U.S. patent application number 12/025582 was filed with the patent office on 2008-09-25 for semiconductor wafer handling and transport.
Invention is credited to Christopher C Kiley, Patrick D. Pannese, Raymond S. Ritter, Thomas A. Schaefer, Peter van der Meulen.
Application Number | 20080232948 12/025582 |
Document ID | / |
Family ID | 38712144 |
Filed Date | 2008-09-25 |
United States Patent
Application |
20080232948 |
Kind Code |
A1 |
van der Meulen; Peter ; et
al. |
September 25, 2008 |
SEMICONDUCTOR WAFER HANDLING AND TRANSPORT
Abstract
Modular wafer transport and handling facilities are combined in
a variety of ways deliver greater levels of flexibility, utility,
efficiency, and functionality in a vacuum semiconductor processing
system. Various processing and other modules may be interconnected
with tunnel-and-cart transportation systems to extend the distance
and versatility of the vacuum environment. Other improvements such
as bypass thermal adjusters, buffering aligners, batch processing,
multifunction modules, low particle vents, cluster processing
cells, and the like are incorporated to expand functionality and
improve processing efficiency.
Inventors: |
van der Meulen; Peter;
(Newburyport, MA) ; Kiley; Christopher C;
(Carlisle, MA) ; Pannese; Patrick D.; (Lynnfield,
MA) ; Ritter; Raymond S.; (Boxborough, MA) ;
Schaefer; Thomas A.; (Groveland, MA) |
Correspondence
Address: |
STRATEGIC PATENTS P.C..
C/O PORTFOLIOIP, P.O. BOX 52050
MINNEAPOLIS
MN
55402
US
|
Family ID: |
38712144 |
Appl. No.: |
12/025582 |
Filed: |
February 4, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11679829 |
Feb 27, 2007 |
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12025582 |
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10985834 |
Nov 10, 2004 |
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11679829 |
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60518823 |
Nov 10, 2003 |
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60607649 |
Sep 7, 2004 |
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60777443 |
Feb 27, 2006 |
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60779684 |
Mar 5, 2006 |
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60779707 |
Mar 5, 2006 |
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60779478 |
Mar 5, 2006 |
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60779463 |
Mar 5, 2006 |
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60779609 |
Mar 5, 2006 |
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60784832 |
Mar 21, 2006 |
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60746163 |
May 1, 2006 |
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60807189 |
Jul 12, 2006 |
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60823454 |
Aug 24, 2006 |
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Current U.S.
Class: |
414/805 |
Current CPC
Class: |
H01L 21/67161 20130101;
H01L 21/67745 20130101; H01L 21/67748 20130101; H01L 21/67196
20130101; H01L 21/68792 20130101; Y10S 414/139 20130101; B65G 37/00
20130101; H01L 21/67742 20130101; B65G 25/02 20130101 |
Class at
Publication: |
414/805 |
International
Class: |
H01L 21/67 20060101
H01L021/67 |
Claims
1. A method for moving a wafer in a semiconductor manufacturing
process that includes a tunnel having a vacuum environment, a
plurality of ports, and a track for guiding cart motion within the
tunnel, each one of the plurality of ports having an isolation
valve that opens and closes the port and a robotic arm operable to
reach through the port from outside the tunnel, the method
comprising: retrieving a wafer with a robotic arm; position the
wafer outside a port of the tunnel; positioning a cart inside the
port of the tunnel; opening the port; inserting the robotic arm
into the tunnel and placing the wafer on the cart; withdrawing the
robotic arm from the tunnel; and closing the port.
Description
RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 11/679,829 filed Feb. 27, 2007 which is a continuation-in-part
of U.S. application Ser. No. 10/985,834 filed on Nov. 10, 2004
which claims the benefit of U.S. Prov. App. No. 60/518,823 filed on
Nov. 10, 2003 and U.S. Prov. App. No. 60/607,649 filed on Sep. 7,
2004.
[0002] This application is a continuation of U.S. application Ser.
No. 11/679,829 filed Feb. 27, 2007 which claims the benefit of U.S.
Prov. App. No. 60/777,443 filed on Feb. 27, 2006; U.S. Prov. App.
No. 60/779,684 filed on Mar. 5, 2006; U.S. Prov. App. No.
60/779,707 filed on Mar. 5, 2006; U.S. Prov. App. No. 60/779,478
filed on Mar. 5, 2006; U.S. Prov. App. No. 60/779,463 filed on Mar.
5, 2006; U.S. Prov. App. No. 60/779,609 filed on Mar. 5, 2006; U.S.
Prov. App. No. 60/784,832 filed on Mar. 21, 2006; U.S. Prov. App.
No. 60/746,163 filed on May 1, 2006; U.S. Prov. App. No. 60/807,189
filed on Jul. 12, 2006; and U.S. Prov. App. No. 60/823,454 filed on
Aug. 24, 2006.
[0003] This application is a continuation-in-part of U.S.
application Ser. No. 11/681,809 filed Mar. 5, 2007.
[0004] The entire contents of each of the foregoing applications is
incorporated herein by reference.
BACKGROUND
[0005] 1. Field of the Invention
[0006] The invention herein disclosed generally relates to
semiconductor processing systems, and specifically relates to
vacuum semiconductor processing work piece handling and
transportation.
[0007] 2. Description of the Related Art
[0008] Current semiconductor manufacturing equipment takes several
different forms, each of which has significant drawbacks. Cluster
tools, machines that arrange a group of semiconductor processing
modules in a radius about a central robotic arm, take up a large
amount of space, are relatively slow, and, by virtue of their
architecture, are limited to a small number of semiconductor
process modules, typically a maximum of about five or six. Linear
tools, while offering much greater flexibility and the potential
for greater speed than cluster tools, do not fit well with the
current infrastructure of most current semiconductor fabrication
facilities. Moreover, linear motion of equipment components within
the typical vacuum environment of semiconductor manufacturing leads
to problems in current linear systems, such as unacceptable levels
of particles that are generated by friction among components.
Several hybrid architectures exist that use a combination of a
radial process module arrangement and a linear arrangement.
[0009] As semiconductor manufacturing has grown in complexity, it
becomes increasingly necessary to transfer wafers among a number of
different process modules or clusters of process modules, and
sometimes between tools and modules that are separated by
significant distances. This poses numerous difficulties,
particularly when wafers are transferred between separate vacuum
processing facilities. Transfers between vacuum environments, or
between a vacuum and other processing environments often results in
increased risk of particle contamination (due to the pumping and
venting of wafers in load locks) as well as higher thermal budgets
where wafers are either heated or cooled during transfers.
[0010] There remains a need for improved wafer transport and
handling system for use in semiconductor manufacturing
environments.
SUMMARY
[0011] Provided herein are methods and systems used for improved
semiconductor manufacturing handling, and transport. Modular wafer
transport and handling facilities are combined in a variety of ways
deliver greater levels of flexibility, utility, efficiency, and
functionality in a vacuum semiconductor processing system. Various
processing and other modules may be interconnected with
tunnel-and-cart transportation systems to extend the distance and
versatility of the vacuum environment. Other improvements such as
bypass thermal adjusters, buffering aligners, batch processing,
multifunction modules, low particle vents, cluster processing
cells, and the like are incorporated to expand functionality and
improve processing efficiency.
[0012] As used herein, "robot" shall include any kind of known
robot or similar device or facility that includes a mechanical
capability and a control capability, which may include a
combination of a controller, processor, computer, or similar
facility, a set of motors or similar facilities, one or more
resolvers, encoders or similar facilities, one or more mechanical
or operational facilities, such as arms, wheels, legs, links,
claws, extenders, grips, nozzles, sprayers, end effectors,
actuators, and the like, as well as any combination of any of the
above. One embodiment is a robotic arm.
[0013] As used herein "drive" shall include any form of drive
mechanism or facility for inducing motion. In embodiments it
includes the motor/encoder section of a robot.
[0014] As used herein, "axis" shall include a motor or drive
connected mechanically through linkages, belts or similar
facilities, to a mechanical member, such as an arm member. An
"N-axis drive" shall include a drive containing N axes; for example
a "2-axis drive" is a drive containing two axes.
[0015] As used herein, "arm" shall include a passive or active
(meaning containing motors/encoders) linkage that may include one
or more arm or leg members, bearings, and one or more end effectors
for holding or gripping material to be handled.
[0016] As used herein, "SCARA arm" shall mean a Selectively
Compliant Assembly Robot Arm (SCARA) robotic arm in one or more
forms known to those of skill in the art, including an arm
consisting of one or more upper links connected to a drive, one or
more lower links connected through a belt or mechanism to a motor
that is part of the drive, and one or more end units, such as an
end effector or actuator.
[0017] As used herein, "turn radius" shall mean the radius that an
arm fits in when it is fully retracted.
[0018] As used herein, "reach" shall include, with respect to a
robotic arm, the maximum reach that is obtained when an arm is
fully extended. Usually the mechanical limit is a little further
out than the actual effective reach, because it is easier to
control an arm that is not completely fully extended (in
embodiments there is a left/right singularity at full extension
that can be hard to control).
[0019] As used herein, "containment" shall mean situations when the
arm is optimally retracted such that an imaginary circle can be
drawn around the arm/end effector/material that is of minimum
radius.
[0020] As used herein, the "reach-to-containment ratio" shall mean,
with respect to a robotic arm, the ratio of maximum reach to
minimum containment.
[0021] As used herein, "robot-to-robot" distance shall include the
horizontal distance between the mechanical central axis of rotation
of two different robot drives.
[0022] As used herein, "slot valve" shall include a rectangular
shaped valve that opens and closes to allow a robot arm to pass
through (as opposed to a vacuum (isolation) valve, which controls
the pump down of a vacuum chamber). For example, the SEMI
E21.1-1296 standard (a published standard for semiconductor
manufacturing) the slot valve for 300 mm wafers in certain
semiconductor manufacturing process modules has an opening width of
336 mm, a opening height of 50 mm and a total valve thickness of 60
mm with the standard also specifying the mounting bolts and
alignment pins.
[0023] As used herein, "transfer plane" shall include the plane
(elevation) at which material is passed from a robot chamber to a
process module chamber through a slot valve. Per the SEMI
E21.1-1296 standard for semiconductor manufacturing equipment the
transfer plane is 14 mm above the slot valve centerline and 1100 mm
above the plane of the factory floor.
[0024] As used herein, "section" shall include a vacuum chamber
that has one or more robotic drives in it. This is the smallest
repeatable element in a linear system.
[0025] As used herein, "link" shall include a mechanical member of
a robot arm, connected on both ends to another link, an end
effector, or the robot drive.
[0026] As used herein, "L1," "L2", "L3" or the like shall include
the numbering of the arm links starting from the drive to the end
effector.
[0027] As used herein, "end effector" shall include an element at
an active end of a robotic arm distal from the robotic drive and
proximal to an item on which the robotic arm will act. The end
effector may be a hand of the robot that passively or actively
holds the material to be transported in a semiconductor process or
some other actuator disposed on the end of the robotic arm.
[0028] As used herein, the term "SCARA arm" refers to a robotic arm
that includes one or more links and may include an end effector,
where the arm, under control, can move linearly, such as to engage
an object. A SCARA arm may have various numbers of links, such as
3, 4, or more. As used herein, "3-link SCARA arm" shall include a
SCARA robotic arm that has three members: link one (L1), link two
(L2) and an end effector. A drive for a 3-link SCARA arm usually
has 3 motors: one connected to L1, one to the belt system, which in
turn connects to the end effector through pulleys and a Z (lift)
motor. One can connect a fourth motor to the end effector, which
allows for some unusual moves not possible with only three
motors.
[0029] As used herein, "dual SCARA arm" shall include a combination
of two SCARA arms (such as two 3 or 4-link SCARA arms (typically
designated A and B)) optionally connected to a common drive. In
embodiments the two SCARA arms are either completely independent or
share a common link member L1. A drive for a dual independent SCARA
arm usually has either five motors: one connected to L1-A, one
connected to L1-B, one connected to the belt system of arm A, one
connected to the belt system of arm B, and a common Z (lift) motor.
A drive for a dual dependent SCARA arm usually has a common share
L1 link for both arms A and B and contains typically four motors:
one connected to the common link L1, one connected to the belt
system for arm A, one connected to the belt system for arm B, and a
common Z (lift) motor.
[0030] As used herein, "4-link SCARA arm" shall include an arm that
has four members: L1, L2, L3 and an end effector. A drive for a
4-link SCARA arm can have four motors: one connected to L1, one to
the belt systems connected to L2 and L3, one to the end effector
and a Z motor. In embodiments only 3 motors are needed: one
connected to L1, one connected to the belt system that connects to
L2, L3 and the end effector, and a Z motor.
[0031] As used herein, "Frog-leg style arm" shall include an arm
that has five members: L1A, L1B, L2A, L3B and an end effector. A
drive for a frog-leg arm can have three motors, one connected to
L1A--which is mechanically by means of gearing or the like
connected to L1B--, one connected to a turret that rotates the
entire arm assembly, and a Z motor. In embodiments the drive
contains three motors, one connected to L1A, one connected to L1B
and a Z motor and achieves the desired motion through coordination
between the motors.
[0032] As used herein, "Dual Frog-leg style arm" shall include an
arm that has eight members L1A, L1B, L2A-1, L2A-2, L2B-1, L2B-2 and
two end effectors. The second link members L2A-1 and L2B-1 form a
single Frog-leg style arm, whereas the second link members L2A-2
and L2B-2 also form a single Frog-leg style arm, however facing in
an opposite direction. A drive for a dual frog arm may be the same
as for a single frog arm.
[0033] As used herein, "Leap Frog-leg style arm" shall include an
arm that has eight members L1A, L1B, L2A-1, L2A-2, L2B-1, L2B-2 and
two end effectors. The first link members L1A and L1B are each
connected to one of the motors substantially by their centers,
rather than by their distal ends. The second link members L2A-1 and
L2B-1 form a single Frog-leg style arm, whereas the second link
members L2A-2 and L2B-2 also form a single Frog-leg style arm,
however facing in the same direction. A drive for a dual frog arm
may be the same as for a single frog arm.
[0034] Disclosed herein are methods and systems for combining a
linkable, flexible robotic system with a vacuum tunnel system using
moveable carts for carrying one or more wafers in vacuum between
process modules. The vacuum tunnel cart may be employed to transfer
wafers between process modules or clusters, while a linkable
robotic system is employed within each module or cluster for local
wafer handling. The carts may employ any transportation medium
suitable for a vacuum environment, such as magnetic
levitation/propulsion.
[0035] Disclosed herein are also various configurations of vacuum
transport systems in which heterogeneous handling systems are
combined in a modular fashion to allow for more diverse
functionality within a single process environment. In general,
robots may be provided for wafer handling inside and between
process modules that are in proximity to each other, while allowing
for rapid, convenient transport of wafers between process cells
that are relatively distant. Such heterogeneous handling systems
may include, for example, systems in which robotic arms, such as
SCARA arms, are used to handle wafers within process modules or
clusters, while carts or similar facilities are used to transport
wafers between process modules or clusters. A cart or similar
facility may include a levitated cart, a cart on a rail, a tube
system, or any of a wide variety of cart or railway systems,
including various embodiments disclosed herein.
[0036] The methods and systems disclosed herein also include
various configurations of robot handling systems in combination
with cart systems, including ones in which cart systems form "U"
and "T" shapes, circuits, lines, dual linear configurations
(including side-by-side and above and below configurations) and the
like.
[0037] Disclosed herein are methods and systems for supporting
vacuum processing and handling modules in vacuum semiconductor
processing systems. The pedestal support systems herein disclosed
may precisely position vacuum modules to facilitate proper vacuum
sealing between adjacent modules. In embodiments, the pedestal's
cylindrical shape affords opportunity for convenient manufacturing
methods while providing stability to the supported vacuum module
with a small footprint.
[0038] In embodiments, the pedestal support system further may
incorporate a robot motor mechanism for a robot operating within
the vacuum module, further reducing the overall size and cost of
the vacuum processing system.
[0039] A pedestal support system with a rolling base may also
provide needed flexibility in reconfiguring processing and handling
modules quickly and cost effectively.
[0040] These and other systems, methods, objects, features, and
advantages of the present invention will be apparent to those
skilled in the art from the following detailed description of the
preferred embodiment and the drawings. All documents mentioned
herein are hereby incorporated in their entirety by reference.
BRIEF DESCRIPTION OF THE FIGURES
[0041] The foregoing and other objects and advantages of the
invention will be appreciated more fully from the following further
description thereof, with reference to the accompanying drawings,
wherein:
[0042] FIG. 1 shows equipment architectures for a variety of
manufacturing equipment types.
[0043] FIG. 2 shows a conventional, cluster-type architecture for
handling items in a semiconductor manufacturing process.
[0044] FIGS. 3A and 3B show a series of cluster-type systems for
accommodating between two and six process modules.
[0045] FIG. 4 shows high-level components of a linear processing
architecture for handling items in a manufacturing process.
[0046] FIG. 5 shows a top view of a linear processing system, such
as one with an architecture similar to that of FIG. 4.
[0047] FIGS. 6A and 6B show a 3-link SCARA arm and a 4-link SCARA
arm.
[0048] FIG. 7 shows reach and containment characteristics of a
SCARA arm.
[0049] FIG. 8 shows high-level components for a robot system.
[0050] FIG. 9 shows components of a dual-arm architecture for a
robotic arm system for use in a handling system.
[0051] FIG. 10 shows reach and containment capabilities of a 4-link
SCARA arm.
[0052] FIGS. 11A and 11B show interference characteristics of a
4-link SCARA arm.
[0053] FIG. 12 shows a side view of a dual-arm set of 4-link SCARA
arms using belts as the transmission mechanism.
[0054] FIGS. 13A, 13B, and 13C show a dual-arm set of 4-link SCARA
arms using a spline link as the transmission mechanism.
[0055] FIG. 14 shows an external return system for a handling
system having a linear architecture.
[0056] FIG. 14a shows a U-shaped configuration for a linear
handling system.
[0057] FIG. 15 shows certain details of an external return system
for a handling system of FIG. 14.
[0058] FIG. 16 shows additional details of an external return
system for a handling system of FIG. 14.
[0059] FIG. 17 shows movement of the output carrier in the return
system of FIG. 14.
[0060] FIG. 18 shows handling of an empty carrier in the return
system of FIG. 14.
[0061] FIG. 19 shows movement of the empty carrier in the return
system of FIG. 14 into a load lock position.
[0062] FIG. 20 shows the empty carrier lowered and evacuated and
movement of the gripper in the return system of FIG. 14.
[0063] FIG. 21 shows an empty carrier receiving material as a full
carrier is being emptied in the return system of FIG. 14.
[0064] FIG. 22 shows an empty carrier brought to a holding
position, starting a new return cycle in the return system of FIG.
14.
[0065] FIG. 23 shows an architecture for a handling facility for a
manufacturing process, with a dual-arm robotic arm system and a
return system in a linear architecture.
[0066] FIG. 24 shows an alternative embodiment of an overall system
architecture for a handling method and system of the present
invention.
[0067] FIGS. 25A and 25B show a comparison of the footprint of a
linear system as compared to a conventional cluster system.
[0068] FIG. 26 shows a linear architecture deployed with oversized
process modules in a handling system in accordance with embodiments
of the invention.
[0069] FIG. 27 shows a rear-exit architecture for a handling system
in accordance with embodiments of the invention.
[0070] FIGS. 28A and 28B show a variety of layout possibilities for
a fabrication facility employing linear handling systems in
accordance with various embodiments of the invention.
[0071] FIG. 29 shows an embodiment of the invention wherein a robot
may include multiple drives and/or multiple controllers.
[0072] FIG. 30 shows transfer plane and slot valve characteristics
relevant to embodiments of the invention.
[0073] FIG. 31 shows a tumble gripper for centering wafers.
[0074] FIG. 32 shows a passive sliding ramp for centering
wafers.
[0075] FIG. 33 illustrates a fabrication facility including a
mid-entry facility.
[0076] FIGS. 34A, 34B and 34C illustrate a fabrication facility
including a mid-entry facility from a top view.
[0077] FIG. 35 illustrates a fabrication facility including the
placement of optical sensors for detection of robotic arm position
and materials in accordance with embodiments of the invention.
[0078] FIGS. 36A, 36B and 36C illustrate a fabrication facility in
a cross-sectional side view showing optical beam paths and
alternatives beam paths.
[0079] FIGS. 37A and 37B illustrate how optical sensors can be used
to determine the center of the material handled by a robotic
arm.
[0080] FIG. 38 shows a conventional 3-axis robotic vacuum drive
architecture
[0081] FIG. 39 shows a 3-axis robotic vacuum drive architecture in
accordance with embodiments of the invention.
[0082] FIG. 40 illustrates a vertically arranged load lock assembly
in accordance with embodiments of the invention.
[0083] FIG. 40B illustrates a vertically arranged load lock
assembly at both sides of a wafer fabrication facility in
accordance with embodiments of the invention.
[0084] FIG. 41 shows a vertically arranged load lock and vertically
stacked process modules in accordance with embodiments of the
invention.
[0085] FIG. 42 shows a linearly arranged, two-level handling
architecture with vertically stacked process modules in a
cross-sectional side view in accordance with embodiments of the
invention.
[0086] FIG. 43 shows the handling layout of FIG. 42 in a top
view.
[0087] FIG. 44 shows an instrumented object on a robotic arm with
sensors to detect proximity of the object to a target, in
accordance with embodiments of the invention.
[0088] FIG. 45 illustrates how the movement of sensors over a
target can allow the robotic arm to detect its position relative to
the obstacle.
[0089] FIG. 46 shows how an instrumented object can use radio
frequency communications in a vacuum environment to communicate
position to a central controller.
[0090] FIG. 47 illustrates the output of a series of sensors as a
function of position.
[0091] FIG. 48 illustrates how heating elements can be placed in a
load lock for thermal treatment of objects in accordance with
embodiments of the invention.
[0092] FIGS. 49A and 49B show an end effector tapered in two
dimensions, which reduces active vibration modes in the end
effector.
[0093] FIGS. 50A and 50B show how vertical tapering of robotic arm
elements for a robot planar arm can be used to reduce vibration in
the arm set, without significantly affecting vertical stacking
height.
[0094] FIGS. 51A and 51B illustrate a dual independent SCARA
robotic arm.
[0095] FIGS. 52A and 52B illustrate a dual dependent SCARA robotic
arm.
[0096] FIGS. 53A and 53B illustrate a frog-leg style robotic
arm.
[0097] FIGS. 54A and 54B illustrate a dual Frog-leg style robotic
arm.
[0098] FIG. 55A illustrates a 4-Link SCARA arm mounted on a
moveable cart, as well as a 4-Link SCARA arm mounted on an inverted
moveable cart.
[0099] FIG. 55B illustrates a top view of FIG. 55A.
[0100] FIG. 56 illustrates using a 3-Link single or dual SCARA arm
robotic system to pass wafers along a substantially a linear
axis.
[0101] FIG. 57 illustrates a 2-level vacuum handling robotic system
where the top and bottom process modules are accessible by means of
a vertical axis in the robotic arms.
[0102] FIG. 58A shows a two level processing facility where
substrates are passed along a substantially linear axis on one of
the two levels.
[0103] FIG. 58B illustrates a variation of FIG. 58a where
substrates are removed from the rear of the system.
[0104] FIG. 59A shows a manufacturing facility which accommodates
very large processing modules in a substantially linear axis.
Service space is made available to allow for access to the interior
of the process modules.
[0105] FIG. 59B illustrates a more compact layout for 4 large
process modules and one small process module.
[0106] FIGS. 60A and 60B illustrate a dual Frog-Leg style robotic
manipulator with substrates on the same side of the system.
[0107] FIG. 61 is a plan view of a preferred embodiment wherein a
vacuum tunnel cart is configured with a process module through a
transfer robot.
[0108] FIG. 62 is a plan view of a preferred embodiment wherein a
vacuum tunnel cart is configured with a plurality of process
modules through a plurality of transfer robots.
[0109] FIG. 63 shows the embodiment of FIG. 62 further including
process modules along both sides of the vacuum tunnel.
[0110] FIG. 64 is a plan view of a preferred embodiment wherein a
vacuum tunnel cart is configured with a cluster process cell
through a transfer robot.
[0111] FIG. 65 shows the embodiment of FIG. 64 further including a
plurality of cluster process cells and a plurality of transfer
robots along both sides of the vacuum tunnel.
[0112] FIG. 66 is a plan view of a preferred embodiment wherein a
vacuum tunnel cart is configured with a linear process cell through
a transfer robot.
[0113] FIG. 67 shows the embodiment of FIG. 66 further including a
plurality of linear process cells.
[0114] FIG. 68 is a plan view of a preferred embodiment wherein a
plurality of cluster process cells and a plurality of linear
process cells are configured with a tunnel transfer cart.
[0115] FIG. 69 shows the embodiment of FIG. 68 further including a
plurality of transfer carts.
[0116] FIG. 70 is a plan view of an alternate embodiment wherein
alternate cluster processing cells are combined with both tunnel
transport cart systems and a linear processing group.
[0117] FIG. 71 is a plan view of an alternate embodiment wherein
the tunnel forms a shape of an "L".
[0118] FIG. 72 is a plan view of an alternate embodiment wherein
the tunnel forms a shape of a "T".
[0119] FIG. 73 is a plan view of an alternate embodiment wherein
the tunnel forms a shape of a "U".
[0120] FIG. 74 is a plan view of an alternate embodiment wherein
both long duration processes and short processes are required.
[0121] FIG. 75 shows the embodiment of FIG. 74 with a plurality of
transport carts in the transport tunnel.
[0122] FIG. 76 is an alternate embodiment wherein a plurality
tunnel transport cart systems are interconnected by work piece
handling vacuum modules.
[0123] FIG. 77 shows the embodiment of FIG. 76 wherein the tunnel
transport cart system forms a complete loop.
[0124] FIG. 78 shows an alternate embodiment depicting a complete
process group.
[0125] FIG. 79 shows an embodiment of a work piece buffer zone in a
vacuum processing system.
[0126] FIG. 80 shows dual side-by-side independent transport carts
in a vacuum tunnel.
[0127] FIG. 81 shows a side view of dual vertically opposed
independent transport carts in a vacuum tunnel.
[0128] FIG. 82 shows an embodiment of transport cart with a robotic
arm in a processing system that also includes transfer robots for
work piece handling.
[0129] FIG. 83 shows an embodiment of dual independent transport
tunnels, each with a transport cart.
[0130] FIG. 84 shows an embodiment of the embodiment depicted in
FIG. 83 wherein a work piece elevator is used to move a work piece
from the lower tunnel to the upper tunnel.
[0131] FIG. 85 is an embodiment of a system wherein two types of
frog-leg style robots are configured as the main work piece
handling transfer robots.
[0132] FIG. 86 illustrates another embodiment of the systems
described herein.
[0133] FIGS. 87-91 illustrate additional embodiments using vertical
lifters and/or elevators.
[0134] FIG. 92 shows a system for sharing metrology or lithography
hardware.
[0135] FIG. 93 shows a linear processing system combining a cart in
a tunnel, a work piece handling vacuum module, process modules, and
a multi-function module in-line and parallel to the processing
flow.
[0136] FIG. 94 depicts a side cut away view of a bypass capable
thermal adjustment module with work piece handling vacuum module
access.
[0137] FIG. 95 is a perspective view of a configurable
multi-function semiconductor vacuum module as it would be used in a
semiconductor vacuum processing system.
[0138] FIG. 96 shows a plurality of vacuum extension tunnels in a
vacuum processing system.
[0139] FIG. 97 depicts the buffer aligner module with four stored
semiconductor work pieces.
[0140] FIG. 98 depicts an alignment operation of the aligner of
FIG. 97.
[0141] FIG. 99 depicts an alignment of a second work piece in the
aligner of FIG. 97.
[0142] FIG. 100 depicts a batch of aligned work pieces being
transferred from the aligner of FIG. 97.
[0143] FIG. 101 depicts a vacuum module support pedestal in a
vacuum processing system environment.
[0144] FIG. 102 is an exploded perspective view of a portion of a
semiconductor processing system incorporating modular utility
delivery modules.
[0145] FIG. 103 is a side view of a modular utility delivery system
in an application with process chambers and elevated vacuum handing
modules.
[0146] FIG. 104 shows a modular utility delivery modules attached
to a modular vacuum processing system.
[0147] FIG. 105 shows a side view of an embodiment of a low
particle vent system used with a semiconductor vacuum module.
[0148] FIG. 106 shows a batch processing system.
[0149] FIG. 107 shows a robotic arm for use in a batch processing
system.
[0150] FIG. 108 shows a multi-shelf buffer for use in a batch
processing system.
DETAILED DESCRIPTION
[0151] FIG. 1 shows equipment architectures 1000 for a variety of
manufacturing equipment types. Each type of manufacturing equipment
handles items, such as semiconductor wafers, between various
processes, such as chemical vapor deposition processes, etching
processes, and the like. As semiconductor manufacturing processes
are typically extremely sensitive to contaminants, such as
particulates and volatile organic compounds, the processes
typically take place in a vacuum environment, in one or more
process modules that are devoted to specific processes.
Semiconductor wafers are moved by a handling system among the
various processes to produce the end product, such as a chip.
Various configurations 1000 exist for handling systems. A prevalent
system is a cluster tool 1002, where process modules are positioned
radially around a central handling system, such as a robotic arm.
In other embodiments, a handling system can rotate items
horizontally, such as in the embodiment 1004. An important aspect
of each type of tool is the "footprint," or the area that the
equipment takes up in the semiconductor manufacturing facility. The
larger the footprint, the more space required to accommodate
multiple machines in a fabrication facility. Also, larger
footprints typically are associated with a need for larger vacuum
systems, which increase greatly in cost as they increase in size.
The architecture 1004 rotates items in a "lazy susan" facility. The
architecture in 1006 moves items in and out of a process module
where the process modules are arranged next to each other. The
architecture 1008 positions process modules in a cluster similar to
1002, with the difference that the central robot handles two wafers
side by side. Each of these systems shares many of the challenges
of cluster tools, including significant swap time delays as one
wafer is moved in and another out of a given process module, as
well as considerable difficulty maintaining the cleanliness of the
vacuum environment of a given process module, as more and more
wafers are moved through the system.
[0152] FIG. 2 shows a conventional cluster-type architecture 2000
for handling items in a semiconductor manufacturing process. A
robotic arm 2004 moves items, such as wafers, among various process
modules 2002 that are positioned in a cluster around the robotic
arm 2004. An atmospheric substrate handling mini-environment
chamber 2008 receives materials for handling by the equipment and
holds materials once processing is complete. Note how difficult it
would be to add more process modules 2002. While one more module
2002 would potentially fit, the practical configuration is limited
to five process modules 2002. Adding a sixth module may
significantly impact the serviceability of the equipment, in
particular the robotic arm 2004.
[0153] FIGS. 3A and 3B show cluster tool modules, atmospheric
mini-environment handling chambers, vacuum handling chambers and
other components 3000 from a flexible architecture system for a
vacuum based manufacturing process. Different modules can be
assembled together to facilitate manufacturing of a desired process
technology. For example, a given chip may require chemical vapor
deposition of different chemical constituents (e.g., Titanium
Nitride, Tungsten, etc.) in different process modules, as well as
etching in other process modules. The sequence of the processes in
the different process modules produces a unique end product. Given
the increasing complexity of semiconductor components, it is often
desirable to have a flexible architecture that allows the
manufacturer to add more process modules. However, the cluster
tools described above are space-limited; therefore, it may be
impossible to add more process modules, meaning that in order to
complete a more complex semiconductor wafer it may be necessary to
move manufacturing to a second cluster tool. As seen in FIG. 3A and
FIG. 3B, cluster tools can include configurations with two 3002,
three 3004, four 3006, five 3008, 3010 or six 3012 process modules
with staged vacuum isolation. Other components can be supplied in
connection with the equipment.
[0154] FIG. 4 shows high-level components of a linear processing
architecture 4000 for handling items in a manufacturing process.
The architecture uses two or more stationary robots 4002 arranged
in a linear fashion. The robots 4002 can be either mounted in the
bottom of the system or hang down from the chamber lid or both at
the same time. The linear system uses a vacuum chamber 4012 around
the robot. The system could be comprised of multiple connected
vacuum chambers 4012, each with a vacuum chamber 4012 containing
its own robot arranged in a linear fashion. In embodiments, a
single controller could be set up to handle one or more sections of
the architecture. In embodiments vacuum chambers 4012 sections are
extensible; that is, a manufacturer can easily add additional
sections/chambers 4012 and thus add process capacity, much more
easily than with cluster architectures. Because each section uses
independent robot drives 4004 and arms 4002, the throughput may
stay high when additional sections and thus robots are added. By
contrast, in cluster tools, when the manufacturer adds process
chambers 2002, the system increases the load for the single robot,
even if that robot is equipped with a dual arm, eventually the
speed of the robot can become the limiting factor. In embodiments,
systems address this problem by adding additional robot arms 4002
into a single drive. Other manufacturers have used a 4-axis robot
with two completely independent arms such as a dual SCARA or dual
Frog-leg robots. The linear system disclosed herein may not be
limited by robot capacity, since each section 4012 contains a
robot, so each section 4012 is able to transport a much larger
volume of material than with cluster tools.
[0155] In embodiments the components of the system can be
controlled by a software controller, which in embodiments may be a
central controller that controls each of the components. In
embodiments the components form a linkable handling system under
control of the software, where the software controls each robot to
hand off a material to another robot, or into a buffer for picking
up by the next robot. In embodiments the software control system
may recognize the addition of a new component, such as a process
module or robot, when that component is plugged into the system,
such as recognizing the component over a network, such as a USB,
Ethernet, firewire, Bluetooth, 802.11a, 802.11b, 802.11g or other
network. In such embodiments, as soon as the next robot, process
module, or other component is plugged in a software scheduler for
the flow of a material to be handled, such as a wafer, can be
reconfigured automatically so that the materials can be routed over
the new link in the system. In embodiments the software scheduler
is based on a neural net, or it can be a rule-based scheduler. In
embodiments process modules can make themselves known over such a
network, so that the software controller knows what new process
modules, robots, or other components have been connected. When a
new process module is plugged into an empty facet, the system can
recognize it and allow it to be scheduled into the flow of material
handling.
[0156] In embodiments the software system may include an interface
that permits the user to run a simulation of the system. The
interface may allow a user to view the linking and configuration of
various links, robotic arms and other components, to optimize
configuration (such as by moving the flow of materials through
various components, moving process modules, moving robots, or the
like), and to determine what configuration to purchase from a
supplier. In embodiments the interface may be a web interface.
[0157] The methods and system disclosed herein can use optional
buffer stations 4010 between robot drives. Robots could hand off to
each other directly, but that is technically more difficult to
optimize, and would occupy two robots, because they would both have
to be available at the same time to do a handoff, which is more
restrictive than if they can deposit to a dummy location 4010
in-between them where the other robot can pick up when it is ready.
The buffer 4010 also allows higher throughput, because the system
does not have to wait for both robots to become available.
Furthermore, the buffers 4010 may also offer a good opportunity to
perform some small processing steps on the wafer such as heating,
cooling, aligning, inspection, metrology, testing or cleaning.
[0158] In embodiments, the methods and systems disclosed herein use
optional vacuum isolation valves 4006 between robot areas/segments
4012. Each segment 4012 can be fully isolated from any other
segment 4012. If a robot handles ultra clean and sensitive
materials (e.g., wafers) in its segment 4012, then isolating that
segment 4012 from the rest of the system may prevent
cross-contamination from the dirtier segment 4012 to the clean
segment 4012. Also the manufacturer can now operate segments 4012
at different pressures. The manufacturer can have stepped vacuum
levels where the vacuum gets better and better further into the
machine. The big advantage of using vacuum isolation valves 4006
between segments 4012 may be that handling of atomically clean
wafers (created after cleaning steps and needing to be transported
between process modules without contamination from the environment)
can be done without out-gassing from materials or wafers in other
parts of the system entering the isolated chamber segment 4012.
[0159] In embodiments, vacuum isolation between robots is possible,
as is material buffering between robots, such as using a buffer
module 4010, a mini-process module or an inspection module
4010.
[0160] FIG. 5 shows a top view of a linear processing system 4000,
such as one with a linear architecture similar to that of FIG.
4.
[0161] Different forms of robots can be used in semiconductor
manufacturing equipment, whether a cluster tool or a linear
processing machine such as disclosed in connection with FIGS. 4 and
5.
[0162] FIGS. 6A and 6B show a 3-link SCARA arm 6002 and a 4-link
SCARA arm 6004. The 3-link or 4-link arms 6002, 6004 are driven by
a robot drive. The 3-link arm 6002 is commonly used in industry.
When the 3-link SCARA arm 6002 is used, the system is not optimized
in that the reach-to-containment ratio is not very good. Thus, the
vacuum chambers need to be bigger, and since costs rise
dramatically with the size of the vacuum chamber, having a 3-link
SCARA arm 6002 can increase the cost of the system. Also the
overall footprint of the system becomes bigger with the 3-link
SCARA arm 6002. Moreover, the reach of a 3-link SCARA arm 6002 is
less than that of a 4-link arm 6004. In some cases a manufacturer
may wish to achieve a large, deep handoff into a process module,
and the 4-link arm 6004 reaches much farther beyond its containment
ratio. This has advantages in some non-SEMI-standard process
modules. It also has advantages when a manufacturer wants to cover
large distances between segments.
[0163] The 4-link arm 6004 is advantageous in that it folds in a
much smaller containment ratio than a 3-link SCARA arm 6002, but it
reaches a lot further than a conventional 3-link SCARA 6002 for the
same containment diameter. In combination with the ability to have
a second drive and second 4-link arm 6004 mounted on the top of the
system, it may allow for a fast material swap in the process
module. The 4-link SCARA arm 6004 may be mounted, for example, on
top of a stationary drive as illustrated, or on top of a moving
cart that provides the transmission of the rotary motion to actuate
the arms and belts. In either case, the 4-link arm 6004, optionally
together with a second 4-link arm 6004, may provide a compact,
long-reach arm that can go through a small opening, without
colliding with the edges of the opening.
[0164] FIG. 7 shows reach and containment characteristics of a
4-link SCARA arm 7004. In embodiments, the 4-link SCARA arm 7004
link lengths are not constrained by the optimization of reach to
containment ratio as in some other systems. Optimization of the
reach to containment ratio may lead to a second arm member that is
too long. When the arm reaches through a slot valve that is placed
as close as practical to the minimum containment diameter, this
second arm member may collide with the inside edges of the slot
valve. Thus the second (and third) links may be dimensioned based
on collision avoidance with a slot valve that the arm is designed
to reach through. This results in very different ratios between L1,
L2 and L3. The length of L2 may constrain the length of L3. An
equation for optimum arm length may be a 4th power equation
amenable to iterative solutions.
[0165] FIG. 8 shows high-level components for a robot system 8002,
including a controller 8004, a drive/motor 8008, an arm 8010, an
end effector 8012, and a material to be handled 8014.
[0166] FIG. 9 shows components of a dual-arm 9002 architecture for
a robotic arm system for use in a handling system. One arm is
mounted from the bottom 9004 and the other from the top 9008. In
embodiments both are 4-link SCARA arms. Mounting the second arm on
the top is advantageous. In some other systems arms have been
connected to a drive that is mounted through the top of the
chamber, but the lower and upper drives are conventionally
mechanically coupled. In embodiments, there is no mechanical
connection between the two drives in the linear system disclosed in
connection with FIG. 4 and FIG. 5; instead, the coordination of the
two arms (to prevent collisions) may be done in a software system
or controller. The second (top) arm 9008 may optionally be included
only if necessary for throughput reasons.
[0167] Another feature is that only two motors, just like a
conventional SCARA arm, may be needed to drive the 4-link arm.
Belts in the arm may maintain parallelism. Parallelism or other
coordinated movements may also be achieved, for example, using
parallel bars instead of belts. Generally, the use of only two
motors may provide a substantial cost advantage. At the same time,
three motors may provide a functional advantage in that the last
(L4) link may be independently steered, however the additional
belts, bearings, connections, shafts and motor may render the
system much more expensive. In addition the extra belts may add
significant thickness to the arm mechanism, making it difficult to
pass the arm through a (SEMI standard) slot valve. Also, the use of
fewer motors generally simplifies related control software.
[0168] Another feature of the 4-link SCARA arm disclosed herein is
that the wrist may be offset from centerline. Since the ideal
system has a top-mount 9008 as well as a bottom 9004 mount 4-link
arm, the vertical arrangement of the arm members may be difficult
to adhere to if the manufacturer also must comply with the SEMI
standards. In a nutshell, these standards specify the size and
reach requirements through a slot valve 4006 into a process module.
They also specify the level above centerline on which a wafer has
to be carried. Many existing process modules are compliant with
this standard. In systems that are non-compliant, the slot valves
4006 are of very similar shape although the opening size might be
slightly different as well as the definition of the transfer plane.
The SEMI standard dimensional restrictions require a very compact
packaging of the arms. Using an offset wrist allows the top 9008
and bottom 9004 arms to get closer together, making it easier for
them to pass through the slot valve 4006. If the wrist is not
offset, then the arms need to stay further apart vertically and
wafer exchanges may take more time, because the drives need to move
more in the vertical direction. The proposed design of the top arm
does not require that there is a wrist offset, but a wrist offset
may advantageously reduce the turn radius of the system, and allows
for a better mechanical arm layout, so no interferences occur.
[0169] FIG. 10 shows reach and containment capabilities of a 4-link
SCARA arm 6004.
[0170] FIG. 11 shows interference characteristics 1102 of a 4-link
SCARA arm 6004. The wrist offset may help to fold the arm in a
smaller space than would otherwise be possible.
[0171] FIG. 12 shows a side view of a dual-arm set of 4-link SCARA
arms 6004. Because of the packaging constraints of particularly the
top arm, it may be necessary to construct an arm that has some
unique features. In embodiments, one link upon retracting partially
enters a cutout in another arm link. Belts can be set in duplicate,
rather than a single belt, so that one belt is above 12004 and one
below 12008 the cutout. One solution, which is independent of the
fact that this is a 4-link arm, is to make L2 significantly lower
12002, with a vertical gap to L1, so that L3 and L4 can fold
inside. Lowering L2 12002 may allow L3 and L4 to reach the correct
transfer plane and may allow a better containment ratio. Because of
the transfer plane definition, the lowering of L2 12002 may be
required.
[0172] FIG. 13 shows an embodiment in which a combination of belts
and linkages is used. The transmission of motion through L1 13002
and L3 13006 may be accomplished by either a single belt or a dual
belt arrangement. In contrast, the motion transmission in L2 13004
may be accomplished by a mechanical linkage (spline) 13010. The
advantage of such an arrangement may be that enclosed joints can be
used which reduces the vertical dimension of the arm assembly that
may allow an arm to more easily pass through a SEMI standard slot
valve.
[0173] FIG. 14 shows an external return system for a handling
system having a linear architecture 14000. The return mechanism is
optionally on the top of the linear vacuum chamber. On conventional
vacuum handling systems, the return path is often through the same
area as the entry path. This opens up the possibility of cross
contamination, which occurs when clean wafers that are moving
between process steps get contaminated by residuals entering the
system from dirty wafers that are not yet cleaned. It also makes it
necessary for the robot 4002 to handle materials going in as well
as materials going out, and it makes it harder to control the
vacuum environment. By exiting the vacuum system at the rear and
moving the wafers on the top back to the front in an air tunnel
14012, there are some significant advantages: the air return may
relatively cheap to implement; the air return may free up the
vacuum robots 4002 because they do not have to handle materials
going out; and the air return may keep clean finished materials out
of the incoming areas, thereby lowering cross-contamination risks.
Employing a small load lock 14010 in the rear may add some costs,
and so may the air tunnel 14012, so in systems that are short and
where vacuum levels and cross contamination are not so important,
an air return may have less value, but in long systems with many
integrated process steps the above-system air return could have
significant benefits. The return system could also be a vacuum
return, but that would be more expensive and more complicated to
implement. It should be understood that while in some embodiments a
load lock 14010 may be positioned at the end of a linear system, as
depicted in FIG. 14, the load lock 14010 could be positioned
elsewhere, such as in the middle of the system. In such an
embodiment, a manufacturing item could enter or exit the system at
such another point in the system, such as to exit the system into
the air return. The advantage of a mid-system exit point may be
that in case of a partial system failure, materials or wafers can
be recovered. The advantage of a mid-system entry point may be that
wafers can be inserted in multiple places in the system, allowing
for a significantly more flexible process flow. In effect, a mid
system entry or exit position behaves like two machines connected
together by the mid-system position, effectively eliminating an
EFEM position. It should also be understood that while the
embodiment of FIG. 14 and subsequent figures is a straight line
system, the linear system could be curvilinear; that is, the system
could have curves, a U- or V-shape, an S-shape, or a combination of
those or any other curvilinear path, in whatever format the
manufacturer desires, such as to fit the configuration of a
fabrication facility. In each case the system optionally includes
an entry point and an exit point that is down the line (although
optionally not a straight line) from the entry point. Optionally
the air return returns the item from the exit point to the entry
point. Optionally the system can include more than one exit point.
In each case the robotic arms described herein can assist in
efficiently moving items down the line, without the problems of
other linear systems. FIG. 14A shows an example of a U-shaped
linear system.
[0174] Referring still to FIG. 14, an embodiment of the system uses
a dual carrier mechanism 14008 so that wafers that are finished can
quickly be returned to the front of the system, but also so that an
empty carrier 14008 can be placed where a full one was just
removed. In embodiments the air return will feature a carrier 14008
containing N wafers. N can be optimized depending on the throughput
and cost requirements. In embodiments the air return mechanism may
contain empty carriers 14008 so that when a full carrier 14018 is
removed from the vacuum load lock 14010, a new empty carrier 14008
can immediately be placed and load lock 14010 can evacuated to
receive more materials. In embodiments the air return mechanism may
be able to move wafers to the front of the system. At the drop-off
point a vertical lift 14004 may be employed to lower the carrier to
a level where the EFEM (Equipment Front End Module) robot can
reach. At the load lock point(s) the vertical lift 14004 can lower
to pick an empty carrier 14008 from the load lock.
[0175] In embodiments the air return mechanism may feature a
storage area 14014 for empty carriers 14008, probably located at
the very end and behind the location of the load lock 14010. The
reason for this is that when the load lock 14010 releases a carrier
14018, the gripper 14004 can grip the carrier 14018 and move it
forward slightly. The gripper 14004 can then release the full
carrier 14018, move all the way back and retrieve an empty carrier
14008, place it on the load lock 14010. At this point the load lock
14010 can evacuate. The gripper 14004 can now go back to the full
carrier 14018 and move it all the way to the front of the system.
Once the carrier 14018 has been emptied by the EFEM, it can be
returned to the very back where it waits for the next cycle.
[0176] It is also possible to put the lift in the load lock rather
than using the vertical motion in the gripper, but that would be
more costly. It would also be slightly less flexible. A
manufacturer may want a vertical movement of the carrier 14018 in a
few places, and putting it in the gripper 14004 would be more
economical because the manufacturer then only needs one vertical
mechanism.
[0177] FIG. 15 shows certain additional details of an external
return system for a handling system of FIG. 14.
[0178] FIG. 16 shows additional details of an external return
system for a handling system of FIG. 14.
[0179] FIG. 17 shows movement of the output carrier 14018 in the
return tunnel 14012 of FIG. 14.
[0180] FIG. 18 shows handling of an empty carrier 14008 in the
return system 14012 of FIG. 14.
[0181] FIG. 19 shows movement of the empty carrier 14008 in the
return tunnel 14012 of FIG. 14 into a load lock 14010 position.
[0182] FIG. 20 shows the empty carrier 14008 lowered and evacuated
and movement of the gripper 14004 in the return system of FIG.
14.
[0183] FIG. 21 shows an empty carrier 14008 receiving material as a
full carrier 14018 is being emptied in the return tunnel 14012 of
FIG. 14.
[0184] FIG. 22 shows an empty carrier 14008 brought to a holding
position, starting a new return cycle in the return tunnel 14012 of
FIG. 14.
[0185] FIG. 23 shows an architecture for a handling facility for a
manufacturing process, with a dual-arm robotic arm system 23002 and
a return system in a linear architecture.
[0186] FIG. 24 shows an alternative embodiment of an overall system
architecture for a handling method and system of the present
invention.
[0187] FIG. 25 shows a comparison of the footprint of a linear
system 25002 as compared to a conventional cluster system 25004.
Note that with the linear system 25002 the manufacturer can easily
extend the machine with additional modules without affecting system
throughput. For example, as shown in FIG. 25A, for the vacuum
section only, W=2*750+2*60+440=2060. Similarly,
D=350*2+440*1.5+3*60+745/2=1913, and A=3.94 m.sup.2. With respect
to FIG. 25B, for the vacuum section only, W=2*750+2*60+1000=2620.
Similarly, D=920+cos(30)*(500+60+750)+sin(30)*745/2=2174;
accordingly, A=6.9 m.sup.2, which is 45% bigger.
[0188] FIG. 26 shows a linear architecture deployed with oversized
process modules 26002 in a handling system in accordance with
embodiments of the invention.
[0189] FIG. 27 shows a rear-exit architecture for a handling system
in accordance with embodiments of the invention.
[0190] FIG. 28 shows a variety of layout possibilities for a
fabrication facility employing linear handling systems in
accordance with various embodiments of the invention.
[0191] FIG. 29 shows an embodiment of the invention wherein a robot
29002 may include multiple drives 29004 and/or multiple controllers
29008. In embodiments a controller 29008 may control multiple
drives 29004 as well as other peripheral devices such as slot
valves, vacuum gauges, thus a robot 29002 may be a controller 29008
with multiple drives 29004 or multiple controllers 29008 with
multiple drives 29004.
[0192] FIG. 30 shows transfer plane 30002 and slot valve 30004
characteristics relevant to embodiments of the invention.
[0193] FIG. 31 shows a tumble gripper 31002 for centering wafers.
The advantage of the tumble gripper 31002 over the passive
centering gripper 32002 in FIG. 32 is that there is less relative
motion between the tumblers 31004 and the back-side of the wafer
31008. The tumblers 31004 may gently nudge the wafer 31008 to be
centered on the end effector, supporting it on both sides as it
moves down. In certain manufacturing processes it may be desirable
to center wafers 31008, such as in a vacuum environment. The tumble
gripper 31004 may allow the handling of very fragile wafers 31008,
such as when employing an end effector at the end of a robotic arm,
because it supports both ends of the wafer during handling.
[0194] FIG. 32 shows a passively centering end effector 32002 for
holding wafers 31008. The wafer 31008 is typically slightly
off-center when the end effector lifts (or the wafer 31008 is
lowered). This results in the wafer 31008 sliding down the ramp and
dropping into the cutout 32004. This can result in the wafer 31008
abruptly falling or moving, which in turn can create particles.
[0195] The methods and systems disclosed herein offer many
advantages in the handling of materials or items during
manufacturing processes. Among other things, vacuum isolation
between robots may be possible, as well as material buffering
between robots. A manufacturer can return finished wafers over the
top of the system without going through vacuum, which can be a very
substantial advantage, requiring only half the necessary handling
steps, eliminating cross contamination between finished and
unfinished materials and remaining compatible with existing clean
room designs. When a manufacturer has relatively dirty wafers
entering the system, the manufacturer may want to isolate them from
the rest of the machine while they are being cleaned, which is
usually the first step in the process. It may be advantageous to
keep finished or partially finished materials away from the
cleaning portion of the machine.
[0196] Other advantages may be provided by the methods and systems
disclosed herein. The dual arms (top mounted and bottom mounted)
may work in coordinated fashion, allowing very fast material
exchanges. Regardless of the exact arm design (3-link, 4-link or
other), mounting an arm in the lid that is not mechanically
connected to the arm in the bottom can be advantageous. The link
lengths of the 4-link SCARA arm provided herein can be quite
advantageous, as unlike conventional arms they are determined by
the mechanical limits of slot valves and chamber radius. The 4-link
SCARA arms disclosed herein are also advantageous in that they can
use two motors for the links, along with a Z motor, rather than
three motors plus the Z motor.
[0197] A linear vacuum system where materials exit in the rear may
offer substantial benefits. Another implementation may be to have
both the entry system and exit system installed through two
opposing walls.
[0198] The 4-link SCARA arm disclosed herein may also allow link L3
to swing into and over link L2 for the top robot drive. This may
not be easily done with the 3-link SCARA, nor with existing
versions of 4-link SCARA arms, because they have the wrong link
lengths.
[0199] The gripper for carriers and the multiple carrier locations
in the linear system may also offer substantial benefits in
materials handling in a linear manufacturing architecture.
Including vertical movement in the gripper and/or in the rear load
lock may offer benefits as well.
[0200] While the invention has been described in connection with
certain preferred embodiments, one of ordinary skill in the art
will recognize other embodiments that are encompassed herein.
[0201] FIG. 33 illustrates a fabrication facility including a
mid-entry point 33022. In an embodiment, the fabrication facility
may include a load lock 14010 mid-stream 33002 where wafers 31008
can be taken out or entered. There can be significant advantages to
such a system, including providing a processing facility that
provides dual processing capabilities (e.g. connecting two machines
behind each other, but only need to use one EFEM). In an
embodiment, the air return system 14012 can also take new wafers
31008 to the midpoint 33022 and enter wafers 31008 there.
[0202] FIG. 34 illustrates several top views of a fabrication
facility with mid-entry points 33002. The figure also illustrates
how the combination of a mid-entry point effectively functions to
eliminate one of the EFEMs 34002.
[0203] FIG. 35 illustrates a fabrication facility including a
series of sensors 35002. In many fabrication facilities such
sensors 35002 are commonly used to detect whether a material 35014
is still present on a robotic arm 35018. Such sensors 35002 may be
commonly placed at each vacuum chamber 4012 entry and exit point.
Such sensors 35002 may consist of a vertical optical beam, either
employing an emitter and detector, or employing a combination
emitter/detector and a reflector. In a vacuum handling facility,
the training of robotic stations is commonly accomplished by a
skilled operator who views the position of the robot arm and
materials and adjusts the robot position to ensure that the
material 35014 is deposited in the correct location. However,
frequently these positions are very difficult to observe, and
parallax and other optical problems present significant obstacles
in properly training a robotic system. Hence a training procedure
can consume many hours of equipment downtime.
[0204] Several automated training applications have been developed,
but they may involve running the robotic arm into a physical
obstacle such as a wall or edge. This approach has significant
downsides to it: physically touching the robot to an obstacle risks
damage to either the robot or the obstacle, for example many robot
end effectors are constructed using ceramic materials that are
brittle, but that are able to withstand very high wafer
temperatures. Similarly, inside many process modules there objects
that are very fragile and easily damaged. Furthermore, it may not
be possible to employ these auto-training procedures with certain
materials, such as a wafer 31008 present on the robot end effector.
Moreover, the determination of vertical position is more difficult
because upward or downward force on the arm caused by running into
an obstacle is much more difficult to detect.
[0205] In the systems described herein, a series of sensors
35002-35010 may include horizontal sensors 35004-35010 and vertical
sensors 35002. This combination of sensors 35002-35010 may allow
detection, for example through optical beam breaking, of either a
robotic end effector, arm, or a handled object. The vertical sensor
35002 may be placed slightly outside the area of the wafer 31008
when the robotic arm 35018 is in a retracted position. The vertical
sensor 35002 may also, or instead, be placed in a location such as
a point 35012 within the wafer that is centered in front of the
entrance opening and covered by the wafer when the robot is fully
retracted. In this position the sensor may be able to tell the
robotic controller that it has successfully picked up a wafer 31008
from a peripheral module.
[0206] Horizontal sensors 35004-35010 may also be advantageously
employed. In vacuum cluster tools, horizontal sensors 35004-35010
are sometimes impractical due to the large diameter of the vacuum
chamber, which may make alignment of the horizontal sensors
35004-35010 more complicated. In the systems described above, the
chamber size may be reduced significantly, thus may make it
practical to include one or more horizontal sensors
35004-35010.
[0207] FIG. 36 illustrates other possible locations of the
horizontal sensors 35004-35010 and vertical sensors 35002, such as
straight across the chamber (36002 and 36008) and/or through
mirrors 36006 placed inside the vacuum system.
[0208] FIG. 37 illustrates a possible advantage of placing the
sensor 35002 slightly outside the wafer 37001 radius when the robot
arm is fully retracted. During a retract motion the sensor 35002
detects the leading edge of the wafer 37001 at point "a" 37002 and
the trailing edge at point "b" 37004. These results may indicate
that the wafer 37001 was successfully retrieved, but by tying the
sensor 35002 signal to the encoders, resolvers or other position
elements present in the robotic drive, one can also calculate if
the wafer 37001 is centered with respect to the end effector. The
midpoint of the line segment "a-b" 37002 37004 should correspond to
the center of the end effector because of the circular geometry of
a wafer 37001. If the wafer 37001 slips on the end effector,
inconsistent length measurements may reveal the slippage.
[0209] Additionally, during a subsequent rotation and movement, a
second line segment "c-d" 37008 37010 may be detected when the
wafer 37001 edges pass through the sensor. Again, the midpoint
between "c" 37008 and "d" 37010 should coincide with the center of
the end effector, and may permit a measurement or confirmation of
wafer centering.
[0210] The above method may allow the robot to detect the wafer
37001 as well as determine if the wafer 37001 is off-set from the
expected location on the end effector.
[0211] The combination of horizontal and vertical sensors
35002-35010 may allow the system to be taught very rapidly using
non-contact methods: the robotic arm and end effectors may be
detected optically without the need for mechanical contact.
Furthermore, the optical beams can be used during real-time wafer
37001 handling to verify that wafers 37001 are in the correct
position during every wafer 37001 handling move.
[0212] FIG. 38 illustrates a conventional vacuum drive 38000 with
two rotary axes 38020 and 38018 and a vertical (Z) axis 38004. A
bellows 38016 may allow for the vertical Z-axis 38002 motion. A
thin metal cylinder 38024 affixed to the bottom of the bellows
18016 may provide a vacuum barrier between the rotor and the stator
of the motors 38010 and 38014. This arrangement may require
in-vacuum placement of many components: electrical wires and
feedthroughs, encoders, signal LEDs and pick-ups 38008, bearings
38012, and magnets 38006. Magnets 38006, bearings 38012, wires and
connectors, and encoders can be susceptible to residual processing
gasses present in the vacuum environment. Furthermore, it may be
difficult to remove gasses trapped in the bottom of the cylinder
38024, as the gasses may have to follow a convoluted path 38022
when evacuated.
[0213] FIG. 39 illustrates a vacuum robot drive 39000 that may be
used with the systems described herein. The rotary drive forces may
be provided by two motor cartridges 39004 and 39006. Each cartridge
may have an integral encoder 39008, bearings 39018 and magnets
39020. Some or all of these components may be positioned outside
the vacuum envelope. A concentric dual-shaft rotary seal unit 39016
may provide vacuum isolation for the rotary motion using, for
example, lip-seals or ferrofluidic seals. This approach may reduce
the number of components inside the vacuum system. It may also
permit servicing of the motors 39004, 39006 and encoders 39008
without breaking vacuum, thereby increasing serviceability of the
drive unit.
[0214] FIG. 40 shows a stacked vacuum load lock 4008, 40004 for
entering materials into a vacuum environment. One limiting factor
on bringing wafers 31008 into a vacuum system is the speed with
which the load lock can be evacuated to high vacuum. If the load
lock is pumped too fast, condensation may occur in the air in the
load lock chamber, resulting in precipitation of nuclei on the
wafer 31008 surfaces, which can result in particles and can cause
defects or poor device performance. Cluster tools may employ two
load locks side by side, each of which is alternately evacuated.
The pumping speed of each load lock can thus be slower, resulting
in improved performance of the system. With two load locks 4008
40004 in a vertical stack, the equipment footprint stays very
small, but retains the benefit of slower pumping speed. In
embodiments, the load lock 40004 can be added as an option. In
embodiments the robotic arms 4004 and 40006 can each access either
one of the two load locks 4008 40004. In embodiments the remaining
handoff module 7008 could be a single level handoff module.
[0215] FIG. 40B shows another load lock layout. In this figure
wafers 31008 can be entered and can exit at two levels on either
side of the system, but follow a shared level in the rest of the
system.
[0216] FIG. 41 details how the previous concept of stacked load
locks 4008 40004 can be also implemented throughout a process by
stacking two process modules 41006, 41008. Although such modules
would not be compliant with the SEMI standard, such an architecture
may offer significant benefits in equipment footprint and
throughput.
[0217] FIG. 42 shows a system with two handling levels 4008, 40004,
4010, 42004: wafers may be independently transported between
modules using either the top link 40006 or the bottom link 4004.
Optionally, each handling level may have two load locks to provide
the advantage of reduced evacuation speed noted above. Thus a
system with four input load locks, two handling levels, and
optionally four output load locks, is also contemplated by
description provided herein, as are systems with additional load
lock and handling levels.
[0218] FIG. 43 shows a top view of the system of FIG. 42.
[0219] FIG. 44 depicts a special instrumented object 44014, such as
a wafer. One or more sensors 44010 may be integrated into the
object 44014, and may be able to detect environmental factors
around the object 44014. The sensors 44010 may include proximity
sensors such as capacitive, optical or magnetic proximity sensors.
The sensors 44010 may be connected to an amplifier/transmitter
44012, which may use battery power to transmit radio frequency or
other sensor signals, such as signals conforming to the 802.11b
standard, to a receiver 44004.
[0220] In many instances it may be difficult or impossible to put
instrumentation on an object 44014 used to train a robot, because
the wires that are needed to power and communicate to the
instruments and sensors interfere with proper robotic motion or
with the environment that the robot moves through. By employing a
wireless connection to the object, the problem of attached wires to
the object may be resolved.
[0221] The object 44014 can be equipped with numerous sensors of
different types and in different geometrically advantageous
patterns. In the present example, the sensors 1 through 6 (44010)
are laid out in a radius equal to the radius of the target object
44008. In embodiments these sensors are proximity sensors. By
comparing the transient signals from the sensors 44010, for example
sensor 1 and sensor 6, it can be determined if the object 44014 is
approaching a target 44008 at the correct orientation. If the
target 44008 is not approached correctly, one of the two sensors
44010 may show a premature trigger. By monitoring multiple sensors
44010, the system may determine if the object 44010 is properly
centered above the target 44008 before affecting a handoff. The
sensors 44010 can be arranged in any pattern according to, for
example, efficiency of signal analysis or any other constraints.
Radio frequency signals also advantageously operate in a vacuum
environment.
[0222] FIG. 45 shows the system of FIG. 44 in a side orientation
illustrating the non-contact nature of orienting the instrumented
object 44014 to a target 44008. The sensors 44010 may include other
sensors for measuring properties of the target 44008, such as
temperature.
[0223] FIG. 46 depicts radio frequency communication with one or
more sensors. A radio frequency sensor signal 44016 may be
transmitted to an antenna 46002 within a vacuum. Appropriate
selection of wavelengths may improve signal propagation with a
fully metallic vacuum enclosure. The use of sensors in wireless
communication with an external receiver and controller may provide
significant advantages. For example, this technique may reduce the
time required for operations such as finding the center of a
target, and information from the sensor(s) may be employed to
provide visual feedback to an operator, or to automate certain
operations using a robotic arm. Furthermore, the use of one or more
sensors may permit measurements within the chamber that would
otherwise require release of the vacuum to open to atmosphere and
physically inspect the chamber. This may avoid costly or time
consuming steps in conditioning the interior of the chamber, such
as depressurization and baking (to drive out moisture or water
vapor).
[0224] FIG. 47 illustrates the output from multiple sensors 44010
as a function of the robot movement. When the robot moves over the
target 44008 the motion may result in the sensors providing
information about, for example, distance to the target 44008 if the
sensors are proximity sensors. The signals can be individually or
collectively analyzed to determine a location for the target 44008
relative to the sensors. Location or shape may be resolved in
difference directions by moving the sensor(s) in two different
directions and monitoring sensor signals, without physically
contacting the target 44008.
[0225] FIG. 48 depicts a technique for inserting and removing
wafers 48008 from a vacuum system. One or more heating elements,
such as a set of heating elements 48002, 48004, and 48006 may be
employed, individually or in combination, to heat a chamber 4008
and a substrate material 48008 to an elevated temperature of
50.degree. C. to 400.degree. C. or more. This increase in starting
temperature may mitigate condensation that would otherwise occur as
pressure decreases in the chamber, and may allow for a more rapid
pump down sequence to create a vacuum. When heated wafers 48008 are
moved to the load lock 4008 by the robotic arm 4002, they may be
significantly warmer than heating units 48004, 48006, such that the
heating units 48004, 48006 may cool the wafers on contact. A
heating power supply may regulate heat provided to the heating
units 48004 48006 to maintain a desired temperature for the heating
units and/or wafers. A suitable material selection for the heating
units 48004, 48006 may result in the system reacting quickly to
heating power changes, resulting in the possibility of different
temperature settings for different conditions, for example a higher
temperature setting during pump-down of the chamber 4008 and a
lower setting during venting of chamber 4008.
[0226] Preheating the wafers 48008 may reduce condensation and
particles while reducing process time. At the same time, the wafers
48008 may be too hot when exiting the system, such that they
present a safety hazard, or melt handling and support materials
such as plastic. Internal temperatures of about 80 to 100.degree.
C. degrees, and external temperatures of about 50.degree. C.
degrees or less may, for example, meet these general concerns.
[0227] FIG. 49 illustrates a robotic end effector 49002. The
robotic end effector 49002 may be tapered so that it has a
non-uniform thickness through one or more axes. For example, the
robotic end effector 49002 may have a taper when viewed from the
side or from the top. The taper may mitigate resonant vibrations
along the effector 49002. At the same time, a relatively narrow
cross-sectional profile (when viewed from the side) may permit
easier maneuvering between wafers 49006. The side-view taper may be
achieved by grinding or machining, or by a casting process of the
effector 49002 with a taper. Materials such as Aluminum Silicon
Carbide (AlSiC 9) may be advantageously cast into this shape to
avoid subsequent machining or other finishing steps. A casting
process offers the additional advantage that the wafer support
materials 49004 can be cast into the mold during the casting
process, thereby reducing the number of components that require
physical assembly.
[0228] As shown in FIG. 50, similar techniques may be applied to
robotic arm segments 50002 and 50004. The same dampening effect may
be achieved to attenuate resonant vibrations in the arm segments
50002 50004 as described above. The tapered shape may be achieved
using a variety of known processes, and may allow more rapid
movement and more precise control over a resulting robotic arm
segment.
[0229] FIG. 51 shows a dual independent SCARA arm employing five
motors 51014. Each lower arm 51002 and 51008 can be independently
actuated by the motors 51014. The arms are connected at the distal
end to upper arms 51004 and 51010. The configuration gives a
relatively small retract radius, but a somewhat limited
extension.
[0230] FIG. 52 shows a dual dependent SCARA arm employing 4 motors
52010. The links 52002 and 52004 may be common to the end effectors
52006 and 52008. The motors 52010 may control the end effectors
52006 and 52008 in such a way that during an extension motion of
the lower arm 52002, the desired end effector, (say 52008) may be
extended into the processing modules, whereas the inactive end
effector (say 52006) may be pointed away from the processing
module.
[0231] FIG. 53 shows a frog-leg style robotic arm. The arm can be
used in connection with various embodiments described herein, such
as to enable passing of work pieces, such as semiconductor wafers,
from arm-to-arm in a series of such arms, such as to move work
pieces among semiconductor process modules.
[0232] FIG. 54 shows a dual frog-leg arm that can be employed in a
planar robotic system, such as one of the linear, arm-to-arm
systems described in this disclosure.
[0233] FIG. 55A illustrates a 4-Link SCARA arm as described in this
disclosure mounted to a cart 55004. Such a cart may move in a
linear fashion by a guide rail or magnetic levitation track 55008
and driven by a motor 55002 internal or external to the system. The
4-Link SCARA arm has the advantage that it fold into a smaller
retract radius than a 3-Link SCARA arm, while achieving a larger
extension into a peripheral module such as a process module all the
while avoiding a collision with the opening that the arm has to
reach through. An inverted cart 55006 could be used to pass
substrates over the cart 55004.
[0234] FIG. 55B shows a top view of the system described in FIG.
55A.
[0235] FIG. 56 illustrates a linear system described in this
disclosure using a combination of dual independent and single SCARA
robotic arms. Such a system may not be as compact as a system
employing a 4-Link SCARA arm robotic system.
[0236] FIG. 57 demonstrates a vertically stacked handling system
employing a 4-Link SCARA robotic arm, where the arm can reach any
and all of the peripheral process modules 5002. By rotating the
process modules in the top level 57004 by approximately 45 degrees
and mounting the top level components to the bottom level chambers
57002, the top and bottom of each of the process modules may remain
exposed for service access as well as for mounting components such
as pumps, electrodes, gas lines and the like. The proposed layout
may allow for the combination of seven process modules 5002 in a
very compact space.
[0237] FIG. 58A illustrates a variation of FIG. 57, where the
bottom level 58002 of the system consists of a plurality of robotic
systems as described in this disclosure and the top level system
58004 employs process modules 5002 oriented at a 45 degree angle to
the main system axis. The proposed layout allows for the
combination of nine process modules 5002 in a very compact
space.
[0238] FIG. 58B illustrates a variation of FIG. 58A with the use of
a rear-exit load lock facility to remove substrates such as
semiconductor wafers from the system.
[0239] FIG. 59A shows a linear handling system accommodating large
substrate processing modules 59004 while still allowing for service
access 59002, and simultaneously still providing locations for two
standard sized process module 5002.
[0240] FIG. 59B demonstrates a system layout accommodating four
large process modules 59004 and a standard sized process module
5002 while still allowing service access 59002 to the interior of
the process modules 5002.
[0241] FIG. 60 shows a dual frog robot with arms substantially on
the same side of the robotic drive component. The lower arms 60002
support two sets of upper arms 60004 which are mechanically coupled
to the motor set 54010.
[0242] A variety of techniques may be used to handle and transport
wafers within semiconductor manufacturing facilities such as those
described above. It will be understood that, while certain
processing modules, robotic components, and related systems are
described above, other semiconductor processing hardware and
software may be suitably employed in combination with the transport
and handling systems described below. All such variations and
modifications that would be clear to one of ordinary skill in the
art are intended to fall within the scope of this disclosure.
[0243] Referring to FIG. 61, in a vacuum processing system, a
process group 6100 may include a handling interface 6110 such as an
equipment front end module connected to an exchange zone 6120, and
may be further connected to a work piece handling vacuum module
6130 that transfers work pieces from the exchange zone 6120 to a
transport cart 6140 inside a transport tunnel 6150.
[0244] In order to facilitate discussion of various
transport/handling schemes, the combination of the transfer robot
6131 with one or more process modules 2002 is referred to herein as
a process cell 6170. It should be understood that process cells may
have many configurations including conventional or unconventional
process modules and/or cluster tools that perform a wide range of
processes, along with associated or additional robotics for
transferring wafers. This may include commercially available
process modules, custom process modules, and so forth, as well as
buffers, heaters, metrology stations, or any other hardware or
combination of hardware that might receive wafers from or provide
wafers to a wafer transportation system. Process modules 2002
and/or process cells 6170 may be disposed in various
configurations, such as in clusters, aligned along the sides of a
line or curve, in square or rectangular configurations, stacked
vertically, or the like. Similarly, one or more robots 6131 that
service process cells 6170 can be configured many ways, to
accommodate different configurations of process modules, including
in vertically stacked or opposing positions, in line with each
other, or the like.
[0245] The process group 6100 may further include one or more
isolation valves 6180 such as slot valves or the like that
selectively isolate vacuum zones within the group 6100 and
facilitate work piece interchange between vacuum zones. The
isolation valves 6180 may provide control to maintain a proper
vacuum environment for each work piece during one or more
processing steps, while permitting intermittent movement of work
pieces between vacuum zones.
[0246] In the embodiment of FIG. 61, the work piece handling vacuum
modules 6130 and 6131 transfer work pieces between other components
of the group 6100, and more particularly transfer work pieces
between the transport cart 6140 and various destinations. The
transport cart 6140 is responsible for moving a work piece from
destination to destination, such as among the work piece handling
vacuum modules 6130 and 6131. In various layouts for fabrication
facilities, process modules and the like may be too far separated
for direct or convenient work piece transfer using robots, such as
the robots 6130, 6131 shown in FIG. 61. This may arise for a number
of reasons, such as the size or shape of processing modules, the
positions of entry and exit points for process modules, the number
of process modules in a particular fabrication layout, and so
forth. As a significant advantage, the use of one or more transport
carts 6140 as an intermediate transportation system permits
flexible interconnection of a wide variety of modules and other
equipment into complex, multi-purpose processing facilities.
[0247] The transport cart 6140 may transport a work piece, such as
a semiconductor wafer, to a position accessible by the work piece
handling vacuum module 6130, and may selectively transport items
such as wafers or other workpieces to a process module 2002 for
processing. The transport cart 6140 can be realized in many
embodiments, including a magnetically levitated and/or driven cart,
a cart on a railway, a cart with an arm or extending member, a cart
on wheels, a cart propelled by a telescoping member, a cart
propelled by an electric motor, a cart that is capable of tipping
or tilting, a cart that may traverse a sloping tunnel to move a
work piece or work pieces from one height to another, an inverted
cart suspended from a transport track, a cart that performs
processing or one of several functions on a work piece during
transport, or the like.
[0248] The cart 6140 may be on gimbals, or suspended as a gondola,
to accommodate variations in horizontal alignment of the path of
the cart 6140. Similarly, the cart may include a wafer holder
(e.g., supports, shelves, grippers, or the like) that is on
gimbals, or that is suspended from a wire or the like, such that
the wafer holder maintains a substantially level orientation while
the cart traverses an incline. Thus, in certain embodiments, the
cart may traverse inclines, declines, or direct vertical paths
while maintaining a wafer or other workpiece in substantially
uniform, level horizontal alignment. Such a cart may have a
selectively fixed horizontal alignment so that movements such as
acceleration or deceleration in a horizontal plane do not cause
tipping of the workpiece. In other embodiments, the cart may be
permitted to tip during acceleration or deceleration in order to
stabilize a position of the work piece on the cart 6140.
[0249] The cart 6140 may be made of materials suitable for use in
vacuum, such as materials that mitigate generation of undesirable
particles or materials that have low outgassing characteristics. In
an embodiment, the cart 6140 is a simple cart, without a robotic
arm. As a significant advantage, using an armless cart mechanically
simplifies the cart, thus saving on maintenance, repairs, and
physical contamination of vacuum environments. In such embodiments,
each entrance/egress from the cart path preferably includes a robot
or similar device to place and retrieve workpieces on the cart.
[0250] In order to distinguish between various possible
implementations, the following description employs the term
"passive cart" to denote a cart without a robotic arm or other
mechanism for loading and unloading wafers. As noted above, this
configuration provides a number of advantages in terms of
simplicity of design and in-vacuum implementation, and provides the
additional advantage of mitigating the creation of contaminants
from mechanical activity. The term "active cart" is employed herein
to denote a cart that includes a robotic arm. Active carts present
different advantages, in particular the improved versatility of
having a robotic arm available arm at all times with the cart and a
relaxation of the corresponding requirement for wafer handling
hardware at each port 6180 of the tunnel 6150. It will be
understood that, while providing a useful vocabulary for
distinguishing between carts with and without robots, a so-called
"passive cart" may nonetheless have other mechanical or active
components such as wheels, sensors, and so forth.
[0251] The cart 6140 may include space for a single wafer or the
like. In some embodiments, the cart 6140 may include a plurality of
shelves so that multiple wafers can be transported by the cart. The
shelves may have a controllable height or the like in order to
accommodate access to different ones of the wafers by a
fixed-height robot, or the shelves may have a fixed height for use
with robotic handlers having z-axis control. In still other
embodiments, the cart 6104 may include a single surface having room
for multiple wafers. While multi-wafer variations require an
additional degree of processing control (to account for multiple
possible positions of a wafer on each cart), they also provide
increased flexibility and capacity to the systems described herein.
In other embodiments, the cart 6140 may be adapted to carry a
multi-wafer carrier or for concurrent handling and/or processing of
multiple wafers.
[0252] The cart 6140 may provide supplemental functionality. For
example, the cart 6140 may include a wafer cooling or heating
system that controls wafer temperature during transport. The cart
6104 may also, or instead, include wafer center finding sensors,
wafer metrology sensors, and the like. It will be appreciated that,
while a range of possible supplemental functions may be supported
by the cart 6104, those functions that employ solid state sensing
and processing may be preferably employed to facilitate
preservation of a clean processing environment.
[0253] The tunnel 6150 may be of any cross-sectional shape and size
suitable for accommodating the transport cart 6140 and any
associated payload. In general, the tunnel 6150 will be capable of
maintaining an environment similar or identical to various process
cells connected thereto, such as a vacuum. The vacuum environment
may be achieved, for example by providing slot valves or the like
for independent vacuum isolation of each port 6180 (generally
indicated in FIG. 61 as coextensive with slot valves 6180, although
it will be understood that the slot valve identifies the mechanism
by which seals are opened and closed, while the port refers to the
opening through which wafers and the like may be passed). While a
slot valve or slit valve is one common form of isolation device,
many others are known and may be suitable employed with the systems
described herein. Thus it will be understood that terms such as
slot valve, slit valve isolation valve, isolation mechanism, and
the like should be construed broadly to refer to any device or
combination of devices suitable for isolating various chambers,
process modules, buffers, and so forth within a vacuum environment,
unless a narrower meaning is explicitly provided or otherwise clear
from the context.
[0254] In some embodiments, the tunnel 6150 may maintain an
intermediate environment where, for example, different process
cells employ different vacuum levels, or include other gasses
associated with processing. While depicted as a straight line, the
tunnel 6150 may include angles, curves, and other variations in
path suitable for accommodating travel of the transport cart 6140.
In addition, the tunnel 6150 may include tracks or other surfaces
consistent with the propulsion system used to drive the transport
cart 6140 from location to location. In some embodiments, the
tunnel 6150 may include inclines or other variations that
accommodate changes in height among various process cells connected
thereto. All such variations that can be used with a cart 6140 to
move wafers or other workpieces within a processing environment are
intended to fall within the scope of this disclosure.
[0255] FIG. 62 shows another embodiment of a wafer processing
system including a transport system. As shown, the system 6100 may
include a plurality of transfer robots and process modules capable
of simultaneously handling and/or processing a plurality of wafers.
The system 6100 may also include a controller such as computing
facility (not shown) interconnected with the transport and
processing system members to schedule motion of the cart 6140
according to various processes within the system 6100. Processing
of each work piece may be controlled so that transport cart 6140
position and availability is coordinated with start and stop times
of the processes within a number of process cells 6170. The process
cells 6170 may be identical or different. In various embodiments,
the system 6100 may perform serial processing, parallel processing,
or combinations of these to process a plurality of work pieces at
one time, thereby improving utilization of the processing resources
within the process cells 6170.
[0256] FIG. 63 shows another embodiment of a semiconductor
processing facility including a wafer transport system. As depicted
in FIG. 63, process cells 6170 may be connected to both sides of a
transport tunnel 6150. Numerous variations in work piece
processing, such as those depicted in FIGS. 61-62 above, may be
employed in combination with the configuration of FIG. 63. As
illustrated by these figures, any number of process cells 6170 in a
variety of configurations, may be readily accommodated by a
transport cart 6140 interconnecting process cells 6170. This
includes greater numbers of processing cells 6170, as well as
curved, angled, multi-lane, and other cart paths. For example,
cells on one side of a cart path may mirror process cells on the
right side, to provide dual three-step process groups having a
common tunnel 6150, transport cart 6140, transfer robot 6130,
exchange zone 6120 and interface module 6110.
[0257] FIG. 64 illustrates a configuration that uses a work piece
handling vacuum module 6131 and a plurality of process modules 2002
arranged as a cluster tool 6410. This layout offers the compact
footprint and functionality of a cluster tool, along with a
cart-based transport system that can be flexibly interconnected to
any number of additional process cells.
[0258] FIG. 65 shows another embodiment of a semiconductor
processing facility including a transport system. In this system, a
number of cluster tools 6410 are interconnected using a transport
cart 6140 and tunnel 6150 as described generally above. It will be
noted that this arrangement permits interconnection of any number
of cluster tools regardless of size. As a significant advantage,
this reduces the need for a dense group of cluster tools arranged
around a single or multi-robot handling system.
[0259] FIG. 66 shows another embodiment of a semiconductor
manufacturing facility using a wafer transport system. In this
embodiment, a linear processing system 6610 is constructed with a
plurality of process modules 2002A-2002D functionally
interconnected through a number of robots 6131, 6632, 6633 that
employ robot-to-robot hand offs for wafer handling within the
linear system 6610. This linear system 6610 may include an
interface to a transport cart 6140 which may move wafers to and
from the linear system 6610 and any other process cells 6170
connected to the transport system. It will be understood that,
while in the depicted embodiment, each transfer robot services two
process modules 2002 and handles transfer of work pieces to another
transfer robot, other linear layouts may also be employed.
[0260] In operation, work pieces may move into the linear process
cell by manipulation with the transfer robot 6131 from transport
cart 6140. The transfer robot 6131 may either transfer the work
piece to transfer robot 6632 or to one of two process modules 2002A
or 2002B. The transfer robot 6632 may receive a work piece to be
processed from the transfer robot 6631 and either transfers it to
the transfer robot 6633 or to one of two process modules 2002C or
2002D. The transfer robot 6633 may receive a work piece to be
processed from the transfer robot 6632. Finished work pieces may be
transferred to consecutive, adjacent transfer robots until passing
through the transfer robot 6131 onto tunnel transport cart 6140. In
one embodiment, a load lock may be provided at one end of the
linear system 6610 to permit the addition or removal of wafers at
an opposing end of the linear system 6610 from the transport cart
interface.
[0261] FIG. 67 shows a semiconductor fabrication facility including
a transport system. As shown in FIG. 67, a number of linear systems
6610 may be interconnected using a transport cart 6140 and tunnel
6150. As a significant advantage, a single vacuum environment for a
number of different linear systems 6610 may be interconnected
regardless of the layout and physical dimensions of each linear
system 6610. Additionally, longer sequences of processing, or
increased throughput of work pieces for individual process cells,
can readily be achieved using the cart and tunnel systems described
herein.
[0262] In one aspect, the selection of process cells connected to
the tunnel 6150 may be advantageously made to balance or control
system-wide throughput. Thus, for example, process cells with
relatively quick process times can be combined with a suitable
number of parallel process cells providing a different process with
a slower process time. In this manner, a process cell with quick
process time can be more fully utilized by servicing multiple
downstream or upstream process cells within a single vacuum
environment. More generally, using the transport cart 6140 and
tunnel 6150, or a number of such carts and tunnels, greater design
flexibility is provided for fabrication process layouts to balance
load and/or improve utilization among process cells with varying
process times and throughput limitations.
[0263] FIG. 68 shows a semiconductor fabrication facility with a
transport system. As shown, a fabrication facility may include a
variety of different tool and module types. For example, the
facility may include plurality of cluster process cells 6410 and a
plurality of linear process cells 6610, along with a storage cell
6820 that provides a multi-wafer buffer for temporary in-vacuum
storage of work pieces. As further depicted, the system may include
more than one front end module using, for example, two front end
modules on opposing ends of a tunnel 6150. As will be clear from
the following description, other shapes are possible, and may
include T-junctions, Y-junctions, X-junctions, or any other type of
interconnections, any or all of which may end at a front end module
or connect to one or more additional tunnels 6150. In this manner,
large, complex layouts of interconnected processing modules may be
more readily implemented. It will be further understood that
individual process cells may be added or removed from such a system
in order to adapt a processing facility to different process
requirements. Thus, a modular and flexible fabrication layout
system may be achieved.
[0264] FIG. 69 shows a semiconductor fabrication facility with a
transport system. In the embodiment of FIG. 69, an isolation valve
6180 is provided within a straight length of vacuum tunnel 6150.
The isolation valve 6180 permits isolation of portions of the
tunnel 6150, and more particularly allows processes in which
different vacuum environments are appropriate for different groups
of process cells. In this embodiment, a second transport cart 6940
is included so that each half of the tunnel 6150 includes an
independent transportation vehicle while the isolation valve 6180
is closed. It will be understood that, in certain processes, the
isolation valve may remain open and both carts may service both
halves of the tunnel 6150. More generally, this illustrates the
flexibility of the transportation system to accommodate complex
processes using a variety of different processing tools. As
depicted in FIG. 69, the system may also include a work piece
storage elevator 6920 to provide storage for a plurality of work
pieces.
[0265] Referring to FIG. 70, cluster and linear processing groups
may be combined with a plurality of tunnel transport cart systems
to provide a complex process group. In the embodiment of FIG. 70,
two cluster processing cells, a first cluster processing cell 7010
at a first end of the processing group, and a second cluster
processing cell 7011 at a second end of the processing group, each
interconnect with tunnel transport cart 6140, 6140A for
transporting work pieces among the process cells. As depicted, the
linear processing cell 7050 may include an access port on each
end.
[0266] In the embodiment of FIG. 70, an example work piece flow may
include receiving the work piece in first cluster processing cell
7010 from input interface module 6110, processing the work piece as
necessary in the cluster cell 7010. The first tunnel transport cart
6140 may then transport the work piece to a linear processing group
7050 where it is received by the work piece handling vacuum module
6130 and processed, as required, in one or more process modules
2002. Within the linear processing group 7050 the work piece may be
transferred between adjacent transfer robots until all processing
within the linear processing group 7050 is complete for the work
piece, at which time the work piece is transferred to a second
tunnel transport cart 6140A for transport to a second cluster
processing cell 7011. Further processing of the work piece, as
required, may be performed in the second cluster processing cell
7011 and received into an exit interface module 7020 for automated
or manual retrieval.
[0267] It will be appreciated that the system may handle multiple
wafers at one time. In some embodiments, wafers may flow uniformly
from one entrance (e.g., a first front end module 7020) to one exit
(e.g., a second front end module 6110). However, the depicted
layout can readily accommodate wafers simultaneously traveling in
the opposing direction, or wafers entering and exiting through a
single one of the front end modules, or combinations of these. As
noted above, this permits the deployment of fabrication facilities
that significantly improve utilization of particular processing
tools, and permits the implementation of numerous, different
processes within a single fabrication system.
[0268] FIG. 71 shows a two-ended tunnel 7110 having an L-shape.
FIG. 72 shows a three-ended tunnel 7210 having a T-shape. FIG. 73
shows a two-ended tunnel 7130 having a U-shape. It will be
understood that tunnels may use any of these shapes, as well as
other shapes, and combinations thereof in order to accommodate
design factors ranging from floor space within a facility to the
shape and size of individual pieces of equipment. As depicted by
these figures, a variety of different process cell types may be
connected to a tunnel as appropriate to a particular process.
[0269] Referring to FIG. 74, a transport cart 6140 may interconnect
systems having different processing times. For example, the
transport cart 6140 may connect a preclean process 6130 to a system
7410 with relatively long process times such as Chemical Vapor
Deposition ("CVD") and a system 7420 with relatively short process
times such as Physical Vapor Deposition ("PVD").
[0270] For configurations that include process steps of
substantially different durations, slower processes 7410 may be
supported by a relatively large number of associated tools (which
may be deployed as clusters or linear groups) in order to balance
throughput for the combined processing system 7400. Thus, using the
transport systems described herein, conceptual bottlenecks in
complex semiconductor manufacturing processes can be addressed by
simply expanding capacity around longer processes, thereby
improving utilization of tools having relatively shorter processes.
By way of example and not of limitation, processes having relative
durations of 1 (preclean):2 (PVD):10 (CVD) can be supported by a
facility having 2 preclean tools, 20 CVD processing tools, and 4
PVD processing tools working together in a single vacuum
environment supported by a cart 6140 and tunnel 6150. While
preserving this ratio, the total number of each tool type may be
expanded or contracted according to further process constraints
such as the throughput capacity of front end modules or other
separate systems within a fabrication facility.
[0271] Referring to FIG. 75, the configuration of FIG. 74
alternatively may include a plurality of carts 6140 in one tunnel
6150 wherein each cart transports work pieces over a portion of the
tunnel 6150. Coordination of the carts may be employed to avoid
collision of adjacent carts at a common side process cell.
[0272] An alternate embodiment may include a tunnel configured as a
loop to allow transport carts that have reached the end process
cell to continue in a loop to an input interface module to accept a
new work piece for transport. The loop may be configured either as
a horizontal loop or a vertical loop, or a combination of
these.
[0273] Referring to FIG. 76, a plurality of tunnel transport carts
may be interconnected by work piece handling vacuum modules. In the
embodiment of FIG. 76, a transfer robot 6130 may serve as an
interface between two separate tunnel transport carts 6140 and
6140A, and may further serve as an interface to a front end module
6110 for purposes of transferring work pieces into and out of the
vacuum environment. The embodiment of FIG. 76 may accommodate
substantial flexibility of use of the process cells. Each interface
module may enable access to both of the tunnel transport carts,
facilitating increased capacity if the process cells associated
with each tunnel are the same. Alternatively, the embodiment of
FIG. 76 may allow redundancy of processes; a common interface
module for different processes, or may support additional
processing steps by combining the separate tunnel transport cart
systems into one process group.
[0274] FIG. 77 shows a system 6100 wherein the transport system
forms a complete loop 7710. In this embodiment, a transport cart
6140 may move continuously in a single direction around the loop,
while adding or removing work pieces at appropriate locations
within the process. In addition, one or more locations may be
serviced by an equipment front end module for transferring work
pieces to and from the vacuum environment. As a significant
advantage, this layout permits direct transfer between any two
process cells connected to the system. It will be understood that
any number of transport carts 6140 may share the tunnel, and having
more than one transport cart 6140 increases processing options by
permitting multiple inter-cell transfers at a single time.
[0275] FIG. 78 shows a semiconductor processing system including a
transportation system. The system 7800 is a complex system
including a variety of cart and processing module configurations.
In particular, the system 7800 of FIG. 78 includes four front end
modules, one storage module, four independent cart transport
systems, and six separate linear processing modules. By way of
illustration, it will be noted that one of the linear processing
modules 6110 includes two front end modules (one on each end), and
intersects two tunnels for interconnection to adjacent processing
systems. More generally, and as generally noted above, any
arrangement of tools, clusters, and related hardware can be shared
using one or more tunnels and carts as described herein. The
embodiment of FIG. 78 may allow work pieces to be removed from the
vacuum environment at a number of locations (illustrated as front
end modules) to undergo atmospheric processes such as inspection,
chemical mechanical polishing, or electro-plating. Work pieces may
also be returned to the vacuum environment as needed. A wide
variation of possibilities emerges from this type of system.
[0276] In the configuration of FIG. 78, transfer robots 6130 may be
used to transfer work pieces from a transport cart 6140 to a
process cell 6170, or an interface module 6110, as well as
transferring work pieces between carts 6140 on separate transport
vacuum tunnels 6150.
[0277] This configuration permits a work piece to be processed on
one or more of the processes associated with one or more of the
transport vacuum tunnels without the work piece having to be
removed from the vacuum environment. Linking transport vacuum
tunnels by transfer robots allows for isolation of one or more of
the transport vacuum tunnels, thus permitting adjacent use of
different vacuum environments and enabling independent operation of
the processes associated with each of the transport vacuum
tunnels.
[0278] FIG. 79 shows an embodiment which includes vacuum tubes 7910
located between processing modules. More generally, these vacuum
tubes 7910 may be placed between any adjacent vacuum hardware to
extend a vacuum environment across a physical void. The vacuum
tubes 7910 may be fashioned of any suitable material including,
where interior visibility is desired, glass or the like. These
vacuum tubes 7910 can be intended to provide additional
functionality such as described in previous paragraphs and below,
and have very few design constraints except that they preferably
form a vacuum seal where they physically connect to other system
components, and they provide sufficient interior space for passage
of wafers, workpieces, and any robotic arms or the like associated
with handling same. In general, the vacuum tubes 7910 serve as a
physical buffer between adjacent hardware, such as processing
modules (or, as depicted, pairs of modules serviced by a single
robot) in order to permit functional couplings that cannot be
achieved directly due to physical dimensions of the hardware.
[0279] FIG. 80 shows a semiconductor processing system including a
transportation system. The embodiment of FIG. 80 includes dual
side-by-side independent transport carts in a single vacuum tunnel.
Carts 6140 and 6140A may operate independently on non-interfering
paths 8010 and 8011 within the tunnel 6150. Robots 6130 may
transfer a work piece among a first cart 6140, a second cart 6140A,
and an interface 6110. In one embodiment, the robots 8030 that
service one or more of the process cells may be configured to reach
across the tunnel 6150 so that workpieces may be picked from or
placed to either of the carts 6140A, 6140B. A number of work piece
handling vacuum modules may move work pieces between the carts
6140, 6140A and their respective process cells. The embodiment of
FIG. 80 allows for faster transfer of work pieces among process
cells than would an embodiment with dual coordinated transport
carts or a single path. In another aspect, the paths 8010, 8011 may
include exchanges or cross-overs to permit each cart 6140, 6140A to
switch between the paths 8010, 8011 for increased flexibility in
material handling. One or more isolation valves may be provided to
isolate various segments of the tunnel 6150.
[0280] FIG. 81 shows a side view of dual vertically opposed
independent transport carts in a vacuum tunnel. In the embodiment
of FIG. 81, a tunnel 6150 encloses two transport carts 6140 running
on railway or levitation systems 8130. A robot 6130 may access work
pieces through an isolation valve 6180 for loading and unloading
the work pieces among an interface 7410 (such as a load-lock or
equipment front end module) and the transport carts 8110. In a
similar way, transfer robots (not shown) may transfer work pieces
among carts 8110 and process cells 8120. The transfer robot 6130
may be vertically adjustable through use of a robot lift 8140 or
other z-axis controller to facilitate transferring a work piece
between different cart levels.
[0281] FIG. 82 shows an embodiment of transport cart with a robotic
arm in a processing system that also includes transfer robots for
work piece handling. Transfer robots 6130 and 6130A may coordinate
with a cart robot 8210 to facilitate handling of work pieces. One
or more vacuum extensions 7910 may be provided to physically
accommodate adjacent process cells.
[0282] FIG. 83 illustrates a semiconductor manufacturing system
with dual independent transport tunnels 6150. Each tunnel may
include a transport cart 6140. In the embodiment of FIG. 83, a
transfer robot 8310 with vertical motion capabilities may transfer
work pieces among the transport cart in the lower tunnel, the
transport cart in the upper tunnel, and a load-lock 1410.
Similarly, transfer robots (not shown) may transfer work pieces
among the upper cart 6140, the lower cart 6140 and the process
cells 8120.
[0283] FIG. 84 is an alternate embodiment of the embodiment
depicted in FIG. 83 wherein a work piece elevator 8410 is used to
move a work piece from the lower tunnel to the upper tunnel.
Additionally, a transfer robot 6130 may be associated with each
tunnel 6150 to transfer the work piece between the work piece
elevator 8410 and the transport cart 6140. Additionally a transfer
cart 6130 may be required between the work piece elevator 8410 and
the load-lock 1410 to facilitate transfer of work pieces between
the work piece elevator 8410 and the load-lock 1410.
[0284] FIG. 85 shows an embodiment of a tunnel system using
frog-leg type robots. The frog-leg type robot may be the main work
piece handling transfer robot. The transfer robot 8510 may be used
to transfer work pieces from the interface 6110 to the cart 6140,
and is depicted as a fully retracted frog-leg robot. The transfer
robot 8520 may also be retracted and is shown in a cluster cell
configuration on the right side of tunnel 6150. Additional robots
within the system may be frog-leg robots, as illustrated generally
in the linear processing arrangement on the left side of the tunnel
6150. In the linear processing group, the transfer robot 8530 may
extend into a process chamber, while transfer the robot 8540
extends toward the transfer robot 8550, which is depicted as a dual
frog-leg robot partially extended toward both associated process
chambers simultaneously.
[0285] FIG. 86 illustrates an embodiment of an integration scheme
of a "bucket-brigade" 8610 linear group, a wafer transport shuttle
system 8620 and traditional cluster tool systems 8630. More
generally, any combination of traditional cluster tools 8630,
linear "bucket-brigade" systems 8610 and shuttle systems 8620 is
possible. In one application, short processes on the cluster tool
can be combined with longer processes in the bucket brigade to
improve per-tool utilization within the system.
[0286] While numerous arrangements of semiconductor handling and
processing hardware have been described, it will be understood that
numerous other variations are possible to reduce floor space usage
and shorten the distance between related processing groups. For
example, vacuum transport systems may be usefully deployed
underneath floors, behind walls, on overhead rails, or in other
locations to improve the layout of fabrication facilities, such as
by clearing floor space for foot traffic or additional machinery.
In general, these embodiments may employ vertical lifts in
combination with robotic arms and other handling equipment when
loading or transferring wafers or other work pieces among
processing modules. FIG. 87 depicts such a system including a
vertical lift.
[0287] FIG. 87 shows a typical loading/unloading system for use in
wafer fabrication. An overhead track 8702 may deliver a cart 8704
with work pieces, to a wafer Front Opening Unified Pod (FOUP) which
may include a load point 8708 and an equipment front end module
(EFEM) 8710. A load lock 14010 may be employed to transfer wafers
from the FOUP 8708 to one or more processing modules using, for
example, the work piece handling vacuum module 6130 depicted in
FIG. 87. A plurality of work piece handling vacuum modules
supported by pedestals 10110 with intervening vacuum modules 4010
may be configured as a semiconductor vacuum processing system. Work
pieces may be transferred in a cassette 8718 that the cart 8704 may
lower to the FOUP 8708 using an elevator or vertical extension
8720.
[0288] FIG. 88 illustrates an improved wafer handling facility in
which a transport cart 6140 in a vacuum tunnel 6150 is installed
beneath a factory floor. A vertical lift 8810 may be employed to
move wafers, or a cassette carrying one or more wafers to the
processing level. It will be understood that, while a single cart
6140 in a single tunnel 6150 is depicted, any number of tunnels
6150 and/or carts 6140 may intersect at a lifter 8810 that
transfers wafers to a bottom access load lock 14010.
[0289] FIG. 89 illustrates an embodiment of an overhead cart 6140
and vacuum tunnel system 6150. This system may be used with any of
the layouts described above. The configuration depicted in FIG. 89
facilitates transferring a cart 6140 carrying one or more wafers
from a tunnel 6150 to a load lock 14010. However, in general, the
lifter 8810 may be employed to move wafers and/or carts from a top
access load lock (which is at a processing level) to an overhead
vacuum tunnel 6150 where a cart 6140 can transport the work pieces
along a transport system, such as a rail system. In one embodiment,
drive elements of the lifter (not shown) may be installed below the
processing level (e.g. on a floor or beneath a floor), or above the
processing level. Deploying the mechanical aspects of the lifter
below the processing level may advantageously reduce the number
and/or size of particles that may fall on wafers being carried by
the lifter.
[0290] FIG. 90 depicts a semiconductor vacuum processing system
including two processing groups, such as a linear processing groups
interconnected by a beneath-processing-level tunnel 6150. The
tunnel 6150, which may include any of the vacuum tunnel systems
described above, may be deployed, for example, beneath a factory
floor. The tunnel 6150 may connect groups of processing modules
separated by large distances, and may improve the handling
capabilities of the interconnected system by providing, e.g.,
storage areas, switches, sorting systems, and so forth. Processing
groups may include process chambers, load locks, work piece
handling vacuum modules 6130, vacuum modules 4010, multifunction
modules, bypass thermal adjustment modules, lithography, metrology,
mid-entry load locks, vacuum tunnels extensions for extending the
reach of a vacuum system, and a wide variety of semiconductor
processing related functions. Processing groups may also include
modules supported by a pedestal. One or more processing groups,
including the tunnel 6150 and cart 6140 may be controlled by a
controller, such as a computing facility executing a software
program
[0291] FIG. 91 depicts two processing groups interconnected by an
overhead tunnel network. The tunnel network 9102, which may include
any of the vacuum tunnel systems described above, may be deployed,
for example, on a second floor above a factory floor or suspended
from a factory ceiling. The tunnel network 9102 may connect groups
of processing modules separated by large distances, and may improve
the handling capabilities of the interconnected system by
providing, e.g., storage areas, switches, sorting systems, and so
forth.
[0292] FIG. 92 shows a system for sharing metrology or lithography
hardware. As illustrated, the tunnel network and other module
interconnection systems described herein may incorporate, e.g.,
shared metrology or lithography resources 9205 wherein the vacuum
based cart system removes and returns a sample wafer from a flow.
Generally wafers "flow" from one equipment front end module 9203 or
other atmospheric interface entrance station to another equipment
front end module 9204. If an in-process inspection is desirable to
check for certain process parameters, such an inspection could be
performed in a location such as an inter-module buffer 9207. In the
present system there are several such interim locations where such
an inspection could be performed. However, some measurement systems
can be physically quite large and can be difficult to accommodate
in module interconnections such as the inter-module buffer 9207
because of their size.
[0293] In such a situation it may be desirable to provide a vacuum
cart and tunnel system as generally disclosed herein to remove one
or more wafers from the flow under vacuum to a standalone metrology
or lithography system 9205. A cart 9208 may be positioned in the
flow at a location 9201 between process modules to receive a wafer.
It will be understood that, while a particular location is
identified in FIG. 92 as the location 9201, any number of locations
within the system 9200 may be similarly employed according to
desired process flows, capabilities, physical space constraints,
and so forth. Software or setup logic may determine which wafer to
remove from the flow at 9201. In other embodiments, the cart may
dock with a module 9202 within the system 9200, where a wafer
handling robot may load a wafer on the cart for transport to the
metrology or lithography system 9205.
[0294] As depicted in FIG. 92, a metrology or lithography system
9205 may be shared by more than one work piece processing system.
In an example, a wafer originating from the first loading system
9203 may be assessed in a metrology system 9205 that can also be
accessed by wafers originating from a second system 9206. While two
linear systems are depicted, it will be understood that other
arrangements of processing modules may similarly employ shared
resources such as metrology or lithography systems according to the
general principles described with reference to FIG. 92. For
example, using a variety of rail configurations with, for example,
curves, switches, and so forth, the system may be configured to
concentrate metrology or lithography systems and/or other shared
resources for any number of processing systems in a common
location. Such a system could apply metrology or lithography to
wafers from multiple locations and multiple systems. As described
above with respect to processes having different process times, a
single metrology or lithography system may be shared among numerous
process cells or system to achieve high utilization of metrology or
lithography resources in a semiconductor manufacturing system.
[0295] As noted above, the cart and work piece handling vacuum
module systems described herein may be combined with simple vacuum
tube extensions that may be disposed in-line with, or adjacent to
work piece handling vacuum modules 6130 to facilitate greater
levels of flexibility in the arrangement and interconnection of
different processing hardware. Referring to FIG. 93, a
semiconductor work piece processing system may include a cart, a
tunnel, an EFEM, a plurality of work piece handling vacuum modules,
various process chambers, and a vacuum extension tunnel 9304.
[0296] In addition one or more link modules 9302, 9308 may be
provided to interconnect any of the above hardware. In addition to
accommodating hardware spacing (in the same manner as vacuum
extensions), a module 9302, 9308 may provide a variety of
supplemental functions associated with a semiconductor processing
system. For example, a link module 9308 may provide storage,
operating as a buffer in a wafer process flow. A link module 9302
may provide metrology, measurement, or testing of wafers. A link
module 9308 may provide operator access to a work piece, in which
case the link module 9308 may include an isolation valve and vacuum
pump. A link module 9302, 9308 may provide thermal management, such
as by cooling or heating a wafer between processes. A link module
may provide buffering and/or aligning capacity for single and/or
multiple wafers such as provided by the buffering aligner apparatus
9700 described below. With respect to the buffering aligner, it
will be understood that this use in a link module is an example
only, and that a buffering alignment module may also or instead be
usefully employed at other points in a process, such as in an
equipment front end module. For example, if process chambers
process wafers in mini-batches of 2, 3, 4 or 5 or more wafers, then
it may be efficient to employ a buffering system at an aligner to
prevent the alignment time from becoming a bottleneck in a larger
process. Once the proper number of wafers has been prepared in the
buffer of an EFEM, an atmospheric robot can affect a batch transfer
of these (aligned) wafers to a load lock.
[0297] A link module may provide bypass capabilities, permitting
two or more wafers to cross paths between process modules. More
generally, a link module 9302, 9308 may provide any function that
can be usefully performed in a vacuum environment between
processing tools, including any of those identified above as well
as combinations of same.
[0298] As a significant advantage, such multi-function link modules
can reduce the need for additional processing modules, and reduce
wait times between processing modules in a variety of ways. For
example, bypass capabilities alleviate the need to complete remove
one wafer from a cluster or linear processing module before adding
another, since conflicting paths can be resolved within the bypass
module. As another example, thermal management within link modules
can reduce the need to wait for heating or cooling once a wafer
reaches a particular tool. Other advantages will be apparent to one
of ordinary skill in the art.
[0299] More generally, using the systems and methods described
herein, a workpiece may be processed during transport and/or wait
time between process tools. This may include processing in a link
module 9302, 9308 as described above, as well as processing on a
transport cart 6150, processing in a tunnel 6150, processing in a
buffer, processing in a load lock, or processing at any other point
during wafer handling between process tools.
[0300] FIG. 94 shows a thermal bypass adjusting vacuum module. It
is frequently desirable to heat or cool work pieces between process
steps of a semiconductor manufacturing process. It may also be
desirable to simultaneously allow other work pieces to pass by the
work piece being heated or cooled. Since cooling or heating a work
piece may take approximately 20 to 60 or more seconds, it is also
advantageous to facilitate transfer of other work pieces so that
the cooling or heating does not block work piece flow. A vacuum
module in which work pieces can be exchanged between robots while
facilitating temperature adjustment of another work may also allow
temporary storage of work pieces.
[0301] Such a vacuum module may include an environmentally sealable
enclosure to capture and thermally adjust a work piece in
transition before the work piece is transferred to the next process
step, while allowing coordinated pass through of other work pieces
during the heating or cooling process.
[0302] It may be advantageous to include such a vacuum module in
close proximity to a process chamber in a vacuum semiconductor
processing system, such that a work piece may be heated or cooled
to meet the particular needs of the process chamber for improved
processing. Additionally, including and utilizing such a vacuum
module can facilitate effective use of process chambers in the
system by allowing a second work piece to be brought up to
temperature as a first work piece is being processed.
[0303] Additionally, a work piece may be returned to ambient
temperature immediately after it is taken from a process chamber,
before it is handled by additional transfer robots, thereby
eliminating any waiting time while the work piece cools before
transferring another work piece to the process chamber.
[0304] It may also be beneficial to include a bypass thermal
adjuster in combination with cart/tunnel systems in a semiconductor
processing system to further facilitate flexibility, utility,
process efficiency, and the like. Disclosed in this specification
are examples of beneficial configurations of the bypass thermal
adjuster in combination with work piece handling vacuum modules,
carts 6140, tunnels 6150, and other process and function
modules.
[0305] Referring to FIG. 94, an end effector of a work piece
handling vacuum module 6130 is transferring a work piece into a
thermal adjustment buffer module 9402 for purposes of thermally
adjusting the work piece.
[0306] FIG. 94 further shows a work piece handling vacuum module
6103 placing the work piece on support clips 9404 which are mounted
to an upper interior surface of a moveable enclosure, and may
include fingers or the like to support the edges of a work piece
centered within the enclosure. The moveable enclosure consists of
two portions, an enclosure bottom 9410 and an enclosure top 9412.
When the enclosure top 9412 is lowered into contact with the bottom
9410, a work piece supported by support clips 9404 is fully
isolated from the environment outside enclosure 9408. The bypass
thermal adjuster 9402 also facilitates transferring a second work
piece through the module when the moveable enclosure is closed.
[0307] Various embodiments of tunnel and cart systems have been
described above, as well as other linking hardware such as vacuum
extensions and linking modules. In general, these systems support
modular use and reuse of semiconductor processing tools from
different vendors, and having different processing times and other
characteristics. In one aspect, such systems may be further
improved through variations such as different tunnel shapes
(curvilinear, L, U, S, and/or T shaped tunnels) and shapes
supporting two, three, four, or more equipment front end modules.
In another aspect, additional hardware may be employed to provide
further flexibility in the design and use of semiconductor
manufacturing systems. The following description identifies a
number of additional components suitable for use with the systems
described herein.
[0308] Referring to FIG. 95, a semiconductor work piece handling
robot 6130 may connect through a vacuum port to a configurable
vacuum module 9502. The configurable vacuum module 9502 may include
ports 9504 for utilities such as gas, water, air, and electricity
used during processing.
[0309] The configurable vacuum module 9502 may include a removable
bottom plate which may include a work piece heater for preheating a
work piece before the handling robot 6130 transfers the work piece
into an attached processing module.
[0310] The configurable vacuum module 9502 may include storage for
a plurality of work pieces. As an example, work pieces may be
placed by the handling robot 6130 on a rotating platform within the
configurable vacuum module 9502. The maximum number of work pieces
may be determined by the size of each work piece and the size of
the rotating platform. Alternatively the configurable vacuum module
9502 may include a surface adapted to support semiconductor work
pieces, with the surface sufficiently large to allow a plurality of
work pieces to be placed on the surface in a non-overlapping
arrangement. The storage within the configurable vacuum module 9502
may be enabled by a work piece elevator with a plurality of work
piece support shelves, wherein the elevator can be controlled to
adjust height for selection of a particular shelf to be accessed by
the handling robot 6130.
[0311] The configurable vacuum module 9502 may include metrology
devices for purposes of collecting metrics about the work piece. As
an example, a metrology device such as an optical sensor, can be
used to detect the presence of a work piece in the configurable
vacuum module 9502 and initiate an automated inspection of the work
piece by a machine vision system. Such metrics are useful to
maintain and improve control and quality of the fabrication
processes being performed on the work piece in associated process
modules.
[0312] The configurable vacuum module 9502 may further include
interface ports 9504 capable of supporting ultra high vacuum
operation. The ultra high vacuum may be achieved by configurable
vacuum module 9502 wherein the configurable vacuum module 9502 is
constructed with materials such as stainless steel known to support
an ultra high vacuum environment. Such an environment may be useful
for removing trace gasses in the environment and reducing the
introduction of gasses caused by outgassing of materials in the
environment.
[0313] The configurable vacuum module 9502 may provide a load lock
function for the vacuum processing environment. Such a function may
be useful in work piece exchange between a user ambient environment
and the vacuum processing environment by allowing work pieces
supplied by a user to be introduced into the vacuum environment by
sealing the work pieces in the configurable vacuum module 9502 and
generating a vacuum environment around the sealed work pieces.
[0314] The configurable vacuum module 9502 may support fabrication
processing of a work piece such as rapid thermal anneal or in-situ
wafer cleaning. Rapid thermal anneal may be beneficial in a
semiconductor vacuum processing environment for achieving specific
changes in a semiconductor work piece such as activating dopants,
and densifying deposited films. In-site wafer cleaning can be
needed to remove residue or particles deposited during processing
in the chambers from the wafer surfaces or edges.
[0315] The configurable vacuum module 9502 may also include
combinations of any of the above, as well as any other capabilities
suitable for use between processing tools in a semiconductor
manufacturing environment.
[0316] In general, it is expected that the configurable vacuum
module 9502 may be configured at a fabrication site through the
addition or removal of hardware associated with desired functions.
Thus, for example, temperature sensors and a heating element may be
removed, and replaced with multiple shelves for wafer storage.
Other aspects, such as construction from materials appropriate for
high vacuum, may be implemented during manufacture of the module
9502. In general, a configurable vacuum module 9502 as described
herein is characterized by the removability/replaceability of
module hardware, or by an adaptation to a particular process using
a combination of hardware that provides multiple capabilities
(e.g., heating, cooling, aligning, temperature sensing, cleaning,
metrology, annealing, scanning, identifying, moving, storing, and
so forth).
[0317] The functions described above may also be implemented
directly within the cart and tunnel systems described above, either
as link modules within a tunnel, or in association with a cart or
tunnel, to provide various processing functions during
transportation of a wafer. As described herein, combining work
piece handling vacuum modules and carts/tunnels provides greater
flexibility to a semiconductor processing system by facilitating
the interconnection of local processing groups that are separated
by a large distance, and by facilitating the interconnection of
large processing systems that are in close proximity. Combining a
multifunction module 9502 with a cart/tunnel system can facilitate
the productive use of transport time to achieve more rapid wafer
processing.
[0318] Referring to FIG. 96 a vacuum extension tunnel 9602 is
described in greater detail. The vacuum extension tunnel 9602, also
referred to herein as a vacuum tube or vacuum extension, can be
used in a variety of positions in a semiconductor vacuum processing
system to provide a continuous vacuum connection between vacuum
modules. Vacuum extension tunnel 9602 may have a substantially
rectangular shape, with interface ports on one or more sides. Each
interface port may provide a vacuum sealable industry standard
interface for connection to a variety of vacuum modules. In
embodiments, an isolation valve 4006 may be connected to each
interface port to provide a means of ensuring vacuum isolation
between vacuum extension tunnel 9602 and a connected vacuum
module.
[0319] As shown in FIG. 96, a vacuum extension tunnel 9602 provides
linear extension in a semiconductor processing system, facilitating
the use of varying size process chambers. As an example in FIG. 96,
a process chamber 2002L, which is substantially larger than process
chamber 2002R, would interfere with an equipment front end module
34002 if it were connected without using vacuum extension tunnel
9602. An additional benefit of this use of vacuum extension tunnel
9602 is that large process chambers may be used without increasing
the size of an associated robot vacuum chamber 4012 that provides
wafer transport between adjoining pieces of equipment.
[0320] A vacuum tunnel extension 9602 can also be used with load
locks 14010 to create service access between vacuum modules. Two
such examples illustrated in FIG. 96 include a service access
between an upper and lower pair of process chambers, and one
between the upper pair of process chambers and an equipment front
end module 34002. Service access requires a user to closely
approach the process equipment and perhaps to gain direct access to
work piece handling equipment. Without vacuum tunnel extension
9602, a user could not easily approach closely enough for
servicing.
[0321] A vacuum tunnel extension 9602 may be employed in a variety
of other locations within a system. For example, a vacuum tunnel
extension 9602 may be employed to connect a linear processing
system, a cluster tool, a shared metrology system or an equipment
front end module to a cart and tunnel transport system. A vacuum
tunnel extension 9602 may facilitate forming various layout shapes
of semiconductor processing systems, and may be provided in various
extension lengths.
[0322] More generally any of the above systems may be used in
combination. For example, a linear processing system including work
piece transport, such as that provided by a work piece handling
vacuum module combined with a transport cart 6140 may be associated
with a bypass thermal adjuster. A work piece handling vacuum module
may facilitate transfer of a work piece to/from the bypass thermal
adjuster. A linear processing system including work piece
transport, such as that provided by a work piece handling vacuum
module combined with a transport cart 6140 may be associated with a
wafer center finding method or system. A work piece handling vacuum
module may facilitate collecting data of a work piece being handled
by the work piece handling vacuum module to support the wafer
center finding methods and systems. A work piece handling vacuum
module may include a plurality of work piece sensors to support
wafer center finding. Wafer center finding may also be performed
while the work piece is being transported by the transport cart
6140. In one embodiment, a work piece handling vacuum module,
adapted to facilitate wafer center finding, may be assembled to a
transport cart 6140 so that a wafer/work piece held within the work
piece handling vacuum module may be subjected to a wafer finding
process during transport.
[0323] A linear processing system including work piece transport,
such as that provided by a work piece handling vacuum module
combined with a transport cart 6140 may be associated with a
process chamber. A work piece handling vacuum module may facilitate
transfer of a work piece to/from the process chamber. As herein
described, processing chambers of various types, sizes,
functionality, performance, type, and the like may be combined with
one or more transport carts 6140 to facilitate processing
flexibility of a semiconductor processing system. A linear
processing system including work piece transport, such as that
provided by a work piece handling vacuum module combined with a
transport cart 6140 may be associated with a load lock 10410 as
herein described. In an example a work piece handling vacuum module
may facilitate transfer of a work piece between the load lock and a
transport cart 6140. A linear processing system including work
piece transport, such as that provided by a work piece handling
vacuum module combined with a transport cart 6140 may be associated
with a work piece storage and handling cassette. A work piece
handling vacuum module may facilitate transfer of a work piece
to/from the cassette as shown in FIGS. 68 and 69. A work piece
handling vacuum module may transfer a work piece such as a
production wafer, a test wafer, a calibration wafer, a cleaning
wafer, an instrumented wafer, a wafer centering fixture, and the
like to/from the work piece storage.
[0324] A linear processing system including work piece transport,
such as that provided by a work piece handling vacuum module
combined with a transport cart 6140 may be associated with an
equipment front end module 6110. A work piece handling vacuum
module may facilitate transfer of a work piece to/from the
equipment front end module 6110. The work piece handling vacuum
module may transfer one or more work pieces between two equipment
front end modules 6110 wherein one module is an input module, and
one module is an output module, or wherein one of the modules is a
mid entry input/output module. A transport cart 6140 may be
associated with an equipment front end module 6110 through a work
piece handling vacuum module as shown in FIG. 78. The work piece
handling vacuum module in FIG. 78 may transfer a work piece between
the equipment front end module 6110 and one of a process chamber
2002, another work piece handling vacuum module, or a transport
cart 6140. As can be seen in FIG. 78, combining work piece handling
vacuum modules and equipment front end modules 6110 with transport
carts 6140 within vacuum tunnels 6150 can facilitate configuring
arbitrarily complex or highly flexible processing systems.
[0325] A linear processing system including work piece transport,
such as that provided by a work piece handling vacuum module
combined with a transport cart 6140 may be associated with a work
piece elevator. A work piece handling vacuum module may facilitate
transfer of a work piece to/from the work piece elevator for
transporting one or more work pieces between vertically separated
work piece handling and/or processing systems. Vertically separated
vacuum processing systems may include a processing level and a work
piece return level that is vertically separated. The work piece
return level may include a work piece transport cart or vehicle in
a vacuum tunnel for transporting one or more work pieces to a
different location in the vacuum processing system. FIGS. 88-91
depict exemplary configurations of linear processing systems
including work piece handling vacuum modules, transport carts 6140,
and work piece elevators, also known as lifters 8810.
[0326] A linear processing system including work piece transport,
such as that provided by a work piece handling vacuum module
combined with a transport cart 6140 may be associated with a
cluster system as shown in FIGS. 70 and 86. A work piece handling
vacuum module may facilitate transfer of a work piece to/from the
cluster system. A work piece handling vacuum module may facilitate
transfer of a work piece between a linear processing system
including a transport cart 6140, and a cluster processing cell. The
work piece handling vacuum module may transfer the work piece
to/from an aspect of the cluster system such as a work piece
handling robot, a load lock, a buffer, and the like. The work piece
handling vacuum module may transfer a work piece through a vacuum
extension tunnel 9602 to/from the aspect of the cluster processing
system.
[0327] The work piece handling vacuum module may be modularly
connected to the cluster system so that the work piece handling
vacuum module may provide handling of work pieces while the cluster
processing system may provide processing of semiconductor work
pieces. The work piece handling vacuum module may be connected to
the cluster system through a buffer module, such as a multifunction
module, a passive single work piece buffer, a passive multi work
piece buffer, a thermal bypass adapter, a buffering aligner 9700,
and the like. The buffer module may provide a temporary storage
facility for work pieces being transferred between the work piece
handling vacuum module and the cluster system. A robot controller
of the cluster system may access or deposit a work piece in the
buffer module for the work piece handling vacuum module to
transfer. A plurality of cluster systems may be connected to one
work piece handling vacuum module so that the work piece handling
vacuum module facilitates transfer from one cluster system to
another. Such a configuration may include a load lock 1401 and/or
equipment front end module 6110 for exchange of the work pieces
with an operator. The work piece handling vacuum module may further
include facilities for determining a center of a work piece being
handled by the work piece handling vacuum module so that the work
piece can be transferred to the cluster system centered accurately
to a center reference of the cluster system.
[0328] A linear processing system including work piece transport,
such as that provided by a work piece handling vacuum module
combined with a transport cart 6140 may be associated with other
work piece handling vacuum modules. A work piece handling vacuum
module may facilitate transfer of a work piece to/from the other
work piece handling vacuum module.
[0329] A linear processing system including work piece transport,
such as that provided by a work piece handling vacuum module
combined with a transport cart 6140 may be associated with a
buffer. A work piece handling vacuum module may facilitate transfer
of a work piece to/from the buffer. The buffer may facilitate
holding work pieces queued to be processed. The buffer may further
facilitate reducing bottlenecks associated with robotic work piece
handlers, differences in processing time, delays associated with
vacuum environment changes, and the like.
[0330] A linear processing system including work piece transport,
such as that provided by a work piece handling vacuum module
combined with a transport cart 6140 may be associated with a
controller. The controller may direct the work piece handling
vacuum module to facilitate transfer of a work piece from a first
section of a semiconductor processing system to a second section of
the system. Transfer from the first to second section of the system
may be accomplished by using a transport cart 6140. A section may
include one or more of a buffer, a buffering aligner 9700, another
work piece handling vacuum module, a cluster system, a work piece
storage, a work piece elevator, an equipment front end module, a
load lock, a process chamber, a vacuum tunnel extension, a module
including a low particle vent, a module including a pedestal, a
module including a modular utility supply facility, a bypass
thermal adjuster, a multifunction module, a robot (e.g. single arm,
dual arm, dual end effector, frog leg, and the like), variously
shaped process systems, and the like.
[0331] Referring to FIGS. 97-100, work pieces may be temporarily
stored in buffer modules. A buffer module may, for example, be
placed between two transfer robot modules to facilitate handling
and throughput, or between a tunnel 6150 and a robot for similar
reasons. The buffer module may be accessible from multiple of sides
and/or by multiple robots. The buffer module may have the
capability to hold a plurality of semiconductor work pieces. In
embodiments, the buffer may also be capable of performing alignment
of the semiconductor work pieces that are placed into the buffer.
Such a buffer may be referred to as a buffer aligner module 9700,
an example of which is depicted in FIG. 97. The buffer aligner
module 9700 may include a buffer work piece holder 9702, an aligner
platform 9704, and an aligner vision system 9708. The buffer work
piece holder 9702 may hold multiple semiconductor work pieces 9710,
9712, 9714, and 9718 at one time, which may be vertically stacked
or otherwise arranged within the holder 9702. In embodiments, the
aligner platform 9704 may be capable of holding a single
semiconductor work piece and rotating or translating the work piece
to a desired alignment position as determined by an aligner
controller. The controller may initiate a rotation or translation
once the semiconductor work piece has been placed on the aligner
platform 9704, and determine a stopping position based on signals
provided by the aligner vision system 9708.
[0332] The aligner vision system 9708 may sense a notch or other
marking on the semiconductor work piece, and the controller may use
the notch to determine a correct alignment of the work piece, such
as by stopping rotation of the work piece when the notch is in a
particular location. The aligner vision system 9708 may also employ
optical character recognition (OCR) capabilities or other image
processing techniques to read and record information presented on
the semiconductor work piece, which may include alignment marks as
well as textual information relating to the work piece. The
controller may also, or instead, provide close-loop sense and
control for the alignment of semiconductor work piece placed on the
buffer aligner module 9700.
[0333] FIG. 98A shows a transfer robot 9802 transferring a
semiconductor work piece 9720 onto the aligner platform 9704 of the
buffer aligner module 9700 utilizing a single work piece
end-effector. FIG. 98B shows the aligner platform 9704 rotating a
semiconductor work piece to be aligned 9720. While the aligner
platform 9704 is rotating, the aligner vision system 9708 may sense
the position of the work piece 9720 through some physical
indicator, such as a notch, a marking, or the like. The controller
may stop rotation in response to an appropriate signal from the
aligner vision system 9708 indicating that the work piece is
properly aligned. When aligned, the semiconductor work piece 9720
may be transferred into the buffer work piece holder 9702 as shown
in FIG. 98C.
[0334] FIG. 99A shows a transfer robot 9802 transferring a second
semiconductor work piece 9720 onto the aligner platform 9704. Note
that the first buffered work piece 9710 has been previously stored
in the top slot of the buffer work piece holder. FIG. 99B shows the
second semiconductor work piece 9720 being aligned. FIG. 99C shows
the two aligned semiconductor work pieces stored as a first 9710
and second buffered work piece 9712. Finally, FIG. 100A shows all
aligned and stored work pieces 9710, 9712, 9714, and 9718, being
transferred from the buffer aligner module 9700 by a transfer robot
9802 utilizing a batch end-effector 10002 to simultaneously move
the work pieces 9710, 9712, 9714, and 9718. FIG. 100B shows the
transfer robot 9802 moving the batch of semiconductor work pieces
9710, 9712, 9714, and 9718 to their destination with the batch
end-effector 10002.
[0335] A linear processing system including work piece transport,
such as that provided by a work piece handling vacuum module
combined with a transport cart 6140 may be associated with a
buffering aligner 9700. A work piece handling vacuum module may
facilitate transfer of a work piece to/from the buffering aligner
9700 such as to/from an equipment front end module, load lock, and
other semiconductor fabrication system modules, handlers, and
processors. A buffering aligner 9700 may be beneficially combined
with other elements of a linear processing system to improve
throughput. In an example, a buffering aligner 9700 may be combined
with a transport cart 6140 system that provides transport of a
plurality of aligned wafers in a vacuum environment. A buffering
aligner can be employed when a process chamber requires delivery of
multiple wafers at the same time, in which case buffering at the
alignment can significantly increase the system throughput by
allowing the system to align wafers in the background during
processing and effecting a batch transfer to the process module or
load lock.
[0336] FIG. 101 shows a number of modular linkable handling modules
6130. Each linkable module 6130 may be supported by a pedestal
10110. The pedestal 10110 may form a unitary support structure for
a vacuum robotic handler and any associated hardware, including,
for example, the linking modules described above. The pedestal
10110 may be generally cylindrical in form with adequate external
diameter to physically support robotics and other hardware, and
adequate internal diameter to permit passage of robotic drives,
electricity, and other utilities.
[0337] A robot drive mechanism 10120 may be integrated within the
pedestal 10110. Integration of the robot drive mechanism 10120 into
the support structure may advantageously eliminate the need for
separate conduits or encasements to house the robot drive mechanism
10120. An access port 10125 within the pedestal 10110 may provide
user access to various components of the robot drive 10120 such as
motors, amplifiers, seals etc., so that these components can be
removed as individual units for servicing and the like.
[0338] The pedestal configuration depicted in FIG. 101 provides
additional advantages. By raising the modular linkable handling
modules 6130 substantially above floor level while preserving
significant unused space between the floor and the modules 6130,
the pedestal 10110 offers physical pathways for process chamber
utilities such as water, gas, compressed air, and electricity,
which may be routed below the modular linkable handling modules
6130 and alongside the pedestals 10110. Thus, even without planning
for utility access, a simple arrangement of pedestal-based modules
in close proximity ensures adequate access for wires, tubes, pipes,
and other utility carriers. In order to achieve this result, the
pedestal 10110 preferably has top projection surface area (i.e., a
shape when viewed from the top) that is completely within the top
projection surface area of the module 6130 supported above. Thus
space is afforded all the way around the pedestal.
[0339] The pedestal 10110 may include a rolling base 10130 (with
adjustable stand-offs for relatively permanent installation) on
which additional controls, or equipment 10140 may be included. The
rolling base 10130 further facilitates integration of vacuum
modules 6130 into a modular vacuum processing and handling
system.
[0340] A linear processing system including work piece transport,
such as that provided by a work piece handling vacuum module
combined with a transport cart 6140 may be associated with a
pedestal. A work piece handling vacuum module may be modularly
mounted to the pedestal so that the pedestal may provide at least
support for the work piece handling vacuum module. The pedestal may
further support drive mechanism that provide rotation and other
motion of a robotic work piece handler in the work piece handling
vacuum module. The pedestal may be integrated with the work piece
handling vacuum module as herein described. The pedestal may
further facilitate supporting a work piece handling vacuum module
in a position that facilitates transferring a work piece to a
transport cart 6140 in a tunnel 6150.
[0341] Linking modules 10149 between the vacuum modules 6130 may
provide any of the functions or tools described herein with
reference to, for example, the configurable vacuum modules 9502
described above. This includes auxiliary equipment 10150 such as a
vacuum pump, machine vision inspection tool, heating element, or
the like, as well as various machine utilities (gas, electric,
water, etc.) which may be removably and replaceably affixed in a
vacuum or other functional seal to an opening 10155 in the linking
module 10149.
[0342] FIG. 102 shows how unused space (created by a pedestal
support structure) around a link module may be coherently allocated
among various utilities that might be required to support a
semiconductor manufacturing process. Referring to FIG. 102, a
portion of a modular vacuum processing system is shown in an
exploded view. The portion of the system shown in FIG. 102 includes
a work piece handling and processing system 10200 which may include
one or more linkable vacuum modules 6130. The linkable modules 6130
may be interconnected to each other or to another module such as an
inspection module 4010, a vacuum extension, or any other vacuum
component. As depicted, each linkable module 6130 is mounted on a
pedestal 10130 which is in turn mounted on base 10230.
[0343] Processing tools can connect to the work piece handling
system 10200 at any one of the ports of one of the linkable modules
6130. By applying industry standards for utility hookup type and
position in a process chamber, the position of the utility hookups
outside the volume of the linking modules may be substantially
predetermined based on the position of the linkable module(s) 6130.
Due to the pedestal configuration, however, it is also possible to
allocate the void space around each pedestal to ensure a buffer
zone 10240, 10250, 10260 around the linking modules that affords
substantially arbitrary routing of utilities throughout an
installation using the linkable modules. The handling system 10200
enables a user to take advantage of modular utility delivery
components 10240, 10250, and 10260 when preparing to install
process chambers.
[0344] The buffer zones 10240, 10250, and 10260 facilitate delivery
of utilities such as gas, water, and electricity to any process
chambers connected to the linkable modules 6130. These buffer zones
10240, 10250, and 10260 may specifically accommodate positioning
requirements of industry standards, and may also accommodate any
industry standard requirements for capacity, interfacing,
cleanliness, delivery pressure, and the like (without, of course,
requiring conformity to these standards within the buffer
zones).
[0345] Conceptually, the buffer zones 10240, 10250, and 10260 may
have a structural frame which supports a plurality of conduits
10270 adequate for delivery of the corresponding utilities. Each
conduit 10270 may be constructed with appropriate materials
selected to meet the specific requirements for delivery of a
specific utility, and may be arranged within the buffer zones in
any preferred pattern. Additionally, each conduit device port
hookup 10280, may be arrayed in a predetermined pattern (e.g.
meeting industry standards for utility hookup position) to
facilitate connections outside the buffer zones while ensuring
alignment of utility conduits from module to module within the
buffer zones.
[0346] Device port hookups 10280 may be selected for each utility
type. For example, a hookup for water may provide reliable
interconnect that can withstand water pressure, temperature, and
flow rate requirements, while a hookup for electricity may provide
a reliable interconnect or conduit that meets electrical impedance,
safety, and current capacity requirements. In embodiments, the
position of the device port hookups 10280 within the buffer zones
may be mechanically identified and/or adjustable (e.g. by means of
a flexible conduit).
[0347] In an embodiments, a physical device such as a foam mold or
other structural frame containing hookups 10280 and conduits for
various utilities in each buffer zone 10240, 10250, and 10260 may
be provided as a kit, which may allow for a variety of
configurations to meet installation needs such as height, width,
position of conduit, position of device hookups, and frame mounting
within the constraints of the corresponding standard(s).
[0348] In embodiments, the buffer zones 10240, 10250, 10260 may be
fully customized to meet a specific user installation and
operational needs. In such an embodiment the user may provide
specifications covering aspects of the system such as height,
width, position of conduit, position of device hookups, mounting
method, and optional aspects such as enclosure, and base to a
manufacturer.
[0349] In embodiments, the buffer zones 10240, 10250, and 10260 may
be arranged with one or more of the conduits 10270 in predetermined
patterns forming one or more standard layers for utilities, and one
or more customizable layers. The standard layers for example, may
be for water and electricity, while the customizable layers may be
for gas. The standard layers may additionally incorporate
predetermined conduits for water electrical wiring.
[0350] As shown in FIG. 103, the overall size of the buffer zones
10240, 10250, and 10260 may be predetermined to facilitate
integration with process chambers 2002 and the handling system
10200. As described above, and as depicted in FIG. 103, the buffer
zones may have a volume defined in at least one dimension by the
volume of the associated linkable module 6130.
[0351] In embodiments with differently shaped process chambers,
such as a chamber that is wider in the isolation valve connection
area than in the utility components connection area, the width of
the buffer zones 10240 and 10260 may be different than the
embodiment shown in FIG. 103. Alternatively, the device port
hookups 10280 may be expandable in length to accommodate
differently shaped process chambers.
[0352] The embodiment shown in FIG. 103 allows buffer zones 10240,
10250, and 10260 to be installed under a linkable module and, for
example the inspection module 4010, thereby reducing the foot print
of the combined handling system 10200 while ensuring routing
capability for utilities.
[0353] FIG. 104 shows a number of linkable modules using utility
conduits adapted to the buffer zones described above. As depicted,
utility delivery components 10404, 10406, 10408 are attached to the
base 10230 of each linkable module. Each one of the utility deliver
components may include conduits, interconnects, and connection
ports conforming to any appropriate standards as generally
described above.
[0354] In embodiments, the utility delivery components 10404,
10406, 10408 may include sensors for sensing aspects of each
utility (e.g., fluid flow, gas flow, temperature, pressure, etc.)
and may include a means of displaying the sensed aspects or
transmitting sensor data to a controller or other data acquisition
system. Sensors and associated displays may be useful for
installation, setup, troubleshooting, monitoring, and so forth. For
example, a modular utility delivery component 10404 delivering
water may include a water pressure sensor, a water flow rate
sensor, and/or a water temperature sensor, while a display may
display the corresponding physical data. Other sensors for display
or monitoring may include gas pressure, type, flow rate,
electricity voltage, and current. Additionally, the sensors may
transmit an externally detectable signal which may be monitored by
a utility control computer system.
[0355] A linear processing system including work piece transport,
such as that provided by a work piece handling vacuum module
combined with a transport cart 6140 may be associated with a
modular utility delivery component 10240 that may supply utilities
such as air, water, gas, and electricity to a sections of a
semiconductor processing system through modular connection. Groups
of vacuum modules that are being provided utilities though the
modular utility delivery component, such as process chambers 2002,
multifunction modules 9702, bypass thermal adjusters 9402, work
piece handling vacuum modules, one or more load locks 14010, wafer
storage, and the like may be combined with a transport cart 6140 to
facilitate transport of one or more work pieces between distal
groups. Referring to FIG. 67, linear processing groups 6610 may be
locally configured with modular utility delivery components 10240,
10250, 10260, while transport cart 6140 provides work piece
transport from one group 6610 to another.
[0356] FIG. 105 shows a low particle vent system. The system 10500
transfers work pieces to an from a vacuum processing environment,
and may include work pieces 10510 loaded and ready to be processed
in a semiconductor processing facility once a proper vacuum
environment is created within the system 10500. The system 10500
further includes an adapted gas line 10520 connected to a gas line
valve 10530, a particle filter 10540, and a shock wave baffle
10550.
[0357] In general operation, the system 10500 seals in work pieces
with a door 10501 that may be opened and closed using any of a
variety of techniques known to one or ordinary skill in the art to
isolate the interior 10502 from an exterior environment. In
operation, the system opens and closes the door 10501 to the
chamber 10502, opens the gas valve 10530 to supply gas to an
interior 10502 of the system 10500, closes the gas valve 10530, and
then evacuates the interior 10502 to form a vacuum for the work
pieces 10510. Unloading the work pieces 10510 may be accomplished
in a similar way except that the system 10500 begins with a vacuum
environment and is pressurized by the gas flowing through the open
gas line valve 10530 and the adapted gas line 10520.
[0358] Once the work pieces 10510 are placed in the interior 10502,
venting and pumping may be performed. During this process, the
particle filter 10540, configured in-line with the adapted gas line
10520 or across the opening of the chamber interior 10502, filters
large particles being transported by the gas. In addition, the
baffle 10550 and the adapted gas line 10520 combine to absorb the
supersonic shock waves that result from releasing a vacuum seal for
the interior 10502, thereby preventing or mitigating disruption of
particles within the interior 10502.
[0359] The gas line, typically a cylindrical shaped tube for
passing gas from the valve 10530 to the module, is adapted by
modifying its shape to facilitate absorbing the supersonic shock
wave. In one embodiment, the adapted gas line 10520 may be shaped
similar to a firearm silencer, in that it may have inner wall
surfaces that are angled relative to the normal line of travel of
the gas. More generally, the gas line may include any irregular
interior surfaces, preferably normal to a center axis of the gas
line. Such surfaces disperse, cancel, and or absorb the energy of
the supersonic shock wave (e.g., from releasing a vacuum seal).
[0360] To further reduce the impact of the supersonic shock wave,
the baffle 10550 obstructs travel of any remaining shock wave and
protects the work pieces 10510 from perturbations that might
otherwise carry particle contamination. The baffle 10550 may be
positioned to reflect incident portions of the supersonic shock
wave, canceling some of its energy, resulting in a substantially
reduced shock wave impacting surfaces throughout the interior which
may have particles. The baffle 10550 may be larger than the
opening, as large as the opening, or smaller than the opening, and
may be generally displaced toward the interior of the chamber from
the opening. In one embodiment, the baffle 10550 may be moveable,
so that it may be selectively positioned to obstruct shockwaves or
admit passage of workpieces.
[0361] A low particle vent system as described above may be
deployed at any location within any of the above systems where a
vacuum seal might be released or created.
[0362] Many of the above systems such as the multi-function
modules, batch storage, and batch end effectors may be employed in
combination with the highly modular systems described herein to
preserve floor space and decrease processing time, particularly for
processes that are complex, or for installations that are intended
to accommodate several different processes within a single vacuum
environment. A number of batch processing concepts, and in
particular uses of a batch aligner, are now described in greater
detail.
[0363] FIG. 106 shows a system 10600 including a number of batch
processing modules 10602 that can process a number of wafers at one
time. Each module 10602 may, for example, process 2, 3, 4, or more
wafers simultaneously. The system 10600 may also include a batch
load lock 10604, an in vacuum batch buffer 10606, a buffering
aligner 10608, one or more vacuum robot arms 10610, an atmospheric
robot arm 10612 and one or more front opening unified pods 10614.
Each of the foregoing components may be adapted for batch
processing of wafers.
[0364] The front opening unified pods 10614 may store wafers in
groups, such as four. While a four wafer system is provided for
purposes of illustration, it will be understood that the system
10600 may also, or instead, be configured to accommodate groups of
2, 3, 4, 5, 6, or more wafers, or combinations of these, and all
such groupings may be considered batches as that term is used
herein.
[0365] An in-atmosphere robot 10612 may operate to retrieve groups
of wafers from the FOUPs 10614 which generally manage atmospheric
handling of wafers for processing in the system 10600. The robot
10612 may travel on a track, cart or other mechanism to access the
FOUP's 10614, the load lock 10604, and the buffering aligner 10608.
The robot may include a batch end effector for simultaneously
handling a batch of wafers (or other workpieces. The robot 10612
may also, or instead, include dual arms or the like so that a first
arm can pick and place between the FOUPs 10614 and the batch
aligner 10608 while the other arm provides a batch end effector for
batch transfers of the aligned wafers in the buffer 10608 to the
batch load lock 10604 and from the load lock 10604 back to the
FOUPs 10614.
[0366] The buffering aligner 10608 may accommodate a corresponding
number of wafers (e.g., four) that are physically aligned during
the buffering process. It will be understood that while a single
buffering aligner is shown, a number of buffering aligners may be
arranged around the in-atmosphere robot, or may be vertically
stacked, in order to accommodate groups of batches for processing.
It will also be understood that the buffering aligner 10608 may
employ any active or passive techniques, or combinations of these,
known to one of skill in the art to concurrently align two or more
wafers for subsequent batch handling.
[0367] As a significant advantage, an aligned batch of wafers can
be processed more quickly in batch form downstream. Thus, for
example, an aligned batch of wafers can be transferred to the batch
load lock 10604 by the robot 10612 in a manner that preserves
alignment for transfer to the in vacuum robot 10610, which may
include a dual arm and/or dual end effectors for batch handling of
wafers within the vacuum. Further, the in-vacuum batch buffer 10606
may accommodate batches of wafers using, e.g., shelves or the like
to preserve alignment during in vacuum buffering and/or hand off
between robots. The batch buffer 10606 may, of course, provide
cooling, temperature control storage, or any of the other functions
described above that might be useful between processing modules in
a semiconductor manufacturing process.
[0368] FIG. 107 shows a robotic arm useful with the batch
processing system of FIG. 106. FIG. 107A shows a cross sectional
view of the robot 10700 while FIG. 107B shows a perspective
drawing. In general, a robot 10700 may include a first robotic arm
10702 having a single end effector 10704 and a second robotic arm
10706 having a dual or other batch end effector 10708.
[0369] Using this robotic arm configuration, the single end
effector 10704 may be employed for individual picks and placements
of wafers within modules while the dual end effector 10708 may be
employed for batch transfers between processing modules via, e.g.,
batch buffers 10606, robot-to-robot hand offs, or any other
suitable batch processing technique.
[0370] It will be appreciated that numerous variations to this
batch technique are possible. For example, the batch end effector
may include two blades, three blades, or any other number of blades
(or other suitable wafer supports) suitable for use in a batch
process. At the same time, each robotic arm 10702, 10706 may be a
multi-link SCARA arm, frog leg arm, or any other type of robot
described herein. In addition, depending on particular deployments
of manufacturing processes, the two arms may be fully independent,
or partially or selectively dependent. All such variations are
intended to fall within the scope of this disclosure. In addition
to variations in batch size and robotic arm configurations, it will
be understood that any number of batch processing modules may be
employed. In addition, it may be efficient or useful under certain
circumstances to have one or more non-batch or single wafer process
modules incorporated into a system where process times are suitably
proportional to provide acceptable utilization of the single and
batch process modules in cooperation.
[0371] FIG. 108 illustrates how multiple transfer planes may be
usefully employed to conserve floor space in a batch processing
system. FIG. 108A shows a linking module including multiple
transfer planes to accommodate single or multiple access to wafers
within the linking module. Slot valves or the like are provided to
isolate the linking module. FIG. 108B shows an alternative
configuration in which multiple shelves are positioned between
robots without isolation. In this configuration, the shelves may,
for example, be positioned above the robots to permit a full range
of robotic motion that might otherwise cause a collision between a
robotic arm and wafers on the shelves. This configuration
nonetheless provides batch processing and or multiple wafer
buffering between robots. FIG. 108C shows a top view of the
embodiment of FIG. 108B. As visible in FIG. 108C, the small adapter
with shelves between robots in FIG. 108B permits relatively close
positioning of two robots without requiring direct robot-to-robot
handoffs. Instead each wafer or group of wafers can be transferred
to the elevated shelves for subsequent retrieval by an adjacent
robot. As a significant advantage, this layout reduces the
footprint of two adjacent robots while reducing or eliminating the
extra complexity of coordinating direct robot-to-robot
handoffs.
[0372] Having thus described several illustrative embodiments, it
is to be appreciated that various alterations, modifications, and
improvements will readily occur to those skilled in the art. Such
alterations, modifications, and improvements are intended to form a
part of this disclosure, and are intended to be within the spirit
and scope of this disclosure. While some examples presented herein
involve specific combinations of functions or structural elements,
it should be understood that those functions and elements may be
combined in other ways according to the present invention to
accomplish the same or different objectives. In particular, acts,
elements, and features discussed in connection with one embodiment
are not intended to be excluded from similar or other roles in
other embodiments. Accordingly, the foregoing description and
attached drawings are by way of example only, and are not intended
to be limiting.
[0373] The elements depicted in flow charts and block diagrams
throughout the figures imply logical boundaries between the
elements. However, according to software or hardware engineering
practices, the depicted elements and the functions thereof may be
implemented as parts of a monolithic software structure, as
standalone software modules, or as modules that employ external
routines, code, services, and so forth, or any combination of
these, and all such implementations are within the scope of the
present disclosure. Thus, while the foregoing drawings and
description set forth functional aspects of the disclosed systems,
no particular arrangement of software for implementing these
functional aspects should be inferred from these descriptions
unless explicitly stated or otherwise clear from the context.
[0374] Similarly, it will be appreciated that the various steps
identified and described above may be varied, and that the order of
steps may be adapted to particular applications of the techniques
disclosed herein. All such variations and modifications are
intended to fall within the scope of this disclosure. As such, the
depiction and/or description of an order for various steps should
not be understood to require a particular order of execution for
those steps, unless required by a particular application, or
explicitly stated or otherwise clear from the context.
[0375] The methods or processes described above, and steps thereof,
may be realized in hardware, software, or any combination of these
suitable for a particular application. The hardware may include a
general-purpose computer and/or dedicated computing device. The
processes may be realized in one or more microprocessors,
microcontrollers, embedded microcontrollers, programmable digital
signal processors or other programmable device, along with internal
and/or external memory. The processes may also, or instead, be
embodied in an application specific integrated circuit, a
programmable gate array, programmable array logic, or any other
device or combination of devices that may be configured to process
electronic signals. It will further be appreciated that one or more
of the processes may be realized as computer executable code
created using a structured programming language such as C, an
object oriented programming language such as C++, or any other
high-level or low-level programming language (including assembly
languages, hardware description languages, and database programming
languages and technologies) that may be stored, compiled or
interpreted to run on one of the above devices, as well as
heterogeneous combinations of processors, processor architectures,
or combinations of different hardware and software.
[0376] Thus, in one aspect, each method described above and
combinations thereof may be embodied in computer executable code
that, when executing on one or more computing devices, performs the
steps thereof. In another aspect, the methods may be embodied in
systems that perform the steps thereof, and may be distributed
across devices in a number of ways, or all of the functionality may
be integrated into a dedicated, standalone device or other
hardware. In another aspect, means for performing the steps
associated with the processes described above may include any of
the hardware and/or software described above. All such permutations
and combinations are intended to fall within the scope of the
present disclosure.
[0377] While the invention has been disclosed in connection with
the preferred embodiments shown and described in detail, various
modifications and improvements thereon will become readily apparent
to those skilled in the art. Accordingly, the spirit and scope of
the present invention is not to be limited by the foregoing
examples, but is to be understood in the broadest sense allowable
by law.
[0378] All documents referenced herein are hereby incorporated by
reference.
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