U.S. patent application number 12/696224 was filed with the patent office on 2010-06-17 for elevator-based tool loading and buffering system.
This patent application is currently assigned to Brooks Automation, Inc.. Invention is credited to Michael L. Bufano, William Fosnight, Gerald M. Friedman, Ulysses Gilchrist, Christopher Hofmeister.
Application Number | 20100147181 12/696224 |
Document ID | / |
Family ID | 35968342 |
Filed Date | 2010-06-17 |
United States Patent
Application |
20100147181 |
Kind Code |
A1 |
Bufano; Michael L. ; et
al. |
June 17, 2010 |
Elevator-based tool loading and buffering system
Abstract
An exemplary embodiment a substrate transport system is
provided. The system has a guideway and at least one transport
vehicle. The transport vehicle is adapted for holding at least one
substrate and capable of being supported from and moving along the
guideway. The guideway comprises at least one travel lane for the
vehicle and at least one access lane offset from the travel lane
allowing the vehicle selectable access on and off the travel
lane.
Inventors: |
Bufano; Michael L.;
(Belmont, MA) ; Friedman; Gerald M.; (New Ipswich,
NH) ; Hofmeister; Christopher; (Hampstead, NH)
; Gilchrist; Ulysses; (Reading, MA) ; Fosnight;
William; (Carlisle, MA) |
Correspondence
Address: |
FISH & RICHARDSON PC
P.O. BOX 1022
MINNEAPOLIS
MN
55440-1022
US
|
Assignee: |
Brooks Automation, Inc.
Chelmsford
MA
|
Family ID: |
35968342 |
Appl. No.: |
12/696224 |
Filed: |
January 29, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11211236 |
Aug 24, 2005 |
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12696224 |
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60604406 |
Aug 24, 2004 |
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Current U.S.
Class: |
104/130.01 |
Current CPC
Class: |
H01L 21/67775 20130101;
H01L 21/67715 20130101; H01L 21/67736 20130101 |
Class at
Publication: |
104/130.01 |
International
Class: |
E01B 25/00 20060101
E01B025/00 |
Claims
1. A substrate transport system comprising: a guideway; and at
least one transport vehicle adapted for holding at least one
substrate and capable of being supported from and moving along the
guideway; wherein the guideway comprises at least one travel lane
for the at least one vehicle and at least one access lane extending
substantially along and offset from the travel lane and configured
to define selectable access on and off the travel lane for the
vehicle, the selectable access being arranged so that the travel
lane, access lane and selectable access define a selectable
substantially restrictionless path along the guideway for the
vehicle to have a substantially unrestricted selectably variable
transport rate along the guideway independent of impediments to the
vehicle transport rate disposed along the travel lane.
2. The system according the claim 1, wherein the at least one
travel lane and the at least one access lane are arranged to allow
the at least one vehicle substantially unconstrained on and off
access between the travel lane and access lane.
3. The system according the claim 1, further comprising a
controller communicably connected to the guideway and the at least
one vehicle, and arranged to effect selection of the transport
rate.
4. The system according to claim 1, wherein the selectable access
on and off the travel lane decouples the transport rate of the at
least one vehicle along the at least one access lane from a
guideway transport rate of at least another transport vehicle
positioned serially adjacent to, and traveling along the guideway
in a common direction with the at least one vehicle.
5. The system according to claim 4, wherein the guideway transport
rate is substantially constant along the guideway, and wherein the
at least one travel lane and the at least one access lane are
arranged so that the at least one vehicle and the at least other
transport vehicle travel along the travel lane at the substantially
constant guideway transport rate.
6. The system according to claim 1, wherein the at least one travel
lane and the at least one access lane are arranged so that the at
least one transport vehicle and another serially adjacent transport
vehicle traveling along the at least one travel lane in a common
direction and serial sequence, can change positions relative to
each other to change the serial sequence.
7. The system according to claim 6, wherein one of the at least one
transport vehicle or the other transport vehicle travel along the
at least one travel lane at a guideway transport rate that is
substantially constant along the guideway, when the relative
positions of the transport vehicles are changed to change the
serial sequence.
8. The system according to claim 1, wherein the at least one
transport vehicle is capable of being stopped on the at least one
access lane without affecting transport rate of an immediately
adjacent transport vehicle traveling along the guideway in a common
direction with the at least one vehicle.
9. The system according to claim 1, wherein the at least one travel
lane or the at least one access lane define a bypass lane relative
to each other.
10. The system according to claim 1, wherein the at least one
transport vehicle has a drive arranged to effect substantially
holonomic movement of the vehicle on the guideway.
11. A substrate transport system comprising: a guideway; and
transport vehicles, each of which is adapted for holding at least
one substrate and capable of being supported from and moving along
the guideway; wherein a section of the guideway, defining a
predetermined travel direction for the transport vehicles on the
guideway, comprises at least one travel lane for the transport
vehicles in the predetermined travel direction and at least one
access lane offset from the travel lane and extending substantially
along the travel lane in the predetermined travel direction
allowing the vehicles selectable access on and off the travel lane;
the travel lane and access lane being arranged to enable transport
vehicles serially and proximally positioned on the travel lane and
having different transport rates in the predetermined direction, so
that one of the transport vehicles is overtaking another, to avoid
each other by accessing the access lane substantially without
restriction to the transport rate of the overtaking transport
vehicle.
12. The system according the claim 11, wherein the at least one
travel lane and the at least one access lane are arranged to allow
the transport vehicles substantially unconstrained on and off
access between the travel lane and access lane.
13. The system according the claim 11, further comprising a
controller communicably connected to the guideway and the transport
vehicles, and arranged to effect selection of the transport
rate.
14. The system according to claim 11, wherein a transport rate of
the at least one transport vehicle along the at least one access
lane is decoupled from a guideway transport rate of at least
another transport vehicle positioned serially adjacent to, and
traveling along the guideway in a common direction with the at
least one transport vehicle.
15. The system according to claim 14, wherein the guideway
transport rate is substantially constant along the guideway, and
wherein the at least one travel lane and the at least one access
lane are arranged so that the at least one transport vehicle and
the at least other transport vehicle travel along the travel lane
at the substantially constant guideway transport rate.
16. The system according to claim 11, wherein the at least one
travel lane and the at least one access lane are arranged so that
at least one transport vehicle and another serially adjacent
transport vehicle traveling along the at least one travel lane in a
common direction and serial sequence, can change positions relative
to each other to change the serial sequence.
17. The system according to claim 16, wherein one of the at least
one transport vehicle or the other transport vehicle travel along
the at least one travel lane at a guideway transport rate that is
substantially constant along the guideway, when the relative
positions of the at least one transport vehicle and the other
transport vehicle are changed to change the serial sequence.
18. The system according to claim 11, wherein at least one
transport vehicle is capable of being stopped on the at least one
access lane without affecting transport rate of an immediately
adjacent transport vehicle traveling along the guideway in a common
direction with the at least one vehicle.
19. The system according to claim 11, wherein at least one travel
lane or the at least one access lane define a bypass lane relative
to each other.
20. The system according to claim 11, wherein at least one
transport vehicle has a drive arranged to effect substantially
holonomic movement of the vehicle on the guideway.
21. A substrate transport system comprising: a guideway; and at
least one transport vehicle adapted for holding at least one
substrate and capable of being supported from and moving along the
guideway at a selectably variable transport rate; wherein the
guideway comprises at least one travel lane for the at least one
vehicle and at least one access lane extending substantially along
and offset from the travel lane allowing the vehicle selectable
access on and off the travel lane so that the selectably variable
transport rate of the vehicle along the guideway is selectable
substantially without restriction substantially everywhere along
the guideway.
22. A substrate transport system comprising: a guideway; and at
least one transport vehicle, adapted for holding at least one
substrate and capable of being supported from and moving along the
guideway; wherein a section of the guideway, defining a
predetermined travel direction for the at least one vehicle on the
guideway, comprises at least one travel lane for the at least one
vehicle in the predetermined travel direction and at least one
access lane extending substantially along the travel lane in the
predetermined travel direction and being arranged to allow the at
least one vehicle selectable access on and off the travel lane so
that the at least one vehicle traveling in the predetermined travel
direction along the guideway has a predetermined travel rate
substantially independent of another transport vehicle positioned
serially and proximally to the at least one vehicle on the travel
lane.
Description
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application is a divisional of U.S. patent application
Ser. No. 11/211,236, filed Aug. 24, 2005 and claims the benefit of
U.S. Provisional Application No. 60/604,406 filed Aug. 24, 2004
which are incorporated by reference herein in its entirety.
BACKGROUND
[0002] 1. Field
[0003] A system and method are disclosed for transporting
reduced-capacity wafer carriers within a semiconductor fabrication
facility.
[0004] 2. Brief Description of Related Developments
[0005] There is a desire in the semiconductor industry to reduce
wafer cycle time through the fab and reduce the amount of work in
progress as well as to improve wafer safety. Studies have shown
that by moving to a single wafer carrier, wafer cycle time and WIP
(wafers in process) is significantly reduced. In addition for the
next generation wafer size (450 mm) the ITRS roadmap calls for
single substrate carriers. Benefits of using single wafer or
reduced capacity carriers include WIP reduction, process changeover
time reduction and product ramp time improvement. Problems arise
where conventional single substrate carriers are employed relative
to the ability of both the process tool and material transport
system to effectively maintain the higher pace of the factory due
to the larger number of carrier transport moves as compared to 13
or 25 wafer carriers. One example of such a problem includes where
there is only one slot. It is desired that the robot in the process
tool have the capability to quickly swap (fast swap) the wafer in
the carrier so the carrier may be able to be replaced with another
carrier that has an unprocessed wafer to keep the tool busy. Many
such tools do not have the ability to fast swap, as in the case of
a conventional single blade three axis robot. Another example of
such a problem includes where there is only one slot. It is desired
that the material transport system transporting carrier to tools in
the IC FAB have the capability to supply carriers, at a high rate
and quickly swap the carriers at the process tools load port(s) so
that one carrier at the tool may be able to be replaced with
another carrier that has an unprocessed wafer to keep the tool
busy. Many such material transport systems do not have the ability
to supply carriers at a high rate or with the capability to fast
swap, as in the case of a conventional (overhead transport) OHT
based material transport systems as implemented in conventional 300
mm fabs. Conventional material transport systems are highly rigid
in the transport or movement scheme of the carriers transported
thereby, and do not offer sufficient transport flexibility desired
with carriers having reduced workpiece capacity (e.g. less than
conventional 13 or 25 workpiece pods). For example, conventional
transport systems, whether a continuous moving support based (e.g.
conveyor belt or roller system) or a vehicle based e.g. discrete
vehicles traversing on rails, tracks), employ substantially linear
travel pathways with intersections or junctions for transport
switching between different pathways. The travel pathways are
generally unidirectional each allowing vehicles, or otherwise
transported materials (e.g. workpiece carriers) moving on the
pathway to move serially in sequence along the given direction of
the pathway. Thus vehicles or transport material move along the
pathway in progression with no availability of passing. Opposing
pathways are provided for bidirectional movement (e.g. advance
pathway and return pathway). In addition to service pathways, which
communicate with the FAB tools/tool stations (i.e. the service
pathway has locations where the transport material or vehicles
traversing along the pathway may be stopped for interface to FAB
tools), the conventional transport systems may have dedicated
bypass or high speed (relative to the available transport speed on
the service pathway that is limited by the inability to overtake
stopped transport) pathways between pathway junctions.
Nevertheless, the high speed pathways do not enable transport on a
service pathway to pass stopped or slowed transport on the service
pathway. Moreover transport along a high speed pathway of a
conventional transport system remains linear (in serial sequence)
still without ability to pass. Thus, if a transport stops on the
high-speed pathway for whatever reason (e.g. breakdown) the other
transport on the pathway cannot go around, pass the stopped
transport, and continue on the pathway. As may be realized, the
rigidity of the transport scheme of conventional material transport
systems impairs the ability in directing workpieces to the full
advantage of FAB tool availability with a commensurate degradation
in the achievable FAB throughput. The exemplary embodiments
overcome the problems of conventional systems as will be described
in greater detail below.
[0006] Examples of transport systems, carriers and openers may be
found in U.S. Pat. No. 6,047,812; RE38,221 E; U.S. Pat. Nos.
6,461,094; 6,520,338; 6,726,429; 5,980,183; 6,265,851 United States
Patent Publications 2004/0062633, 2004/0081546, 2004/0081545;
2004/0076496 and pending Brooks Automation application Ser. No.
10/682,808 all of which are incorporated by reference herein in
their entirety.
SUMMARY OF THE EXEMPLARY EMBODIMENTS
[0007] In accordance with an exemplary embodiment a substrate
transport system is provided. The system has a guideway and at
least one transport vehicle. The transport vehicle is adapted for
holding at least one substrate and capable of being supported from
and moving along the guideway. The guideway comprises at least one
travel lane for the vehicle and at least one access lane offset
from the travel lane allowing the vehicle selectable access on and
off the travel lane.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The foregoing aspects and other features of the present
invention are explained in the following description, taken in
connection with the accompanying drawings, wherein:
[0009] FIG. 1 is a schematic top plan view of a substrate
processing system incorporating features in accordance with an
exemplary embodiment;
[0010] FIGS. 1A-1B are respectively another schematic top plan view
and a schematic elevation view of the substrate processing system
in FIG. 1;
[0011] FIG. 2 is a schematic plan view of a substrate processing
system in accordance with another exemplary embodiment;
[0012] FIG. 3A is a schematic to plan view of a transport system
guideway and transport vehicle of the substrate processing system
in accordance with another exemplary embodiment;
[0013] FIG. 3B is a schematic top plan view of a guide portion of
the transport system guideway in accordance with another exemplary
embodiment;
[0014] FIG. 3C is a schematic top plan view of the transport system
guideway and a portion of the transport vehicle in accordance with
another exemplary embodiment;
[0015] FIGS. 4A-4B are respectively a schematic plan view and
elevation view of a transport system guideway and transport vehicle
in accordance with another exemplary embodiment;
[0016] FIGS. 5A-5B are respectively a schematic plan view and
elevation view of a transport system guideway and transport vehicle
in accordance with another exemplary embodiment;
[0017] FIG. 6 is a schematic elevation view of the transport system
guideway and transport vehicles in accordance with another
exemplary embodiment, the vehicles being shown in different
positions on the guideway;
[0018] FIG. 7 is a schematic top plan view of the transport system
guideway, transport vehicle and carriers in accordance with another
exemplary embodiment;
[0019] FIGS. 8A-8C are elevation views of the transport system
guideways, transport vehicles and processing apparatus in
accordance with still another embodiment; FIGS. 8A-8B are end
elevations and FIG. 8C is a side elevation, and each respectively
show the transport vehicles in different positions;
[0020] FIGS. 9A-9E are schematic elevation views showing a
transport vehicle in accordance with respectively different
exemplary embodiments;
[0021] FIG. 10 is a schematic elevation view of the transport
vehicle, carriers C on the vehicle, in accordance with another
exemplary embodiment, buffer and load port stations of a processing
tool; FIGS. 11 and 12A-12C are respectively an elevation view of a
portion of the transport vehicle and a carrier C registered to the
vehicle, perspective views of carriers each having registration
features in accordance with different exemplary embodiments, and
FIG. 12D is a schematic cross-sectional view of a chuck in
accordance with the prior art;
[0022] FIG. 13 is a schematic elevation view of the transport
system guideways, transport vehicle and a substrate processing
station in accordance with another exemplary embodiment;
[0023] FIGS. 14A-14D are schematic plan views showing the motive
system of the transport vehicle in accordance with different
respective exemplary embodiments, and FIG. 14E is a schematic
elevation view of the transport vehicle;
[0024] FIG. 15 is a schematic plan of the transport vehicle control
system;
[0025] FIGS. 16A-16C are side elevation views of a portion of
transport system guideways and transport vehicle respectively
showing the transport vehicle in three different positions, and
FIGS. 17A-17C are end elevation views corresponding to the side
views in FIGS. 16A-16C;
[0026] FIG. 18 is a schematic side elevation view of transport
system guideways and transport vehicle in accordance with another
exemplary embodiment, the vehicle being shown in different
positions; and FIGS. 18A-18B are cross-section views respectively
taken along view lines A-A and B-B in FIG. 18; and
[0027] FIGS. 19A-19C are end elevation views of transport vehicle
of the transport system in accordance with another exemplary
embodiment, respectively showing the vehicle in different
configurations.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
[0028] Referring to FIG. 1, a schematic plan view of a substrate
processing system incorporating features of the disclosed
embodiments, located in a fabrication facility or FAB is
illustrated. Although the embodiments disclosed will be described
with reference to the embodiments shown in the drawings, it should
be understood that the embodiments disclosed can be embodied in
many alternate forms of embodiments. In addition, any suitable
size, shape or type of elements or materials could be used.
[0029] The substrate processing system 10 in the exemplary
embodiment shown in FIG. 1 is representative of any suitable
processing system and generally comprises processing tools S (two
are shown for example purposes) transport system 10 and system
controller 300. The transport system 10 generally comprises a
guideway and transport vehicles 14. In the exemplary embodiment
shown, the guideway 12 may be a passive guideway providing
transport lanes TL, AL for the transport vehicles 14. There is at
least one travel lane TL and at least one access lane AL. The
transport vehicles 14 may be capable of autonomous travel (as will
be described below) on paths along the lanes TL/AL formed by the
guideway 12. The transport vehicles 14 (two vehicles 14 as well as
a recovery vehicle 14R, described later are shown in FIG. 1 for
example purposes) are each capable of holding and transporting one
or more substrate carriers C along the guideway to the desired
processing tools or processing tool stations S connected by the
guideway 12. Vehicles 14 may be seated over or suspended from the
guideway 12. Vehicles may access the process tools S from the
access lane AL. The travel lane TL is available to vehicles for
bypassing stopped or slowed vehicles in the access lane AL. The
vehicles may move freely between travel and access lanes and vice
versa.
[0030] FIG. 1 illustrates merely a representative portion of the
guideway 12, and the guideway may extend as desired, and have any
suitable shape so that the transport paths provided thereby for the
vehicles 14 allow the vehicles access to any desired number of tool
stations S in any desired locations for transfer of carrier C
between tool station and vehicle. The substrate processing tool at
a given tool station S may be of any desired type such as a
fabrication tool (e.g. The GX series tool from Brooks Automation
Inc.), a stocker or sorter. The tool may have a casing or enclosure
defining an interior space into which substrates (independent of
carriers) or the carriers themselves are loaded/unloaded. A
suitable example of a tool is disclosed in U.S. patent application
titled "ELEVATOR-BASED TOOL LOADING AND BUFFERING SYSTEM", attorney
docket No. 390P011937-US(PAR), filed Aug. 23, 2005, incorporated by
reference herein in its entirety. The carrier C may be any suitable
type of carrier capable of holding workpieces such as substrates
(e.g. 200, 300, 450 mm (or any other diameter/size semiconductor
wafer, rectile or flat panel for flat panel displays). The carrier
may have a casing capable of holding the substrates in a controlled
atmosphere. The carrier C may be a reduced capacity carrier.
Reduced capacity carriers may have a capacity of fewer than the
conventional 13 or 25 wafers and may be constructed in a manner
similar to the FOUP defined in SEMI 347, but characterized by
reduced height and weight. A suitable example of a substrate
carrier is disclosed in U.S. patent application titled "REDUCED
CAPACITY CARRIER AND METHOD OF USE", attorney docket No.
390P011935-US(PAR), filed Aug. 19, 2005, which is incorporated by
reference herein in its entirety. The carrier may be front (side)
opening or bottom opening. In alternate embodiments, the carriers
may be any other desired type of carrier as the features of the
exemplary embodiments disclosed are equally applicable to transport
system for any kind of workpiece carrier. The guideway 12 may be
formed from any suitable structure and is shaped (i.e. has suitable
rides surfaces 12S for vehicles 14 to ride on and adequate width)
in this embodiment to provide both, what shall be referred to as, a
travel lane TL and an access lane AL (as will be further
described). The guideway 12 may be located at any desired height in
the FAB. For example, the guideway may be at floor level of the FAB
(the edges or borders of the guideway shown in FIG. 1 in such a
case may not substantively exist (i.e. may not be formed by
structure) but rather are virtually defined by the travel paths of
the vehicles traversing along the lanes TL, AL (i.e. space envelope
of the vehicles moving on the lanes). The guideway 12 may also be
elevated, for example suspended from above or supported from below
at a distance above the floor. As seen in FIG. 1, the guideway 12
may be positioned along a desired interface side of the tool
stations S (or alternatively the tool stations may be located along
the side of the guideway). The guideway 12 has interface stations
I, corresponding to the locations of the tool stations S, where the
vehicle may be stopped for transfer of carriers C between vehicle
14 and tool station S. The tool stations are located in the access
lane AL. In this embodiment the transfer of carriers between tool
station and vehicle at an interface station I is in a lateral
direction to the guideway 12 (see also FIG. 1B which is an end
elevation of interface station I). Referring also to FIG. 2, there
is shown a schematic plan view of a transport system guideway 10'
in accordance with another exemplary embodiment. In the embodiment
shown in FIG. 2, the guideway 12', which is generally similar to
guideway 12 in the embodiment shown in FIG. 1, is located overhead
the tool station S. In this exemplary embodiment, the interface
station I on the guideway (which as seen in FIG. 2 is in the access
lane AL') may be defined by an opening O in the guideway structure.
The opening is sized to allow carrier transfer to/from the vehicle
14' in a direction normal (i.e. down) to the guideway. Such a
pass-through O enables placement of the access lane directly over
the loadports, thereby reducing the aisle width used to accommodate
elevated guideways. The active element transitioning carriers to
and from vehicles may reside on the vehicle or the mating
equipment, or be grounded at the point of transfer. In alternate
embodiments, the transfer direction from an overhead guideway may
be a combination of lateral (outward) and down, and the guideway
may not have a through hole for carrier passage during transfer
(e.g. carrier transfer would be over the side). The vehicle is
configured to be able to traverse the opening. As seen in FIGS.
1-2, in this embodiment the travel and access lanes TL, AL of the
guideway are substantially co-planar and communicate with each
other in a substantially unrestricted manner along the length of
the guideway 12. As may be realized the designation of the lanes as
travel or access lanes is discretionary (the lane designation shown
in the figures is for example purposes) as whether a lane serves as
access or travel lane (or both) is related to the arrangement of
the interface stations I (i.e. locations of tool stations).
Moreover, the designation of access travel lane may be transient.
For example, tool stations S, and hence interface stations I may be
located in both lanes of a guideway 12'' (see FIG. 1A). In the
exemplary embodiment shown in FIG. 1A, a vehicle 14'' is stopped at
an interface station I'', in what may be referred to, at least
while the vehicle 14'' is stopped, as access lane AL''. The
adjoining lane serves as a travel lane for passing vehicles 14A'',
and hence may be referred to as a travel lane. As seen in FIG. 1A,
an interface station IA'' may be located in that lane as well.
However, the interface station IA'' is unoccupied by a vehicle and
hence the lane may operate as a travel lane. When locations of
occupied interface stations I'', IA'' become reversed, then the
designations of travel and access lanes respectively reverse. In
alternate embodiments, the interface stations I'', IA'' in the
different lanes may be sufficiently distanced along the guideway so
that a vehicle may weave around occupied interface stations in
opposite lanes. In that case, each lane would have an access lane
portion, generally commensurate with the interface station, and a
travel lane portion located substantially across from the interface
station in the opposite lane. The transport vehicle may
transition/cross freely between lanes to continue unimpeded travel
along the travel lane(s).
[0031] The guideway 12 may have a guidance system 16 connected to
controller 300 for enabling vehicle guidance on transport paths T1,
ALE, A1 along the travel lanes TL, AL of the guideway 12 (see FIG.
1). The travel paths on the travel lanes illustrated in FIG. 1 are
merely representative, and the vehicles may move along any desired
transport path. In the exemplary embodiment shown in FIG. 1, the
guidance system 16 may include positioning devices 16A allowing for
position determination of the vehicles 14 moving on the guideway
lanes. The positioning devices may be of any suitable type such as
continuous or distributed devices 16T, such as optical, magnetic,
bar-code, fiducial strips, that extend along the guideway and
across (strip 16A) the guideway. The distributed devices 16P, 16A
may be read or otherwise interrogated by a suitable reading device
on the vehicle 14 to allow controller 30 to establish one or both
of longitudinal and/or lateral position of the vehicle on the
travel, access lanes TL AL of the guideway as well as kinematic
state of the vehicle. Alternatively, the devices LGP may sense,
interrogate a sensory item on the vehicle to identify
position/kinematics. The positioning devices 16P may also include,
alone or in combination with distributed devices 16T, 16A, discrete
positioning devices (e.g. laser ranging device, ultrasonic ranging
device, or internal positioning system akin to internal GPS, or
internal reverse GPS) able to sense the position of the moving
vehicle. The controller 300 may combine information from the
guidance system 16 with position feed back information from the
vehicle as will be described further below, to establish and
maintain the transport path(s) of the vehicle along and between the
travel and access lanes TL, AL of the guideway.
[0032] The guideway surface 12S may also be formed to define
vehicle physical guides S16T, S16A that may, if desired form part
of guiding system 16. In alternate embodiments the guideway may be
provided with a guidance system with no physical guides. In other
alternate embodiments, the guidance system may not have remote
sensors. The guideway surface may include or have grooves, rails,
tracks or any other suitable structure forming structural or
mechanical guide surfaces to cooperate with mechanical guidance
features on the vehicles 14. The guideway surface 12S may also
include electrical lines, such as a printed strip, or conductor
providing electronic guidance for the vehicles (e.g. electrical
lines sending a suitable electromagnetic signal that is detected by
suitable guidance system on the vehicles 14). The guideway 12 also
has power system 18 incorporated therein for powering the vehicles.
The power system 18 may include a continuous power system 18P, 18T,
18A, such as conductors or a printed strip, disposed on the
guideway structure and capable of supplying power (e.g. AC current)
to the vehicle 14 as it travels. Although in this embodiment the
continuous power lines 18P, 18T, 18A are shown separate from the
guidance system 16, 16T, 16A, in alternate embodiments the power
lines may be incorporated into guidance means (e.g. the power lines
may be used to provide electronic/electrical guidance for the
vehicle). The power system 18 may also include for example discrete
power supply stations 18PD, where the vehicles 14 may be charged.
The power supply stations 18PD (one is shown only for example
purposes) may be located as desired, such as at locations where the
vehicles 14 are expected to stop, such as for example an interface
station I where transfer of carriers may occur, as illustrated in
FIG. 13. In embodiments where present, the guide surface S16T, S16A
of the guidance system 16, may define the paths T1, AL1, ALi on
lanes TL, AL on which the vehicles 14 may travel (though it may
also be possible for the vehicles 14 to travel on the guideway 12
off the paths on lanes TL, AL). Though only one lane TL, and
accompanying access lane AL is shown for example in FIG. 1, the
guideway 12 may encompass any desired number of travel and access
lanes and any desired number of travel and access paths on the
corresponding travel and access lines similar to lanes TL and AL.
The other lanes may be parallel to lanes TL, AL, or may be disposed
in any other orientation. The travel paths in travel lanes TL may
include furcations 20 (structural in the case of physical guides,
or virtual where no physical guides are used) where paths onto the
access lane AL, AL1-Ali merge/diverge from the travel lanes TL
paths. As seen in FIG. 1A, the access paths AL1 (though only two
are shown in FIG. 1A, the access lane AL of guideway 12 may have
any desired number of access paths similar to path AL1, Ali
disposed serially along path TL and/or in parallel at each
furcation 20) connect the travel path TLI to interface I where
carrier transfer may occur between the vehicles 14 and an
intermediate transport (not shown) servicing corresponding stations
S. The access paths on the access lane AL may be defined by
guidance system 16, and again may be virtual in the case where no
physical guides exist, or may be structural defined by portions
S16A (and power supply means 18PA), and may in this embodiment have
two entry/exit portions at opposite ends of the access path as
shown in FIG. 1. As seen in FIGS. 1-2, the access path AL1-Ali
provides an access way as well as a side path or siding to travel
path TL1 (the vehicles 14 may be moved onto the access lane AL
without having to transfer containers from or onto the vehicle at
the interface) station. Thus, vehicles may be paused if desired on
the access lane. Also, inoperable vehicles may be moved, for
example using another vehicle, or manually onto the access lane.
Further, the access lane may have as a buffer for queuing
vehicle.
[0033] As noted before, at least one autonomous wheeled vehicle 14
is employed on the passive guideway 12. The vehicle 14 may be
propelled, for example, by an on-board electric motor 14M through a
friction drive. Energy for traction and other uses can be stored on
the vehicle in ultra-capacitors and/or batteries, or as mechanical
energy (e.g., with a flywheel). Recharging the stored energy can be
accomplished at discrete locations 18PD or continuously along the
guideway 18P, 18PT, 18PA through contacting or non-contacting
means.
[0034] In the exemplary embodiment, ultra-capacitors 14C may serve
as the primary energy storage devices due to their potential for
rapid recharge. While charging, energy is transferred from guideway
12 to vehicle 14 across mating contacts (not shown) in the form of
alternating current. Transferring AC is desired to DC because it is
inherently self-quenching relative to arcing, a common failure mode
in DC contact charging. Additionally, there may be significant
material cost and cost-of-ownership savings associated with the
elimination of grounded DC supplies and improved distribution
efficiency. In alternate embodiments however, DC current may be
used.
[0035] As noted before, the exemplary embodiment, position feedback
for vehicle trajectory control may be achieved by continuous
odometry, using encoders and/or resolvers at the vehicle wheels,
periodically updated using external references (e.g., optical or
magnetic encoding, bar-codes, fiducials, laser- or
ultrasonic-ranging, etc.) of the guideway guidance system 16. FIG.
15 is a schematic plan view of a vehicle 14 being guided between
two positions (POS1, POS2). In this embodiment, POS2 represents the
position of the vehicle at an exemplary interface station I of the
guideway and may be a final position. In FIG. 15, the initial
position of the vehicle identified as POS1 may be located anywhere
on the guideway. For example, POS1 may be on the access lane, or on
the travel lane. The path PT between the initial and final
positions of the vehicle is representative in this embodiment, and
any suitable path may be selected by the controller 300. The
controller may identify initial position POS1 of vehicle 14 from
the vehicle encoder information, or guidance system 16 or both. The
controller may continuously monitor the vehicle position, or may
employ selective monitoring for example, arrival of the vehicle at
position POS1 (identified to the controller by the vehicle odometry
information, or sensed by guidance system 16) may cause the
controller to identify the vehicle location. The controller may be
suitably programmed to identify the destination of the vehicle
(e.g. POS 2 or some other position past POS 2 and with respect to
which POS 2 is a waypoint) and to send steering commands to the
vehicle causing the vehicle to move along path PT to POS 2.
Position feedback when the vehicle is traversing along path PT may
be provided as noted before.
[0036] FIGS. 14A-14D illustrate a vehicle capable of steering
autonomously to merge and diverge among various travel and access
lanes in accordance with different exemplary embodiments. The
vehicles 14A-14D illustrated in FIGS. 14A-14D are generally similar
to each other and to vehicles 14 shown in FIGS. 1-2, except as
otherwise noted. The vehicles 14A-14D in accordance with the
exemplary embodiments in FIGS. 14A-14D, have a substantially or
near holonomic and substantially no-scuff steering system 14AS,
14BS, 14CS, 14DS. In the embodiment shown in FIG. 14A, the vehicle
steering system 14AS has four independently powered and steerable
wheels 14AW to provide near holonomic movement without scuffing.
The embodiment shown in FIG. 14B has independently drive wheels,
(on opposite sides) of the vehicle and a free caster. The exemplary
embodiment shown in FIG. 14C has two steerable wheels 14CSW at one
side of the vehicle 14C, and a single centered drive wheel 14CDW at
the other end of the vehicle. The exemplary embodiment in FIG. 14D
has two steerable wheels 14DSW and two wheels on a differential
drive axis 14DA. In alternate embodiments, the vehicle may have any
other desired steering system. The autonomous steering allows the
vehicles substantially free movement between travel and access
lanes (TL, AL, see FIGS. 1-2) of the guideway. The location of
points of furcation between travel and access lanes may be located
as desired with minimal or no infrastructure impact (to facilitate
tool movement, for example) or even dynamically (to avoid
unexpected obstacles such as a disabled vehicles). Each vehicle may
have an on board processor (not shown) with suitable memory to
store a facility "map" to facilitate self-directed routing to the
desired destination. If a blocked path is encountered, the vehicle
may have the capability to adjust the trajectory to navigate around
the obstruction along the guideway or to select an alternative path
or guideway. Vehicles may also be provided with a wireless
communication device (not shown) for wireless communication with
other vehicles and/or base stations to enable information sharing
for purposes such as dispatch coordination, location verification,
error reporting, and path accessibility status. As noted before,
the exemplary vehicles may traverse one or more flat, substantially
featureless surfaces--ideally, the floor of the facility to
minimize guideway capital investment and facilitate retrofitting to
existing fabs. Such vehicles are contrasted with traditional
(autonomous guided vehicles) AGVs that have been employed in
semiconductor material handling. Typically, conventional AGVS load
and unload payloads at operator interface points (e.g., at the 900
mm elevation in 300 mm wafer processing facilities) while
navigating along the floor. To accommodate dynamic loads,
conventional AGVs are tall; to prevent tip-over, particularly
during seismic events, they are designed with a low center of
gravity, and possess a mass much greater than that of the payload.
As a consequence, robust operator integrity systems and performance
limitations (such as reduced speed) are employed to allow them to
properly co-exist with human operators. The vehicles 14 in this
embodiment are intended to be used for point-to-point transfer
only, on the floor or on dedicated guideway decks, therefore their
(size and mass) scale is closer to that of the payload to be
conveyed and rendering them dramatically more user friendly to
operators. The small size of the vehicles allows them also to be
manipulated easily by installation and/or service personnel.
Referring to FIG. 14E, accommodations may be added to the vehicle
14E to assist in manual handling (e.g., for recovery_) such as
features which accept a pole to allow manipulation of the vehicle
without compromising ergonomics.
[0037] As noted before, in the vicinity of process tools, or, more
generally, sources and destinations S, an access lane (or siding)
AL is provided where vehicles may decelerate, stop, and if desired
transfer carriers (FIG. 1). The vehicle 14 moves from the
high-speed travel lane into the access lane and decelerates to a
stop then the vehicle delivers the carrier to a process tool, a
tool buffer, or a storage shelf via interface I. When the carrier
transfer is complete, the vehicle 14 accelerates in the access lane
AL and merges back into a travel lane TL. While in the travel lane
TL, the vehicle 14 may travel at a relatively constant velocity
directly to a siding ALL Ali on travel lane AL associated with the
new destination. Thus, access lane AL provides sidings for the
travel path TL, and conversely, the portions TLT of the travel path
TL adjoining the access path AL provide a bypass to the sidings
AL.
[0038] Referring now to FIGS. 3A-3C, routing may be accomplished
with a binary (merge-diverge) path selection scheme, with the
active switching elements 14SW, 14ST located on the vehicles 14.
FIG. 3A shows an exemplary embodiment in which the vehicle has
active switching elements 14SW, 14ST. In this embodiment, the
vehicle has guidance or switching element 14SW at an end of the
vehicle facing the travel direction T, A (one element 14SW is
shown, though the vehicle may have a switching element at each
end). The switching element 14SW may be mechanical or electronic.
For example, the mechanical switch may include a cam surface, such
as formed by a cam plate or cam rollers that is pivotably mounted
to the vehicle chassis. The cam surface may be actuated or passive,
and cooperates with the guidance surface S16T, S16A of the guidance
system 16 in the guideway 12 (see FIG. 1) to position the cam
surface in the direction of the path T1, AL1, Ali desired (see FIG.
1). The cam surface is connected by a suitable transmission
mechanism or system (not shown) to steering system 14ST (e.g.
steerable wheels/rollers as shown in FIGS. 14A-14D, steerable
magnets in the case the vehicle is borne by a magnetic levitation
system). The input from the cam surface is transmitted mechanically
or electronically to the steering gear 14ST to steer movement of
the vehicle on the desired path TL, AL. In the case the switching
element 14SW is electronic, a suitable sensor or detector is
included to sense a desired characteristics (e.g. magnetic field,
optical or RF signals) from the electronic guidance means 16, and
generate a steering signal processed by a servo or any other
suitable steering motor controller to effect steering form the
steering gear 14ST. The active switching elements 14SW, 14ST on the
vehicle 14 allow the vehicle to perform the switch, rather than
relying on active track elements. This eliminates a potential
single point of failure that could disable a portion of the
network. It also affords flexibility in accommodating distributed
or centralized control with minimal communication overhead.
[0039] FIG. 3B illustrates another exemplary embodiment, wherein
moveable switches 16W may be incorporated in the track, for
example, to minimize the complexity of the vehicles. As seen in
FIG. 3B, in this embodiment, the guidance system 16 has a switching
element 16SW located at furcation 20 along travel path TL. The
switching element 16SW is illustrated in this embodiment as being a
mechanical element, though the switching element may also be
electronic (with no moving parts). For example, the mechanical
element has a switch plate or member 40 that is actuated by a
suitable motor or actuator 42. The switch plate 40 is actuated by
actuator 42 between a first position O, in which the switch plate
directs/guides the vehicle 14 to continue on travel path TL, and a
second position P in which the switch plate directs the vehicle
away (or onto depending on direction) from path TL and onto access
path AL. Electronic switching (not shown) may be used in the
embodiments where the vehicle is supported and traverses in
guideway 12 (see FIG. 1A) using contactless means such as magnetic
levitation or air bearings. The electronic switch is electronically
analogous to the mechanical switching 16SW shown in FIG. 3B but in
place of the movable switch plate, generating for example a
magnetic force operating to direct the vehicle to continue along
travel path TL or move onto access path AL. A possible hybrid
approach involves using the vehicle to deflect a selectively
compliant track section by adhering to a cam surface as shown in
FIG. 3C. In this exemplary embodiment, the guide means 16 include
passively selectable switch element 16SW located at a furcation 20
merging/diverging paths TL, AL. The switch element 16SW is
pivotable or movable between position O (substantially aligned with
path TL) and position P (for transfer to path AL). The guide means
16 may also have a grounded cam surface 16G as shown. The vehicle
14, has a switch element 14SW, similar to the embodiment in FIG. 1,
but in this embodiment the switching element 14SW on the vehicle
operates to cause move of the switch 16SW on the guideway thereby
effecting desired steering of the vehicle 14. The vehicle switching
element here includes cam follower 14C following grounded cam
surface 16G on the guideway, and actuation member 14S connected to
the cam follower 14C by a suitable transmission system 14T. The
actuation member 14S is positioned, based on input (mechanical or
otherwise) from the cam follower 14C, and in turn acts on the
movable switch element 16SW of the guideway 12 to position it in
either position O or position P.
[0040] In addition to merging to and from access lanes, vehicles
may switch between converging and diverging travel lanes to
optimize their path from source to destination. Note that transport
capacity may be increased by employing additional local, or
fab-wide, vertically stacked parallel guideways 12D, 12L, as shown
in FIGS. 4A-4B, and 5A-5B. Several travel "decks" 12U, 12L may be
stacked and have similar or opposed desired travel directions. In
the embodiments shown in FIGS. 4A-4B, 5A-5B, only two decks are
shown for example purposes. Though in alternate embodiments any
desired number of decks may be used. Decks 12U, 12L are each
substantially similar to guideway 12 described before. Such decks
may be adjacent to one another as shown, or deployed at different
heights, as for example, one elevated guideway and one floor-level
guideway. In the embodiment shown in FIGS. 5A-5B, a carrier
transfer opening is located in the decks 12V, 12L as seen in FIG.
5B, in this embodiment, the carrier openings OP are aligned with
each other. This allows a vehicle on the upper deck to transfer a
carrier through the lower deck. In alternate embodiments, only the
lower deck may have carrier openings.
[0041] The horizontal displacement between travel and access lanes
in the exemplary embodiment described before is but one method to
effect the desired separation between transport paths (where
vehicles may travel between sources and destinations at a
substantially constant speed) and access paths (where vehicles may
accelerate/decelerate and stop--e.g., to transfer loads and/or
recharge). Alternatives include merging and diverging between and
among vertically displaced tracks, and allowing vehicles to pass
other vehicles stopped in the same track by displacing some or all
of the vehicle structure as desired.
[0042] FIGS. 9A-9E are schematic elevation views of a transport
vehicle 114A-114E of the transport system provided with an integral
elevator mechanism in accordance with different respective
exemplary embodiments. Except as otherwise noted, the vehicles are
generally similar to each other, each having carrier support 114ACS
capable of supporting at least one carrier, and an elevator
mechanism for raising and lowering the carrier support. In the
embodiment shown in FIG. 9A, the elevator mechanism 114AE may
comprise substantially rigid reel members that are wound and
unwound to raise and lower the support. In the embodiment shown in
FIG. 9B, the elevator mechanism 114BE may have scissoring members
which are slidable at one end relative to the vehicle frame. Height
adjustment is achieved by scissoring the members as desired via a
motor and lead screw. In the embodiment shown in FIG. 9C, the
elevator 114CE has a three or four point link system that folds up
and down when powered by a motor and lead screw. In the embodiment
shown in FIG. 9D, the elevator 114DE may have a telescoping rail or
column arrangement, and in the embodiment shown in FIG. 9E, the
elevator may have interlocking chain links capable of being wound
and unwound. As may be realized, in alternate embodiment, any
suitable elevating system (including fluidic and/or magnetic) may
be used. Vehicles may also be provided with elevator mechanism both
top and bottom as shown in FIGS. 16A-16C and 17A-17C. Referring to
FIGS. 16A-16C and 17A-17C a vehicle 214 transitioning from the
lower 12L to upper track 12U. The vehicle 214 in this embodiment is
generally similar to vehicles 114A-114E shown in FIG. 9A-9E, except
in this embodiment vehicle 214 has top and bottom elevator
mechanisms as shown. As may be realized from FIGS. 16B and 17B, one
mechanism is to raise half-way up from the lower wheels while the
upper mechanism raises the upper wheels the remainder of the way to
the upper track. In alternate embodiments, the vehicle may have a
single elevator with sufficient reach. After the upper wheels are
attached to the upper track the lower wheels may be retracted and
result in the configuration shown in FIGS. 16C and 17C. Transition
of the vehicle from top to bottom guideways would be performed in
the reverse manner. In this manner, the vehicle may hop over or
under impeding vehicles on either upper or lower tracks. In this
exemplary embodiment, the vehicle when riding along the upper track
12U, is suspended from the upper track. The vehicle upper wheels
may be held onto the upper track by any suitable means. For
example, in the exemplary embodiment illustrated in FIG. 18A a
vehicle 214' is attached to the upper track by magnetic attraction.
In this embodiment the upper track includes magnetic material, and
the vehicle has a magnet 214M' (permanent or electro/magnetic) or a
permanent/electro-magnetic chuck, as shown in FIG. 12D, that may be
activated to hold the vehicle to the upper track. The chuck has a
safe mode to maintain the vehicle on the track in the event of
power interruption. In alternate embodiments, the vehicle may
include magnetic material attracted to a suitable magnet in the
track. FIG. 18 shows a vehicle 214'' on the upper track supported
by a support surface 12US under the wheels. FIG. 18 is a side view
that shows vehicle 214'' transitioning from the lower to the upper
track with the mechanical configuration in this exemplary
embodiment. The upper support track 12US may have openings where
the upper wheels could pass through after which they would engage
with the upper support track, followed by the retraction of the
lower wheels. To lower from the upper to lower track, the lower
wheels may be lowered in contact with the lower track before an
opening in the upper support track released the upper wheels.
[0043] FIGS. 19A-19C illustrate a vehicle 214'', in accordance with
another exemplary embodiment, passing another vehicle 214A''' on
the same track. FIG. 19A shows vehicle 214''' in a first running
position. FIG. 19B shows vehicle 214''' as it raises its payload.
At the same time as the payload is being raised the wheels 214W'''
are moved outward in the direction of arrows X'''. This may be done
by steering the wheels 214W''' (which may be mounted on laterally
displaceable linkage (not shown) as the vehicle moves forward. FIG.
19C shows vehicle 214''' in its up position with wheels in an out
position. In this condition, vehicle 214A''' may pass under vehicle
214''' between its wheels as shown. The opposite (i.e. inverted
position) of this can be accomplished for a vehicle running on an
upper track.
[0044] In alternate embodiments, transition between vertically
displaced tracks if desired, may be accomplished by incorporating
ramps (similar to access lanes AL shown in FIG. 1 but providing
offsets from travel path TL in both horizontal and vertical
directions) along with horizontal vehicle steering or horizontal
switches similar to those in FIG. 3A-3C. In this case vehicles
would merge to a ramp, follow the ramp to the desired elevation,
then merge into the appropriate travel deck. If such vertical
displacement of vehicles were desired in an access lane, a vertical
track switch as depicted in FIG. 6 could be employed. In this case,
the vertical displacement may be achieved by driving a vehicle 14
to an elevator 12E that moves vehicles between vertically offset
lanes 12U, 12L. Such an elevator may have extra guideway decks
12E1-12E3, as depicted in FIG. 6, to replace the section used to
transfer the vehicle, thus restoring a travel path for following
vehicles.
[0045] As noted before, it may be desired to provide guideways 12
with default travel directions, indicated by arrows T1, A1, in FIG.
1, the vehicles 14 may have the capability of bi-directional travel
to accommodate flexible routing and anomaly (e.g., obstructed path)
handling. Bi-directional motion is achieved by controlling the
vehicle drive motors 14M in a forward and reverse direction. If a
vehicle 14 becomes disabled, the drive motors may be neutralized
and the vehicle may be pushed or pulled to a suitable siding by
another vehicle. The "towing" vehicle may be another standard
vehicle or a dedicated recovery vehicle 14R (see FIG. 1A). In
either case, the towing vehicle has the capability of overriding
the switching element 14SW (see FIGS. 3A-3C) or steering (see FIGS.
14A-14D) of the disabled vehicle to force its transition to an
access lane. In the exemplary embodiment, this may be accomplished
with a mechanical engagement using any suitable coupling (not
shown). Alternatively, other vehicles may simply avoid a disabled
vehicle by selecting alternate paths to their destinations (until
the disabled vehicle is recovered by an operator) and/or steering
around the disabled vehicle using a local obstacle detection
sensing and a collision avoidance algorithm.
[0046] Referring now to FIG. 10, there is shown a schematic
elevation view of a vehicle 314 at an interface station I of
guideway 12 in accordance with another exemplary embodiment. Except
as otherwise noted vehicle 314 is substantially similar to vehicles
14, 114, 214 described before. In this exemplary embodiment,
vehicles 314 may have the capacity to hold two or more carriers C1,
C2 simultaneously. Two carriers C are shown in FIG. 10 for example
purposes, though the vehicle capacity may be any desired number of
carriers. In this embodiment, vehicle 314 generally transport one
carrier C fewer than the maximum, capacity leaving an open position
314S1, 324S2 to enable "fast-swapping" (i.e., the introduction of
one carrier immediately prior to, or simultaneously with, the
extraction of another). The vehicle may interface with a handling
system located at the tool station S to effect the fast swap
transfer of carriers between vehicle 314 and handling system. In
this embodiment, the handling system may transport the carriers to
desired buffer and/or load port stations at the tool stations. The
carrier 314 supports 314S1, 314S2, (as noted above two supports are
shown, but the vehicle may have any desired number of carrier
storage spaces) may be stacked vertically to accommodate side
access or side-by-side for top access (e.g., by an overhead hoist).
In either case, carriers may be supported from below (e.g., nesting
on a horizontally disposed kinematic coupling) or using features on
the top or sides of the carrier. For example, in the embodiment
illustrated in FIG. 10, the carrier supports on the vehicle are
configured to employ a side coupling which may be used alone if
desired in cooperation with suitable carriers (e.g., reduced lot
carriers as described before. FIG. 11 illustrates a representative
support 314S' of the vehicle 314 (see FIG. 10) coupled to a
face/side of carrier C. The coupling between support 314S' and
carrier may be at the kinematic registration/coupling face of the
carrier used when the carrier is registered to a tool station load
port. In this embodiment, the carrier may be a face opening carrier
with the registration features located on the face with the
opening. In this manner a single set of registration may be
provided to the carrier commonly used for all carrier docking
whether to a tool station, transport vehicle, etc. In alternate
embodiments, coupling between the carrier support structure on the
vehicle and carrier may be to any desired face/surface of the
carrier. The coupling 314SC between support structure 314S1 and
carrier may be of any suitable type. For example, passive coupling
or active coupling systems may be used similar to the registration
systems disclosed in U.S. patent application titled "ELEVATOR-BASED
TOOL LOADING AND BUFFERING SYSTEM" previously incorporated by
reference. By way of example, the coupling 314SC may include a
permanent electro-magnetic chuck as illustrated in FIG. 12D that
interacts with magnetic material in the carrier C. FIGS. 12A-12C
show a carrier CA, CB, CC having magnetic material CAM, CBM, CCM
positioned at or proximate the registration face of the carrier in
accordance with a number of different embodiments. The permanent
electromagnetic chuck is located in the vehicle support structure
314S1 and is arranged to suit the placement of the magnetic
material in the carrier. Activation of the chuck captures the
carrier to the vehicle and deactivation releases the carrier
vehicle coupling. In any case, as noted before the configuration of
support may be common among the vehicle nests and carrier nesting
locations associated with tool interface devices (buffers,
loadports, and the like) to minimize overall automation hardware
complexity. Such a pass-through D enables placement of the access
lane directly over the loadports, thereby reducing the aisle width
required to accommodate elevated guideways. The active element
transitioning carriers to and from vehicles may reside on the
vehicle or the mating equipment, or be grounded at the point of
transfer.
[0047] In the exemplary embodiment illustrated in FIGS. 8A-8C, the
vehicle drives directly to the tool loadport, eliminating a
separate carrier loading mechanism for transferring carriers from
vehicle to load port docking stations. In the exemplary embodiment
shown, upper and lower guideways 12U, 12L are located at elevations
above and below the tool loading height. The upper and lower
guideway 12U, 12L and vehicles are similar to those previously
described. FIG. 8A shows a section view through the aisle of the
FAB in which the guideways 12U, 12L are situated with tool stations
S on either side of the guideways. This arrangement is exemplary
and any other suitable arrangement may be provided. A load-port is
attached to the front face of the tool station at a desired
elevation (e.g. above) 900 mm. The vehicles 214 are located on the
guideways as shown. The guideways in this embodiment are spaced
vertically apart such that the vehicles on the lower and upper
guideways do not interfere with each other at any time. Similar to
FIGS. 1-2, the upper and lower guideways may each have a travel or
a "fast" lane similar to lane TL in FIG. 1). In this embodiment,
the travel/fast lane is located down the center and vehicles 214
may run freely at high speed while sidings (similar to access lanes
AL in FIG. 1) next to the load-ports are used for the vehicles 214
to "pull off". When a vehicle 214L has "pulled off" at a load-port,
FIG. 8B. The vehicle is capable of raising, or conversely lowering,
the payload C as desired to be level with any of a number of port
locations thereby allowing access to any desired port locations.
When the payload is at the appropriate level a mechanism located at
the load-port may be used to transfer the payload to or from the
vehicle. In a similar fashion, a payload may be transferred to/from
a vehicle on the upper track except that the payload would be
lowered from the vehicle. In this embodiment, running of the
vehicles may be done with the payloads normally retracted. Although
only one carrier payload is shown, the vehicle may as noted before
also accommodate more than one payload at a time, (e.g. one above
the other). Both payload positions may move simultaneously. FIG. 8C
shows a front view of an EFEM with two load-ports, each for example
with three reduced capacity carrier positions. The vehicle 214L1 on
the lower track 12L is shown with its payload raised to the second
level. If vehicle travel is in the direction of the arrow Y it can
be seen that another vehicle 214L2, 214V on the lower or upper
track 12L, 12U may access the remaining load-port to either deposit
or pick-up a payload. A vehicle 214V on the upper track 12U may
also pull-off above the vehicle 214L1 on the lower track and wait
until the lower vehicle has retracted its payload before the upper
vehicle proceeds to access the ports at this location from above.
As a completed payload is being removed and replaced by a vehicle,
the process tool is accessing any one of the other locations as
necessary.
[0048] As noted before the guideway 12 may be positioned at any
desired elevation in the FAB. Such as the FAB floor (which uses
minimal added infrastructure and enables easy operator access to
vehicles), and the elevated right-of-way reserved in SEMI E15 for
overhead transportation. Alternatively, the guideway could be
placed at other convenient elevations (e.g., below the raised metal
floor, or near the loadport height). The vehicles are an exemplary
flexibly deployable on guideways at any or several locations. In
this way additional transport network capacity and coverage may be
modified to suit the needs of a particular facility.
[0049] Security of the carrier "hand-off" between the transport
system and tool loading/buffering stations may be managed by a
time-optimized parallel I/O scheme similar to SEMI standards E
[0050] 23 and E84. Alternatively, the transportation and tool
loading hardware can be treated as an integrated system, with all
sensing and computation necessary to guarantee a safe transition
residing locally.
[0051] Referring now to FIG. 7, if desired, carriers C may be
transitioned to positions next to one or more of the access lanes
AL to provide storage or buffering of the carriers at the process
tools and fab wide buffering.
[0052] It should be understood that the foregoing description is
only illustrative of the invention. Various alternatives and
modifications can be devised by those skilled in the art without
departing from the invention. Accordingly, the present invention is
intended to embrace all such alternatives, modifications and
variances which fall within the scope of the appended claims.
* * * * *