U.S. patent application number 12/117945 was filed with the patent office on 2008-11-13 for transfer chamber with vacuum extension for shutter disks.
Invention is credited to Jason Schaller.
Application Number | 20080276867 12/117945 |
Document ID | / |
Family ID | 39968389 |
Filed Date | 2008-11-13 |
United States Patent
Application |
20080276867 |
Kind Code |
A1 |
Schaller; Jason |
November 13, 2008 |
TRANSFER CHAMBER WITH VACUUM EXTENSION FOR SHUTTER DISKS
Abstract
The present invention relates to a cluster tool for processing
semiconductor substrates. One embodiment of the present invention
provides a mainframe for a cluster tool comprising a transfer
chamber having a substrate transferring robot disposed therein. The
substrate transferring robot is configured to shuttle substrates
among one or more processing chambers directly or indirectly
connected to the transfer chamber. The mainframe further comprises
a shutter disk shelf configured to store one or more shutter disks
to be used by the one or more processing chambers, wherein the
shutter disk shelf is accessible to the substrate transferring
robot so that the substrate transferring robot can transfer the one
or more shutter disks between the shutter disk shelf and the one or
more processing chambers directly or indirectly connected to the
transfer chamber.
Inventors: |
Schaller; Jason; (Austin,
TX) |
Correspondence
Address: |
PATTERSON & SHERIDAN, LLP - - APPM/TX
3040 POST OAK BOULEVARD, SUITE 1500
HOUSTON
TX
77056
US
|
Family ID: |
39968389 |
Appl. No.: |
12/117945 |
Filed: |
May 9, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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60916921 |
May 9, 2007 |
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60916924 |
May 9, 2007 |
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60916932 |
May 9, 2007 |
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Current U.S.
Class: |
118/719 |
Current CPC
Class: |
H01L 21/67173 20130101;
H01L 21/67196 20130101; H01L 21/67742 20130101; H01L 21/67184
20130101; C23C 14/568 20130101 |
Class at
Publication: |
118/719 |
International
Class: |
C23C 16/00 20060101
C23C016/00 |
Claims
1. A mainframe for a cluster tool, comprising: a transfer chamber
having a substrate transferring robot disposed therein, wherein the
substrate transferring robot is configured to shuttle substrates
among one or more processing chambers directly or indirectly
connected to the transfer chamber; and a shutter disk shelf
configured to store one or more shutter disks to be used by the one
or more processing chambers, wherein the shutter disk shelf is
accessible to the substrate transferring robot so that the
substrate transferring robot can transfer the one or more shutter
disks between the shutter disk shelf and the one or more processing
chambers directly or indirectly connected to the transfer
chamber.
2. The mainframe of claim 1, wherein the substrate transferring
robot is configured to shuttle substrates in a range of motion
extending beyond the location of the shutter disk shelf.
3. The mainframe of claim 1, further comprising an extension
chamber connected to the transfer chamber, wherein the shutter disk
shelf is disposed in the extension chamber.
4. The mainframe of claim 3, further comprising one of a load lock
chamber or a pass through chamber connected to the extension
chamber, wherein the load lock chamber or the pass through chamber
is configured to connect the transfer chamber with a front end
environment, and an inner volume of the extension chamber provides
a robot passage between the load lock chamber or the pass through
chamber and the transfer chamber for the substrate transferring
robot.
5. The mainframe of claim 4, wherein the shutter disk shelf is
positioned in the inner volume of the extension chamber away from
the robot passage.
6. The mainframe of claim 4, wherein the shutter disk shelf is
movably disposed in the inner volume of the extension chamber.
7. The mainframe of claim 6, further comprising an indexer coupled
to the shutter disk shelf, wherein the indexer is configured to
move the shutter disk shelf vertically within the inner volume of
the extension chamber.
8. The mainframe of claim 3, wherein the transfer chamber and the
extension chamber are in fluid communication, and a vacuum pump is
adapted to a pressure modification port formed on a bottom wall of
the extension chamber and configured to provide a low pressure
environment to the transfer chamber.
9. The mainframe of claim 1, wherein the shutter disk shelf
comprises: a first post; a second post disposed opposing the first
post; and one or more pairs supporting fingers extending from each
of the first and second posts, wherein the one or more pairs of
supporting fingers form one or more slots, and each slot is
configured to support one shutter disk thereon.
10. The mainframe of claim 9, wherein each of the supporting
fingers comprises two contact balls configured to be in contact
with a back side of a shutter disk.
11. A transfer chamber assembly for a cluster tool, comprising: a
main chamber having a central robot disposed therein, wherein the
main chamber configured to connect to a plurality of chambers, the
central robot is configured to shuttle one or more substrates among
the plurality of chambers connected to the main chamber; an
extension chamber connected to the main chamber; a shutter disk
shelf disposed in the extension chamber, wherein the shutter disk
shelf is configured to support one or more shutter disks therein,
and the shutter disk shelf is accessible to the central robot.
12. The transfer chamber assembly of claim 11, wherein main chamber
and the extension chamber form a single vacuum enclosure.
13. The transfer chamber assembly of claim 12, wherein the
extension chamber has a low pressure port formed therein configured
to connect to a vacuum system.
14. The transfer chamber assembly of claim 11, wherein the shutter
disk shelf is disposed in a first portion of an inner volume of the
extension chamber, and a second portion of the inner volume of the
extension chamber is configured to provide a passage for the
central robot to access a load lock chamber or a pass through
chamber connected to the extension chamber.
15. The transfer chamber assembly of claim 14, wherein the shutter
disk shelf is disposed in a lower portion of the inner volume.
16. The transfer chamber assembly of claim 14, wherein the shutter
disk shelf is movably disposed in the inner volume of the extension
chamber.
17. The transfer chamber assembly of claim 16, further comprising
an indexer connected to the shutter disk shelf, wherein the indexer
is configured to transfer the shutter disk shelf vertically in the
extension chamber so that the shutter disk shelf is accessible to
the central robot.
18. A cluster tool configured to process semiconductor substrates,
comprising: a first transfer chamber having a first central robot
disposed therein; a first extension chamber connected to the first
transfer chamber, the first extension chamber having a first
shutter disk shelf positioned therein, wherein the first shutter
disk shelf is configured to support one or more shutter disks
thereon, and the first shutter disk shelf is accessible by the
first central robot; one or more processing chambers connected to
the first transfer chamber; and a load lock chamber connected to
the first extension chamber.
19. The cluster tool of claim 18, further comprising: a pass
through chamber connected to the first transfer chamber; a second
transfer chamber having a second central robot disposed therein,
wherein the second transfer chamber is connected with the pass
through chamber; and one or more processing chambers connected to
the second transfer chamber.
20. The cluster tool of claim 19, further comprising a second
extension chamber disposed between the pass through chamber and the
second transfer chamber, wherein the second extension chamber
comprises a second shutter disk shelf disposed therein and
accessible to the second central robot.
21. The cluster tool of claim 18, wherein the first shutter disk
shelf is movably disposed in the first extension chamber.
22. The cluster tool of claim 18, further comprising a pumping
system connected to the first extension chamber, wherein the
pumping system is configured to maintain a low pressure environment
in the first extension chamber and the first transfer chamber.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims benefit of U.S. Provisional Patent
Application Ser. No. 60/916,921 (Attorney Docket No. 011776), filed
May 9, 2008, U.S. Provisional Patent Application Ser. No.
60/916,924 (Attorney Docket No. 011803), filed May 9, 2008, and
U.S. Provisional Patent Application Ser. No. 60/916,932 (Attorney
Docket No. 011804), filed May 9, 2008. Each of the aforementioned
patent applications is herein incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] Embodiments of the invention generally relate to an
integrated processing system configured to process semiconductor
substrates. More particularly, the invention relates a cluster tool
has a mainframe including a transfer chamber and an extension
chamber configured to store shutter disks therein.
[0004] 2. Description of the Related Art
[0005] The process of forming semiconductor devices is commonly
done in a multi-chamber processing system (e.g., a cluster tool)
which has the capability to process substrates, (e.g.,
semiconductor wafers) in a controlled processing environment. A
typical controlled processing environment includes a system that
has a mainframe which houses a substrate transfer robot configured
to transport substrates among a load lock chamber and multiple
vacuum processing chambers, which are connected to the mainframe.
The controlled processing environment has many benefits, such as
minimizing contamination of the substrate surfaces during transfer
and during completion of the various substrate processing steps.
Processing in a controlled environment thus reduces the number of
generated defects and improves device yield.
[0006] A mainframe for a cluster tool generally includes a central
transfer chamber housing a robot adapted to shuttle one or more
substrates. Processing chambers and load locks are mounted on the
central transfer chamber. During processing, an internal volume of
the central transfer chamber is typically maintained at a vacuum
condition to provide an intermediate region in which substrates may
be shuttled from one processing chamber to another, and/or to a
load lock chamber positioned at a front end of the cluster
tool.
[0007] Some processing chambers, such as a physical vapor
deposition (PVD) chamber, comprise a shutter disk which may be used
to protect a substrate support during conditioning operation.
Typically, a PVD processing is performed in a sealed chamber having
a pedestal for supporting a substrate disposed thereon. The
pedestal typically includes a substrate support that has electrodes
disposed therein to electrostatically hold the substrate against
the substrate support during processing. A target, generally
comprised of a material to be deposited on the substrate, is
supported above the substrate, typically fastened to a top of the
chamber. A plasma formed from a gas, such as argon, is supplied
between the substrate and the target. The target is biased, causing
ions within the plasma to be accelerated toward the target. Ions
impacting the target cause material to become dislodged from the
target. The dislodged material is attracted towards the substrate
and deposit a film of material thereon.
[0008] Conditioning operations, such as burn-in process, pasting,
and/or cleaning operations, are performed periodically to ensure
processing performance of the PVD chamber. During conditioning
operations, a dummy substrate or a shutter disk is disposed on the
pedestal to protect the substrate support from any deposition or
particle contamination. The state of the art PVD chambers generally
include a shutter disk storage space designated storing a shutter
disk during process, and a robotic arm configured to transfer the
shutter disk between the shutter disk storage space and the
substrate support for conditioning operations. The shutter disk
stays in the shutter disk storage space within the PVD chamber
during deposition, and covers the substrate support during
conditioning operations. The shutter disk storage space and the
robotic arm designed to transfer the shutter disk increases
complexity and volume of the PVD chamber.
[0009] FIG. 1A schematically illustrates a PVD processing chamber
10 of prior art. The PVD processing chamber 10 includes a chamber
body 2 and a lid assembly 6 that defines an evacuable process
volume. The chamber body 2 generally includes sidewalls and a
bottom 54. The sidewalls generally contain a plurality of apertures
that include an access port, pumping port and a shutter disk port
56 (access and pumping ports not shown). The sealable access port
provides for entrance and egress of the substrate 12 from the PVD
processing chamber 10. The pumping port is coupled to a pumping
system (also not shown) that evacuates and controls the pressure
within the process volume. The shutter disk port 56 is configured
to allow at least a portion of a shutter disk 14 therethrough when
the shutter disk 14 is in the cleared position. A housing 16
generally covers the shutter disk port 56 to maintain the integrity
of the vacuum within the process volume.
[0010] The lid assembly 6 of the body 2 generally supports an
annular shield 62 suspended therefrom that supports a shadow ring
58. The shadow ring 58 is generally configured to confine
deposition to a portion of the substrate 12 exposed through the
center of the shadow ring 58.
[0011] The lid assembly 6 further includes a target 64 and a
magnetron 66. The target 64 provides material that is deposited on
the substrate 12 during the PVD process while the magnetron 66
enhances uniform consumption of the target material during
processing. The target 64 and substrate support 4 are biased
relative each other by a power source 84. A gas such as argon is
supplied to the process volume 60 from a gas source 82. A plasma is
formed between the substrate 12 and the target 64 from the gas.
Ions within the plasma are accelerated toward the target 64 and
cause material to become dislodged from the target 64. The
dislodged target material is attracted towards the substrate 12 and
deposits a film of material thereon.
[0012] The substrate support 4 is generally disposed on the bottom
54 of the chamber body 2 and supports the substrate 12 during
processing. A shutter disk mechanism 8 is generally disposed
proximate the substrate support 4. The shutter disk mechanism 8
generally includes a blade 18 that supports the shutter disk 14 and
an actuator 26 coupled to the blade 18 by a shaft 20. Typically,
the blade 18 is moved between the cleared position shown in FIG. 1A
and a second position that places the shutter disk 114
substantially concentric with the substrate support 4. In the
second position, the shutter disk 14 may be transferred (by
utilizing the lift pins) to the substrate support 4 during the
target burn-in and chamber pasting process. Typically, the blade 18
is returned to the cleared position during the target burn-in and
chamber pasting process. The actuator 26 may be any device that may
be adapted to rotate the shaft 20 through an angle that moves the
blade 18 between the cleared and second positions.
[0013] FIG. 1B schematically top and sectional plan views of the
PVD processing chamber. FIG. 1B illustrates the housing 16 relative
to the shutter disk 14, the blade 18 and the substrate support
4.
[0014] Therefore, the state of the art PVD processing chambers with
built-in shutter disk storage and transfer mechanism are not only
complex but also bulky. There are usually multiple processing
chambers require a shutter disk in a cluster tool configured to
perform one or more PVD process steps. With multiple chambers
having shutter disk storage and transferring mechanisms, footprint
and cost of a cluster tool can be increased greatly.
[0015] Therefore, there is need for an efficient shutter disk
storage and transferring mechanism in a cluster tool.
SUMMARY OF THE INVENTION
[0016] The present invention generally provides an apparatus and
method for processing semiconductor substrates. Particularly, the
present invention provides a cluster tool having an extension
chamber connected to a transfer chamber, wherein the extension
chamber comprises a shutter disk shelf to store shutter disks to be
used in processing chambers connected to the transfer chamber.
[0017] One embodiment of the present invention provides a mainframe
for a cluster tool comprising a transfer chamber having a substrate
transferring robot disposed therein, wherein the substrate
transferring robot is configured to shuttle substrates among one or
more processing chambers directly or indirectly connected to the
transfer chamber, and a shutter disk shelf configured to store one
or more shutter disks to be used by the one or more processing
chambers, wherein the shutter disk shelf is accessible to the
substrate transferring robot so that the substrate transferring
robot can transfer the one or more shutter disks between the
shutter disk shelf and the one or more processing chambers directly
or indirectly connected to the transfer chamber.
[0018] Another embodiment of the present invention provides a
transfer chamber assembly for a cluster tool comprising a main
chamber having a central robot disposed therein, wherein the main
chamber configured to connect to a plurality of chambers, the
central robot is configured to shuttle one or more substrates among
the plurality of chambers connected to the main chamber, an
extension chamber connected to the main chamber, a shutter disk
shelf disposed in the extension chamber, wherein the shutter disk
shelf is configured to support one or more shutter disks therein,
and the shutter disk shelf is accessible to the central robot.
[0019] Yet another embodiment of the present invention provides a
cluster tool configured to process semiconductor substrates
comprising a first transfer chamber having a first central robot
disposed therein, a first extension chamber connected to the first
transfer chamber, the first extension chamber having a first
shutter disk shelf positioned therein, wherein the first shutter
disk shelf is configured to support one or more shutter disks
thereon, and the first shutter disk shelf is accessible by the
first central robot, one or more processing chambers connected to
the first transfer chamber, and a load lock chamber connected to
the first extension chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] So that the manner in which the above recited features of
the present invention can be understood in detail, a more
particular description of the invention, briefly summarized above,
may be had by reference to embodiments, some of which are
illustrated in the appended drawings. It is to be noted, however,
that the appended drawings illustrate only typical embodiments of
this invention and are therefore not to be considered limiting of
its scope, for the invention may admit to other equally effective
embodiments.
[0021] FIG. 1A schematically illustrates a sectional side view of a
PVD processing chamber of prior art.
[0022] FIG. 1B schematically illustrates a top view of the PVD
processing chamber of prior art.
[0023] FIG. 2 schematically illustrates a plan view of a cluster
tool in accordance with one embodiment of the present
invention.
[0024] FIG. 3A schematically illustrates a sectional side view of a
cluster tool having a vacuum extension with a movable shelf to
store shutter disks in accordance with one embodiment of the
present invention.
[0025] FIG. 3B schematically illustrates a sectional side view of a
cluster tool having a vacuum extension with a stationary shelf to
store shutter disks in accordance with one embodiment of the
present invention.
[0026] FIG. 3C schematically illustrates a partial isometric bottom
view showing one embodiment of supporting legs of the cluster tool
of FIG. 3A.
[0027] FIG. 3D schematically illustrates a partial isometric bottom
view showing another embodiment of supporting legs of the cluster
tool of FIG. 3A.
[0028] FIG. 4A schematically illustrates an isometric sectional
view of a transfer chamber in accordance with one embodiment of the
present invention.
[0029] FIG. 4B schematically illustrates a top view of the transfer
chamber of FIG. 4A.
[0030] FIG. 4C schematically illustrates a sectional side view of
the transfer chamber of FIG. 4A.
[0031] FIG. 4D schematically illustrates a bottom view of the
transfer chamber of FIG. 4A.
[0032] FIG. 4E schematically illustrates an isometric sectional
view of the transfer chamber of FIG. 4A with a central robot in a
rotation mode.
[0033] FIG. 4F schematically illustrates an isometric sectional
view of the transfer chamber of FIG. 4A in connection with a vacuum
extension of the present invention.
[0034] FIG. 5A schematically illustrates a plan view a cluster tool
having a transfer chamber in accordance with one embodiment of the
present invention.
[0035] FIG. 5B schematically illustrates a plan view of the cluster
tool of FIG. 5A wherein a central robot in a transfer chamber is in
a rotation mode.
[0036] FIG. 5C schematically illustrates a plan view of the cluster
tool of FIG. 5A wherein a central robot in a transfer chamber is
accessing a vacuum extension connected to the transfer chamber.
[0037] FIG. 5D schematically illustrates a plan view of the cluster
tool of FIG. 5A wherein a central robot in a transfer chamber is
accessing a load lock chamber connected with the transfer
chamber.
[0038] FIG. 5E schematically illustrates a plan view of the cluster
tool of FIG. 5A wherein a central robot in a transfer chamber is
accessing processing chamber connected to the transfer chamber
[0039] FIG. 6A schematically illustrates an exploded view of a
vacuum extension in accordance with one embodiment of the present
invention. The vacuum extension has a movable shelf.
[0040] FIG. 6B schematically illustrates a sectional side view of
the vacuum extension shown in FIG. 6A.
[0041] FIG. 6C schematically illustrates a sectional side view of
the vacuum extension of FIG. 6A with the movable shelf in a down
position.
[0042] FIG. 7A schematically illustrates an isometric view of the
movable shelf of FIG. 6A.
[0043] FIG. 7B schematically illustrates a supporting finger in
accordance with one embodiment of the present invention.
[0044] FIG. 7C schematically illustrates a supporting finger in
accordance with another embodiment of the present invention.
[0045] FIG. 8A schematically illustrates an isometric sectional
view of a vacuum extension having a stationary shelf in accordance
with one embodiment of the present invention.
[0046] FIG. 8B schematically illustrates a sectional side view of a
mainframe having a vacuum extension of FIG. 8A.
[0047] FIG. 8C schematically illustrates a sectional side view of
the mainframe of FIG. 8B showing a robot accessing shutter disks
disposed in the vacuum extension.
[0048] FIG. 9 schematically illustrates a plan view of a cluster
tool in accordance with one embodiment of the present
invention.
[0049] FIG. 10 schematically illustrate a sectional side view of
the cluster tool of FIG. 9.
[0050] FIG. 11A schematically illustrates an isometric view of the
cluster tool of FIG. 9 with transporting braces.
[0051] FIG. 11B schematically illustrates a transporting brace in
accordance with one embodiment of the present invention.
[0052] To facilitate understanding, identical reference numerals
have been used, where possible, to designate identical elements
that are common to the figures. It is contemplated that elements
disclosed in one embodiment may be beneficially utilized on other
embodiments without specific recitation.
DETAILED DESCRIPTION
[0053] The present invention generally provides an apparatus and
method for processing substrates using a multi-chamber processing
system. Embodiments of the present invention include a mainframe
comprising a transfer chamber configured to host a substrate
transferring robot and an extension chamber configured to provide a
low pressure environment to the mainframe. Extension chambers in
accordance with embodiments of the present invention also comprise
a shelf for storing and support shutter disks used by processing
chambers connected to the mainframe.
[0054] FIG. 2 schematically illustrates a plan view of a cluster
tool 100 in accordance with one embodiment of the present
invention. The cluster tool 100 comprises multiple processing
chambers coupled to a single mainframe.
[0055] The cluster tool 100 comprises a front-end environment 102
(also referred to as a factory interface, or FI) in selective
communication with a load lock chamber 104. One or more pods 101
are coupled to the front-end environment 102. The one or more pods
101 are configured to store and transport substrates. A factory
interface robot 103 is disposed in the front-end environment 102.
The factory interface robot 103 is configured to transfer
substrates between the pods 101 and the load lock chamber 104.
[0056] The load lock chamber 104 provides a vacuum interface
between the front-end environment 102 and a mainframe 110. An
internal region of the mainframe 110 is typically maintained at a
vacuum condition and provides an intermediate region to shuttle
substrates from one chamber to another and/or to a load lock
chamber.
[0057] In one embodiment, the mainframe 110 is divided into two
parts to minimize the footprint of the cluster tool 100. In one
embodiment of the present invention, the mainframe 110 comprises a
transfer chamber 108 and a vacuum extension chamber 107. The
transfer chamber 108 and the vacuum extension chamber 107 are
coupled together and in fluid communication with one another and
form an inner volume in the mainframe 110. An inner volume of the
mainframe 110 is typically maintained a low pressure or vacuum
condition during processing. The load lock chamber 104 may be
connected to the front-end environment 102 and the vacuum extension
chamber 107 via slit valves 105 and 106 respectively.
[0058] The transfer chamber 108 is configured to house a central
robot 109 and provide interfaces to a plurality of processing
chambers, and/or pass through chambers for connecting to additional
mainframes to extend the cluster tool 100. In one embodiment, the
transfer chamber 108 may be a polygonal structure having a
plurality of sidewalls, a bottom and a lid. The plurality sidewalls
may have opening formed therein and are configured to connect with
processing chambers, vacuum extension chambers and/or pass through
chambers. The transfer chamber 108 shown in FIG. 2 has a square
horizontal profile and is coupled to processing chambers 111, 112,
113, and the vacuum extension chamber 107. In one embodiment, the
transfer chamber 108 may be in selective communication with the
processing chambers 111, 112, 113 via slit valves 116, 117, 118
respectively. In one embodiment, the central robot 109 may be
mounted in the transfer chamber 108 at a robot port formed on the
bottom of the transfer chamber 108.
[0059] The central robot 109 is disposed in an internal volume of
the transfer chamber 108 and is configured to shuttle substrates
114 in a substantially horizontal orientation among the processing
chambers 111, 112, 113 and to and from the load lock chamber 104
through the vacuum extension chamber 107. Details of suitable
robots may be found in commonly assigned U.S. Pat. No. 5,469,035,
entitled "Two-axis magnetically coupled robot", filed on Aug. 30,
1994; U.S. Pat. No. 5,447,409, entitled "Robot Assembly" filed on
Apr. 11, 1994; and U.S. Pat. No. 6,379,095, entitled "Robot for
Handling Semiconductor Substrates", filed on Apr. 14, 2000, which
are hereby incorporated by reference in their entireties. In one
embodiment, the central robot 109 may comprise two blades for
holding substrates, each blade mounted on an independently
controllable robot arm coupled to the same robot base. In another
embodiment, the central robot 109 is configured to control the
vertical elevation of the blades.
[0060] The vacuum extension chamber 107 is configured to provide an
interface to a vacuum system to the transfer chamber 108. In one
embodiment, the vacuum extension chamber 107 comprises a bottom, a
lid and sidewalls. A pressure modification port 115 may be formed
on the bottom of the vacuum extension chamber 107 and is configured
to adapt to a vacuuming pump system, such as a cryogenic pump,
which is required to maintain high vacuum in the transfer chamber
108. The pressure modification port 115 may be blocked with a blank
off when only a smaller vacuum pump is needed. A smaller vacuum
pump may be coupled to the transfer chamber 108 through a smaller
port formed in on the transfer chamber 108.
[0061] It should be noted that the vacuum extension chamber 107 is
much smaller/narrower compared to the transfer chamber 108 since
the vacuum extension chamber 107 only needs to be wide enough to
allow a substrate pass through.
[0062] Openings may be formed on the sidewalls so that the vacuum
extension chamber 107 is in fluid communication with the transfer
chamber 108, and in selective communication with chambers connected
thereon, such as load lock chambers, pass through chambers, and/or
processing chamber.
[0063] In one embodiment, the cluster tool 100 may be configured to
deposit a film on semiconductor substrates using physical vapor
deposition (PVD) process.
[0064] Typically, PVD is performed in a sealed chamber having a
pedestal for supporting a substrate disposed thereon. The pedestal
typically includes a substrate support that has electrodes disposed
therein to electrostatically hold the substrate against the
substrate support during processing. A target, generally comprised
of a material to be deposited on the substrate, is supported above
the substrate, typically fastened to a top of the chamber. A plasma
formed from a gas, such as argon, is supplied between the substrate
and the target. The target is biased, causing ions within the
plasma to be accelerated toward the target. Ions impacting the
target cause material to become dislodged from the target. The
dislodged material is attracted towards the substrate and deposit a
film of material thereon.
[0065] Conditioning operations, such as burn-in process, pasting,
and/or cleaning operations, are performed periodically to ensure
processing performance of the PVD chamber. During conditioning
operations, a dummy substrate or a shutter disk is disposed on the
pedestal to protect the substrate support from any deposition or
particle contamination. The state of the art PVD chambers generally
include an integral shutter disk storage space designated storing a
shutter disk during the PVD process, and a robotic arm configured
to transfer the shutter disk between the shutter disk storage space
and the substrate support for conditioning operations. The shutter
disk stays in the shutter disk storage space within the PVD chamber
during deposition, and covers the substrate support during
conditioning operations. The shutter disk storage space and the
robotic arm designed to transfer the shutter disk increases
complexity and volume of the PVD chamber.
[0066] In one embodiment of the present invention, the vacuum
extension chamber 107 comprises a shutter disk shelf, further
described in FIGS. 3A-B, configured to store one or more shutter
disks. PVD chambers connected to the transfer chamber 108 may store
their shutter disks in the shutter disk shelf and use the central
robot 109 to transfer the shuttle disks. It is also contemplated
that the PVD chambers may share one or more shutter disks. In one
embodiment, the shutter disk shelf may be configured to store one
shutter disk for each processing chambers connected to the transfer
chamber 108.
[0067] The shutter disk shelf positioned in the vacuum extension
chamber may also be used for storage, queuing, and/or accommodating
any other disks used in the system. Additionally, the shutter disk
shelf may be used to store and facilitate quick access to any
substrate form devices, i.e. 300 mm disk, that are reusable in the
system. The vacuum extension chamber of the present invention may
also provide space for an inspection station, or cooling/heating
station during a process.
[0068] In one embodiment, the shutter disk shelf may provide a
recharging station for a vision calibration substrate. The vision
calibration substrate is a reusable device having one or more
wireless cameras disposed thereon. The vision calibration substrate
may be used to measure, inspect and calibration interiors of a
cluster tool accessible to the central robot, including the
transfer chambers, extension chambers, load lock chambers, pass
through chambers, and the processing chambers. The vision
calibration substrate may also be used to calibrate the central
robot. A detailed description of the vision calibration substrate
may be found in the U.S. Pat. No. 7,085,622, entitled "Vision
System", which is hereby incorporated by reference.
[0069] The vision calibration substrate comprises one or more
wireless cameras, which have rechargeable power supplies so that
the cameras can work wirelessly in the interior of the cluster
tool. Currently, the power supplies to the wireless cameras are
charged and recharged outside the cluster tool. The charged vision
calibration substrate is generally fed into the cluster tool from
the front-end environment while halting the process. The vision
calibration substrate is taken out of the cluster tool after the
task is completed or the power supplies are depleted. In one
embodiment of the present invention, electrical contacts may be
formed in one or more slots of the shutter disk shelf for charging
a vision calibration substrate. One or more vision calibration
substrates may be stored in the shutter disk shelf and are ready to
use at any time. The measurement using the vision calibration
substrates may be performed with much reduced interruption to the
processing in the cluster tool.
[0070] Positioning shutter disks within a mainframe of a cluster
tool simplifies processing chambers that require shutter disks by
eliminating a designated region for shutter disks within the
processing chambers, and devices for transferring and/or monitoring
the shutter disks, hence reducing cost of the processing chambers.
Positioning shutter disks within a mainframe of a cluster tool may
also improves gas flows and electrical characteristics, and thus
processing. Additionally, cost of ownership may also be reduced due
to decrease of the overall volume of the cluster tool since the
processing chambers are smaller.
[0071] In one embodiment, the cluster tool 100 may comprises a
pre-clean chamber, a PVD chamber and a degassing chamber connected
to the transferring chamber 108 at positions for processing
chambers 111, 112, 113.
[0072] FIG. 3A schematically illustrates a sectional side view of
the cluster tool 100 of FIG. 2. The vacuum extension chamber 107
comprises a movable shutter disk shelf 122 configured to support at
least one shutter disk 123 therein.
[0073] In one embodiment of the present invention, the load lock
chamber 104 comprises an upper load lock chamber 104a stacked over
a lower load lock chamber 104b. The upper load lock chamber 104a
and the lower load lock chamber 104b may be operated independently
so that transferring of substrates between the front-end
environment 102 and the mainframe 110 can be conducted in both
directions simultaneously.
[0074] The load lock chambers 104a, 104b provide a first vacuum
interface between the front-end environment 102 and the mainframe
110 via slit valves 105a, 106a, 105b, 106b respectively. In one
embodiment, the two load lock chambers 104a, 104b are provided to
increase throughput by alternatively communicating with the
mainframe 110 and the front-end environment 102. While one load
lock chamber 104a or 104b communicates with the mainframe 110, a
second load lock chamber 104b or 104a can communicate with the
front-end environment 102.
[0075] In one embodiment, one of the load lock chambers 104a, 104b
may be used as a processing chamber, such as a degas chamber, an
inspection station, a pre-heat chamber, a cooling chamber, or
curing chamber. For example, the slit valve 105b may be replaced by
a permanent blocker so that the lower load lock chamber 104b only
opens to the mainframe 110. The central robot 109 may shuttle
substrates to and from the lower load lock chamber 104b prior to
and after a degassing process through the slit valve 106b.
[0076] Referring to FIG. 3A, the internal volume of the mainframe
110 is defined by an internal volume 119 of the vacuum extension
chamber 107 connected to an internal volume 120 of the transfer
chamber 108. An opening 128 is formed between the transfer chamber
108 and the vacuum extension chamber 107. The opening 128 provides
fluid communication between the vacuum extension chamber 107 and
the transfer chamber 108, and are large enough to allow the central
robot 109 to shuttle substrates to and from the load lock chamber
104.
[0077] A vacuum system 125 is coupled the vacuum extension chamber
107 and is configured to provide a low pressure environment to both
the internal volume 119 and the internal volume 120. A robotic
mechanism 126 is coupled to the transfer chamber 108. The transfer
chamber 108 and the vacuum extension chamber 107 are constructed to
minimize the foot print of the cluster tool 100.
[0078] For a cluster tool, when a vacuum system, such as a
cryogenic pump, is required to maintain vacuum, usually high
vacuum, within a transfer chamber, a large vacuum port is generally
formed in the transfer chamber. The transfer chamber, thus, has
both a robot port configured to adapt to a robotic transport
mechanism and a vacuum port for the vacuum system. The robot port
is generally positioned near a center of the transfer chamber,
while the vacuum port positioned in a satellite position relative
to the robot port leaving enough space for both the robotic
transport mechanism and the vacuum pump. As a result, the transfer
chamber has a large foot print and a large internal volume. The
large foot print of the transfer chamber greatly enlarges the foot
print of the cluster tool as a whole since processing chambers,
load lock chambers and/or pass through chambers are distributed
around the transfer chamber.
[0079] Embodiments of the present invention provides a vacuum
system connection to the transfer chamber for obtaining high vacuum
without greatly enlarge the foot print of the transfer chamber and
the cluster tool. By "outsourcing" the pressure modification port
to a separated extension chamber, size of the transfer chamber may
be minimized to be just enough to provide space for the central
robot. Size of the extension chamber may be determined by the size
of the vacuum system needed. The combined footprint of a transfer
chamber with a robot port only and its extension chamber with a
robot port is much smaller compared to the state of a state of the
art transfer chamber with both a vacuum port and a robot port. The
decrease of the foot print of a cluster tool is more pronounced
since a cluster tool may be built around a minimized transfer
chamber when the extension chamber is positioned to take a space of
a load lock chamber around the transfer chamber.
[0080] It should be noted that the size of the extension chamber is
usually much smaller than the size of the transfer chamber since
the extension chamber only needs to be large enough to accommodate
passage of a substrate, while the transfer chamber generally needs
to host the central robot.
[0081] Additionally, internal volume of a transfer chamber and
extension chamber of the present invention is reduced compared to
the state of the art transfer chambers. This allows fast pump
downs, requires less energy to maintain vacuum and smaller, less
costly pumps.
[0082] In one embodiment, an indexer 124 is coupled to the movable
shutter disk shelf 122 and is configured to vertically move the
movable shutter disk shelf 122. The movable shutter disk shelf 122
may be positioned on an upper portion of the internal volume 119 of
the vacuum extension chamber 107 when the central robot 109
transfers substrates to and from the load lock chamber 104 through
a lower portion of the internal volume 1 19. The movable shutter
disk shelf 122 may be lowered to the lower portion of the internal
volume 119 by the indexer 124 so that the central robot 109 can
pick up a shutter disk from the movable shutter disk shelf 122 or
drop a shutter disk on the movable shelf 122.
[0083] FIG. 3B schematically illustrates a sectional side view of a
cluster tool 100a having a mainframe 110a in accordance with one
embodiment of the present invention. The mainframe 110a comprises a
vacuum extension chamber 133 with a stationary shelf 135 configured
for storing one or more shutter disks.
[0084] A load lock chamber 130 provides a first vacuum interface
between the front-end environment 102 and the mainframe 110a. In
one embodiment, the load lock chamber 130 comprises an upper
substrate support 131 and a lower substrate support 132 stacked
within the load lock chamber 130. The upper substrate support 131
and the lower substrate support 132 are configured to support
substrates thereon. In one embodiment, the upper substrate support
131 and the lower substrate support 132 may be configured to
support incoming and outgoing substrates respectively. The upper
substrate support 131 and the lower substrate support 132 may
comprise features for temperature control, such as a built-in
heater or cooler to heat or cool substrates during
transferring.
[0085] The internal volume of the mainframe 110a is defined by an
internal volume 134 of the vacuum extension chamber 133 connected
to the internal volume 120 of the transfer chamber 108. An opening
128a is formed between the transfer chamber 108 and the vacuum
extension chamber 133. The opening 128a provides fluid
communication between the vacuum extension chamber 133 and the
transfer chamber 108, and are large enough to allow the central
robot 109 to shuttle substrates to and from the load lock chamber
130, as well as access the stationary shelf 135 of the vacuum
extension chamber 133.
[0086] In one embodiment, the stationary shelf 135 may be
positioned on a lower portion of the internal volume 134 of the
vacuum extension 133 while the central robot 109 is configured to
transfer substrates to and from the load lock chamber 130 through
an upper portion of the internal volume 134.
[0087] In one embodiment, the stationary shelf 135 may comprise
supporting fingers extending from posts positioned on opposite
sides of the internal volume 134.
[0088] It should be noted that the robot 109 may be suspended from
a top wall of the transfer chamber 108. Embodiments of the present
invention may include robots capable of vertical or z-motion.
[0089] Referring back to FIG. 3A, the mainframe 110 of the cluster
tool 100 is supported by supporting legs 127. The supporting legs
127 provide vertical and lateral support to the mainframe 110 and
chambers connected to the mainframe 110. Each of the supporting
legs 127 is configured to support at least a portion of the weight
of the mainframe 110 including the transfer chamber 108, the vacuum
extension chamber 107, and optionally the processing chambers
connected thereon. Each of the supporting legs 127 may be
vertically adjustable so that the mainframe 110 and chambers
connected thereon may be leveled on site. The supporting legs 127
are coupled to sidewalls of the mainframe 110 and/or chambers
coupled to the mainframe 110 to provide lateral support to the
cluster tool 100.
[0090] In one embodiment, each of the supporting legs 127 may
comprise a foot 127b connected to a steel tube body 127a. The steel
tube body 127a is configured to be coupled to the mainframe 110.
The foot 127b is configured to contact the ground and adjustable
relative to the steel tube body 127a. Vertical dimension of the
supporting leg 127 may be adjusted by adjusting the foot 127b to
provide tolerance in supporting the cluster tool 100.
[0091] In one embodiment, the mainframe 110 may be supported by for
supporting legs 127 independently mounted on opposite sides of the
mainframe 110, as shown in FIG. 2, and FIGS. 3C-3D. Two of the
supporting legs 127 are independently fastened to sidewalls of the
transfer chamber 108 and two of the supporting legs 127 are
independently fastened to sidewalls of the vacuum extension chamber
107. In another embodiment, two of the supporting legs 127 may be
positioned near the joint region of the vacuum extension chamber
107 and the load lock chamber 104. In one embodiment, notches may
be formed on sidewalls of the mainframe 110 for the supporting legs
127 to engage with.
[0092] Screws may be used to fasten each supporting leg 127 to a
corresponding location in the mainframe 110. FIG. 4E illustrates
screw holes 318, 319 formed in the chamber body 301 configured to
secure supporting legs in the notches 309.
[0093] FIG. 3C schematically illustrates a partial isometric bottom
view showing one embodiment of supporting legs of a cluster tool
100b similar to the cluster tool 100 of FIG. 3A. As shown in FIG.
3C, the cluster tool 100b is supported by four independent
supporting legs 1271-4. Each of the supporting legs 1271-4 is
independently mounted on the cluster tool 100. FIG. 3C shows a
central structure 160, which includes the transfer chamber 108 and
the vacuum extension chamber 107, and the load lock chamber 104
coupled together. Additional components, such as processing
chambers, pass through chambers, and front end interface may be
extended from the central structure 160. The supporting legs 1271-4
are coupled to the central structure 160 providing support to the
cluster tool 100 in a whole. A pair of notches 161 may be formed in
the bottom walls near a joint region of the load lock chamber 104
and the vacuum extension chamber 107. The notches 161 are
configured to provide lateral support to the supporting leg 127
mounted therein. A pair of notches 162 may be formed in the
transfer chamber 108 and configured to engage supporting legs
1273-4. The notches 162 also provide lateral support to the
supporting legs 127 mounted therein. The notches 161, 162 may be
placed in locations such that the supporting legs 1271-4 provide
balanced support to the cluster tool 100, including the central
structure 160 and/or chambers connected to the central structure
160.
[0094] FIG. 3D schematically illustrates a partial isometric bottom
view showing another embodiment of supporting legs of the cluster
tool 100 of FIG. 3A. In this embodiment, the supporting legs 1271-4
may be mounted on sidewalls of the load lock chamber 104, or the
vacuum extension chamber 107.
[0095] The design of independent supporting legs has several
advantages over conventional cluster tool support, which generally
includes a welded base used to provide a ridged support. The
conventional base is typically in an integral form and is
configured to provide support to multiple components of a cluster
tool. The conventional base is costly to build providing high
precision demanded by the semiconductor processing. The
conventional base is also difficult to assemble because it has to
be coupled to multiple components of a cluster tool. The
conventional base usually poses clearance issues for other
components in a cluster tool causing disconnection of utility
during utility routing or removal of chamber components from the
base.
[0096] The independent leg supporting of the present invention
largely reduces cost over conventional base. Each supporting leg is
manufactured separately avoiding manufacture cost of a high
precision structure. Each supporting leg is generally coupled to
one component, which makes leveling and other adjustment much
easier. The supporting leg is not limited to any cluster tool
configuration. When one or more components, such as a load lock
chamber, are altered, the supporting legs do not need to be
replaced. Furthermore, the supporting leg of the present invention
is much easier to transport.
[0097] FIG. 4A schematically illustrates an exploded sectional view
of a transfer chamber 300 in accordance with one embodiment of the
present invention. The transfer chamber 300 may be used as the
transfer chamber 108 of FIGS. 2, and FIGS. 3A-B. The transfer
chamber 300 comprises a chamber body 301 having a top wall 313, a
plurality of sidewalls 314 and a bottom wall 315. The chamber body
301 defines an inner volume 312 (shown in FIG. 4C) configured to
accommodate a substrate transferring means, such as a robot,
therein. In one embodiment, a central robot may be disposed in a
robot port 304 formed on the bottom wall 315 of the transfer
chamber 300.
[0098] The transfer chamber 300 further comprises a chamber lid 302
configured to seal an opening 303 formed on the top wall 313 of the
chamber body 301. The opening 303 may be configured to assist
installation and/or maintenance of the substrate transferring
means. In one embodiment, the chamber lid 302 may be coupled to the
chamber body 301 with a seal ring 317 and a plurality of screws
307. The chamber lid 302 may have a pair of handles 308.
[0099] In one embodiment, the chamber body 301 has a rectangular
profile and comprises four sidewalls 314. Each of the sidewalls 314
has an opening 305 formed therein. The openings 305 are configured
to provide selective communication between the inner volume 312 and
processing chambers, load lock chambers, and/or vacuum extensions
coupled to the transfer chamber 300. A gland 306 may be formed
around the opening 305 and configured to accommodate a seal ring
(not shown) to maintain a pressure barrier around the inner volume
312.
[0100] FIG. 4A schematically illustrates a processing chamber 390
mounted to the transfer chamber 300 via a chamber port assembly 370
in accordance with one embodiment of the present invention. The
chamber port assembly 370 provides an interface between the
transfer chamber 300 and the processing chamber 390. In one
embodiment, the chamber port assembly 370 provides a housing for a
slit valve assembly 380 configured to open and close a substrate
opening 392 formed through a sidewall 391 of the processing chamber
390. The substrate opening 392 is configured to provide a passage
to allow entry and egress of substrates from the processing chamber
390. Additionally, the chamber port assembly 370 allows mismatch
between the opening 305 of the transfer chamber 300 and the
substrate opening 392 of the processing chamber 390.
[0101] The chamber port assembly 370 comprises a body 371 having a
transfer chamber opening 372 open towards one side of the body 371.
The transfer chamber opening 372 is configured to cover the opening
305 of the transfer chamber 300. The transfer chamber opening 372
is connected to a chamber opening 373 which opens on an opposite
side of the body 371 to define a substrate passage through the
chamber port assembly 370. The chamber opening 373 is configured to
align with the substrate opening 392 of the processing chamber 390.
A gland 377 may be formed on an outer side of the substrate opening
392 to accommodate a seal ring (not shown) to prevent leakage
between the chamber port assembly 370 and the processing chamber
390.
[0102] The slit valve assembly 380 generally comprises a slit valve
door 382 activated by an activation member 381 configured to move
the slit valve door 382 between an opening position and a closed
position. The slit valve door 382 of the slit valve assembly 380
may be positioned on an inner side of the chamber opening 373 and
selectively connects and disconnects the transfer chamber opening
372 and the chamber opening 373, hence, selectively connecting the
transfer chamber 300 and the processing chamber 390.
[0103] In one embodiment, a plurality of screws 374 may be used to
fasten the chamber port assembly 370 to the transfer chamber 300.
In one embodiment, a seal ring 378 may be used in the gland 306
circumscribing the opening 305 between the transfer chamber 300 and
the chamber port assembly 370 to fluidly isolate the inner region
of the chamber port assembly 370 and the transfer chamber 300 from
an outside environment. A plurality of screws 393 and a seal ring
394 may be used to mount the processing chamber 390 to the chamber
port assembly 370.
[0104] Additionally, the transfer chamber opening 372 may provide a
pocket of extra room that accommodates the tip of a robot
positioned in the transfer chamber 300 as the blade is rotated in a
horizontal plane (further described with FIG. 4B). The pocket of
extra room in the chamber port assembly 370 allows further reducing
in size of the transfer chamber 300, hence reducing foot print of
the system. In one embodiment, the chamber port assembly 370 may
comprise one or more sensors configured to detect substrate and/or
robot parts within the transfer chamber opening 372. FIG. 4A
schematically shows optical sources 376 and optical receivers 375
used as sensors to detect substrates and/or robot parts.
[0105] It should be noted that a load lock chamber may be coupled
to one of the sidewall 314 of the transfer chamber 300 directly or
via a chamber port assembly similarly to the chamber port assembly
370.
[0106] In one embodiment, two notches 309 may be formed near
corners of the bottom wall 315. Each of the notches 309 is
configured to receive a supporting leg 360 therein. Each of the
supporting legs 306 is configured to bear at least part of the
weight of the transfer chamber 300 and devices mounted thereto. The
supporting leg 360 may be fastened against the transfer chamber 300
by screws 361. The notch 309 provides two planes for lateral
support for the supporting leg 360.
[0107] FIG. 4B schematically illustrates a plan view of the
transfer chamber 300 of FIG. 4A. FIG. 4C schematically illustrates
a sectional side view of the transfer chamber 300 of FIG. 4A.
Referring to FIG. 4C, the chamber body 301 may be formed by cast
aluminum and defining the inner volume 312 configured to provide
space for movement of a central robot position therein. In one
embodiment, the inner volume 312 may be minimized to be just large
enough to accommodate required movement of a robot disposed
therein.
[0108] FIG. 4E schematically illustrates an isometric sectional
view of the transfer chamber 300 of FIG. 4A with a central robot
316 in a rotation mode. The central robot 316 comprises a top blade
329 and a bottom blade 330, each configured to transfer a substrate
331 independently. The central robot 316 is capable of rotating
about z axis, translating along the z axis, and translating
parallel to x-y plane. Other suitable robots may be used in the
transfer chamber 300. The central robot 316 may be suspended from
the top wall 313 of the transfer chamber 300 as well with
corresponding changes of other structures.
[0109] During processing, the central robot 316 may extend the top
blade 329 or the bottom blade 330 through one of the openings 305
on the sidewalls 314 of the transfer chamber 300 to retrieve a
substrate in a processing chamber/load lock chamber connected to
the transfer chamber 300, or a shutter disk stored in a vacuum
extension chamber connected to the transfer chamber 300. The
central robot 316 may need to translate vertically, i.e. along z
axis, so that the top blade 329 or the bottom blade 330 is aligned
with the target substrate or shutter disk. Upon picking up the
substrate/shutter disk, the central robot 316 retrieves the top
blade 329 or the bottom blade 330 back to the inner volume 312 of
the transfer chamber 300, and rotates the top blade 329 or the
bottom blade 330 within the inner volume 312 so that the top blade
329 or the bottom blade 330 is align with an opening 305 connecting
a target chamber for the substrate/shutter disk. The central robot
316 then extends the top blade 329 or the bottom blade 330 to
access the target chamber and drops the substrate/shutter disk
therein.
[0110] It is desirable to minimize the inner volume 312 of the
transfer chamber 300 to reduce system foot print and to reduce
volume of the controlled environment. In one embodiment, the inner
volume 312 of the transfer chamber 300 is defined to match a motion
envelop described by circles 324 and 325, shown in FIGS. 4B and 4C,
necessary for the central robot 316 to perform required functions.
The motion envelop of cylindrical with a large center portion
having a radius of the circle 325, and small upper and lower
portions having a radius of the circle 324. The large center
portion of the motion envelop is partially accommodated by a large
middle portion with a radius of 311 in the inner volume 312 and
extra room in the chamber port assembly 370 and the vacuum
extension chamber 350 connected to the transfer chamber 300.
[0111] In one embodiment, the motion envelop includes space needed
for the central robot 316 to perform rotation and required vertical
movement therein. The motion envelop has a substantially
cylindrical shape with an enlarged middle portion marked by circle
325 configured to allow tips of the blades 329, 330 during
rotation. Accordingly, the inner volume 312 is substantially
cylindrical with a radius marked by line 310 and an enlarged middle
portion having a radius marked by line 311. To further reduce size
of the transfer chamber 300, part of the enlarged middle portion
325 may be outside the transfer chamber 300 and extends to a vacuum
extension chamber and/or chamber port assemblies 370 connected to
the transfer chamber 300, for example, to the transfer chamber
opening 372 of the chamber port assembly 370.
[0112] In one embodiment, a radial clearance 327, shown in FIG. 4C,
between the inner volume 312 and the motion envelop may be about
0.25 inch and the vertical clearances 326, 328 may be about 0.338
inch.
[0113] In one embodiment, software constraints may be used in a
control system so that the central robot 316 stays within the
motion envelop.
[0114] FIG. 4D schematically illustrates a bottom view of the
transfer chamber 300 of FIG. 4A. One or more heater ports 320 may
be formed on the bottom wall 315 and configured to connect to
cartridge heaters for heating the chamber body 301 during
processing. A gage port 321 may be formed in the bottom wall 315.
The gage port 321 may be used to adapt sensors, such as a pressure
sensor, therein. An optional pressure modification port 322, and
vents 323 may also be formed on the bottom wall 315 for connection
to suitable pumping devices. The gage port 321, the pressure
modification port 322, and the vents 323 may be sealed off when not
needed.
[0115] FIG. 4F schematically illustrates an exemplary vacuum
extension chamber 350 configured to couple with one of the
sidewalls 314 of the transfer chamber 300. In one embodiment, the
vacuum extension chamber 350 is configured to provide the transfer
chamber 300 an extra space for connection to a vacuum system to
keep the inner volume 312 of the transfer chamber 300 in a vacuum
condition during processing while minimizing the volume of the
transfer chamber 300 and overall internal volume of the mainframe.
The vacuum extension chamber 350 may also provide a pass way for a
robot positioned in the transfer chamber 300 to a factory interface
via a load lock chamber or another transfer chamber via a pass
through chamber.
[0116] A pressure modification port 354 configured to adapt to a
vacuum pump, such as a cryogenic pump, may be formed on a bottom
wall 355 of the vacuum extension chamber 350. An opening 351
configured to connect the transfer chamber 300 is formed in a
sidewall 353 of the vacuum extension chamber 350. The sidewall 353
of the vacuum extension chamber 350 is secured against the sidewall
314 of the transfer chamber 300, for example by a plurality of
screws 352, when the vacuum extension chamber 350 is mounted on the
transfer chamber 300. The opening 351 is aligned with the opening
305 to facilitate fluid communication and/or substrate traffic
between the transfer chamber 300 and the vacuum extension chamber
350. In one embodiment, a seal ring 356 disposed in the gland 306
circumscribing the opening 305 may be used to fluidly isolate the
inner volume of the vacuum extension chamber 350 and the transfer
chamber 300 from an outside environment.
[0117] FIG. 5A schematically illustrates a plan view a cluster tool
400 having a transfer chamber in accordance with one embodiment of
the present invention. The cluster tool 400 comprises a transfer
chamber 401, similar to the transfer chamber 300 of FIG. 4A. The
transfer chamber 401 is connected to a vacuum extension chamber
408, which is further connected to a load lock chamber 410 via a
slit valve assembly 409. Three processing chambers 406 are
connected to the transfer chamber 401 via chamber port assemblies
407, similar to the chamber port assembly 370 of FIG. 4A. The
transfer chamber 401 defines an inner volume 402 which may be
maintained in a vacuum condition during processing by a pump system
coupled to the vacuum extension chamber 408. The vacuum extension
401 may be configured to store one or more shutter disks to be used
by the processing chambers 406.
[0118] A central robot 403 is disposed in the inner volume 402 of
the transfer chamber 401. The central robot 403 is configured to
transfer substrates and/or shutter disks among the processing
chambers 406, the vacuum extension chamber 408 and the load lock
chamber 410. The central robot 403 comprises a top arm 405 and a
bottom arm 404, each having a blade configured to carry a substrate
or shutter disk 411 thereon. Shown in FIG. 5A, both the top arm 405
and the bottom arm 404 are positioned in the transfer chamber
401.
[0119] FIG. 5B schematically illustrates a plan view of the cluster
tool 100 of FIG. 5A wherein the central robot 403 in the transfer
chamber 401 rotates an angel from the central robot 403 shown in
FIG. 5A. The central robot 403 may rotate both arms 404, 405
together or independently within the inner volume 402.
[0120] FIG. 5C schematically illustrates a plan view of the cluster
tool 100 of FIG. 5A wherein the bottom arm 404 of the central robot
403 is accessing the vacuum extension chamber 408 connected to the
transfer chamber 401.
[0121] FIG. 5D schematically illustrates a plan view of the cluster
tool 100 of FIG. 5A wherein the bottom arm 404 of the central robot
403 is accessing a load lock chamber 410 connected with the
transfer chamber 401 through the vacuum extension chamber 408.
[0122] FIG. 5E schematically illustrates a plan view of the cluster
tool 100 of FIG. 5A wherein the top arm 405 of the central robot
403 is accessing the processing chamber 406 connected to the
transfer chamber 401.
[0123] FIG. 6A schematically illustrates an exploded view of a
vacuum extension assembly 500 in accordance with one embodiment of
the present invention. The vacuum extension assembly 500 is
configured to connect to a transfer chamber, such as the transfer
chamber 300 of FIG. 4A, and to provide an interface between the
transfer chamber and a load lock chamber and a fluid communication
between the transfer chamber and a vacuum system.
[0124] The vacuum extension assembly 500 comprises a body 501
defining an inner volume 512 (marked in FIG. 6B), a top plate 502
disposed on a top wall 527 of the body 501, and a shelf cover 504
disposed on the top plate 502.
[0125] A pressure modification port 514 may be formed on a bottom
wall 528 of the body 501. The pressure modification port 514 is
configured to connect a vacuum pump 508 to provide a low pressure
environment to the inner volume 512 and volumes in fluid
communication with the inner volume 512. In one embodiment, an
opening 513 may be formed on the top wall 527 of the body 501. The
opening 513 may be used to access the inner volume 512 during
installation and/or maintenance of the vacuum pump 508.
[0126] As shown in FIG. 6A, the top plate 502 is configured to
cover the opening 513 on the top wall 527. The top plate 502 may
have a slit valve opening 519 and a shelf opening 520 formed
therein. The slit valve opening 519 is configured for installation
of a slit valve 506. The shelf opening 520 is configured to allow a
movable shelf 503 to be positioned at a selected elevation within
the inner volume 512.
[0127] In one embodiment, a chamber opening 510 may be formed on a
sidewall 529 which is configured to be coupled with a transfer
chamber, such as the transfer chamber 300 of FIG. 4A. The chamber
opening 510 is configured to provide fluid communication with the
transfer chamber and to provide passage for robot blades coupled to
a robot disposed in the transfer chamber, to transfer substrates,
and/or shutter disks. Therefore, width of the chamber opening 510
is generally slightly larger than a diameter of the largest
substrate configured to be processed in a cluster tool. The height
of the chamber opening 510 is determined by the motion range of the
robot blades.
[0128] In one embodiment, a load lock opening 511 may be formed on
a sidewall 530 opposite to the sidewall 529. The load lock opening
511 is configured to provide selective communication between the
inner volume 512 and one or more load lock chambers coupled to the
side wall 529. In one embodiment, one or more slit valves may be
used to selectively seal the load lock opening 511. As shown in
FIG. 6A, a slit valve opening 515 is formed on the bottom wall 528
and is configured to allow a slit valve 507 to be disposed inside
the inner volume 512 and to selectively seal the load lock opening
511. In one embodiment, two slit valves 506, 507 may be used to
provide selective fluid communication between the inner volume 512
and two load lock chambers independently via the load lock opening
511.
[0129] In one embodiment, the shelf cover 504 is disposed above the
top plate 502 sealing the shelf opening 520. The shelf cover 504
provides space in connection with the inner volume 512 to store a
movable shelf 503 therein. The movable shelf 503 is configured to
support one or more shutter disks thereon. The shutter disks may be
used by processing chambers connected to the transfer chamber that
connects to the vacuum extension assembly 500. In one embodiment,
the movable shelf 503 may comprise two opposing posts 521, each
having one or more supporting fingers 522 extending therefrom. The
supporting fingers 522 are configured to support a shutter disk
from the edge.
[0130] In one embodiment, the movable shelf 503 may be connected to
an indexer 505. The indexer 505 may be disposed above the shelf
cover 504. A shaft 532 extends from the indexer 505 through an
aperture 557 in the shelf cover 504 and connects to the movable
shelf 503. The shaft 532 moves vertically providing vertical
movement to the movable shelf 503, so that the elevation of the
movable shelf 503 may be selected.
[0131] In one embodiment, notches 533 may be formed on the bottom
wall 528 and configured to accept independent supporting legs 509
therein. In one embodiment, windows 516, 517 may be formed on
sidewalls 531, 534 of the body 501 and utilized for observing the
interior of the vacuum extension assembly 500. Transparent
materials, such as quartz, may be used to seal the windows 516,
517.
[0132] FIG. 6B schematically illustrates a sectional side view of
the vacuum extension assembly 500 shown in FIG. 6A. A transfer
chamber 551, partially shown, is connected to the vacuum extension
assembly 500. The transfer chamber 551 is in fluid communication
with the inner volume 512 of the vacuum extension assembly 500 via
the chamber opening 510 of the vacuum extension assembly 500 and an
opening 554 of the transfer chamber 551. Load locks chambers 555,
556 are connected to the vacuum extension assembly 500 on a side
opposing the transfer chamber 551. The load lock chamber 555, 556
are connected to the inner volume 512 via slit valve doors 525, 526
respectively. Robot blades 552, 553, disposed in the transfer
chamber 551, are configured to access the load lock chambers 555,
556 via the inner volume 512 of the vacuum extension assembly
500.
[0133] As shown in FIG. 6B, the movable shelf 503 is retracted to
an upper portion of the inner volume 512, thus providing a clear
passage for the robot blades 552, 553 extend past the movable shelf
503 to the load lock chambers 555, 556.
[0134] FIG. 6C schematically illustrates a sectional side view of
the vacuum extension assembly 500 with the movable shelf 503
lowered to a down position. The movable shelf 503 is positioned by
the indexer 505 in a lower portion of the inner volume 512 such
that shutter disks 523 may be picked up from and dropped onto the
supporting fingers 522 by the robot blades 552, 553. The hand-off
between the robot blades 552, 553 and the movable shelf 503 may be
facilitated by at least one of moving the movable shelf 503 or the
robot blades 552, 553 vertically.
[0135] The body 501, top plate 502, shelf cover 504, and movable
shelf 503 may be made from any suitable material. In one
embodiment, the body 501, top plate 502, shelf cover 504, and
movable shelf 503 are made of cast aluminum.
[0136] It should be noted that position of indexer 505 may be
positioned in a bottom of the vacuum extension assembly 500 while
the vacuum pump 508 are mounted on top.
[0137] FIG. 7A schematically illustrates an isometric view of the
movable shelf 503 in accordance with one embodiment of the present
invention. The movable shelf 503 comprises a bottom disk 580 and
two posts 521 extended from the bottom disk 580. The two posts 521
may be positioned on opposite sides of the bottom disk 580. One or
more supporting fingers 522 extend from each of the posts 521. Each
pair of supporting fingers 522 extending from opposite posts 521 is
configured to support a disk near an edge of the disk. In one
embodiment, vertical distance between neighboring support fingers
522 may be arranged so that a robot blade may pick up or drop off
shutter disks from/to each pair of support fingers 522. A bridge
581 may be formed between the posts 521. The bridge 581 may be
configured to couple with an indexer so that the movable shelf 503
may be translated.
[0138] FIG. 7B schematically illustrates a supporting finger 522a
in accordance with one embodiment of the present invention. The
supporting finger 522a is configured to directly support a shutter
disk near the edge.
[0139] FIG. 7C schematically illustrates a supporting finger 522b
in accordance with one embodiment of the present invention. The
supporting finger 522 has two contact posts 585 disposed on a top
surface. The contact posts 585 are configured to contact a shutter
disk and provide point support to reduce particle contamination. In
one embodiment, the contact posts 585, including a substrate
supporting roller, may be made from non-metallic material, such as
silicon nitride (SiN).
[0140] FIG. 8A schematically illustrates an isometric sectional
view of a vacuum extension assembly 600 having a stationary shelf
in accordance with one embodiment of the present invention. The
vacuum extension assembly 600 is configured to connect to a
transfer chamber, such as the transfer chamber 300 of FIG. 4A, and
to provide an interface between the transfer chamber and a load
lock chamber and to provide fluid communication between the
transfer chamber and a vacuum system.
[0141] The vacuum extension assembly 600 comprises a body 601 and a
top plate 602 defining an inner volume 617 (marked in FIG. 8B). A
pressure modification port 607 may be formed on a bottom wall 606
of the body 601. The pressure modification port 607 is configured
to connect a vacuum system 612 to provide a low pressure
environment to the inner volume 617 and volumes in fluid
communication with the inner volume 617. In one embodiment, a
sensor 613 may be disposed on the vacuum system 612 outside the
body 601 and configured to monitor status of the vacuum system 612.
In one embodiment, an opening 614 may be formed on a top wall of
the body 601. The opening 614 may be used to access the inner
volume 617 during installation and/or maintenance of the vacuum
system 612. The top plate 602 is used to seal the opening 614.
[0142] In one embodiment, a chamber opening 603 may be formed on a
sidewall 615 of the vacuum extension assembly 600 which is
configured to be coupled with a transfer chamber, such as the
transfer chamber 300 of FIG. 4A. The chamber opening 603 is
configured to provide fluid communication with the transfer chamber
and to provide passage for robot blades, typically disposed on a
robot in the transfer chamber, to transfer substrates, and/or
shutter disks. Therefore, width of the chamber opening 603 is
generally slightly larger than a diameter of the largest substrate
configured to be processed in a cluster tool. The height of the
chamber opening 603 is selected to allow an appropriate range for
robotic suitable for exchanging substrate and/or shutter disks
between the shelf and the robot blades.
[0143] In one embodiment, a load lock opening 604 may be formed on
a sidewall 605 opposite to the sidewall 615. The load lock opening
604 is configured to provide selective communication between the
inner volume 617 and one or more load lock chambers coupled to the
side wall 605. A slit valve opening 608 is formed through the
bottom wall 606 and is configured to allow a slit valve 609 to be
disposed inside the inner volume 617. The slit valve 609
selectively seals the load lock opening 604.
[0144] In one embodiment, a shutter disk shelf 616 is disposed
within the inner volume 617 of the vacuum extension assembly 600.
The shutter disk shelf 616 is configured to support one or more
shutter disks thereon. The shutter disks may be used by processing
chambers connected to the vacuum extension assembly 600 via the
transfer chamber. The shutter disk shelf 616 is positioned in a
portion of the inner volume 617 so that the passage between the
chamber opening 603 and the load lock opening 604 is maintained to
allow the robot clear access through the vacuum extension assembly
600. In one embodiment, as shown in FIG. 8B, the shutter disk shelf
616 is positioned in a lower portion of the inner volume 617, while
the load lock opening 604 corresponding to an upper portion of the
inner volume 617. The height of the chamber opening 603 is large
enough to accommodate sufficient vertical motion of the robot
blades to allow access to both the load lock opening 603 and the
shutter disk shelf 616.
[0145] In one embodiment, the shutter disk shelf 616 may comprise
two opposing posts 618, each having one or more supporting fingers
619 extending therefrom. The supporting fingers 619 are configured
to support a shutter disk near a periphery. Embodiments of the
supporting fingers 619 may be similar to those shown in FIGS. 7B-C.
In one embodiment, the fingers 619 may include a roller contact for
supporting the shutter disk thereon.
[0146] In one embodiment, a window 611 may be formed through a
sidewall 620 of the body 601 to allow the interior of the vacuum
extension assembly 600 to be viewed. Transparent materials, such as
quartz, may be used to seal the window 611.
[0147] The body 601, top plate 602, and shutter disk shelf 616 may
be made from any suitable material. In one embodiment, the body
601, top plate 602, and shutter disk shelf 616 are made of cast
aluminum.
[0148] FIG. 8B schematically illustrates a sectional side view of a
mainframe having the vacuum extension assembly 600 of FIG. 8A. A
transfer chamber 650 is connected to the vacuum extension assembly
600. An inner volume 654 of the transfer chamber 650 is in fluid
communication with the inner volume 617 of the vacuum extension
assembly 600 via the chamber opening 603 of the vacuum extension
assembly 600 and an opening 655 of the transfer chamber 650. A load
lock chamber 660 is connected to the vacuum extension assembly 600
on a side opposing the transfer chamber 650. The load lock chamber
660 may comprise a substrate support 661 configured to support one
or more substrates. The load lock chamber 660 is selectively
connected to the inner volume 617 via a slit valve door 610. A
central robot 651 is disposed in the inner volume 654 of the
transfer chamber 650. The central robot 651 comprises two robot
blades 652, 653. The central robot 651 is configured with arrange
of motion to allow the robot blades 652,653 to access the load lock
chamber 660 via an upper portion of the inner volume 617 of the
vacuum extension assembly 600, and to the shutter disk shelf 616
disposed in the lower portion of the inner volume 617 of the vacuum
extension assembly 600.
[0149] As shown in FIG. 8B, the robot blades 652, 653 may be
actuated over the shelf 616 on the way to the load lock chamber 660
to pick up substrates 622. The slit valve door 610 is moved to an
open position to allow the robot blades 652, 653 to enter the load
lock chamber 660.
[0150] FIG. 8C schematically illustrates a sectional side view of
the mainframe of FIG. 8B showing the central robot 651 positioning
the robot blades 652, 653 in a lowered position to access the
shutter disks 621 disposed in the shutter disk shelf 616 within the
vacuum extension assembly 600.
[0151] FIG. 9 schematically illustrates a plan view of a cluster
tool 200 in accordance with one embodiment of the present
invention. FIG. 10 schematically illustrates a sectional side view
of the cluster tool 200 of FIG. 9. The cluster tool 200 comprises
multiple processing chambers coupled a mainframe comprising two
transfer chambers.
[0152] The cluster tool 200 comprises a front-end environment 202
in selective communication with a load lock chamber 204. One or
more pods 201 are coupled to the front-end environment 202. The one
or more pods 201 are configured to store substrates. A factory
interface robot 203 is disposed in the front-end environment 202.
The factory interface robot 203 is configured to transfer
substrates between the pods 201 and the load lock chamber 204.
[0153] The load lock chamber 204 provides a vacuum interface
between the front-end environment 202 and a first transfer chamber
assembly 210. An internal region of the first transfer chamber
assembly 210 is typically maintained at a vacuum condition and
provides an intermediate region in which to shuttle substrates from
one chamber to another and/or to a load lock chamber.
[0154] In one embodiment, the first transfer chamber assembly 210
is divided into two parts. In one embodiment of the present
invention, the first transfer chamber assembly 210 comprises a
transfer chamber 208 and a vacuum extension chamber 207. The
transfer chamber 208 and the vacuum extension chamber 207 are
coupled together and in fluid communication with one another. An
inner volume of the first transfer chamber assembly 210 is
typically maintained a low pressure or vacuum condition during
process. The load lock chamber 204 may be connected to the
front-end environment 202 and the vacuum extension chamber 207 via
slit valves 205 and 206 respectively.
[0155] In one embodiment, the transfer chamber 208 may be a
polygonal structure having a plurality of sidewalls, a bottom and a
lid. The plurality sidewalls may have opening formed therethrough
and are configured to connect with processing chambers, vacuum
extension and/or pass through chambers. The transfer chamber 208
shown in FIG. 9 has a square or rectangular shape and is coupled to
processing chambers 211, 213, a pass through chamber 231 and the
vacuum extension chamber 207. The transfer chamber 208 may be in
selective communication with the processing chambers 211, 213, and
the pass through chamber 231 via slit valves 216, 218, and 217
respectively.
[0156] In one embodiment, a central robot 209 may be mounted in the
transfer chamber 208 at a robot port formed on the bottom of the
transfer chamber 208. The central robot 209 is disposed in an
internal volume 220 of the transfer chamber 208 and is configured
to shuttle substrates 214 among the processing chambers 211, 213,
the pass through chamber 231, and the load lock chamber 204. In one
embodiment, the central robot 209 may include two blades for
holding substrates, each blade mounted on an independently
controllable robot arm mounted on the same robot base. In another
embodiment, the central robot 209 may have the capacity for
vertically moving the blades.
[0157] The vacuum extension chamber 207 is configured to provide an
interface to a vacuum system to the first transfer chamber assembly
210. In one embodiment, the vacuum extension chamber 207 comprises
a bottom, a lid and sidewalls. A pressure modification port may be
formed on the bottom of the vacuum extension chamber 207 and is
configured to adapt to a vacuuming pump system. Openings are formed
on the sidewalls so that the vacuum extension chamber 207 is in
fluid communication with the transfer chamber 208, and in selective
communication with the load lock chamber 204.
[0158] In one embodiment, the cluster tool 200 may be configured to
deposit a film on semiconductor substrates using physical vapor
deposition (PVD) process. During conditioning operations, a dummy
substrate or a shutter disk is disposed on the pedestal to protect
the substrate support from any deposition.
[0159] In one embodiment of the present invention, the vacuum
extension chamber 207 comprises a shutter disk shelf 222, shown in
FIG. 10, configured to store one or more shutter disks 223.
Processing chambers directly or indirectly connected to the
transfer chamber 208 may store their shutter disks in the shutter
disk shelf 222 and use the central robot 209 to transfer the
shuttle disks.
[0160] The cluster tool 200 further comprises a second transfer
chamber assembly 230 connected to the first transfer chamber
assembly 210 by the pass through chamber 231. In one embodiment,
the pass through chamber 231, similar to a load lock chamber, is
configured to provide an interface between two processing
environments. In this case, the pass through chamber 231 provides a
vacuum interface between the first transfer chamber assembly 210
and the second transfer chamber assembly 230.
[0161] In one embodiment, the second transfer chamber assembly 230
is divided into two parts to minimize the footprint of the cluster
tool 200. In one embodiment of the present invention, the second
transfer chamber assembly 230 comprises a transfer chamber 233 and
a vacuum extension chamber 232 in fluid communication with one
another. An inner volume of the second transfer chamber assembly
230 is typically maintained a low pressure or vacuum condition
during process. The pass through chamber 231 may be connected to
the transfer chamber 208 and the vacuum extension chamber 232 via
slit valves 217 and 238 respectively so that the pressure within
the transfer chamber 208 may be maintained at different vacuum
levels.
[0162] In one embodiment, the transfer chamber 233 may be a
polygonal structure having a plurality of sidewalls, a bottom and a
lid. The plurality sidewalls may have opening formed therein and
are configured to connect with processing chambers, vacuum
extension and/or pass through chambers. The transfer chamber 233
shown in FIG. 9 has a square or rectangular shape and is coupled to
processing chambers 235, 236, 237, and the vacuum extension chamber
232. The transfer chamber 233 may be in selective communication
with the processing chambers 235, 236, via slit valves 241, 240,
239 respectively.
[0163] A central robot 234 is mounted in the transfer chamber 233
at a robot port formed on the bottom of the transfer chamber 233.
The central robot 234 is disposed in an internal volume 249 of the
transfer chamber 233 and is configured to shuttle substrates 214
among the processing chambers 235, 236, 237, and the pass through
chamber 231. In one embodiment, the central robot 234 may include
two blades for holding substrates, each blade mounted on an
independently controllable robot arm mounted on the same robot
base. In another embodiment, the central robot 234 may have the
capacity for moving the blades vertically.
[0164] In one embodiment, the vacuum extension chamber 232 is
configured to provide an interface between a vacuum system and the
second transfer chamber assembly 230. In one embodiment, the vacuum
extension chamber 232 comprises a bottom, a lid and sidewalls. A
pressure modification port may be formed on the bottom of the
vacuum extension chamber 232 and is configured to adapt to a vacuum
system. Openings are formed through the sidewalls so that the
vacuum extension chamber 232 is in fluid communication with the
transfer chamber 233, and in selective communication with the pass
through chamber 231.
[0165] In one embodiment of the present invention, the vacuum
extension chamber 232 includes a shutter disk shelf 243, shown in
FIG. 10, configured to store one or more shutter disks 223.
Processing chambers directly or indirectly connected to the
transfer chamber 233 may store their shutter disks in the shutter
disk shelf 243 and use the central robot 234 to transfer the
shuttle disks.
[0166] In one embodiment, the cluster tool 200 may be configured to
perform a PVD process. The processing chamber 211 may be a
pre-clean chamber configured to perform a cleaning process prior to
a PVD process. The processing chambers 235, 236, 237 may be PVD
chambers configured to deposition a thin film on a substrate using
physical vapor deposition. The processing chamber 213 may be a
de-gas chamber configured to degas and clean a substrate after a
deposition process in a PVD chamber.
[0167] In one embodiment, the transfer chambers 208, 233 may have a
similar design as shown in FIGS. 4A-4F. The transfer chambers 208,
233 are configured to minimize foot print of the cluster tool 200
and are connected to a vacuum system through separated vacuum
extensions.
[0168] The vacuum extension chambers 207, 232 may have similar
designs of the vacuum extension assemblies 500 and 600 shown in
FIGS. 6A-6C and FIGS. 8A-8C.
[0169] As shown in FIG. 10, the load lock chamber 204 comprises an
upper load lock chamber 204a stacked over a lower load lock chamber
204b. The upper load lock chamber 204a and the lower load lock
chamber 204b may be operated independently so that substrate
transferring between the front-end environment 202 and the first
transfer chamber assembly 210 can be conducted in both directions
simultaneously.
[0170] The load lock chambers 204a, 204b provide a first vacuum
interface between the front-end environment 202 and the first
transfer chamber assembly 210. In one embodiment, two load lock
chambers 204a, 204b are provided to increase throughput by
alternatively communicating with the first transfer chamber
assembly 210 and the front-end environment 202. While one load lock
chamber 204a or 204b communicates with the first transfer chamber
assembly 210, a second load lock chamber 204b or 204a can
communicate with the front-end environment 202.
[0171] In one embodiment, the load lock chambers 204a, 204b are a
batch type load lock chamber that can receive two or more
substrates from the factory interface, retain the substrates while
the chamber is sealed and then evacuated to a low enough vacuum
level to transfer of the substrates to the first transfer chamber
assembly 210.
[0172] The internal volume of the first transfer chamber assembly
210 is defined by an internal volume 219 of the vacuum extension
chamber 207 connected to an internal volume 220 of the transfer
chamber 208. An opening 228 is formed between the transfer chamber
208 and the vacuum extension chamber 207. The opening 228 provides
fluid communication between the vacuum extension chamber 207 and
the transfer chamber 208, and are large enough to allow the central
robot 209 to shuttle substrates to and from the load lock chamber
204.
[0173] A vacuum system 225 is coupled the vacuum extension chamber
207 and configured to provide a low pressure environment to both
the internal volume 219 and the internal volume 220. A robotic
mechanism 226 is coupled to the transfer chamber 208. The transfer
chamber 208 and the vacuum extension chamber 207 are constructed to
minimize the foot print of the cluster tool 200.
[0174] In the one hand, the duel load lock chamber improves system
throughput by allowing simultaneous two way substrate
transportation. In the other hand, stacked load lock chambers
require more vertical access space. To allow the robot, such as the
central robot 209, to access the stacked load lock chambers 204a,
204b and the shutter disk shelf 222, the shutter disk shelf 222 in
the vacuum extension chamber 207 is made vertically movable. An
indexer 224 is coupled to the shutter disk shelf 222 and is
configured to vertically move the shutter disk shelf 222 into a
position that allows unobstructed movement of the robot through the
vacuum extension chamber 207. The shutter disk shelf 222 may be
lowered to the lower portion of the internal volume 219 by the
indexer 224 so that the central robot 209 interface with the
shutter disk shelf 222 to pick up a shutter disk or drop a shutter
disk to the shutter disk shelf 222.
[0175] As shown in FIG. 10, the pass through chamber 231 provides
an interface between the first transfer chamber assembly 210 and
the second transfer chamber assembly 230 allowing the first and
second transfer chamber assemblies 210, 230 to have different
levels of vacuum. In one embodiment, the pass through chamber 231
may comprise a temperature controlled substrate supports 246, 247
to prepare substrates for a subsequent processing step. In one
embodiment, the substrate support 246 may be heated while the
substrate support 247 may be cooled.
[0176] The internal volume of the second transfer chamber assembly
230 is defined by an internal volume 248 of the vacuum extension
chamber 232 connected to an internal volume 249 of the transfer
chamber 233. An opening 244 is formed between the transfer chamber
233 and the vacuum extension chamber 232. The opening 244 provides
fluid communication between the vacuum extension chamber 232 and
the transfer chamber 233, and are large enough to allow the central
robot 234 to shuttle substrates to and from the pass through
chamber 231.
[0177] A vacuum system 242 is coupled the vacuum extension and
configured to provide a low pressure environment to both the
internal volume 248 and the internal volume 249. A robotic
mechanism 245 is coupled to the transfer chamber 233. The transfer
chamber 233 and the vacuum extension chamber 232 are constructed to
minimize the foot print of the cluster tool 200. In embodiment
wherein the transfer chambers remain at the same vacuum level, only
one of the vacuum systems may optionally be utilized.
[0178] As shown in FIG. 10, the shutter disk shelf 243 of the
vacuum extension chamber 232 is stationary. The shutter disk shelf
243 is positioned on a lower portion of the internal volume 248 of
the vacuum extension chamber 232 while the central robot 234 is
configured to transfer substrates to and from the pass through
chamber 231 through an upper portion of the internal volume
248.
[0179] It should be noted that any processing chambers connected to
a transfer chamber may be replaced by a pass through and/or
extension chamber so that another transfer chamber may be added to
a cluster tool.
[0180] As shown in FIG. 10, the cluster tool 200 is supported by
supporting legs 227. The supporting legs 227 provide vertical and
lateral support to the mainframe and chambers of the cluster tool
200. Each of the supporting legs 227 may be vertically adjustable
on site. The supporting legs 227 are coupled to sidewalls of the
transfer chambers 208, 233, the vacuum extension chambers 207, 232,
and/or the load lock chamber 204 and the pass through chamber 231
for lateral support to the cluster tool 200.
[0181] In one embodiment, four pairs supporting legs 227 may be
used to support the cluster tool 200. One pair of supporting legs
227 are coupled to a backend (away from the front-end environment
202) of each of the transfer chambers 208, 233. Notches may be
formed on the backend of the transfer chamber 208, 233 for
providing lateral support to the supporting legs 227. A pair of
supporting legs 227 is coupled to near a joint region of the load
lock chamber 204 and the vacuum extension chamber 207. Another pair
of supporting legs 227 is coupled to near a joint region of the
pass through chamber 231 and the vacuum extension chamber 232.
[0182] Independent supporting legs of the present invention not
only greatly reduces the cost compared a supporting frame, but also
provide great flexibility to the system. If desired, the cluster
tool of the present invention may also be transported with the
independent supporting legs assembled.
[0183] FIG. 11A schematically illustrates an isometric view of the
cluster tool 200 of FIG. 9 with transporting braces 260 configured
to engage the supporting legs 227 with transporting tools, such as
a fork lift, for transporting the cluster tool 200 in a whole or
partially assembled. One or more transporting braces 260 may be
coupled to a cluster tool 200 for transporting the cluster tool 200
fully or partially assembled. In one embodiment, each of the
transporting braces 206 is coupled to a pair of the independent
supporting legs 127.
[0184] FIG. 11B schematically illustrates the transporting brace
260 in accordance with one embodiment of the present invention. The
transporting brace 260 has a elongated body 261 formed from a
ridged material, such as steel, and aluminum. The body 261 may be a
tube, for reduced weight, with a rectangular or squared shape. Two
lifting openings 262 may be formed near two ends of the body 261.
The lifting opening 262 is configured to provide interface to a
lifting tool, such as a fork lift. Distance between the two lifting
openings 262 on the transporting brace 260 may be configured to
adapt a lifting tool, for example, to adapt a distance between the
forks of a fork lift. In one embodiment, an independent supporting
leg 227 may be bolted to the transporting brace 260 through one or
more coupling holes 263 formed on the body 261. The coupling holes
263 may be elongated to provide tolerance on distance variations
between a pair of independent supporting legs 227.
[0185] Referring back to FIG. 11A, one or more transporting braces
260 may be coupled to the independent supporting legs 227 of the
cluster tool 200 at substantially similar elevation with the
lifting openings 262 substantially aligned. A lifting tool may
thread thought the lifting openings 262 of two or more transporting
braces 260 to lift and transport the cluster tool 200.
[0186] The transporting braces of the present invention provide an
interface and robust structure to supporting assembly, such as the
independent supporting legs, during transportation. The transport
braces may be easily coupled to and removed from the cluster tool
for transportation and processing. The transport braces allow the
cluster tool to have a simple, non obstructive supporting assembly
using independent supporting legs, as well as a reinforced
structure for transportation if needed.
[0187] Even though, a PVD process is describe in accordance with
the present application, the cluster tools of the present invention
may be used for any suitable processes.
[0188] While the foregoing is directed to embodiments of the
present invention, other and further embodiments of the invention
may be devised without departing from the basic scope thereof, and
the scope thereof is determined by the claims that follow.
* * * * *