via an arm 161. In addition to
coupling the head assembly 42 to the lift and rotate assembly 44,
the arm 161 generally defines an axis of rotation 163 (FIG. 22)
about which the head assembly 42 rotates.
[0114] The head assembly 42 includes a slot 162 through which a
workpiece can be received. After the head assembly 42 receives the
workpiece, the workpiece is then lowered onto the workpiece
standoffs 164. Angled surfaces associated with the sidewalls 166
serve to properly position the workpiece as it is lowered onto the
workpiece standoffs 164. One portion of the sidewalls 166 is
primarily suited for properly positioning a square workpiece as it
is placed on the workpiece standoffs 164. The other portion of the
sidewalls 166 is primarily suited for properly positioning a
circular workpiece as it is placed on the workpiece standoffs
164.
[0115] The head assembly shown in FIG. 21 further illustrates
sockets 144 for receiving positioning points 140 of the travel
guide 136. The sockets 144 in combination with the positioning
points 140 when properly adjusted insures a consistent spatial
relationship between a workpiece and the paddle 132. A method of
adjustment is illustrated in connection with FIG. 28, and discussed
below in greater detail.
[0116] The head assembly 42 further provides for a workpiece
engagement mechanism 168, which applies backside pressure against a
received workpiece for pressing the workpiece up and against a
current thief assembly 170 (FIGS. 25 and 26), attached thereto. The
current thief assembly 170 is coupled to the head assembly 42 via a
quick release mechanism 172. The operation of the quick release
mechanism is discussed in greater detail in connection with U.S.
patent application Ser. No. 09/429,446, entitled "Method,
Chemistry, and Apparatus for Noble Metal Electroplating on a
Microelectronic Workpiece", the disclosure of which is incorporated
herein by reference.
[0117] FIGS. 22-24 illustrate in greater detail the workpiece
engagement mechanism 168. Specifically, FIG. 23 provides an
exploded isometric view of the workpiece engagement mechanism 168,
while FIGS. 22 and 24 provide cross sectional side plan views of
the workpiece engagement mechanism 168, both separately (FIG. 24)
and incorporated as part of the head assembly 42 (FIG. 22).
[0118] The workpiece engagement mechanism 168 includes a conductive
ring base 174, which has a center opening 176 through which a
non-conductive base member 178 is received. The non-conductive base
member 178 has an outer diameter, which generally corresponds to
the inner diameter of the conductive ring base 174. The conductive
ring base 174 includes a generally circular depression along the
interior surface, within which the conductive ring base 174 is
adapted for receiving a first end of a biasing spring 180. Coupled
to the other end of the biasing spring 180 is an upper ring
conductor 182. The upper ring conductor 182 is coupled to a
connector 184 for receiving processing power. The biasing spring
being conductive provides a path through which the processing power
is relayed to the conductive ring base 174.
[0119] Similarly coupled between the conductive ring base 174 and
the upper ring conductor 182, and encompassing the biasing spring
180 is a bellows 185, which has sides which expand and contract
with the relative motion of the conductive ring base 174 and the
upper ring conductor 182. The bellows 185 provides a physical
barrier, which prevents external fluids from entering portions of
the workpiece engagement mechanism 168.
[0120] Coupled to the non-conductive base member 178 is a dual
acting pneumatic cylinder 186. Coupled to the dual acting pneumatic
cylinder 186 are two ports 188 through which fluid lines can be
connected for actuating the pneumatic cylinder 186. Actuating the
pneumatic cylinder 186 creates a force for exerting lateral
pressure against the non-conductive base member 178. The force is
aligned along the same axis in both the same and opposite direction
as the corresponding force created by the biasing spring 180. The
pneumatic cylinder 186 in combination with the biasing spring 180
produce a force which extends and retracts the workpiece engagement
mechanism 168 so as to engage and release the workpiece received by
the head assembly 42. The spring provides the additional beneficial
feature that if for some reason the pneumatic cylinder 186 were to
lose pressure, the spring would provide sufficient force to retain
the workpiece engagement mechanism 168 in a closed fail safe
position.
[0121] The pneumatic cylinder 186 similarly provides the mechanism
for supplying a backside nitrogen gas purge to the workpiece.
[0122] Additionally coupled to the pneumatic cylinder 186 is a
circuit board assembly 190 including a pair of sensors 192 for
monitoring the lateral travel of the pneumatic cylinder 186
relative to the conductive ring base 174. In a accordance with one
embodiment, the sensors 192 are optical sensors, which detect the
passage of an external flag. The external flag interrupts a beam of
light traveling between corresponding elements of the sensor. The
flag 194 is coupled to the conductive ring base 174, whereas the
sensors are coupled to the pneumatic cylinder 186.
[0123] A first of two sensors 192 defines an open position for the
workpiece engagement mechanism 168. A second of two sensors 192
defines a closed position for the workpiece engagement mechanism
168.
[0124] Coupled to the exterior surface of the conductive ring base
174 is a belville ring contact 196. When the workpiece engagement
mechanism 168 is in the closed position, contact is made with the
backside surface of a workpiece received by the head assembly 42,
via the belville ring contact 196. The belville ring contact 196
includes a continuous conductive ring around which conductive
elements 198 are coupled thereto at discrete positions. The
conductive elements extend inward toward the center of the ring. It
is the discrete inwardly extending elements 198, which generally
make contact with the backside of the workpiece, and supply
processing power thereto. In at least one embodiment seventy-two
conductive elements 198 are provided at seventy-two discrete
positions around the perimeter of the belville ring contact
196.
[0125] The workpiece engagement mechanism 168 additionally includes
a further seal 200, which is coupled to the conductive ring base
174 and partially encloses the belville ring contact 196.
[0126] FIG. 25 illustrates an isometric top view of a current thief
assembly 170 for use in connection with the head assembly 42, shown
in FIGS. 21 and 22. The operation of a current thief is previously
well known in the art. Generally a current thief redirects the
plating of material away from the outer edges of the workpiece. In
absence of using a current thief, a greater amount of material is
generally deposited at the outer edge of the workpiece. This is
because of certain edge effects. The current thief generally moves
the edge effect away from the outer edge of the workpiece to the
outer edge of the current thief. The current thief assembly 170 as
shown in FIG. 25, is adapted for receiving a square workpiece.
[0127] Accordingly, the current thief assembly 170 has a square
center opening 202 for receiving the square workpiece. Generally
the exposed surface is coated with a dielectric material, with the
exception of the portion of the exposed surface immediately
adjacent and extending around the workpiece opening. The exposed
portion of the conductive surface not coated with a dielectric
material functions as a current thief 204.
[0128] By altering the size and shape of the opening, and the size
and shape of the area immediately adjacent and extending around the
opening which is not coated with a dielectric material, a current
thief assembly 170 can be adapted for use with workpieces having a
variety of sizes and shapes.
[0129] It is noted that in accordance with one embodiment, the
current thief assembly 170 has an outer size and shape, which is
sufficiently large to provide a complementary surface opposite the
surface of the paddle 132, which extends the full length of the
paddle as the paddle moves through its full range of travel.
[0130] The current thief assembly 170 additionally includes a pair
of posts 206 located on opposite sides of the current thief
assembly 170. The posts 206 are used for coupling the current thief
assembly 170 to the head assembly 42 via the quick release
mechanisms 172.
[0131] In addition to providing a physical connection, the posts
206 additionally provide for an electrical connection. In the
disclosed embodiment, located within the quick release mechanism
172 is a banana plug connector 208 (FIG. 26), which is received
within the post 206. As the post engages the quick release
mechanism 172, the banana plug 208 is compressed causing the center
portion of the banana plug 208 to expand outward and engage the
internal surface of the post 206, thereby making an electrical
connection. In this way processing power can be supplied to the
current thief 204.
[0132] FIG. 26 illustrates an isometric view of the head assembly
42, shown in FIGS. 21 and 22, with the current thief assembly 170,
shown in FIG. 25, attached thereto. FIG. 26 further illustrates a
portion of both the head assembly 42 and the current thief assembly
170, cut away, so as to illustrate the banana plug 208 making a
connection with the post 206.
[0133] FIG. 27 illustrates a cross sectional side view of the
workpiece engagement mechanism 168, shown in FIGS. 23 and 24
applying backside pressure against a received workpiece 210 for
pressing the workpiece against the current thief assembly 170,
shown in FIG. 26.
[0134] Specifically, as the conductive ring base 174 of the
workpiece engagement mechanism 168 moves against the workpiece 210,
the discrete inwardly extending elements 198 are pressed down and
scrape into the backside of the workpiece 210. At approximately the
same time, the seal 200 similarly engages the backside surface of
the workpiece 210. The workpiece 210 is similarly brought into
contact with a non-conductive seal 212 located at the backside
surface of the current thieving portion 204 of the current thief
assembly 170.
[0135] In connection with the above noted process, backside contact
is possible wherein the workpiece 210 has a substrate 214, which is
conductive. Processing power is supplied to the portion of the
workpiece 210 to be processed through the conductive substrate 214,
and around the generally non-conductive barrier layer 216, via a
seed layer 218, which extends around the barrier layer 216 and
contacts the substrate 214. The path of the processing power is
illustrated by arrow 220.
[0136] While a backside contact has been disclosed in connection
with the disclosed embodiment, one skilled in the art should
readily appreciate that other embodiments incorporating front side
contact would similarly be possible.
[0137] As discussed previously in connection with one embodiment,
the relative distance between the paddle 132 and the workpiece is
between approximately 40 thousandths of an inch and 80 thousandths
of an inch. FIG. 28 illustrates one suitable method for adjusting
the paddle distance. Specifically, FIG. 28 illustrates an isometric
view of the processing station 28 shown in, FIGS. 4-6, wherein the
portion of the paddle actuation sub-assembly 90 corresponding to
FIG. 17 has been removed and placed upon the head assembly 42,
shown in FIGS. 21 and 22, when the head assembly 42 is oriented in
a position for receiving a workpiece. More specifically positioning
points 140 of the paddle actuation sub-assembly 90 are aligned with
corresponding sockets 144 of the head assembly 42.
[0138] One of the benefits to placing the portion of the paddle
actuation sub-assembly on top of the head assembly 42 is that it
provides easier access to the gap distance, away from the rest of
the paddle assembly 40, which limits access thereto. This is
possible because the gap distance is controlled by positioning
points 140 of the paddle actuation sub-assembly 90, the sockets 144
of the head assembly 42, and the corresponding structure
therebetween, which has been similarly positioned onto the head
assembly 42.
[0139] A blank 224 having a thickness consistent with the thickness
of the workpiece can be received within the head assembly 42, and
the head assembly can be placed into a closed position. This will
insure that the relative spacing of the workpiece is accounted for.
The relevant portion of paddle actuation sub-assembly 90 is then
placed upon the head assembly 42, wherein the positioning points
140 are aligned with the corresponding sockets 144. A gauge for
measuring spacing can then be placed between the paddle 132 and the
blank 224, and checked while the paddle 132 is positioned at
various travel points relative to the head assembly 42. If
necessary the height of the paddle 132 can be adjusted. In this way
the desired spacing can be provided between the paddle 132 and the
workpiece.
[0140] As noted previously the paddle 132, described above, is
capable of being used in connection with at least two types of
processing. The first type of processing uses the paddle 132 to
facilitate fluid agitation of the processing fluid proximate the
surface of the workpiece 138, when the portion of the workpiece 138
to be processed is immersed within a processing fluid. In this
instance the fluid agitation is achieved by moving the paddle
relative to the portion of the workpiece 138 to be processed. In
this way relatively fresh processing fluid whose chemical
concentrations have not yet been been significantly affected by the
localized effects of the reaction taking place at the surface of
the workpiece will mix in and continuously replace the stale
fluid.
[0141] As also noted previously the delivery or recovery of
processing fluid by one or more sets of fluid recovery ports 152
and one or more sets of fluid delivery ports 150 could similarly be
used to enhance fluid agitation or supply fresh chemistry proximate
the workpiece 138.
[0142] The second type of processing uses the paddle to supply and
recover fluids proximate the surface of the workpiece 138, when the
portion of the workpiece 138 to be processed is not immersed within
a processing fluid. In this instance fluid is supplied to the
portion of the workpiece 138 to be processed via one or more sets
of fluid delivery ports 150. In conjunction with supplying the
fluid to the portion of the workpiece 138 to be processed, the
fluid may similarly be recovered via one or more sets of fluid
recovery ports 152.
[0143] By additionally recovering the fluid via one or more sets of
fluid recovery ports 152, the fluid supplied can be confined to the
approximate space located between the paddle 132 and the workpiece
138, without coming into contact with chemically distinct
processing fluid, which may be similarly located in the processing
station 28 or 30 or come into contact with surfaces which may later
be exposed to other chemistry.
[0144] FIG. 29 illustrates a partial cross sectional side view of
the paddle 132, shown in FIGS. 18-20, and a workpiece 138, wherein
the paddle 132 is both supplying a fluid to the workpiece 138 and
recovering a fluid supplied to the workpiece 138.
[0145] The paddle 132 is shown moving in a direction from left to
right, as illustrated by arrow 222. FIG. 29 helps to further
illustrate the confined nature of the processing fluid supplied to
space between the paddle 132 and the workpiece 138, via the set of
fluid delivery ports 150, wherein one or more sets of fluid
recovery ports 152 are similarly recovering the processing
fluid.
[0146] Generally the fluid is retained within the space as a result
of the volume of processing fluid not being allowed to exceed the
volume of fluid, which can be supported by the corresponding
surface tension. At the same time sufficient fluid needs to be
present to fill the gap. Accordingly, the rate of recovery of
processing fluid via the fluid recovery ports 152 needs to be set
taking into account the rate of supply of processing fluid via the
fluid delivery ports 150.
[0147] As a result of the movement of the paddle 132, the fluid
tends to trail behind the paddle 132. However so long as the
overall fluid volume is maintained between acceptable levels, the
fluid can still be confined within the appropriate space. An
example of possible fluid flow within the volume of fluid formed
within the space is illustrated by small arrows.
[0148] In the process noted above in connection with the formation
of read/write heads, the paddle 132 is used to provide a rinse
function while the workpiece 138 is present within the processing
station 28 or 30, which similarly provides for the electroplating
of material onto the workpiece 138. After the plating step is
concluded, the level of the processing fluid relative to the
workpiece 138 is adjusted so that the workpiece 138 is no longer
immersed within the processing fluid. The paddle then supplies to
and recovers from the workpiece 138, a fluid different from the
processing fluid within which the workpiece 138 was previously
immersed. In this case the fluid is a rinse solution. More
particularly the rinse solution is de-ionized water. After the
workpiece is rinsed, the workpiece 138 may be directly forwarded to
the next processing station 28 or 30.
[0149] By delivering fluids to the workpiece 138 via the space
located between the paddle 132 and the workpiece 138, the present
system has the benefit that a minimal volume of chemistry is used.
Furthermore the area of delivery can be much more precisely
controlled. Consequently, spraying can be reduced as well as
backside exposure of the workpiece 138. Still further, the
sequential movement of the workpiece 138 through multiple
processing stations 12 can be greatly simplified.
[0150] In the above noted example, the paddle 132 delivers
de-ionized water to the workpiece. The paddle could further supply
de-ionized water, where ozone has been dissolved therein. In these
or other instances a source of ozone may be separately supplied
within the processing chamber. Furthermore, the fluid supplied by
the paddle 132 could additionally include a temperature
differential, wherein a cooled or a heated fluid is supplied to the
workpiece.
[0151] As previously noted, the specific construction of the paddle
132 could be adjusted to accommodate further fluid supplies and
fluid recoveries to allow even greater flexibility, including
multiple sequential processes simultaneously.
[0152] Other processes which would be also suitable for use with
the expanded capabilities of the paddle 132, provided for by the
present invention, include: electroplating, electroless plating;
etching metal; developing photo resist, cleaning a workpiece
surface including using an acid, a solvent, and/or de-ionized
water, metal lift off, thinning silicon, chemically etching, and/or
chemically machining.
[0153] 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.
* * * * *