U.S. patent application number 11/452609 was filed with the patent office on 2007-01-04 for integrated system for processing semiconductor wafers.
Invention is credited to Jalal Ashjaee, Bulent M. Basol, Bernard M. Frey, Boris Govzman, Boguslaw A. Nagorski, Homayoun Talieh, Douglas W. Young.
Application Number | 20070004316 11/452609 |
Document ID | / |
Family ID | 27808617 |
Filed Date | 2007-01-04 |
United States Patent
Application |
20070004316 |
Kind Code |
A1 |
Ashjaee; Jalal ; et
al. |
January 4, 2007 |
Integrated system for processing semiconductor wafers
Abstract
An integrated process tool for chemical mechanical processing,
cleaning and drying a semiconductor workpiece is provided. The
integrated process tool includes a CMP module and a cleaning and
drying module. After being processed, the workpiece is transported
from the CMP module to the cleaning and drying module using a
movable housing. In the cleaning and drying module, a cleaning
mechanism is used to clean the workpiece while the workpiece is
rotated and held by a support stucture of the movable housing. A
drying mechanism of the cleaning and drying module picks up the
workpiece from the moveable housing and spin dries it. Throughout
the CMP process, cleaning and drying, the processed surface of the
wafer faces down.
Inventors: |
Ashjaee; Jalal; (Cupertino,
CA) ; Govzman; Boris; (Sunnyvale, CA) ; Frey;
Bernard M.; (Livermore, CA) ; Nagorski; Boguslaw
A.; (San Jose, CA) ; Young; Douglas W.;
(Sunnyvale, CA) ; Basol; Bulent M.; (Manhattan
Beach, CA) ; Talieh; Homayoun; (San Jose,
CA) |
Correspondence
Address: |
KNOBBE MARTENS OLSON & BEAR LLP
2040 MAIN STREET
FOURTEENTH FLOOR
IRVINE
CA
92614
US
|
Family ID: |
27808617 |
Appl. No.: |
11/452609 |
Filed: |
June 13, 2006 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
10369118 |
Feb 18, 2003 |
7059944 |
|
|
11452609 |
Jun 13, 2006 |
|
|
|
09795687 |
Feb 27, 2001 |
6953392 |
|
|
10369118 |
Feb 18, 2003 |
|
|
|
60259676 |
Jan 5, 2001 |
|
|
|
60261263 |
Jan 16, 2001 |
|
|
|
60357148 |
Feb 15, 2002 |
|
|
|
60397740 |
Jul 20, 2002 |
|
|
|
Current U.S.
Class: |
451/5 ;
451/67 |
Current CPC
Class: |
H01L 21/68707 20130101;
B24B 37/345 20130101; H01L 21/67046 20130101; H01L 21/67745
20130101; H01L 21/67034 20130101; H01L 21/67051 20130101; H01L
21/67219 20130101; Y02P 90/20 20151101; G05B 2219/32272 20130101;
Y02P 90/02 20151101; H01L 21/67028 20130101; G05B 19/41865
20130101; H01L 21/68728 20130101; H01L 21/67173 20130101; G05B
2219/45031 20130101 |
Class at
Publication: |
451/005 ;
451/067 |
International
Class: |
B24B 51/00 20060101
B24B051/00; B24B 7/00 20060101 B24B007/00 |
Claims
1. An integrated wafer processing system for processing a plurality
of wafers comprising: at least one electrochemical mechanical
polishing (ECMP) station to remove material from a front surface of
each of the plurality of wafers; at least one chemical mechanical
polishing station that contains separate wafer entry and wafer exit
points; and a wafer-handling subsystem for transporting each of the
plurality of wafers into and out of the at least one
electrochemical mechanical polishing station and the at least one
chemical mechanical polishing station.
2. The system of claim 1, wherein each of the stations is disposed
in a cluster arrangement adjacent the wafer-handling subsystem.
3. The system of claim 1, wherein the wafer-handling subsystem
includes at least one wafer-handling robot.
4. The system of claim 1, wherein the wafer-handling subsystem
comprises: a first wafer handling robot for removing each of the
plurality of wafers from a cassette and placing the wafer in a
buffer, and removing each of the plurality of wafers from the
buffer and replacing the wafer in the cassette; and a second wafer
handling robot for removing each of the plurality of wafers from
the buffer and placing the wafer in one of the stations, and
removing each of the plurality of wafers from the station and
replacing the wafer in the buffer.
5. An integrated wafer processing system for processing a plurality
of wafers comprising: at least one electrochemical deposition
station to deposit metal onto surfaces of the plurality of wafers
in sequence; at least one electrochemical mechanical polishing
(ECMP) station for removing metal from surfaces of the plurality of
wafers; an annealing station; at least one chemical mechanical
polishing station that contains separate wafer entry and wafer exit
points; and a wafer-handling subsystem for transporting the
plurality wafers into and out of the at least one electrochemical
deposition station, the at least one electrochemical mechanical
polishing station, the annealing station, and the at least one
chemical mechanical polishing station.
6. The system according to claim 5, wherein the annealing station
includes an annealing area and a chilling area.
7. The system of claim 5, wherein each of the stations is disposed
in a cluster arrangement adjacent the wafer-handling subsystem.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 10/369,118, filed Feb. 18, 2003, which is a continuation in
part of U.S. application Ser. No. 09/795,687, filed Feb. 27, 2001,
now U.S. Pat. No. 6,953,392, which claims priority from U.S.
provisional application Nos. 60/259,676, filed Jan. 5, 2001, and
60/261,263, filed Jan. 16, 2001, all of which are entirely
incorporated herein by reference. This application also claims
priority by way of U.S. application Ser. No. 10/369,118 to U.S.
provisional application Nos. 60/357,148, filed Feb. 15, 2002, and
60/397,740, filed Jul. 20, 2002, all of which are entirely
incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to semiconductor processing
technologies and, more particularly, to an integrated system for
processing semiconductor wafers. The invention also includes
individual process modules for performing specific tasks, for
example, a workpiece cleaning and drying module.
BACKGROUND OF THE INVENTION
[0003] In the semiconductor industry, various processes can be used
to deposit and etch materials on wafers. Deposition techniques
include processes such as electrochemical deposition (ECD) and
electro chemical mechanical deposition (ECMD). In both processes, a
conductor is deposited on a semiconductor wafer or workpiece by
having electrical current carried through an electrolyte that comes
into contact with the surface of the workpiece (cathode). The ECMD
process is able to uniformly fill the holes and trenches on the
surface of the workpiece with the conductive material while
maintaining the planarity of the surface. A more detailed
description of the ECMD method and apparatus can be found in the
U.S. Pat. No. 6,176,992, entitled "Method and Apparatus For Electro
Chemical Mechanical Deposition", commonly owned by the assignee of
the present invention.
[0004] If a conventional plating process is performed to deposit
the conductive material in a deposition chamber, the workpiece may
be transferred to another chamber in the cluster tool for chemical
mechanical polishing (CMP). As is known, the material removal can
also be carried out using electrochemical etching by making the
workpiece anodic (positive) with respect to an electrode after
completing an ECD or ECMD process.
[0005] Regardless of which process is used, the workpiece is next
transferred to a rinsing/cleaning station or module after the
deposition and/or polishing steps. During the rinsing/cleaning
step, various residues generated by the deposition and/or polishing
processes are rinsed off the workpiece with a fluid such as
de-ionized water or de-ionized water with small amounts of other
cleaning and/or passivating agents, and subsequently the workpiece
is dried.
[0006] Conventionally, processing chambers are designed in multiple
processing stations or modules that are arranged in a cluster to
form a cluster tool or system. Such cluster tools or systems are
often used to process a multiple number of workpieces at the same
time. Generally, cluster tools are configured with multiple
processing stations or modules and are designed for a specific
operation. However, in such conventional cluster tools, deposition
and cleaning processing steps both typically require separate
chambers. For this reason, in known cluster tools, for a workpiece
to be processed and cleaned, it must be moved to another station or
system. Thus, such configured systems require picking workpieces
from a particular processing environment and placing them into a
cleaning environment. The workpiece can be cleaned and dried in a
cleaning and a drying module using, for example, a rinse and spin
process, as known in the art.
[0007] When the workpiece is transferred to the cleaning and drying
module, contaminants may have attached themselves on the workpiece
surface. The source of these contaminants may be the
plating/polishing agent, transferring mechanism, surrounding air,
the processing facility, personnel, process chemicals, and the
like. The workpiece surface should be free of such contaminants;
otherwise, the contaminants may affect device performance
characteristics and may cause device failure to occur at faster
rates than usual.
[0008] The speed of which the workpiece is transferred from one
module to the next is also critical. As is well known in the
semiconductor industry, the production line for manufacturing the
workpiece from beginning to end must be performed in the most
efficient manner.
SUMMARY OF THE INVENTION
[0009] The present invention is directed to a novel cleaning and
drying module of the overall cluster tool. The present invention
further provides a more cost effective, efficient, contaminant free
method and apparatus for cleaning and dying workpieces than those
currently available.
[0010] In one aspect of the present invention, an apparatus for
processing, cleaning and drying a semiconductor workpiece is
provided. The apparatus includes a process area to process a
surface of the workpiece and a cleaning drying area to clean and
dry the workpiece. A movable housing transports the workpiece from
the process area to a cleaning and drying area. The movable housing
includes a support structure adapted to hold the workpiece. A
cleaning mechanism cleans the workpiece while the workpiece is
rotated and held by the support structure. A drying mechanism
receives the workpiece from the moveable housing for drying the
workpiece. The workpiece is held and cleaned and dried while the
processed surface of the workpiece faces down.
[0011] In another aspect of the present invention, a method for
cleaning and drying a workpiece in a process module, that has a
cleaning and drying section and a process section, is provided. The
method includes placing the workpiece on a movable housing, moving
the movable housing into the cleaning and drying section of the
process module, cleaning a surface of the workpiece using a
cleaning fluid in the cleaning and drying section, transferring the
workpiece from the moveable housing to a drying mechanism having a
spinning wheel and drying the workpiece. Before the step of placing
the workpiece onto the movable housing, the surface of the
workpiece is processed in the process section adjacent the cleaning
and drying section of the process module prior to the step of
placing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a schematic illustration of a system of the
present invention including an embodiment of an integrated chemical
mechanical process station of the present invention;
[0013] FIG. 2 is a schematic illustration of another system of the
present invention including the chemical mechanical polishing
process station of the present invention;
[0014] FIG. 3 is a schematic illustration of another system of the
present invention including the chemical mechanical polishing
process station and an anneal station of the present invention;
[0015] FIG. 4 is a schematic illustration of the chemical
mechanical polishing processing station of the present
invention;
[0016] FIG. 5 is a schematic illustration of a cleaning drying
module of the present invention including the cleaning and drying
mechanisms according to one embodiment of the present
invention;
[0017] FIG. 6 is a schematic illustration of a wafer indicating the
relative positions of the holding spools and the dryer clamps;
[0018] FIG. 7 is a schematic illustration of an embodiment of a
wafer release and hold mechanism of the dryer.
[0019] FIG. 8 is a schematic illustration of another system of the
present invention having a plurality of chemical mechanical
polishing stations and anneal stations;
[0020] FIG. 9 is a schematic illustration of the anneal station of
the present invention wherein the station has an anneal slot and an
buffer slot to be used as a buffer zone;
[0021] FIG. 10 is a schematic illustration of another embodiment of
the integrated chemical mechanical polishing processing
station;
[0022] FIG. 11 is a schematic illustration of a chemical
treatment/cleaning/rinsing-drying module of the of the integrated
chemical mechanical polishing processing station of the present
invention;
[0023] FIG. 12 is a schematic plan view of the chemical
treatment/cleaning/rinsing-drying module of the present
invention;
[0024] FIG. 13 is a schematic illustration of a chemical
treatment/cleaning/rinsing-drying module of the of the present
invention wherein a wafer is cleaned by a cleaning mechanism of the
module;
[0025] FIGS. 14A-14B are schematic illustrations of the roller
brushes used in the module;
[0026] FIG. 15 is a schematic illustration of the chemical
treatment/cleaning/rinsing-drying module of the present invention
wherein the wafer is being picked up by a drying spindle after the
wafer is cleaned;
[0027] FIG. 16 is a schematic illustration of a chemical
treatment/cleaning/rinsing-drying module of the of the present
invention wherein a wafer is spin dried by the drying spindle of
the module; and
[0028] FIG. 17 is a schematic illustration of a system of the
present invention including a plurality of the chemical
treatment/cleaning/rinsing-drying modules.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0029] The present invention will now be described in greater
detail, which will serve to further the understanding of the
preferred embodiments of the invention. As described elsewhere
herein, various refinements and substitutions of the various
embodiments are possible based on the principles and teachings
herein.
[0030] The preferred embodiments of the present invention will be
described with reference to FIGS. 1-17, wherein like components,
parts, rollers, gears, tracks, motors, bars, etc. are designated by
like reference numbers throughout the various figures. Further,
specific parameters and components are provided herein, which are
intended to be explanatory rather than limiting.
[0031] The preferred embodiments will be described using the
example of a workpiece or wafer, but different applications such as
packaging, flat panel displays, and magnetic heads can be used with
the present invention. The present invention describes a workpiece
cleaning and drying module. The cleaning and drying module of the
present invention is capable of processing workpieces with
different diameters at different times, but will typically process
workpieces of the same size for a given processing run. The
workpiece can be transferred from a plating or polishing processing
module using a movable housing.
[0032] The present invention provides a system for semiconductor
device fabrication. The system comprises several process modules to
perform process steps such as Electrochemical Mechanical Processing
(ECMPR), electrochemical deposition (ECD), chemical mechanical
polishing (CMP) and electrochemical polishing (EC-polishing)
integrated with other process steps such as cleaning, edge bevel
removal and drying. The term of Electrochemical Mechanical
Processing (ECMPR) is used to include both Electrochemical
Mechanical Deposition (ECMD) processes as well as Electrochemical
Mechanical Etching (ECME), which is also called Electrochemical
Mechanical Polishing (ECMP). It should be noted that in general
both ECMD and ECME processes are referred to as electrochemical
mechanical processing (ECMPR) since both involve electrochemical
processes and mechanical action.
[0033] Additionally, an integrated tool of the present invention is
designed to utilize these process modules to perform multiple
processing steps related to electrochemical deposition, chemical
mechanical polishing, and electrochemical polishing.
[0034] Following the ECD, ECMP, CMP or electrochemical polishing
processes, the electrolyte residues need to be rinsed off the
wafer, and subsequently wafer needs to be dried. Additionally,
after such processes, it may be necessary to remove a portion of
the metal that is deposited near the edge of the wafer surface.
This process is often referred to as "bevel edge clean" or "edge
removal" step. In the present invention, certain exemplary process
chambers, i.e., ECD, ECMPR, or electrochemical polishing chambers,
and their respective cleaning chambers are stacked vertically,
although there is also described herein an additional CMP chamber
in which the cleaning chamber is horizontally disposed from the
chemical mechanical polishing area. The edge removal step may be
carried out in the cleaning chamber, whether such cleaning chamber
is vertically disposed with respect to the process or not. In the
context of this application, the cleaning chamber is the chamber
where cleaning (using a fluid such as water or the like to remove
residues therefrom) and drying and possibly edge removal process
steps are performed.
[0035] FIG. 1 illustrates an integrated tool 100 or system of the
present invention which comprises a wafer processing section 102
and a load/unload section 104 or a cassette section connected to
the processing section 102 through a buffer section 106. The
processing section 102 may comprise one or more electrochemical
mechanical process stations or subsystems 108A-108C and one or more
chemical mechanical polishing process stations or subsystems 108D,
which are each configured with respect to a wafer handling section
109 within the wafer processing section 102, as in the manner shown
in FIG. 1. In this embodiment, the process stations 108A-108C may
preferably be vertically stacked chambers that have both an
electrochemical mechanical deposition (ECMD) chamber and a cleaning
chamber (i.e., ECMD/cleaning chamber).
[0036] As so configured, the integrated tool 100 of the present
invention is able to process wafers with different diameters at
different times, but will typically process wafers of only the same
size for a given processing run. An exemplary vertical chamber
design and operation for the process chambers 108A-108C is
disclosed in the U.S. Pat. No. 6,352,623, entitled "Vertically
Configured Chamber Used for Multiple Processes," commonly owned by
the assignee of the present invention.
[0037] In a preferred sequence of operations, wafers 110 or
workpieces to be plated are delivered to the cassette section 104
in a cassette 112 and then each may be picked up and transferred to
the buffer section 106 by a first robot 114. Each wafer 110 can
then be transferred to one of the processing stations 108A-108C in
the processing section 102 by a second robot 116. As mentioned
above, the processing stations 108A-108D can be either adapted to
process 200 or 300 millimeter (mm) wafers, or other size workpiece
if desired. After the electro chemical mechanical deposition and
cleaning processes are complete, each wafer is transferred into the
chemical mechanical polishing processing station 108D.
[0038] The chemical mechanical polishing processing station 108D,
described hereinafter, contains a wafer entry area 402 and a
separate wafer exit area 404 as shown in FIG. 4. As will be
described hereinafter, the chemical mechanical polishing processing
station 108D is particularly suited for processing wafers that have
had copper overburden deposited up to several thousand angstroms
deposited that requires removal, with most of the removal typically
being obtained using the chemical mechanical polishing processing
station 108D. Wafers 110 are loaded into the wafer entry area 402
(see FIG. 4) of the chemical mechanical polishing processing
station 108D using the second robot 116, and then removed from the
chemical mechanical polishing processing station 108D at the wafer
exit area 404 (see FIG. 4) using the first robot 114.
[0039] While the preferred sequence of operations is described
above, it is noted that the system 100 is capable of moving the
wafers 110 from each subsystem to another subsystem, in an order
different from that recited above. Accordingly, usage of certain
processing subsystems without others, as well as usage of
processing subsystems in an order that is different than that
recited above are within the scope of the present invention.
[0040] FIG. 2 illustrates another embodiment of an integrated tool
200 or system of the present invention. In this embodiment, the
processing stations 208A-208C are populated with various types of
deposition tools, such as the electrochemical mechanical processing
station 208A and electrochemical processing station 208B and C.
Each processing station 208A-208C is preferably configured as a
vertical chamber as described above and further described in the
U.S. Pat. No. 6,352,623, entitled "Vertically Configured Chamber
Used for Multiple Processes," commonly owned by the assignee of the
present invention. This allows variation between the type of
processing that is used, and thus more flexibility in terms of the
types of processing operations that can be performed.
[0041] The preferred sequence of operations is, nonetheless, the
same as that discussed previously with respect to FIG. 1, in which
one of the processing stations 208A-208C is first used, and
thereafter the chemical mechanical polishing processing station
208D is used. Thus, processing section 202, cassette 212 with
cassette section 204, handling section 209, buffer section 206,
first robot 214, and second robot 216 operate in the same manner as
processing section 102, cassette 112 with cassette section 104,
handling section 109, buffer section 106, first robot 114, and
second robot 116 respectively described with reference to FIG.
1.
[0042] While the preferred sequence of operations is described
above, it is noted that the system 200 is capable of moving the
wafers 210 from each subsystem to another subsystem, in an order
different from that recited above. Accordingly, usage of certain
processing subsystems without others, as well as usage of
processing subsystems in an order that is different than that
recited above are within the scope of the present invention.
[0043] It is also within the scope of the present invention that
the above systems may also comprise an anneal chamber to anneal the
wafers. When an anneal chamber is included, it is preferable to
have the anneal chamber located in proximity to the buffer area,
and for the anneal chamber processing subsystem to include both a
"hot" section capable of heating the wafer, and a "cool" section
capable of cooling the wafer after annealing has been completed.
Such an anneal chamber will typically have the ability to operate
upon a single wafer at a time, and is well known. Thus, further
description is not believed necessary. What is advantageous with
respect to the present invention is the manner in which the anneal
chamber is integrated with the other processing sections, in order
to maximize efficiency and throughput. In particular, as shown in
FIG. 3, both of the robots 314 and 316 can place wafers into or
take wafers 310 out of the anneal chamber processing station 308E.
If both robots can perform such operation, as described below, then
if there are no further operations after annealing, the anneal
chamber can act as a substitute buffer area.
[0044] In a preferred operation mode, however, a further chemical
mechanical processing operation is performed after the anneal
operation. In this operation mode, the integrated system 300
illustrated in FIG. 3 is advantageous for the following
reasons.
[0045] As illustrated in FIG. 3, integrated tool 300 or system of
the present invention using an anneal chamber processing station
308E as described above. The anneal chamber processing station 308E
includes a processing section 302 and a load/unload section 304
connected to the wafer processing section 302, as will be described
in further detail hereinafter. Separate from, but disposed
vertically with respect to the anneal chamber processing station
308E, is a buffer section 306 that allows for movement of the wafer
to and from the cassette 312 within cassette section 304, from and
to the processing section 302 through the buffer section 306. As
will also be described hereinafter, this allows for the system 300
to be configurable, either with an anneal chamber processing
station 308E or without the anneal chamber processing station
308E.
[0046] The processing section 302 may comprise a first, second,
third and fourth process stations 308A, 308B, 308C, and 308D in
addition to the anneal chamber processing station 308E, which may
be clustered around the handling section 309, as in the manner
shown in FIG. 3. While the process stations 308A-308D can each
perform a different type of process taken from the processes
described above, in a preferred embodiment each of the process
stations 308A-308C are the same type of process stations, such as
an ECMPR process station, and the station 308D is comprised of a
CMP processing subsystem that has an entry area 402 and an exit
area 404 (see FIG. 4), as will be described further
hereinafter.
[0047] In a preferred sequence of operations, wafers 310 or work
pieces to be plated (with ECD and/or ECMD) are delivered to the
cassette section 304 in a cassette 312 and then each may be
transferred to the buffer section 306 by a first robot 314. Each
wafer 310 may then be picked up and transferred to one of the
vertical chamber stations 308A-308C by a second robot 316 so that
plating and/or removal of conductive material from the front
surface of the wafer and an initial cleaning is performed.
Thereafter, the second robot 316 picks up the wafer 310 and
transfers it to the annealing chamber processing station 308E. Once
annealed and chilled within the annealing chamber processing
station 308E, the wafer 310 can then be picked up by the second
robot 316 and transported to the entry area 402 (see FIG. 4) of the
CMP chamber processing station 308D. Once conductive material is
removed from the front face of the wafer using the CMP chamber
processing station 308D, which processing station 308D will also
perform cleaning as described further herein, it is located in the
wafer exit area 404 (see FIG. 4) so that the first robot 314 can
directly pick up and transfer the wafer 310 to the cassette section
304.
[0048] While the preferred sequence of operations is described
above, it is noted that the system 300 is capable of moving the
wafers 310 from each subsystem to another subsystem, in an order
different from that recited above. In particular, it may be useful
to perform the chemical mechanical polishing operation prior to the
annealing operation. Accordingly, usage of certain processing
subsystems without others, as well as usage of processing
subsystems in an order that is different than that recited above
are within the scope of the present invention.
[0049] FIG. 4 illustrates an overview of the chemical mechanical
polishing processing station 400, which is then used for processing
station 108D illustrated in FIG. 1, 208D illustrated in FIG. 2, and
308D illustrated in FIG. 3. For purposes of FIGS. 4-7, the wafer
being operated upon is designated wafer 410.
[0050] The chemical mechanical processing station 400 will be
described in detail hereinafter. An initial overview of its
operation is initially provided. As is apparent from FIG. 4, the
chemical mechanical polishing processing station 400 includes a
movable input housing 414 receives a wafer 410 from a second robot,
such as robot 116 illustrated in FIG. 1, at a wafer input area 402.
As shown in FIG. 4, the movable input housing 414 can then move the
wafer 410 disposed thereon between the wafer input area 402 and a
chemical mechanical processing apparatus 420 that chemically
mechanically polishes the wafer 410. Another movable housing 432
moves the wafer 410 between the chemical mechanical processing
apparatus 420 and cleaning and drying areas that are covered by
cover 442, which cleaning and drying areas clean and dry the wafer,
respectively. Within the cleaning and drying areas is also a wafer
output area 404 (depicted as a box in FIG. 4) from which location
the wafer 410 can be removed from the chemical mechanical polishing
processing station 400 by a first robot, such as robot 114
illustrated in FIG. 1.
[0051] In the description that follows, the chemical mechanical
polishing processing station 400 will be described with reference
to a single wafer 410 that moves through the station 400. An
advantage of the station 400 that will be apparent from this
description is that more than one wafer 410 can be located within
the station 400 at a time. In particular, at any given time, up to
three wafers can be located within the system. With three wafers,
one wafer is disposed on the movable input housing 414, waiting to
place its wafer on the chemical mechanical processing apparatus
420, a second wafer is operated on by the chemical mechanical
processing apparatus 420, and a third wafer is operated upon within
the cleaning and drying areas. This configuration thus improves
throughput, as chemical mechanical polishing can take place on one
wafer and cleaning and drying can take place on another wafer at
the same time.
[0052] The chemical mechanical polishing processing station 400
will now be described in more detail. The wafer entry area 402
mentioned previously includes a plurality of at least three holding
pins 418 mounted on a movable housing 414. The pins 418 are each
configured so that the wafer 410 will rest on a portion of each pin
418, with all of the pins 418 thus supporting the wafer on the
movable housing 414. With the wafer 410 being supported by the pins
418, the movable housing 414 can be moved along a track 438 between
the wafer entry area 402 and the chemical mechanical polishing
processing apparatus 420. Movement of the movable housing 414
preferably uses a cylinder (not shown) that is operated under
electronic control 490 (shown in FIG. 5), which electronic control
is preferably computer based and operates using application
software written to control the movement of the various components
described herein.
[0053] A robot, such as robot 116 in FIG. 1, will place the wafer
410 in the wafer entry area 402 so that the wafer holding pins 418
can hold it as described above. Once so held, the movable housing
414 moves the wafer 410 to the chemical mechanical polishing
processing apparatus 420. Once within the chemical mechanical
polishing apparatus 420, the wafer 410 is preferably centered using
a centering apparatus 422. As illustrated in FIG. 4, the centering
apparatus includes a rod 423 that is mechanically moved, such as by
a piston, and laterally pushes the wafer so that it is properly
positioned using the top edge 418A of two of the pins 418 and the
end of the rod 423. This ensures that the wafer 410 is in proper
position for the carrier head 426 to then pick up the wafer 410.
When the carrier head 426 picks up the wafer 410, the front surface
of the wafer 410 is disposed in a down position and movement of the
carrier head 426 will allow the front surface to contact the pad or
belt 424 associated with the chemical mechanical polishing process.
Chemical mechanical polish processing, using either an abrasive pad
or belt 424, or a slurry or both can take place in a conventional
manner in the chemical mechanical polish processing apparatus 420,
preferably with the carrier head rotating and the chemical
mechanical polishing apparatus 420 having a polishing pad that
either rotates or, most preferably, moves bi-linearly. With the
most preferred bi-linear movement of the chemical mechanical
polishing apparatus 420, the chemical mechanical processing system
uses a chemical mechanical polishing apparatus 420 as described in
U.S. Pat. No. 6,468,139, assigned to the same assignee as the
present invention.
[0054] Once chemical mechanical polishing in the chemical
mechanical polish processing apparatus 420 is complete, another
movable housing 432, to which supports 434 that hold wafer holding
spools 436 are attached, is moved underneath the chemical
mechanical polish processing apparatus 420, with the movable
housing 414 being moved to the wafer entry area 402, awaiting
receipt of another wafer. The wafer 410 is unloaded from the
carrier head 426 onto the wafer holding spools 436. The holding
spools 436 are preferably round from a top view, made of a hard
rigid material that does not interact with the wafer and cleaning
solutions, and have a lower lip 436A that is longer than an upper
lip 436B. This construction allows for the release of the wafer 410
onto the lower lip 436B when the spools 436 are in an open
position. Once the wafer 410 has been removed from the carrier head
426 onto the lower lip 436A of the spools 436, the spools 436 are
then positioned into a closed position using a motor not shown that
is controlled by the electronic control 490 illustrated in FIG. 5.
With the spools 436 in the closed position, the wafer 410 is
tightly held at its edges between the lower lips 436A and the upper
lip 436B. With the wafer 410 in place, the movable housing 432
transports the wafer 410 to cleaning and drying areas that are
within an area covered by cover 442.
[0055] Once the wafer 410 is within the cleaning area 440, a
portion 442A of cover 442 is lowered to cover the wafer 410 and the
movable housing 432 so that cleaning and drying processes can take
place. As will be described hereinafter, the cleaning process takes
place while the wafer is still attached to the movable housing 432,
and, once cleaning occurs, a rotatable wafer transport device 460
will pick the wafer 410 off the movable housing 432 and rotate it
for drying. Once the wafer 410 is dry, it will be held by the
rotatable wafer transport device 460 in the exit area 404 mentioned
previously, the cover portion 442A will be raised, and then another
robot, such as either robot 114 or robot 116 depending upon the
system configuration used, will pick up the wafer 410 from its held
position on the rotatable wafer transport device 460 and transport
the wafer 410 to the next location.
[0056] FIG. 5 illustrates in further detail the components that are
located within the cleaning and drying area 440. As illustrated,
two cleaning rolls 452 and 454 are disposed on the front and back
surfaces of the wafer 410, respectively, are moved over a portion
the wafer 410 such that the entire radius of the wafer 410 is
covered. The rolls 452 and 454 are then rotationally driven, shown
by a motor 456 and, controlled by electronic control 490, although
other drive and control mechanisms could be used. With the rolls
452 and 454 spinning, the spools 436 are rotated using a motor, not
shown, disposed within the movable housing 432 and controlled by
electronic control 490. Rotation of the spools 436, each in the
same rotational direction, cause rotation of the wafer 410, so that
each part of the front and back surfaces of the wafer 410 contact
one of the rolls 452 and 454 at some point in time during the
cleaning process. During cleaning, as is known, a cleanser is
typically applied onto the wafer and the cleaning rolls remove
residue left from the chemical mechanical polishing process, and
then a DI water rinse is performed using spray jets 458. As noted
above, the rolls 452 and 454 and the spray jets 458 will operate
upon the wafer 410 while it is still maintained between the holding
spools 436 on the movable housing 432.
[0057] Once the wafer has been cleaned, it must be dried. For
drying, the rotatable wafer transport device 460 is used to pick
the wafer 410 off the holding spools 436, raise the wafer to a
rotation position, and rotate the wafer to dry it. The components
that make up the rotatable wafer transport device 460 include
rotatable shaft 462 that is rotated using a motor 470 and drive
components 472, and which is moved up and down using up/down
cylinder 474 connected through up/down drive components 476, all of
which are controlled through electronic control 490. Attached to
the rotatable shaft 462 is a wafer carrier 464 that contains clamps
466, the operation of which will be described further hereinafter
in conjunction with the release mechanism 480 that is also operated
through electronic control 490.
[0058] FIG. 6 illustrates a top view of the wafer 410 when it is
positioned between the holding spools 436, and the orientation of
clamps 466 with respect to the holding spools 436 so that provision
can be made to ensure that the wafer 410 is not dropped. In the
transfer of the wafer 410, the holding spools 436 are retained in
the closed position to ensure their hold on the wafer 410 until the
clamps 466 also have that hold, at which time the spools 436 are
moved to the open position, and the wafer 410 can move up, past the
upper lips 436B of the spools which are no longer holding the wafer
410. FIG. 7 further illustrates the release mechanism 480, that is
used to control the position of clamps 466, so that at certain
times the clamps are in a position that holds the wafer 410, and at
other times are in an outward position so that they do not
interfere with the wafer 410, as will now be described.
[0059] In the initial position after the wafer 410 has been cleaned
as described above, the wafer carrier 464 is disposed above the
wafer 410 so that the clamps 466 do not interfere with the cleaning
operation. The rotatable wafer transport device 460 must then be
moved into a position to pick up the wafer 410. When this movement
occurs, the clamps 466 must be disposed in an open position. This
open position is ensured by using the release mechanism 480, which,
through electronic control will cause activation of the rod 483
associated with the release cylinder 482, and cause downward
movement of release lever 484, and thus movement of release bar
485. The downward movement of release bar 485 will cause the angled
edge area 486 of the release bar 485 to move each horizontal
release member 487, associated with each clamp 466, and thus cause
each clamp 466 to pivot outwardly around pivot point 465. This open
position of clamps 466 is maintained even during a power outage
since the release cylinder 482 is locked into with the rod 483 in
the outward position, which requires another active signal from the
electronic control 490 to release the rod 483 that will thus allow
the clamps 466 to close.
[0060] Once the clamps 466 are in the correct position for holding
the wafer 410, but still in an open position, the active signal is
applied, and the clamps automatically close, since the spring force
from the springs 488 will cause retraction of the horizontal
release members 487, which in turn will cause the upward movement
of release bar 485.
[0061] With the clamps 466 in a closed position, the entire wafer
carrier 464, along with the release mechanism 480, is moved to a
spin position, where the wafer carrier 464, and thus the wafer 410,
is rotated for drying.
[0062] Thereafter, the wafer carrier 464 is moved so that the wafer
410 is in the exit position 404, and the wafer can be removed from
the clamps 466 onto another robot. It is noted that if a power
outage occurs when the clamps 466 hold the wafer 410, that the bias
from the springs 488 will still retain the wafer 410 and it will
not drop.
[0063] As shown in FIGS. 1-3, in these embodiments the wafer exit
position 404 is such that the first robot within the cassette
section will pick up the wafer. This reduces the number of
transport tasks required of the second robot within the handling
area of the processing section.
[0064] While the first robot within the cassette section can be
used to pick up the wafer from the wafer exit position, that is not
necessary for all configurations. Rather, in certain
configurations, the second robot can also pick up the wafer from
the wafer exit position.
[0065] One embodiment in which the second robot picks up the wafer
from the wafer exit position is illustrated in FIG. 8, which
embodiment shows a plurality of chemical mechanical polishing
stations 808D, made as described above, and which are used either
with or without an anneal processing station 808E. In this
embodiment, the robot 816 in the wafer handling area 809 moves the
wafers from the buffer 806 into either the anneal processing
station 808E or one of the chemical mechanical polishing stations
808D. The first robot 814 disposed within the cassette section 804
will move the wafers from their cassette to the buffer 806.
[0066] In each of the above embodiments, it is noted that it is
desirable for the first robot within the cassette section to pick
up the wafer with the front side up, and place the wafer with the
front side down on the buffer. Thereafter, the robot within the
wafer handling area of the processing section, and each of the
processing subsystems, will operate on the wafer with the front
side down. While this is not required, it reduces complexity and
minimizes movements of the wafer that could cause dropping of the
wafer.
[0067] FIG. 9 illustrates a view of the anneal chamber processing
station 908E in further detail. As illustrated, the anneal chamber
processing station 908E contains an open area 910 which allows the
anneal chamber processing station 908E to be added to an existing
system, with the open area 910 corresponding to the position of the
buffer 906. Thus, the buffer 906 is disposed above or below (above
as shown) the wafer entry/exit area 912 of the anneal chamber
processing station 908E.
[0068] In the various embodiments mentioned above, it has been
noted that the present invention is capable of operating upon
different sized wafers, which wafers are placed into a cassette
section. The size of the wafer in each of the different cassette is
known through, for example, a software tag that is used by a system
controller. Further, the robot arms that lift the wafers are
configured so that they can detect the center of each wafer,
regardless of size, and properly pick the wafer up.
[0069] In addition, for each wafer, the system controller is also
loaded with the process sequence, or recipe, that is needed for
that wafer, with various portions of the process sequence performed
by different processing stations. When sending a particular wafer
to a particular processing station, that portion of the recipe can
be sent in a command by the system controller to a processing
station module, and that process can then take place, which then
also allows tracking of the wafers that are being routed.
[0070] While in a production environment it is typical for each
wafer to have the same process sequence, and that is contemplated
by the present invention as well, in certain research settings,
have more control over the processing of each wafer has been found
beneficial. Thus, as each wafer is transported to the appropriate
processing station, which can include processing stations of the
same type which operate upon different sized wafers, the system
controller will track of the progress of the wafer through the
system, so that coordination of the transport of the wafer from
processing station to processing station can occur.
[0071] Each of the various subsystems that are referred to herein
preferably contain electronic control, such as the electronic
control 490 described with respect to the chemical mechanical
polishing apparatus 400, that allow each of the various subsystems
to operate in the integrated system and independently. During
operation with the integrated system, the electronic control of
each particular subsystem will work with the system controller to
ensure that operations with other subsystems and the wafer handling
system are synchronized with the overall system operation. During
operation of each subsystem independently, the electronic control
of the particular subsystem is capable of controlling the
operations performed by that particular subsystem. Accordingly,
since subsystems can be used together and independently, the same
subsystems can be used in a greater variety of configurations, thus
increasing their flexibility.
[0072] FIGS. 10-16 illustrates a chemical
treatment/cleaning/rinsing-drying module in accordance with another
embodiment of the present invention. The module of the present
invention is able to perform chemical treatment, apply mechanical
and megasonic cleaning means as well as rinse and dry processes in
the same module. In general, the chemical
treatment/cleaning/rinsing-drying module includes chemical
treatment/cleaning/rinse devices and drying devices placed in an
enclosure, and a movable housing. Chemical treatment/cleaning/rinse
devices may be roller brushes and various nozzles to spray DI water
or the chemical treatment solutions on the workpiece as well as
megasonic nozzles. Drying devices may be a spinner to spin dry the
workpiece. The enclosure of the module has an opening to allow the
movable housing in and out of the module.
[0073] The movable housing includes a support structure which
includes holders to hold a workpiece on the movable housing. The
holders may be comprised of support members and holding spools
placed on top of the support members. One of the holding spools can
also be used as a driving spool that rotates the workpiece as the
workpiece is held by the spools during the cleaning process. In
this embodiment, the movable housing may include a door, which
closes and seals the opening of the module when the housing is
inside the module. However, other mechanisms, which may seal the
opening of the module, may be used and is within the scope of this
invention. Once the movable housing is inside the module, the
driving spool also engages a gear connected to a drive motor and
rotates. This, in turn, rotates the workpiece on the movable
housing during the cleaning done by the chemical
treatment/cleaning/rinse devices and drying device. Once the
workpiece is cleaned, the drying assembly picks up the workpiece
and spin dries it. Although any other means of drying can also be
used to dry the workpiece. After the spin drying process, the
workpiece is transferred out of the module using a robotic arm.
[0074] FIG. 10 illustrates a simplified side view of a cluster tool
1100 including an embodiment of a chemical
treatment/cleaning/rinsing-drying module 1104 in accordance with
the present invention. In this embodiment, the cluster tool 1100
may include a plating or polishing module 1102, the chemical
treatment/cleaning/rinsing-drying module 1104, and a movable
housing 1106. The tool 1100 may be used in any of the systems
described above in connection with FIGS. 1, 2, 3 and 8. The
chemical treatment/cleaning/rinsing-drying module 1104 will be
referred to as module hereinafter. It is understood that the module
1104 may be used as an integral part of the tool 1100 or as an
individual stand-alone chemical treatment/cleaning/rinsing-drying
module. If the individual version of the module is preferred the
wafers may be fed and removed manually or by a robot. As shown in
FIG. 17, a plurality of modules may be placed in a system.
[0075] Although in the preferred embodiment the plating or
polishing module 1102 is a CMP module, it can be any process module
used in the overall workpiece manufacturing process such as ECMD,
ECME or ECD. It is understood that the cluster tool shown in FIG.
10 is similar to the CMP processing station 400 shown in FIG. 4.
Similar to the previous embodiment, a movable input housing (not
shown) receives a wafer from a robot 116, such as the second robot
shown in FIG. 1. The movable input housing (not shown) then moves
the wafer to the CMP module 1102. A workpiece 1108 can be
transferred from any module (i.e., the plating or polishing module
1102) to the module 1104 using the movable housing 1106.
[0076] The movable housing 1106 includes a center portion 1109
which is connected to a base 1114. Support members, namely
horizontal support members 1110 and vertical support members 1111,
are connected to the center portion 1109 by the horizontal support
members 1110. As will be described more fully below the workpiece
1108 is held over the vertical support members 1111. The movable
housing 1106 includes the base 1114 for moving the housing 1106
along tracks 1112. A door 1113 is connected to the base 1114 and
can be considered part of the housing 1106. The housing 1106 can be
moved along the tracks 1112 using any known method.
[0077] In conjunction with the movable housing 1106, the module
1104 is comprised of an enclosure 1105, a drying assembly 1200 and
chemical treatment/cleaning/rinse assembly 1300 such as brushes,
cleaning solution nozzles, megasonic cleaner nozzles and their
associated components.
[0078] The enclosure 1105 of the module 1104 includes an open end
1123 along the side wall of the enclosure. The open end 1123 is
known as the entry and exit area for the movable housing 1106. When
the housing 1106 is in the module 1104, the entry and exit area
1123 of the housing 1106 is sealed by the door 1113 when the
movable housing 1106 is in the module 1104.
[0079] The drying assembly 1200 is comprised of a rotatable wafer
transport device 1202 or a spinner and a spinner moving assembly
1204. The spinner 1202 of the module 1104 is comprised of a
rotating shaft 1190 and a spinning wheel 1118 that is attached to
the lower end of the shaft 1190. As will be described more fully
below, the spinner 1202 is rotated by the moving assembly 1204.
Clamps 1136 for holding the workpiece 1108 are attached to the
spinning wheel 1118 at its outer circumference. When the cleaning
and spin drying processes are completed, the workpiece 1108 is
transferred out of the module 1104 through the workpiece exit area
1140. The workpiece 1108 may be transferred out of the module 1104
using a robotic arm with a blade and vacuum. The workpiece 1108 can
also be transferred out using any other known transfer apparatus
and method.
[0080] FIG. 11 illustrates a side view of the module when the
movable housing 1106 is moved inside module 1104. The movable
housing 1106 holds wafer 1108 to be cleaned and spin dried while
the entrance 1123 of the module is sealed by the door 1113 of the
housing. In FIG. 11, the spinner is in fully retracted position to
allow cleaning of the workpiece. As previously explained, in the
previous embodiment, the housing retains the work piece such as a
wafer upside down so that a front side 1108' of the wafer 1108
faces down while a back side 1108'' of the wafer faces up. The
front side of the wafer may be preprocessed using CMP. FIG. 12
shows movable housing, in plan view, inside the module 1104.
Referring to FIGS. 11 and 12, center portion 1109 of the movable
housing is secured to the base 1114 in the center of the movable
housing 1106. The housing is moved using the rails 1112 engaged
both sides of the base 1114. Three of the horizontal support
members 1110 extend between the center portion and the vertical
support members 1111 and radially uniformly disposed around the
center portion 1109. The angle between two horizontal support
members is preferably 120 degrees. In this embodiment, the housing
has three horizontal and three vertical support members. The
vertical support members 1111 are attached to the outer ends of the
horizontal support members, and extend vertically and parallel to
the vertical axis "A" of the center portion 1109. Referring to FIG.
11, the upper ends of the vertical supports 1111 further include
spools or holding spools 1302 that are used to secure the workpiece
1108 during the cleaning process. Holding spools are previously
described above and in connection with FIGS. 4-5. The radial
position of the vertical supports 1111 can be arranged to
accommodate workpieces of different sizes (i.e., 200 mm, 300 mm,
etc.).
[0081] FIG. 11 also shows part of the spinner moving assembly 1204
and the spinner 1202. The spinner 1202 is attached to and is
rotated by a spinner drive motor 1116 of the moving assembly 1204
that is located on the ceiling 1183 of the enclosure 1105. The
drive motor 1116 is installed on a platform 1315 that is further
attached to an air cylinder 1314 (see FIG. 15). The air cylinder
1314 shown in FIG. 15 moves the drive motor 1116 and the spinner
vertically up and down by the air pressure. The drive motor 1116 is
attached to an upper end of the shaft 1190 of the spinner.
[0082] Clamps 1136 of the spinning wheel hold the workpiece 1108
during the drying process. Clamps 1136 are movably attached to the
ends of arms 1130 and are pneumatically controlled to pick up, hold
and release the workpiece before, during and after the spin-drying
process. The spinning wheel includes three arms 1130. Airlines 1135
from an air supply (not shown) runs through the shaft and then
distributed into the arms 1130 of the spinning wheel 1118. The
clamps 1136 are moved into open and closed positions by the pushers
1122', 1122'' which are movably located at the ends of the arms.
The pushers 1122' are spring loaded and bias and keep the clamps in
closed position. The pushers 1122'' are located at the end of the
airlines 1135 in each arm 1130. In order to open the clamps,
pressurized air from the air lines 1135 is used to move air
activated pushers 1122' towards the clamps and thus cause each
clamp to pivot outwardly around pivot point P. When the air
pressure is released, the pusher 1122' causes clamps to pivot
inwardly around the pivot point "P" and thereby closing them. The
spinner and its components can be controlled by an electronic
control system similar to the one described in the previous
embodiment.
[0083] FIG. 13 shows a side view of the module 1104 with the
chemical treatment/cleaning/rinse assembly 1300 including
mechanical cleaners, such as a pair of rollers brushes 1132 and
megasonic nozzle 1137 and spray nozzles 1141a-1141e. Nozzles are
placed on the side walls or floor of the enclosure 1105 of the
module. In this embodiment, nozzle 1141a spray a solution depicted
by S to the back side of the workpiece 1108 while the nozzles
1141b-1141e are able to spray the solution S to the front side of
the workpiece while the workpiece is rotated on the movable housing
1106. In this embodiment, solution depicted by S may be a chemical
solution to chemically treat the workpiece or DI water to rinse the
workpiece.
[0084] Referring to FIG. 12 and FIG. 13 brushes 1132 and megasonic
nozzle 1137 are shown in home position I and cleaning positions II
and III. The roller brushes clean the front and back sides 1108',
1108'' of the rotating wafer 1108 while rotating and performing a
sweeping action between the positions II and III. Various
mechanical actions of the brushes and the megasonic nozzle are
controlled by a drive unit 1139. As will be described below, the
workpiece is rotated on the movable housing 1106 using a workpiece
rotating mechanism. Megasonic nozzle is next to the brush 1132 that
works on the back side 1108'' of the workpiece. Megasonic nozzle
1137 generates megasonic waves during the cleaning process. In
particular, megasonic waves dislodge the particulates that are hard
to remove using brushes. In this respect, the megasonic nozzle may
be used with the brushes at the same time or by itself before the
brush cleaning or again by itself after the brush cleaning.
[0085] FIG. 13 also illustrates a workpiece rotating mechanism 1123
in accordance with the present invention. The workpiece 1108 can be
rotated using one of the vertical supports, which will be referred
to as drive support. The drive support includes a support gear. As
previously mentioned, one of the vertical supports 1111 is
furnished with a drive member that enables it to rotate. As this
particular support rotates, it also rotates the spool 1302 on top
of it. Rotation of the spool 1302 in turn rotates the wafer that is
held by the spools. The support is rotated by a drive gear 1128 of
the workpiece rotating mechanism 1123 when support gear 1129 of the
drive support engages the drive gear 1128 of the workpiece rotating
mechanism 1123. The drive gear 1128 is attached to a plunger 1126
that is movable placed in a sleeve 1127 which allows the plunger
1126 to move back and forth and rotate in the sleeve. When plunger
is rotated by a drive motor (not shown) attached on a side wall,
the drive gear 1128 rotates and also rotates the drive support.
[0086] As shown in FIGS. 14A and 14B, in one embodiment, roller
brushes are used. They may be cylindrical and a cleaning solution
may be delivered through them. In this embodiment, the roller
brushes 1132 may have a conical or tapered shape. In one
manufacturing method, a brush section 1400, which is cylindrical,
is fitted onto a brush shaft 1410 that has conical shape, thereby
taking the shape of the shaft. This configuration eliminates the
cleaning differential between the slow moving central region and
the fast moving edge region of a workpiece or the wafer during
brush cleaning. With conventional cylindrical roller brushes,
cleaning of the slow moving central region of the wafer takes
longer time. This cleaning differential may be avoided if a roller
brush is able to exert more pressure on the central region than the
edge region. This may be provided by making the brush conical so
that a first end 1420 of the brush that touches the central region
of the wafer applies more pressure and speeds up the cleaning. A
second end 1430 of the brush is narrower, thus exerts less pressure
to the edge region of the wafer. Force applied onto the central
region compensates the cleaning difference that occurs due to the
difference in velocities of edge and central regions of the
wafer.
[0087] FIG. 15 shows the details of the moving assembly of the
spinner 1202. In FIG. 15, the spinner is in fully extended position
to pick up the wafer for drying process from the movable housing
after the chemical treatment, cleaning and rinsing steps of the
process. The drive motor 1116 of the spinner is installed on the
platform 1315 that is further attached to the air cylinder 1314.
The air cylinder 1314 moves the drive motor 1116 and the spinner
vertically up and down. The drive motor 1116 is attached to an
upper end of the shaft 1190 of the spinner. Spring 1117 is also
attached to the platform 1315 for balance purposes.
[0088] FIG. 16 shows the module 1104 in side view in which the
spinner 1202 has picked up the wafer 1108 and fully retracted to
spin dry the wafer 1180. During operation, once plating or
polishing is completed, the movable housing 1106 receives the
workpiece on three holding spools installed on supports 1111. As
described earlier, the supports 1111 are attached to the bars 1110
and the center portion 1109. As soon as a sensor (not shown) senses
that the workpiece 1108 is positioned on the holding spools, the
workpiece 1108 is secured, and the movable housing 1106 is moved
into the module 1104 through the opening 1123. The door 1113 makes
contact with the side wall of module 1104 and adjusts itself to
provide a proper seal. The movable housing 1106 then positions
itself in the center of the module 1104.
[0089] When the movable housing 1106 is properly positioned, the
drive support gear engages with the gear on the plunger. The
rotation of the drive support causes the workpiece 1108 to rotate.
When the workpiece 1108 is rotating, cleaning rolls 1132 can then
make contact with the top and bottom surfaces of the workpiece 1108
to begin the chemical treatment/cleaning/rinsing-drying process.
Although it may be applied in different order, the process may
include a chemical treatment first step, a second step of brush and
megasonic cleaning and a third step of DI rinsing followed by spin
drying. The chemical treatment step may be performed by spraying
acidic or basic solutions from the nozzles to clean the wafer. The
nature of the solution depends on the material to be cleaned. The
chemical treatment solution may also contain a passivating agent
(for corrosion prevention). A passivation step may also be
performed using a passivation solution. For example, for post CMP
copper cleaning of wafers, citric acid may be used to clean wafers.
In this example, a passivating agent such as BTA may be used with
the chemical treatment solution or rinsing water or by itself.
Rollers and the megasonic nozzle may be used during the chemical
treatment or after the treatment as a separate cleaning step. After
the chemical treatment, brush and megasonic cleaning, the wafer
1108 can be rinsed using de-ionized water, as discussed earlier.
The passivation agent may also be added to the rinsing water.
[0090] After the workpiece 1108 is rinsed, a drying process is
required. Before the drying process, rotation mechanism is
disengaged from the movable housing to stop rotating the wafer.
Clamps 1136 are used to pick up the workpiece from the spools of
the supports 1111. The spinner moves downward and compressed air is
delivered to the spinning wheel 1118. The pushers 1122' then push
the clamps 1136 to an "open" position. Simultaneously, the center
portion 1109 opens to release the workpiece 1108. When air is shut
off, the pushers 1122' push the clamps 1136, thereby forcing them
to contract on the workpiece 1108. Afterwards, spinning wheel 1118
with the workpiece 1108 is moved vertically upwardly and the wheel
1118 and the workpiece 1108 are spun. After the workpiece 1108 is
dried, an outside robotic arm from location 1140 (FIG. 10) engages
the workpiece 1108 so it can be transferred out of the module
1104.
[0091] As shown in FIG. 17, a plurality of chemical
treatment/cleaning/rinsing-drying modules, made as described above,
may form a system 1500. The system 1500 may comprise a cassette
section 1502, a buffer 1504, a wafer handling area 1505 and
chemical treatment/cleaning/rinsing-drying modules 1506A-1506F. In
this embodiment, the robot 1508 in the wafer handling area moves
the wafers from the buffer 1504 into one of the chemical
treatment/cleaning/rinsing-drying modules. The first robot 1510
disposed within the cassette section 1502 will move the wafers from
their cassette to the buffer 1504. In this embodiment location of
the chemical treatment/cleaning/rinsing-drying modules may be
configured side by side as in the manner shown in FIG. 17, or any
other configuration for example the modules may be stacked on top
of each other.
[0092] Although various preferred embodiments have been described
in detail above, those skilled in the art will readily appreciate
that many modifications of the exemplary embodiment are possible
without materially departing from the novel teachings and
advantages of this invention.
* * * * *