U.S. patent application number 11/695310 was filed with the patent office on 2007-07-26 for wafer handler method and system.
Invention is credited to Stanley W. Stone.
Application Number | 20070173044 11/695310 |
Document ID | / |
Family ID | 34520848 |
Filed Date | 2007-07-26 |
United States Patent
Application |
20070173044 |
Kind Code |
A1 |
Stone; Stanley W. |
July 26, 2007 |
Wafer Handler Method and System
Abstract
Systems and methods for handling wafers include retrieving a
first wafer from a wafer cassette using a first arm, transferring
the first wafer from the first transfer arm to a second arm,
delivering the first wafer for processing to a process chamber
using the second arm, removing the first wafer from the process
chamber using the first arm, and returning the first wafer to the
cassette using the first arm. The systems and methods can include
retrieving a first wafer from a wafer cassette using a first arm,
delivering the first wafer for processing to a process chamber
using the first arm, removing a processed wafer from the process
chamber using a second arm, returning the processed wafer to the
cassette using the second arm, and iteratively retrieving,
delivering, removing and returning wafers from the cassette while
alternating arms between iterations.
Inventors: |
Stone; Stanley W.;
(Rockport, MA) |
Correspondence
Address: |
FOLEY HOAG, LLP;PATENT GROUP, WORLD TRADE CENTER WEST
155 SEAPORT BLVD
BOSTON
MA
02110
US
|
Family ID: |
34520848 |
Appl. No.: |
11/695310 |
Filed: |
April 2, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10687023 |
Oct 16, 2003 |
7214027 |
|
|
11695310 |
Apr 2, 2007 |
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Current U.S.
Class: |
438/514 ;
414/222.01 |
Current CPC
Class: |
Y10S 414/139 20130101;
H01L 21/67201 20130101; H01L 21/67745 20130101; H01L 21/67184
20130101 |
Class at
Publication: |
438/514 ;
414/222.01 |
International
Class: |
H01L 21/425 20060101
H01L021/425 |
Claims
1. A system for handling wafers, the system comprising: a first arm
for handling wafers, a distinct second arm for handling wafers, a
first cassette of wafers, and, a wafer processing system, where
wafers are delivered to the processing system from the first
cassette using the first arm and the second arm, and where the
delivery includes, individually retrieving a first wafer from the
cassette using the first arm, transferring the first wafer from the
first arm to the second arm, delivering the first wafer for
processing by the wafer processing system using the second arm,
processing the first wafer to generate a processed wafer, while
retrieving a next wafer from the cassette using the first arm,
transferring the next wafer to the second arm, removing the
processed wafer using the first arm and delivering the next wafer
for processing using the second arm, processing the next wafer to
generate a processed wafer while returning the processed wafer to
the cassette, and iteratively performing the processing,
transferring, removing, and processing to process the wafers in the
cassette.
2. A system according to claim 51, further including a first load
lock for the first cassette.
3. A system according to claim 51, further including an orienter
for orienting the wafers before processing and transferring the
wafers between the first arm and the second arm.
4. A system according to claim 51, further including a platen for
retrieving wafers from the second arm for delivering the wafers,
and transferring processed wafers to the first arm for removing the
processed wafers.
5. A system for handling wafers, the system comprising: a first arm
for handling wafers, a distinct second arm for handling wafers, a
first cassette of wafers, and, a wafer processing system, where
wafers are delivered to the processing system from the first
cassette using the first arm and the second arm, and where the
delivery includes, individually retrieving a first wafer from the
cassette using the first arm, delivering the first wafer for
processing by the wafer processing system using the first arm,
returning a processed wafer to the cassette using a second arm
while processing the first wafer to generate a processed wafer,
retrieving a next wafer from the cassette using the second arm,
removing the processed wafer using the first arm and delivering the
next wafer for processing using the second arm, processing the next
wafer to generate a processed wafer while returning the processed
wafer to the cassette, and iteratively performing the retrieving,
delivering, returning, retrieving, removing, and processing to
process the wafers in the cassette.
6. A system according to claim 55, further including a first load
lock for the first cassette.
7. A system according to claim 55, further including an orienter
for orienting the wafers before processing.
8. A system according to claim 55, further including a platen for
retrieving wafers from the first and second arms for processing the
wafers, and transferring processed wafers to the first and second
arms for removing the processed wafers.
9. A system according to claim 55, further including at least one
carriage for moving the first and second arms relative to the
cassette for returning and retrieving wafers from the cassette.
Description
RELATED APPLICATIONS
[0001] This application is a divisional of, claims priority to, and
incorporates by reference, the entire disclosure of U.S. patent
application Ser. No. 10/687,023, filed on Oct. 16, 2003.
BACKGROUND
[0002] 1. Field
[0003] The disclosed methods and systems relate generally to
semiconductor processing, and more particularly to wafer handling
methods and systems.
[0004] 2. Description of Relevant Art
[0005] Some challenges of semiconductor manufacturing include
providing a manufacturing process that produces reduced process
defects with increased process throughput. These manufacturing
concerns can also be balanced with other requirements that include
a need for reduced contamination.
[0006] FIG. 18 provides one semiconductor wafer processing system
10 where, for example, a cassette of semiconductor wafers
("wafers") can be presented to left and right load locks 12, 14 to
allow wafer transfers to a processing chamber 16 such as, for
example, an ion implantation chamber. The load locks 12, 14 can be
understood to be an interface between a loading station and the
processing chamber 16. Because the wafers can be loaded from a
loading station that may often be at atmospheric pressure, once the
wafers are presented to the load locks 12, 14, the lock loads 12,
14 can be isolated from the loading station and the processing
chamber 16. A load lock vacuum pump, for example, can thus reduce
the load lock pressure, or "evacuate" a respective load lock 12,
14, in accordance with, or to be consistent with the processing
chamber pressure.
[0007] Wafers from the cassettes in the left and right load locks
12, 14 can be processed in turn, alternating between left and right
load locks 12, 14. Accordingly, in a system according to FIG. 18,
the left and right load locks 12, 14 can be substantially
simultaneously evacuated and thereafter opened or otherwise
interfaced to the processing chamber 16. For exemplary purposes, a
left arm 18 can retrieve a wafer from the left load lock cassette,
and present the retrieved wafer to a left orienter 20 that can
locate a wafer notch to align the wafer center with the orienter
axis of centricity. The left arm 18 can thereafter deliver the
wafer to a platen 22 in the process chamber 16, and thereafter, the
left arm 18 can be displaced to allow wafer processing. Once the
wafer is processed, the left arm 18 can deliver the wafer from the
platen 22 to the left orienter 20 and hence to the left load lock
cassette. As FIG. 18 indicates, a wafer from the right load lock
cassette can be retrieved by a right robot 24 and placed on a right
orienter 26 before being delivered to the platen 22 for processing.
Such wafer can also be returned to the right load lock 14 after
processing is complete. As provided previously herein, throughput
for a system according to FIG. 18 can be improved by coordinating
the alternating delivery of wafers from the left and right load
lock cassettes to reduce delay between deliveries to the platen
22.
[0008] For a system according to FIG. 18, once the wafers from the
left and right load lock cassettes are processed and returned to
the load lock cassettes, the load locks 12, 14 can be isolated from
the processing chamber 16 to allow a substantially simultaneous
venting of the load locks 12, 14 and a return to a pressure
according to, or otherwise consistent with the loading station
pressure. The interfaces between the respective load locks 12, 14
and the loading station(s) can then be opened to allow transfer of
the left and right cassettes in accordance with a processing
methodology.
[0009] Batch vacuum load locks such as those according to FIG. 18
can experience poor cycle time because the larger volume of a batch
load lock can present a longer evacuation time, during which wafers
are being processed from neither the left nor right load locks 12,
14.
SUMMARY
[0010] The systems and methods disclosed herein can include wafer
handling methods and systems for retrieving wafers from a storage
position, delivering the wafers to a process chamber and returning
the processed wafers to the storage position a method for handling
wafers can include retrieving a first wafer from a wafer cassette
using a first arm, transferring the first wafer from the first arm
to a second arm, delivering the first wafer for processing using
the second arm so as to generate a processed wafer, removing the
processed wafer from processing using the first arm and returning
the processed wafer to the storage position using the first
arm.
[0011] The method can include delivering the first wafer using the
second arm while retrieving a next wafer from the storage position
using the first arm. The first wafer can be oriented prior to being
transferred. The method can further include processing the first
wafer in the process chamber, wherein processing can include
performing photoresist, dry etch, ion implantation, chemical
deposition, and/or diffusion. Processing can also include orienting
the next wafer and/or transferring the next wafer from the first
arm to the second arm.
[0012] The storage position can be a wafer cassette and retrieving
the first wafer or returning the processed wafer can include
indexing the cassette.
[0013] Returning the processed wafer using the first arm can
include delivering the next wafer for processing using the second
arm or placing the second arm in a standby position. Transferring
the wafers between arms can include aligning the first arm and the
second arm to facilitate the transfer. Transferring can include
controlling an orienter to transfer the first wafer from the first
arm to the second arm.
[0014] In another embodiment a method for handling wafers can
include retrieving a first wafer from a wafer cassette using a
first arm, transferring the first wafer from the first arm to a
second arm, delivering the first wafer for processing using the
second arm while retrieving a distinct next wafer from the wafer
cassette using the first arm, processing the first wafer to
generate a processed wafer, while transferring the next wafer from
the first arm to the second arm, removing the processed wafer from
processing using the first arm and delivering the next wafer for
processing using the second arm while returning the processed wafer
to the cassette using the first arm.
[0015] The method can include retrieving a distinct next wafer from
the cassette using the first arm while processing the next wafer,
and iteratively performing the processing, removing, and
delivering. Processing can include performing photoresist, dry
etch, ion implantation, chemical deposition, and/or diffusion.
Transferring can include controlling an orienter to transfer the
first wafer between the first arm and the second arm. Retrieving
can include indexing the cartridge.
[0016] In a further embodiment, a method for processing wafers from
two or more load locks can include processing wafers from a first
wafer cassette in a first load lock, where the wafers are delivered
for processing from the first wafer cassette using two arms,
performing load lock processing for at least a second load lock to
obtain a processed load lock while processing the wafers of the
first wafer cassette, completing the processing of the first wafer
cassette and processing wafers from a second wafer cassette in the
processed load lock, where the wafers are delivered for processing
from the second wafer cassette using two arms. The method can
include performing load lock processing of the first load lock upon
completion of processing of the first wafer cassette. Additionally,
the method can include performing load lock processing of the first
load lock upon completion of processing of the first wafer
cassette, completing the processing of the second wafer cassette
and processing wafers from a replacement wafer cassette in the
first load lock, where the wafers are delivered for processing from
the replacement wafer cassette using two arms. Performing load lock
processing can include evacuating, venting, isolation, cassette
removal, cassette replacement, cassette installation, and/or lock
valve control.
[0017] In one embodiment a system for handling wafers can include a
first arm for handling wafers, a distinct second arm for handling
wafers, a first cassette of wafers and a wafer processing
system.
[0018] The wafers can be delivered to the processing system from
the first cassette using the first arm and the second arm, and the
delivery can include individually retrieving a first wafer from the
cassette using the first arm, transferring the first wafer from the
first arm to the second arm, delivering the first wafer for
processing by the wafer processing system using the second arm,
processing the first wafer to generate a processed wafer, while
retrieving a next wafer from the cassette using the first arm,
transferring the next wafer to the second arm, removing the
processed wafer using the first arm and delivering the next wafer
for processing using the second arm, processing the next wafer to
generate a processed wafer while returning the processed wafer to
the cassette and iteratively performing the processing,
transferring, removing, and processing to process the wafers in the
cassette.
[0019] The system can include a first load lock for the first
cassette, an orienter for orienting the wafers before processing
and transferring the wafers between the first arm and the second
arm and a platen for retrieving wafers from the second arm for
delivering the wafers, and transferring processed wafers to the
first arm for removing the processed wafers.
[0020] In a further embodiment a method for handling wafers can
include retrieving a next wafer from a selected cassette using a
first arm, transferring the next wafer to a second arm, removing a
processed wafer from a process system using the first arm,
delivering the next wafer to the process system using the second
arm and returning the processed wafer to the selected cassette
using the first arm.
[0021] In one aspect, the method can iteratively return to
retrieving. Transferring can include using an orienter to transfer
the next wafer. The processed wafer can be oriented before
returning the processed wafer and a cassette can be selected prior
to retrieving. The method can determine whether unprocessed wafers
remain in the selected cassette, and, based on the determination,
can select a new cassette and iteratively return to retrieving,
and/or perform load lock processing associated with the processed
cassette.
[0022] In one embodiment, a method for handling wafers can include
retrieving a next wafer from a storage position using a first arm,
removing a processed wafer from processing using a second arm,
delivering the next wafer for processing, returning the processed
wafer to the storage position, and iteratively performing the
retrieving, delivering and returning while alternating using the
first arm and the second arm between iterations. Returning can
include returning while processing the next wafer in a process
chamber. Processing can include performing at least one of
photoresist, dry etch, ion implantation, chemical deposition, and
diffusion. The method can include orienting the next wafer prior to
delivering the next wafer. The storage position can be a wafer
cassette, and retrieving and returning the processed wafer to the
cassette can include indexing the cassette. Returning the processed
wafer to the storage position using the second arm can include
placing the first arm in a standby position.
[0023] In one embodiment, a method for handling wafers can include
retrieving a first wafer from a wafer cassette using a first arm
while removing a processed wafer from processing using a second
arm, delivering the first wafer for processing, returning the
processed wafer to the wafer cassette while processing the first
wafer to generate a processed wafer, retrieving a next wafer from
the wafer cassette using the second arm while removing the
processed wafer from processing using the first arm, delivering the
next wafer for processing, returning the processed wafer to the
wafer cassette while processing the next wafer to generate a next
processed wafer, and iteratively performing the retrieving,
delivering and returning while alternating using the first arm and
the second arm between iterations. The method can include orienting
the first wafer prior to delivering the first wafer, and orienting
the next wafer prior to delivering the next wafer. Retrieving can
include indexing the cassette. Delivering the first and next wafers
can include processing the first and next wafers in a process
chamber and processing can include performing at least one of
photoresist, dry etch, ion implantation, chemical deposition, and
diffusion.
[0024] In one embodiment, a system for handling wafers can include
a first arm for handling wafers, a distinct second arm for handling
wafers, a first cassette of wafers, and a wafer processing system,
where wafers are delivered to the processing system from the first
cassette using the first arm and the second arm, and where the
delivery includes, individually retrieving a first wafer from the
cassette using the first arm, delivering the first wafer for
processing by the wafer processing system using the first arm,
returning a processed wafer to the cassette using a second arm
while processing the first wafer to generate a processed wafer,
retrieving a next wafer from the cassette using the second arm,
removing the processed wafer using the first arm and delivering the
next wafer for processing using the second arm, processing the next
wafer to generate a processed wafer while returning the processed
wafer to the cassette, and iteratively performing the retrieving,
delivering, returning, retrieving, removing, and processing to
process the wafers in the cassette.
[0025] The system can include a first load lock for the first
cassette and an orienter for orienting the wafers before
processing. The system can include a platen for retrieving wafers
from the first and second arms for processing the wafers, and
transferring processed wafers to the first and second arms for
removing the processed wafers. The system can include at least one
carriage for moving the first and second arms relative to the
cassette for returning and retrieving wafers from the cassette.
[0026] Other objects and advantages will become apparent
hereinafter in view of the specification and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 illustrates a system that includes a first and second
arm for handling wafers;
[0028] FIG. 2 illustrates a first arm in a load lock retrieval
position, with a second arm in a standby position;
[0029] FIG. 3 illustrates the first arm in an orienter position,
with the second arm in a standby position;
[0030] FIG. 4 illustrates the first and second arms in the orienter
positions for a delivery of an initial wafer for processing;
[0031] FIG. 5 illustrates the first arm in a load lock retrieval
position, with the second arm in a process position;
[0032] FIG. 6 illustrates the first arm in the orienter position,
with the second arm in a standby position;
[0033] FIG. 7 illustrates the first and second arms in the orienter
positions for a delivery of a non-initial wafer for processing;
[0034] FIG. 8 illustrates the first arm in a platen retrieval
position, with the second arm in a process position;
[0035] FIG. 9 illustrates the first arm in an orienter position,
with the second arm in a process position;
[0036] FIG. 10 illustrates the first arm in a load lock delivery
position, with the second arm in a standby position;
[0037] FIG. 11 illustrates the first arm in an orienter position,
with the second arm in a standby position;
[0038] FIG. 12 illustrates the first arm in a load lock retrieval
position, with the second arm in a standby position;
[0039] FIG. 13 illustrates the first arm in an orienter position,
with the second arm in a standby position;
[0040] FIG. 14 illustrates the first and second arms in the
orienter positions for a delivery of a non-initial wafer for
processing;
[0041] FIG. 15 illustrates a block diagram for one disclosed system
and method;
[0042] FIGS. 16A- 16C illustrate an embodiment of a system that
includes a first and second arm for handling wafers;
[0043] FIG. 17 illustrates a block diagram for another disclosed
system and method; and,
[0044] FIG. 18 illustrates a prior art system.
DESCRIPTION
[0045] To provide an overall understanding, certain illustrative
embodiments will now be described; however, it will be understood
by one of ordinary skill in the art that the systems and methods
described herein can be adapted and modified to provide systems and
methods for other suitable applications and that other additions
and modifications can be made without departing from the scope of
the systems and methods described herein.
[0046] Unless otherwise specified, the illustrated embodiments can
be understood as providing exemplary features of varying detail of
certain embodiments, and therefore, unless otherwise specified,
features, components, modules, and/or aspects of the illustrations
can be otherwise combined, separated, interchanged, and/or
rearranged without departing from the disclosed systems or methods.
Additionally, the shapes and sizes of components are also exemplary
and unless otherwise specified, can be altered without affecting
the disclosed systems or methods.
[0047] The disclosure includes wafer handling methods and systems
for retrieving wafers from a wafer cassette in a load lock,
delivering the wafers to a process chamber, and returning the
processed wafers to the cassette. The methods and systems include a
first arm and a second arm that can be coordinated to perform the
retrieval, delivery, and return of wafers to allow wafers from the
same cassette and/or load lock to be sequentially processed. As
provided herein, sequential processing is not to be understood as
implying an order of retrieval from the cassette.
[0048] Accordingly, for the disclosed methods and systems, a first
arm for handling wafers can be understood to be a robotic or other
mechanical, electrical, and/or electromechanical arm that may be
capable of handling wafers as provided herein. The first arm can be
of varying shape such as c-shaped, u-shaped, or another shape, and
the methods and systems herein are not limited by a type and/or
shape of arm, or a method or system by which the arm may be
controlled. The methods and systems also include a second arm.
Although the illustrated embodiments indicate that the second arm
can be the same as the first arm, one of ordinary skill will
recognize that the first arm and the second arm can have a
different shape, structure, components, and methods, and may have a
different controller from the first arm, although in an embodiment
where different controllers may be used, such first arm and second
arm controllers can be coordinated to provide a method and system
as provided herein.
[0049] Although the figures presented herein illustrate two load
locks referred to as left and right load locks 12, 14, the
disclosed methods and systems are not so limited, and include
methods and systems with one or more load locks. Further, it can be
understood that for the illustrated embodiments that indicate two
load locks and where the methods and systems are described relative
to the left load lock 12, such methods and systems can also be
applied to the right load lock 14.
[0050] FIG. 1 shows one embodiment according to the disclosed
methods and systems for handling wafers that includes left and
right load locks 12, 14. As provided herein, the methods and
systems will be described relative to the left load lock 12 with
the understanding that the methods and systems can be applied to
the right load lock 14. The Figures illustrate positions that may
be engaged by a first arm 18 and a second arm 30 that can access
the left load lock 12. As will be provided herein, the first arm 18
can be positioned in positions that include at least a load lock
position to allow the first arm 18 to retrieve and/or return a
wafer from/to the cassette 32 in the left load lock 12, an orienter
position to allow the first arm 18 to interface with at least an
orienter 20, and a process position to allow the first arm 18 to
retrieve a wafer from a process chamber 16. Those of ordinary skill
will recognize that the methods and systems can be applied to
various process systems for delivering wafers to process chambers
that perform, for example, at least one of photoresist, dry etch,
ion implantation, chemical deposition, and diffusion, although such
examples are provided for illustration and not limitation, and
other processing can be performed in the process chamber 16.
Although the illustrated embodiments indicate the use of wafer
cassette 32, one of ordinary skill will recognize that other wafer
storages means that that can present wafers for retrieval from a
storage position such as a load lock can be employed and that the
systems and methods described herein can be adapted for use
therewith.
[0051] The second arm 30 can be positioned in positions that
include at least a standby position to allow the second arm 30 to
not interfere with processing of a wafer or with the first arm's
interaction with the orienter 20, an orienter position to allow the
second arm 30 to interface with at least the orienter 20, and a
process position to allow the second arm 30 to deliver a wafer to
the process chamber 16. Accordingly, based on an embodiment, a
standby position and an orienter position may be the same position
for the second arm 30. One of ordinary skill thus recognizes that
unlike the other arm positions described herein that can be based
on, for example, the orienter, the load lock, and a platen, the
standby position is not so defined and may include a number of
positions, including other defined positions.
[0052] It can thus be recognized that the first arm 18 and the
second arm 30 include orienter positions and process chamber
positions, and as provided herein, vertical transfers of wafers
between the first arm 18 and the second arm 30 can be performed
while such arms 18, 30 may be maintained in such positions.
Accordingly, the first arm 18 and the second arm 30 can be arranged
to allow a distance that facilitates independent operation when
vertically aligned, while recognizing that a reduced vertical
distance between the first and second arms 18, 30 may reduce
processing time to transfer wafers between the same. Although such
vertical distance between such arms 18, 30 can thus vary based on
system characteristics, in one embodiment, when vertically aligned,
the first and second arms 18, 30 can be separated by less than
approximately five-eights to one-half of one inch.
[0053] Returning again to FIG. 1, one of ordinary skill may
recognize that the chamber 16 is shown to be enlarged to
accommodate the second arm 30 which may be understood to be
illustrated in one of the aforementioned standby positions. It can
be understood that such enlargement of the process chamber 16 is
optional, and in some embodiments, such enlargement may not be
necessary to accommodate one or more standby positions for the
second arm 30.
[0054] As one of ordinary skill in the art also recognizes, the
cassette 32 can be introduced to the load lock 12 via a loading
station, where the load lock can be isolated from the loading
station and the process chamber 16 to allow the load lock pressure
to be altered according to (e.g., to be consistent with) the
pressure in the process chamber 16. For example, a vacuum or other
pressure device can lower the pressure in the load lock. Once the
load lock pressure is sufficiently altered, a valve 34 or other
mechanism can be altered to allow at least the first arm 18 from
the process chamber 16 to access the load lock 12, and
specifically, wafers included in the cassette 32.
[0055] It may thus be understood that the cassette can include one
or more wafers, but in an illustrative example, can include
approximately twenty-five to fifty wafers. Referring to FIG. 2, the
first arm 18 can thus be configured to access wafers in the
cassette 32 to allow the first arm 18 to retrieve a wafer. Those of
ordinary skill will recognize that the cassette 32 may be
controlled and/or indexed and such control and/or indexing may be
coordinated with the operation of the first arm 18 to facilitate
retrieval of a wafer. FIG. 2 illustrates the second arm 30 in a
standby mode, and although such may be the case for an initial
wafer retrieved from a cassette 32, as provided herein, for
subsequent wafer retrievals, the second arm 30 may not be
positioned in a standby mode. Furthermore, the second arm 30 may be
in another "standby" position, such as in the orienter
position.
[0056] FIG. 3 presents the first arm 18 in the orienter position to
allow the retrieved wafer to be oriented for processing. Those of
ordinary skill in the art will recognize that the orienter 20 can
be controlled or otherwise operated in the illustrated systems to
allow for the orienter 20 to be vertically aligned with at least
the first arm 18 when the first arm 18 is in the orienter position,
and accordingly, the orienter 20 can be adjusted as needed to
interface with the first arm 18 to allow orientation of the wafer.
At such time, the second arm 30 may be in a standby position,
although as provided herein, the second arm 30 may be in another
position such as the orienter position.
[0057] Referring to FIG. 4, the orienter 20 can facilitate a
transfer of the wafer from the first arm 18 to the second arm 30,
where such first and second arms 18, 30 can be vertically aligned
to allow such transfer by the orienter 20. Accordingly, the
illustrated orienter 20 can be controlled for vertical
displacement. It may be recognized that the vertical alignment of
the first and second arms 18, 20 can be performed at a time prior
to the transfer of the wafer by the orienter 20, and the disclosed
methods and systems are not limited by the moment and/or timing of
the alignment unless otherwise provided herein. Accordingly, the
alignment may occur during orientation, or the alignment may occur
prior to wafer orientation.
[0058] FIG. 5 shows a delivery of the wafer by the second arm 30
for processing, where in the illustrated systems, the processing
area can be a platen 22. As FIG. 5 also illustrates, as the second
arm 30 is in the process position, the first arm 18 can be in a
load lock position to retrieve a second (or "next") wafer from the
cassette 32. Accordingly, the cassette 32 can be controlled or
indexed in association with the first arm 18 to allow the first
arm's 18 retrieval of the next wafer.
[0059] For the discussion herein, the "next" wafer can be
understood to the be next wafer retrieved for processing, and will
be referred to as the "next" wafer until the wafer is processed,
whereupon such wafer can be referred to as the processed wafer.
[0060] FIG. 6 indicates the first arm 18 in an orienter position
while the second arm 30 resides in an arbitrary standby position.
As FIG. 6 also indicates, the first wafer can be processed 36 in
the process chamber 16 while the next wafer may be oriented by
orienter 20. Further, the second arm 30 may be in an alternate
(e.g., orienter) position, as shown in FIG. 7. FIG. 7 also
accordingly indicates, similar to FIG. 4, a transfer of the next
wafer from the first arm 18 to the second arm 30 where such
transfer is facilitated by the orienter 20 as previously provided
herein with respect to FIG. 4. Depending on the process system, the
first wafer may be processed 30 during such transfer of the second
wafer from first arm 18 to second arm 30.
[0061] FIG. 8 indicates a movement of the first arm 18 and the
second arm 30 to the process position after a transfer of the next
wafer to the second arm 30 and after processing of the first wafer
(now the "processed" wafer). Although FIG. 8 indicates a
simultaneous movement of the first and second arms 18, 30 from an
orienter position to a process position, such movement can be
non-simultaneous. In a configuration according to FIG. 8, the first
or processed wafer can be transferred from and/or by the processing
system to the first arm 18 and the next wafer can be delivered to
the processing system by the second arm 30. Such first/processed
and next wafer transfers between the processing system, first arm
18, and second arm 30 can be coordinated to eliminate interface
between the processed and next wafers. Accordingly, for example, in
an ion implantation system, a platen 22 can be controlled or
otherwise employed to transfer the first wafer to the first arm 18
for removal from processing, while thereafter, the platen 22 can
retrieve the next wafer from the second arm 30.
[0062] FIG. 9 indicates that once the platen 22 transfers the first
or processed wafer to the first arm 18, the first arm 18 can return
to an orienter position while the second arm 30 can remain in the
process position to allow the platen 22 to transfer the next wafer
from the second arm 30. The first or processed wafer can thus also
be returned to the cassette 32 in the left load lock 12, as shown
by FIG. 10. Such illustration thus indicates that the cassette 32
can be controlled or indexed to facilitate a return of the first or
processed wafer. FIG. 10 also shows that upon delivery of the next
wafer to the platen 22, the second arm 30 can return to a standby
or other position that is not the process position.
[0063] FIG. 11 illustrates the next wafer being processed 36 in the
process chamber 16 while the first arm 18 is in the orienter
position, or retracted from the cassette 32, and the second arm 30
is in a standby position. Accordingly, the FIG. 11 cassette 32 can
be controlled or indexed to facilitate a third wafer retrieval,
which can now be referred to as the "next" wafer, where such
retrieval of a third or next wafer by the first arm 18 is
illustrated in FIG. 12. Such third or next wafer retrieval from the
cassette 32 in the load lock 12 can be performed during processing
36 of the second wafer (which is now the "processed" wafer), where
the first arm can return to an orienter position as shown in FIG.
13 to interface the third or next wafer with the orienter 20, and
to thereafter facilitate a transfer of the third or next wafer by
the orienter 20, where such transfer is from the first arm 18 to
the second arm 30 as provided previously herein with respect to
FIGS. 4 and 7, and as shown in FIG. 14, where such transfer can
occur during processing 36 of the second or processed wafer.
[0064] One of ordinary skill will thus recognize that the methods
of FIGS. 8 through 14 can be repeated in an iterative manner to
sequentially process wafers in the cassette 32 in the left load
lock 12, where as provided previously herein, sequential processing
does not imply an order of processing. Accordingly, references to
the next and processed wafers can continue as wafers are retrieved
and processed, with wafers being referred to as the "next" wafer
from retrieval from the cassette 32 through a processing 36 in the
process chamber 16, whereupon such processing causes the "next"
wafer to be referred to as the "processed" wafer.
[0065] The methods and systems are thus not specific to a certain
wafer retrieval sequence, and such sequence can be based on a given
system. Further, some embodiments may not process all wafers in the
cassette. Additionally, although the illustrated methods and
systems indicate that the first arm 18 was vertically displaced in
a certain direction relative to the second arm 30, other
embodiments may reverse the configuration. Similarly, other
embodiments may provide for non-vertical alignment of arms 18, 30,
orienter 20, and/or platen 22.
[0066] When a cassette from, for example, the left load lock 12 of
FIG. 14, is processed, the methods and systems described herein can
be applied to the right load lock 14, and/or another load lock.
During a processing of, for example, the right load lock 14 as
provided herein with respect to FIGS. 1-14, the left load lock 12
can be isolated from the processing chamber, pressurized in
accordance with the loading station, and the cassette 32 can be
removed from the load lock 12. Further, a new cassette 32 can be
loaded from the loading station to the left load lock 12, the left
load lock 12 can be isolated, the left load lock can be evacuated
in accordance with the processing chamber 16, and the load lock
valve 34 can be opened to facilitate processing of the left load
lock cassette 32 upon completion of the right load lock cassette.
Accordingly, the methods and systems allow processing of one
cassette in a first load lock while another cassette is load
lock-processed (e.g., isolated from processing chamber, vented,
interchanged, evacuated, valve opened, etc.) in a second load
lock.
[0067] Further, it can be recognized that while the wafer
processing described relative to FIGS. 1-14 was performed on the
cassette wafers in the left load lock 12, the right load lock 14
could be performing load lock processing, including for example,
isolation from the processing chamber 16, venting the right load
lock 12, changing and/or replacing the right load lock cassette,
isolating the right load lock 12, evacuating the right load lock
12, opening the load lock valve to expose the right load lock to
the processing chamber 16, etc. Also, although not otherwise shown
in the illustrations, one of ordinary skill thus can recognize that
the methods and systems include first and second arms to process
the wafers from the right load lock cassette, where such first and
second arms can be the same as or different from the first and
second arms 18, 30 for processing the left load lock cassette.
Accordingly, some embodiments can use a single set of first and
second arms 18, 30 to access and/or process different load locks,
while some embodiments may associate different first and second
arms for processing different load locks.
[0068] FIG. 15 provides one illustration of a disclosed system and
method. As shown in FIG. 15, a first wafer can be retrieved from a
cassette by the first arm 100, oriented 102, transferred to the
second arm 104, and delivered for processing using the second arm
106. While the first wafer is being processed 108, a second or
"next" wafer can be retrieved from the cassette using the first arm
110, oriented 112, and transferred to the second arm 114. The first
wafer, now the processed wafer, can be removed from processing
using the first arm 116 to allow the second arm to deliver the next
wafer for processing 118. While the next wafer is processed 120,
the processed wafer can be returned to the cassette using the first
arm 122, and based on whether unprocessed wafers remain in the
cassette 124, the first arm can retrieve a "next" wafer from the
cassette 126, orient the next wafer 112, and transfer the next
wafer from the first arm to the second arm 114. Such processing can
continue according to FIG. 15 until a desired number of wafers in
the cassette are processed 124. When the cassette does not include
wafers for which processing is desired 124, a next load lock that
includes a cassette of at least one unprocessed wafer can be
selected 128, and processing 100 can continue on such next load
lock cassette as provided in FIG. 15. Further, load lock processing
can be performed 130 on the load lock that contains the processed
wafers, where such load lock processing can include isolating the
load lock, venting, removing a cassette, replacing a cassette,
inserting a cassette, evacuating the load lock, open the load lock
valve, etc. Accordingly, those of ordinary skill will recognize
that load lock processing can be performed on one or more load
locks while wafer processing can be performed on another load lock.
Further, it can be understood herein that the methods and systems
illustrated by FIG. 15 can be performed in parallel, for example,
as wafer processing 108 and 120 can be performed in parallel with
next wafer retrieval, orienting, and transferral 110-114 and
122-114, respectively.
[0069] Those of ordinary skill will also recognize that although
the methods and systems presented an embodiment where during
processing of a processed wafer, a next wafer is retrieved,
oriented, and transferred from the first arm to the second arm,
some methods and systems may include shorter processing times such
that processing may not coincide completely with retrieval,
orienting, and transferral. Accordingly, in some embodiments,
processing may complete before retrieval, orienting, and
transferral 110, 112, 114, while in other embodiments, processing
may not complete until after retrieval, orienting, and transferral
110, 112, 114, and thus may indicate a delay until removal 116
and/or a measurement or other means to indicate when processing is
complete.
[0070] FIGS. 16A-16C, show a schematic representation of another
embodiment according to the disclosed methods and systems for
handling wafers. FIGS. 16A- 16C show portions of a wafer processing
system that includes a left load lock 12 and right load lock 14. As
previously provided herein, the methods and systems will be
described relative to the left load lock 12 with the understanding
that the methods and systems can be applied to the right load lock
14. The FIGS. 16A-16D illustrate positions that may be engaged by a
first arm 52 and a second arm 54 that can access the left load lock
12. As will be provided herein, the first and second arms 52, 54
can be positioned in positions that include at least a load lock
position to allow the first and second arms 52, 54 to retrieve
and/or return a wafer from/to the cassette 32 in the left load lock
12, an orienter position to allow the first and second arms 52, 54
to interface with at least an orienter 20, and a process position
to allow the first and second arms 52, 54 to place a wafer in
and/or retrieve a wafer from a process chamber 16.
[0071] FIG. 16A can illustrate a first arm 52 in the orienter
position to allow the retrieved wafer to be oriented for
processing. Those of ordinary skill in the art will recognize that
the orienter 20 can be controlled or otherwise operated in the
illustrated systems to allow for the orienter 20 to be vertically
aligned with the first and second arms 52, 54 when the first and
second arms 52, 54 are in the orienter position, and accordingly,
the orienter 20 can be adjusted as needed to interface with the
first and second arms 52, 54 to allow orientation of the wafer. At
such time as the first arm 52 is in the orienter position, the
second arm 54 may be in the process position to retrieve a
processed wafer from platen 22.
[0072] Referring to FIG. 16B, first arm 52 can rotate to the
process position to load the retrieved wafer onto platen 22. Second
arm 54 can rotate to the orienter position. It can be understood
that clearance between first and second arms 52, 54 can be arranged
to allow a distance that facilitates independent operation when
vertically aligned, while recognizing that a reduced vertical
distance between the first and second arms 52, 54 may reduce
processing time to transfer wafers between the first and second
arms 52, 54 and the orienter 20 and the platen 22, as well as time
to index wafer cassette 32. Although such vertical distance between
such arms 52, 54 can thus vary based on system characteristics, in
one embodiment, when vertically aligned, the first and second arms
52, 54 can be separated by less than approximately five-eights to
one-half of one inch.
[0073] Once the retrieved wafer is loaded onto platen 22, first arm
52 can return to the orienter position, or to a standby position
such that the retrieved wafer can be processed 36, as previously
described, while the second arm 54 can return the processed wafer
to the wafer cassette 32, as illustrated in FIG. 16C. As previously
described, one of ordinary skill may recognize that the chamber 16
is shown to be enlarged to accommodate the first arm 52, which may
be understood to be illustrated in one of the aforementioned
standby positions. It can be understood that such enlargement of
the process chamber 16 is optional, and in some embodiments, such
enlargement may not be necessary to accommodate one or more standby
positions for the first and second arms 52, 54.
[0074] In one embodiment, shown in FIG. 16C, first and second arms
52, 54 can be mounted on or otherwise connected to a carriage 56
that can facilitate movement of first and second arms 52, 54 into
and out of load lock 12 for return and retrieval of wafers to and
from wafer cassette 32. In other embodiments, the second arm 54 can
be mounted to or otherwise connected to carriage 56 and the first
arm 52 can be mounted on or otherwise connected to a second
carriage 58, as shown in phantom in FIG. 16C, with carriages 56, 58
being configured for separate movement of the first and second arms
52, 54. In such embodiments, the standby position for the first arm
52 can include the orienter position, as indicated in phantom as 52
'in FIG. 16C, while the second arm 54 can return the wafer to wafer
cassette 32, though it can be understood that other of the
aforementioned standby positions can be utilized. Wafer cassette 32
can be indexed, such that second arm 54 can retrieve a next wafer
for processing.
[0075] The process can be repeated, as described further below with
respect to FIG. 17, with the positions of the first and second arms
52, 54 being alternated in the FIGS. 16A-16C. As shown in FIG. 17,
a first wafer can be retrieved from a cassette by the first arm
200, oriented 202, and delivered for processing using the first arm
204. While this wafer is being oriented, a second or processed
wafer can be removed from processing using the second arm 206. The
first arm can deliver the first wafer for processing 208, while the
second arm returns the next wafer to the cassette 210. Based on
whether unprocessed wafers remain in the cassette 212, the second
arm can retrieve a "next" wafer from the cassette 214 for
orientation of the "next" wafer 216, while the first wafer is
processing. The first wafer, now the processed wafer, can be
removed from processing using the first arm 218 to allow the second
arm to deliver the next wafer for processing 220. While the next
wafer is processed 222, the processed wafer can be returned to the
cassette using the first arm 224, and based on whether unprocessed
wafers remain in the cassette 226, the first arm can retrieve a
"next" wafer from the cassette 200, orient the next wafer 202, and
deliver the next wafer for processing 204. Such processing can
continue according to FIG. 17 until a desired number of wafers in
the cassette are processed 212. When the cassette does not include
wafers for which processing is desired 212, a next load lock that
includes a cassette of at least one unprocessed wafer can be
selected 228, and processing 200 can continue on such next load
lock cassette as provided in FIG. 17. Further, load lock processing
can be performed 230 on the load lock that contains the processed
wafers, where such load lock processing can include isolating the
load lock, venting, removing a cassette, replacing a cassette,
inserting a cassette, evacuating the load lock, open the load lock
valve, etc. Accordingly, those of ordinary skill will recognize
that load lock processing can be performed on one or more load
locks while wafer processing can be performed on another load lock.
Further, it can be understood herein that the methods and systems
illustrated by FIG. 17 can be performed in parallel, for example,
as wafer processing 208 and 222 can be performed in parallel with
return of a processed wafer to the cassette, next wafer retrieval
and orienting, 210-216 and 224, 200-204, respectively.
[0076] Those of ordinary skill will also recognize that although
the methods and systems presented an embodiment where during
processing of a processed wafer, a processed wafer is returned, and
a next wafer is retrieved and oriented, some methods and systems
may include shorter processing times such that processing may not
coincide completely with return, retrieval, and orienting.
Accordingly, in some embodiments, processing may complete before
return, retrieval, and orienting, 210, 114, 216, while in other
embodiments, processing may not complete until after return,
retrieval, and orienting, 210, 214, 216, and thus may indicate a
delay until removal 218 and/or a measurement or other means to
indicate when processing is complete.
[0077] What has thus been described are systems and methods for
handling wafers that include retrieving a first wafer from a wafer
cassette using a first arm, transferring the first wafer from the
first transfer arm to a second arm, delivering the first wafer for
processing to a process chamber using the second arm, removing the
first wafer from the process chamber using the first arm, and,
returning the first wafer to the cassette using the first arm.
[0078] The methods and systems described herein are not limited to
a particular hardware or software configuration, and may find
applicability in many computing or processing environments. For
example, the control of the cassette interchanges, evacuation and
venting, load lock valves, orienters, processing systems (e.g.,
platen, ion implantation, etc.), and the arms, can be implemented
in hardware or software, or a combination of hardware and software.
The methods and systems can be implemented in one or more computer
programs, where a computer program can be understood to include one
or more processor executable instructions. The computer program(s)
can execute on one or more programmable processors, and can be
stored on one or more storage medium readable by the processor
(including volatile and non-volatile memory and/or storage
elements), one or more input devices, and/or one or more output
devices. The processor thus can access one or more input devices to
obtain input data, and can access one or more output devices to
communicate output data. The input and/or output devices can
include one or more of the following: Random Access Memory (RAM),
Redundant Array of Independent Disks (RAID), floppy drive, CD, DVD,
magnetic disk, internal hard drive, external hard drive, memory
stick, or other storage device capable of being accessed by a
processor as provided herein, where such aforementioned examples
are not exhaustive, and are for illustration and not
limitation.
[0079] The computer program(s) is preferably implemented using one
or more high level procedural or object-oriented programming
languages to communicate with a computer system; however, the
program(s) can be implemented in assembly or machine language, if
desired. The language can be compiled or interpreted.
[0080] As provided herein, the processor(s) can thus be embedded in
one or more devices that can be operated independently or together
in a networked environment, where the network can include, for
example, a Local Area Network (LAN), wide area network (WAN),
and/or can include an intranet and/or the Internet and/or another
network. The network(s) can be wired or wireless or a combination
thereof and can use one or more communications protocols to
facilitate communications between the different processors. The
processors can be configured for distributed processing and can
utilize, in some embodiments, a client-server model as needed.
Accordingly, the methods and systems can utilize multiple
processors and/or processor devices, and the processor instructions
can be divided amongst such single or multiple
processor/devices.
[0081] The device(s) or computer systems that integrate with the
processor(s) can include, for example, a personal computer(s),
workstation (e.g., Sun, HP), personal digital assistant (PDA),
handheld device such as cellular telephone, laptop, handheld, or
another device capable of being integrated with a processor(s) that
can operate as provided herein. Accordingly, the devices provided
herein are not exhaustive and are provided for illustration and not
limitation.
[0082] References to "a processor" or "the processor" can be
understood to include one or more processors that can communicate
in a stand-alone and/or a distributed environment(s), and can thus
can be configured to communicate via wired or wireless
communications with other processors, where such one or more
processor can be configured to operate on one or more
processor-controlled devices that can be similar or different
devices. Furthermore, references to memory, unless otherwise
specified, can include one or more processor-readable and
accessible memory elements and/or components that can be internal
to the processor-controlled device, external to the
processor-controlled device, and can be accessed via a wired or
wireless network using a variety of communications protocols, and
unless otherwise specified, can be arranged to include a
combination of external and internal memory devices, where such
memory can be contiguous and/or partitioned based on the
application. Accordingly, references to a database can be
understood to include one or more memory associations, where such
references can include commercially available database products
(e.g., SQL, Informix, Oracle) and also proprietary databases, and
may also include other structures for associating memory such as
links, queues, graphs, trees, with such structures provided for
illustration and not limitation.
[0083] References to a network, unless provided otherwise, can
include one or more intranets and/or the Internet.
[0084] Many additional changes in the details, materials, and
arrangement of parts, herein described and illustrated, can be made
by those skilled in the art. Accordingly, it will be understood
that the following claims are not to be limited to the embodiments
disclosed herein, can include practices otherwise than specifically
described, and are to be interpreted as broadly as allowed under
the law.
* * * * *