U.S. patent application number 14/487341 was filed with the patent office on 2015-03-19 for fluid distribution network for large stator motor.
The applicant listed for this patent is Nikon Corporation. Invention is credited to Yoichi Arai, Derek Coon, Michel Pharand, Joe Rossi, Andrew Tomko.
Application Number | 20150075751 14/487341 |
Document ID | / |
Family ID | 52666896 |
Filed Date | 2015-03-19 |
United States Patent
Application |
20150075751 |
Kind Code |
A1 |
Pharand; Michel ; et
al. |
March 19, 2015 |
FLUID DISTRIBUTION NETWORK FOR LARGE STATOR MOTOR
Abstract
A reaction assembly (20) for supporting a mover (18) includes a
countermass assembly (26) and a fluid distribution network (28).
The fluid distribution network (28) allows for circulating a fluid
(30) to provide cooling for the portion of the mover (18). The
fluid distribution network (28) is positioned substantially
adjacent to the countermass assembly (26), and the fluid
distribution network (28) being substantially thermally decoupled
from the structure of the countermass assembly (26) to inhibit
thermal deformation of the countermass assembly (26).
Inventors: |
Pharand; Michel; (Los Gatos,
CA) ; Tomko; Andrew; (San Jose, CA) ; Coon;
Derek; (Redwood City, CA) ; Arai; Yoichi;
(Saitama-ken, JP) ; Rossi; Joe; (San Jose,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Nikon Corporation |
Tokyo |
|
JP |
|
|
Family ID: |
52666896 |
Appl. No.: |
14/487341 |
Filed: |
September 16, 2014 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
61878517 |
Sep 16, 2013 |
|
|
|
Current U.S.
Class: |
165/104.19 |
Current CPC
Class: |
F28D 2021/0019 20130101;
H01L 21/67109 20130101; G03F 7/70875 20130101; F28F 9/0275
20130101; G03F 7/70766 20130101; G03F 7/70758 20130101 |
Class at
Publication: |
165/104.19 |
International
Class: |
F28D 1/00 20060101
F28D001/00 |
Claims
1. A reaction assembly for supporting a mover relative to a base,
the reaction assembly comprising: a countermass assembly that
supports a portion of the mover; and a fluid distribution network
that provides cooling for the portion of the mover, the fluid
distribution network being positioned substantially adjacent to the
countermass assembly, the fluid distribution network being
substantially decoupled from the structure of the countermass
assembly to inhibit thermal deformation of the countermass
assembly.
2. The reaction assembly of claim 1 wherein the countermass
assembly includes a distribution plate assembly, and wherein a
majority of the fluid distribution network is positioned below and
substantially adjacent to a bottom surface of the distribution
plate assembly.
3. The reaction assembly of claim 2 wherein the distribution plate
assembly includes a plurality of unit apertures, each coil unit is
positioned near one of the unit apertures.
4. The reaction assembly of claim 3 wherein the fluid distribution
network includes a Coil Temperature Control network for cooling
individual coils within the coil units, and a Surface Temperature
Control network for cooling a surface of the coil units.
5. The reaction assembly of claim 3 wherein the distribution plate
assembly includes a plurality of passageways that extend between
the fluid distribution network and the coil units, the passageways
providing the only source of circulation fluid within the
distribution plate assembly.
6. A stage assembly including a stage base, a stage that retains a
device, a stage mover that moves the stage relative to the stage
base, and the reaction assembly of claim 1 that supports a portion
of the stage mover.
7. The stage assembly of claim 6 wherein the portion of the stage
mover includes a conductor array having a plurality of coil units,
and wherein the fluid distribution network provides cooling for the
coil units.
8. A reaction assembly for supporting a mover relative to a base,
the reaction assembly comprising: a countermass assembly that
supports a portion of the mover, the countermass assembly including
a distribution plate assembly; and a fluid distribution network
that cools the portion of the mover, a majority of the fluid
distribution network being positioned below and substantially
adjacent to a bottom surface of the distribution plate
assembly.
9. The reaction assembly of claim 8 wherein the fluid distribution
network is substantially decoupled from the structure of the
countermass assembly to inhibit thermal deformation of the
countermass assembly.
10. The reaction assembly of claim 8 wherein the distribution plate
assembly includes a plurality of unit apertures, one of a plurality
of coil units is positioned near each unit aperture.
11. The reaction assembly of claim 8 wherein the fluid distribution
network is adapted to supply circulation fluid to the coil units to
cool the coil units.
12. The reaction assembly of claim 8 wherein the fluid distribution
network includes a Coil Temperature Control network for cooling
individual coils within the coil units, and a Surface Temperature
Control network for cooling a surface of the coil units.
13. The reaction assembly of claim 8 wherein the distribution plate
assembly includes a plurality of passageways that extend between
the fluid distribution network and the coil units, the passageways
providing the only source of circulation fluid within the
distribution plate assembly.
14. A stage assembly including a stage base, a stage that retains a
device, a stage mover that moves the stage relative to the stage
base, and the reaction assembly of claim 8 that supports a portion
of the stage mover.
15. The stage assembly of claim 14 wherein the portion of the stage
mover includes a conductor array having a plurality of coil units,
and wherein the fluid distribution network provides cooling for the
coil units.
16. A reaction assembly for supporting a mover relative to a base,
the reaction assembly comprising: a distribution plate assembly
that supports a portion of the mover, the distribution plate
assembly including a plurality of plate passageways; and a fluid
distribution network including a fluid source that provides a
circulation fluid that cools the portion of the mover, wherein the
plate passageways extend between the fluid distribution network and
the portion of the mover, the plate passageways providing the only
source of the circulation fluid within the distribution plate
assembly.
17. The reaction assembly of claim 16 wherein a majority of the
fluid distribution network is positioned below and substantially
adjacent to a bottom surface of the distribution plate
assembly.
18. The reaction assembly of claim 16 wherein the fluid
distribution network is substantially decoupled from the structure
of the distribution plate assembly to inhibit thermal deformation
of the distribution plate assembly.
19. The reaction assembly of claim 16 wherein the distribution
plate assembly includes a plurality of unit apertures, one of a
plurality of coil units is positioned near each unit aperture.
20. The reaction assembly of claim 16 wherein the fluid
distribution network includes a Coil Temperature Control network
for cooling individual coils within the coil units, and a Surface
Temperature Control network for cooling a surface of the coil
units.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority on U.S. Provisional
Application Ser. No. 61/878,517 filed on Sep. 16, 2013 and entitled
"FLUID DISTRIBUTION NETWORK FOR LARGE STATOR MOTOR". As far as is
permitted, the contents of U.S. Provisional Application Ser. No.
61/878,517 are incorporated herein by reference.
BACKGROUND
[0002] Exposure apparatuses are commonly used to transfer images
from a reticle onto a semiconductor wafer during semiconductor
processing. A typical exposure apparatus includes an illumination
source, a reticle stage assembly that retains a reticle, a lens
assembly and a wafer stage assembly that retains a semiconductor
wafer. Typically, the wafer stage assembly includes a wafer stage
base, a wafer stage that retains the wafer, and a wafer stage mover
assembly that precisely positions the wafer stage and the wafer.
Somewhat similarly, the reticle stage assembly includes a reticle
stage base, a reticle stage that retains the reticle, and a reticle
stage mover assembly that precisely positions the reticle stage and
the reticle. The size of the images and the features within the
images transferred onto the wafer from the reticle are extremely
small. Accordingly, the precise relative positioning of the wafer
and the reticle is critical to the manufacturing of high density,
semiconductor wafers.
[0003] Unfortunately, the stage mover assemblies generate heat that
can influence the other components of the exposure apparatus.
Conventionally, the stage mover assemblies are cooled by forcing a
coolant around the movers of the stage mover assembly. However,
existing coolant systems do not adequately or efficiently cool the
movers of the stage mover assembly. Additionally, existing coolant
systems do not adequately or efficiently inhibit pressure loss,
i.e. pressure drops, or thermal deformation within the stage mover
assembly. This can reduce the accuracy of positioning of the wafer
relative to the reticle, and degrade the accuracy of the exposure
apparatus.
SUMMARY
[0004] The present invention is directed to a reaction assembly for
supporting a mover relative to a base. In certain embodiments, the
reaction assembly comprises a countermass assembly and a fluid
distribution network. The countermass supports a portion of the
mover. Additionally, the fluid distribution network allows for
circulating a fluid to provide cooling for the portion of the
mover. The fluid distribution network is positioned substantially
adjacent to the countermass assembly, the fluid distribution
network is substantially decoupled from the structure of the
countermass assembly to inhibit thermal deformation of the
countermass. Further, the fluid distribution network can be
designed to inhibit pressure drops within the fluid distribution
network.
[0005] In some embodiments, the countermass assembly includes a
distribution plate assembly. In such embodiments, a majority of the
fluid distribution network is positioned below and substantially
adjacent to a bottom surface of the distribution plate assembly.
Additionally, the distribution plate assembly can include a
plurality of unit apertures, each unit aperture being adapted to
receive one of a plurality of coil units. In one embodiment, the
fluid distribution network is adapted to supply circulation fluid
to the coil units to cool the coil units. Moreover, in one
embodiment, the fluid distribution network includes a Coil
Temperature Control network for cooling individual coils within the
coil units, and a Surface Temperature Control network for cooling a
surface of the coil units.
[0006] The present invention is further directed toward a stage
assembly including a stage base, a stage that retains a device, a
stage mover that moves the stage relative to the stage base, and
the reaction assembly as described above that supports a portion of
the stage mover. In one embodiment, the stage mover includes a
conductor array having a plurality of coil units, and the fluid
distribution network provides cooling for the coil units.
Additionally, the present invention is further directed toward an
exposure apparatus including the stage assembly as described above
that retains the device, and an illumination source that guides a
beam of light energy toward the device; and a process for
manufacturing a wafer that includes the steps of providing a
substrate, and transferring a mask pattern to the substrate with
the exposure apparatus.
[0007] In another application, the present invention is also
directed toward a reaction assembly for supporting a mover relative
to a base, the reaction assembly comprising (i) a countermass
assembly that supports a portion of the mover, the countermass
assembly including a distribution plate assembly; and (ii) a fluid
distribution network that cools the portion of the mover, a
majority of the fluid distribution network being positioned below
and substantially adjacent to a bottom surface of the distribution
plate assembly.
[0008] In still another application, the present invention is
further directed toward a reaction assembly for supporting a mover
relative to a base, the reaction assembly comprising (i) a
distribution plate assembly that supports a portion of the mover
including a plurality of passageways; and (ii) a fluid distribution
network including a fluid source that provides a circulation fluid
that cools the portion of the mover, wherein the passageways extend
between the fluid distribution network and the portion of the
mover, the passageways providing the only source of the circulation
fluid within the distribution plate assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The novel features of this invention, as well as the
invention itself, both as to its structure and its operation, will
be best understood from the accompanying drawings, taken in
conjunction with the accompanying description, in which similar
reference characters refer to similar parts, and in which:
[0010] FIG. 1 is a perspective view of an embodiment of a stage
assembly having features of the present invention;
[0011] FIG. 2A is a simplified view of a coil unit, a portion of a
distribution plate assembly, and a portion of a fluid distribution
network having features of the present invention;
[0012] FIG. 2B is a perspective view of the coil unit of FIG.
2A;
[0013] FIG. 3A is a top plan view of the distribution plate
assembly of FIG. 2A;
[0014] FIG. 3B is a top plan view of a portion of the distribution
plate assembly of FIG. 3A;
[0015] FIG. 3C is a bottom plan view of the portion of the
distribution plate assembly of FIG. 3B;
[0016] FIG. 3D is a cut-away view taken on line 3D-3D in FIG.
3C;
[0017] FIG. 4A is a simplified bottom view of the distribution
plate assembly and a portion of the fluid distribution network;
[0018] FIG. 4B is a bottom view of the portion of the fluid
distribution network of FIG. 4A;
[0019] FIG. 4C is a top view of the portion of the fluid
distribution network of FIG. 4A;
[0020] FIG. 4D is a cutaway perspective view taken from FIG.
4C;
[0021] FIG. 5A is a bottom perspective view of a portion of the
fluid distribution network;
[0022] FIG. 5B is a bottom view of the portion of the fluid
distribution network of FIG. 5A;
[0023] FIG. 6A is a bottom perspective view of a distribution
conduit array;
[0024] FIG. 6B is a top view of the portion of the distribution
conduit array of FIG. 6A;
[0025] FIG. 6C is an inverted side view of the distribution conduit
array;
[0026] FIG. 7A is a bottom perspective view of a portion of the
fluid distribution network;
[0027] FIG. 7B is a bottom view of the portion of the fluid
distribution network of FIG. 7A;
[0028] FIG. 8A is a perspective view of a connector that can be
used to connect a portion of the fluid distribution network to the
distribution plate;
[0029] FIG. 8B is a perspective view of a portion of the
distribution plate and the connector of FIG. 8A;
[0030] FIG. 9 is a schematic illustration of an exposure apparatus
having features of the present invention;
[0031] FIG. 10A is a flow chart that outlines a process for
manufacturing a device in accordance with the present invention;
and
[0032] FIG. 10B is a flow chart that outlines device processing in
more detail.
DESCRIPTION
[0033] FIG. 1 is a perspective view of an embodiment of a stage
assembly 10 having features of the present invention. As
illustrated in this embodiment, the stage assembly 10 includes a
stage base 12, a stage 14 that retains a device 16, a stage mover
18, a countermass reaction assembly 20 (also referred to herein
simply as a "reaction assembly"), and a control system 22. The
design of each of these components can be varied to suit the design
requirements of the stage assembly 10. In certain applications, the
stage assembly 10 can be positioned above a mounting base 24
(illustrated in FIG. 9). The stage mover 18 precisely moves the
stage 14 and the device 16 relative to the stage base 12 and the
reaction assembly 20.
[0034] As an overview, in certain embodiments, the reaction
assembly 20 includes (i) a countermass assembly 26 that supports a
portion of the stage mover 18, and (ii) a fluid distribution
network 28 that effectively and efficiently controls the flow of
fluid in and around the stage mover 18 and the reaction assembly
20. More particularly, the fluid distribution network 28 is
designed to inhibit undesired pressure drops while distributing a
large volume of fluid over a relatively large area of the stage
assembly 10. Additionally, the fluid distribution network 28 is
designed to be substantially decoupled from the physical structure
of the countermass assembly 26 to more effectively manage the
thermal strain that may otherwise exist within the stage assembly
10, e.g., within the stage mover 18.
[0035] Further, the fluid distribution network 28 directs a
circulation fluid 30 (illustrated with small circles) to a portion
of the stage mover 18 and the countermass assembly 26 to control
the temperature around the stage mover 18 and reaction assembly 20.
In one embodiment, the fluid distribution network 28 includes (i) a
body fluid source 32 that circulates the circulation fluid 30 to
primarily remove the heat from the stage mover 18 and the
countermass assembly 26; and (ii) a surface fluid source 32 that
circulates the circulation fluid 30 to control the temperature of
the upper surface of a portion of the stage mover 18 to inhibit the
transfer of heat from the stage mover 18 to the surrounding
environment. It should be noted that either of the fluid sources
32, 34 can be referred to as a first fluid source or a second fluid
source.
[0036] In FIG. 1, each fluid source 32, 34 is illustrated as
including a single source outlet 35A, and a single source inlet
35B. Alternatively, each fluid source 32, 34 can include multiple
source outlets and source inlets. Further, the fluid sources 32, 34
can be combined into a single system or more than two systems.
Moreover, each fluid source 32, 34 can include one or more pumps,
reservoirs, flow regulators, pressure regulators, valves,
temperature controllers, chillers, and/or heaters to precisely
control the temperature and flow rate of the fluid 30.
[0037] In certain embodiments, the body fluid source 32
independently controls the flow rate of the circulation fluid 30 to
different areas of the stage mover 18 so that more circulation
fluid 30 can be directed to the areas of the stage mover 18 that
are used the most and that are generating the most heat, and less
is directed to the areas that are used the least and that are
generating less heat. Moreover, in certain embodiments, the
circulation fluid 30 can be provided at a high flow rate to a large
area of the stage mover 18 while inhibiting thermal deformation and
providing a manufacturable design by using a modular design to
create a fluid flow network wherein the circulation fluid 30 flows
primarily in non-structural parts, and wherein the fluid
distribution network 28 is configured in a hierarchical (tree)
manner. This will allow for the efficient cooling of the stage
mover 18. Still further, the fluid distribution network 28 can
efficiently and accurately maintain a substantially uniform
temperature of the stage mover 18 and the reaction assembly 20,
which, in turn, allows for more accurate positioning of the stage
14 and the device 16.
[0038] The stage assembly 10 is particularly useful for precisely
positioning the device 16 during a manufacturing and/or an
inspection process. The type of device 16 positioned and moved by
the stage assembly 10 can be varied. For example, the device 16 can
be a semiconductor wafer, and the stage assembly 10 can be used as
part of an exposure apparatus for precisely positioning the
semiconductor wafer during manufacturing of the semiconductor
wafer. Alternatively, for example, the stage assembly 10 can be
used to move other types of devices during manufacturing and/or
inspection, to move a device under an electron microscope (not
shown), or to move a device during a precision measurement
operation (not shown).
[0039] Some of the Figures provided herein include an orientation
system that designates an X axis, a Y axis, and a Z axis. It should
be understood that the orientation system is merely for reference
and can be varied. For example, the X axis can be switched with the
Y axis and/or the stage assembly 10 can be rotated. Moreover, these
axes can alternatively be referred to as a first, second, or third
axis.
[0040] The stage base 12 supports a portion of the stage assembly
10 above the mounting base 24. In the embodiment illustrated
herein, the stage base 12 is rigid and generally rectangular
shaped.
[0041] As noted above, the stage 14 retains the device 16. Further,
the stage 14 is precisely moved by the stage mover 18 to precisely
position the device 16. In the embodiments illustrated herein, the
stage 14 is generally rectangular shaped and includes a device
holder (not shown) for retaining the device 16. The device holder
can be a vacuum chuck, an electrostatic chuck, or some other type
of clamp.
[0042] The stage 14 can be maintained spaced apart from (e.g.,
above) the reaction assembly 20 with the stage mover 18 if the
stage mover 18 is a six degree of freedom mover that moves the
stage 14 relative to the reaction assembly 20 with six degrees of
freedom. In this embodiment, the stage mover 18 functions as a
magnetic type bearing that levitates the stage 14. Alternatively,
for example, the stage 14 can be supported relative to the reaction
assembly 20 with a stage bearing (not shown), e.g., a vacuum
preload type fluid bearing. For example, the bottom of the stage 14
can include a plurality of spaced apart fluid outlets (not shown),
and a plurality of spaced apart fluid inlets (not shown). In this
example, pressurized fluid (not shown) can be released from the
fluid outlets towards the reaction assembly 20 and a vacuum can be
pulled in the fluid inlets to create a vacuum preload type, fluid
bearing between the stage 14 and the reaction assembly 20. In this
embodiment, the stage bearing allows for motion of the stage 14
relative to the reaction assembly 20 along the X axis, along the Y
axis and about the Z axis.
[0043] The stage mover 18 controls and adjusts the position of the
stage 14 and the device 16 relative to the reaction assembly 20 and
the stage base 12. For example, the stage mover 18 can be a planar
motor that moves and positions the stage 14 along the X axis, along
the Y axis and about the Z axis ("three degrees of freedom" or "the
planar degrees of freedom"). Further, in certain embodiments, the
stage mover 18 can also be controlled to move the stage 14 along Z
axis and about the X and Y axes. With this design, the stage mover
18 is a six degree of freedom mover. Alternatively, in certain
embodiments, the stage mover 18 can be another type of actuator
designed to move the stage 14 with less than six degrees of
freedom.
[0044] In the embodiments illustrated herein, the stage mover 16
includes a conductor array 36, and an adjacent magnet array 38 that
interacts with the conductor array 36. In FIG. 1, the conductor
array 36 is coupled to the reaction assembly 20, and the magnet
array 38 is secured to the stage 14. Alternatively, in one
embodiment, the conductor array 36 can be coupled to the stage 14
and the magnet array 38 can be coupled to the reaction assembly 20.
As provided herein, the array secured to the stage 14 can be
referred to as the moving component of the stage mover 18, and the
array secured to the reaction assembly 20 can be referred to as the
reaction component (or stator) of the stage mover 18.
[0045] In one embodiment, the conductor array 36 can include a
plurality of coil units 40, and each coil unit 40 can include a
single coil (not shown) that is oriented to provide movement along
the X-axis or the Y-axis. Alternatively, each coil unit 40 can
include more than one coil (e.g. three coils). Still alternatively,
each coil unit 40 can include one of more coils that is oriented to
provide movement along the X-axis, and one or more coils that is
oriented to provide movement along the Y-axis. Each coil can be
made of a metal such as copper or any substance or material
responsive to electrical current and capable of creating a magnetic
field such as superconductors.
[0046] The design and number of coil units 40 in the conductor
array 36 can vary according to the performance and movement
requirements of the stage mover 18. For example, in the embodiment
illustrated in FIG. 1, the conductor array 36 includes two hundred
sixty-four coil units 40 that are arranged in a generally
rectangular twelve by twenty-two array. Additionally, the
individual coil units 40 can be arranged such that a plurality of
Y-coil units and a plurality of X-coil units are positioned and/or
arranged in an alternating pattern in both the X-direction and the
Y-direction. Thus, in such embodiment, the conductor array 36
includes one hundred thirty-two X-coil units 40 and one hundred
thirty-two Y-coil units 40 that are arranged in an alternating
pattern in both the X-direction and the Y-direction.
[0047] Further, the magnet array 38 can include one or more magnets
(not illustrated) that interact with the plurality of coil units
40. The design of the magnet array 38 and the number of magnets in
the magnet array 38 can be varied to suit the design requirements
of the stage mover 18. In some embodiments, each magnet can be made
of a permanent magnetic material such as NdFeB.
[0048] Electrical current (not shown) is supplied to the coil units
40 by the control system 22. The electrical current in the coil
units 40 interacts with the magnetic field(s) of the one or more
magnets in the magnet array 38. This causes a force (Lorentz type
force) between the coil units 40 and the magnets that can be used
to move the stage 14 relative to the stage base 12.
[0049] Unfortunately, the electrical current supplied to the coil
units 40 also generates heat, due to resistance in the coil units
40. The heat from the coil units 40 is subsequently transferred to
the reaction assembly 20. This can cause expansion and distortion
of the reaction assembly 20. Further, the heat from the coil units
40 can be transferred to the surrounding environment, including the
air surrounding the coil units 40. This can adversely influence a
measurement system (not shown in FIG. 1) that measures the position
of the stage 14 and the device 16. For example, certain measurement
systems utilize one or more interferometers. The heat from the
conductor array 36 changes the index of refraction of the
surrounding air. This reduces the accuracy of the measurement
system and degrades machine positioning accuracy. Moreover, the
resistance of the coil units 40 increases as temperature increases.
This exacerbates the heating problem and reduces the performance
and life of the stage mover 16.
[0050] In certain embodiments, to reduce the influence of the heat
from the coil units 40, the present invention actively cools the
reaction assembly 20 and the coil units 40 using the fluid
distribution network 28.
[0051] The reaction assembly 20 counteracts, reduces and/or
minimizes the influence of the reaction forces from the stage mover
18 on the position of the stage base 12 relative to the mounting
base 1324. This minimizes the distortion of the stage base 12 and
improves the positioning performance of the stage assembly 10.
Further, for an exposure apparatus 1334, this allows for more
accurate positioning of the semiconductor wafer.
[0052] As provided above, in the embodiment illustrated in FIG. 1,
the conductor array 36 of the stage mover 18 is coupled to the
reaction assembly 20. With this design, the reaction forces
generated by the stage mover 18 are transferred to the reaction
assembly 20. As a result thereof, when the stage mover 18 applies a
force to move the stage 14, an equal and opposite reaction force is
applied to the reaction assembly 20.
[0053] In FIG. 1, the reaction assembly 20 includes the generally
rectangular shaped countermass assembly 26, which can be maintained
above the stage base 12 with a reaction bearing (not shown), e.g. a
vacuum preload type fluid bearing. For example, the bottom of the
countermass 26 of the reaction assembly 20 can include a plurality
of spaced apart fluid outlets (not shown), and a plurality of
spaced apart fluid inlets (not shown). Pressurized fluid (not
shown) can be released from the fluid outlets towards the stage
base 12 and a vacuum can be pulled in the fluid inlets to create a
vacuum preload type, fluid bearing between the stage base 12 and
the countermass 26. In this embodiment, the reaction bearing allows
for motion of the reaction assembly 20 relative to the stage base
12 along the X axis, along the Y axis and about the Z axis.
Alternatively, for example, the reaction bearing can be a magnetic
type bearing that provides for relative motion along the X, Y, and
Z axes and about the X, Y, and Z axes, or a roller bearing type
assembly.
[0054] With this design, through the principle of conservation of
momentum, (i) movement of the stage 14 with the stage mover 16
along the X axis in a first X direction along the X axis, generates
an equal but opposite X reaction force that moves the reaction
assembly 20 in a second X direction that is opposite the first X
direction along the X axis; (ii) movement of the stage 14 with the
stage mover 16 along the Y axis in a first Y direction, generates
an equal but opposite Y reaction force that moves the reaction
assembly 20 in a second Y direction that is opposite the first Y
direction along the Y axis; and (iii) movement of the stage 14 with
the stage mover 16 about the Z axis in a first theta Z direction,
generates an equal but opposite theta Z reaction force (torque)
that moves the reaction assembly 20 in a second theta Z direction
that is opposite the first theta Z direction about the Z axis.
[0055] The design of the reaction assembly 20 can be varied to suit
the design requirements of the stage assembly 10. In certain
embodiments, the ratio of the mass of the reaction assembly 20 to
the mass of the stage 14 is relatively high. This will minimize the
movement of the reaction assembly 20 and minimize the required
travel of the reaction assembly 20. A suitable ratio of the mass of
the reaction assembly 20 to the mass of the stage 14 is between
approximately 10:1 and 30:1. A larger mass ratio is better, but is
limited by the physical size of the reaction assembly 20.
[0056] In one embodiment, the reaction assembly 20 is made from a
non-electrically conductive, non-magnetic material, such as low
electrical conductivity stainless steel or titanium, or
non-electrically conductive plastic or ceramic.
[0057] Additionally, one or more movers (not shown) can be used to
adjust the position of the reaction assembly 20 relative to the
stage base 12 and/or to counteract moments imparted onto the
reaction assembly 20. For example, the movers can include one or
more rotary motors, voice coil motors, linear motors,
electromagnetic actuators, or other type of actuators.
[0058] The fluid distribution network 28 reduces the influence of
the heat from the coil units 40 of the conductor array 36 from
adversely influencing the other components of the stage assembly 10
and the assemblies nearby the stage assembly 10. In one embodiment,
the fluid distribution network 28 efficiently reduces the amount of
heat transferred from the coil units 40 to the surrounding
environment.
[0059] The design of the fluid distribution network 28 can vary. In
certain embodiments, the fluid distribution network 28 uses a
multi-layer design approach, with each layer being designed to
minimize or inhibit pressure drops and the impact of thermal
deformation on the countermass 26. As described herein, the fluid
management provided via the fluid distribution network 28 and the
structural support of the countermass 26 and the other supporting
members of the stage assembly 10 are mostly decoupled from one
another.
[0060] As described in greater detail herein below, in some
embodiments, the fluid distribution network 28 can include and/or
incorporate two distinct fluid networks. In particular, the fluid
distribution network 28 can include the body fluid source 32
(sometimes referred to as the "first distribution network" or the
"Coil Temperature Control (CTC) network") that is used for cooling
the coils within the coil units 40, which removes the bulk of the
heat from the conductor array 36. Additionally, the fluid
distribution network 28 can further include the surface fluid
source 34 (sometimes referred to as the "second distribution
network" or the "Surface Temperature Control (STC) network") that
is used for cooling and/or maintaining the temperature of the upper
surface (typically the surface that faces the magnet array) of the
individual coil units 40. The second distribution network 34 is
used to shield the area above the coil units 40 from heat generated
by the coil units 40. For mechanical considerations, because of the
delicate nature of the coil units 40, the internal fluid pressure
is limited. In order to achieve the often desired high flow rates
to the large conductor array 36, limiting the pressure drop
downstream to the coil units 40 is critical.
[0061] Further, the fluid distribution network 28 must be able to
minimize and/or inhibit heat transfer to the countermass assembly
26. With the present design, the circulation fluid 30 can be
provided at a high rate while minimizing and/or inhibiting thermal
deformation by having the circulation fluid 30 flow primarily in
non-structural parts. More specifically, with the large mass of the
stage 14 and its high acceleration during certain applications, a
significant amount of heat needs to be removed from the coils units
40 and the countermass assembly 26. Even with a high flow rate of
the circulation fluid 30 there can be a substantial rise in fluid
temperature. The difference between the hot and cold fluid, if not
managed properly, can lead to thermal deformation of the
countermass assembly 26, which in turn could impact the fly height
of the stage 14, the accuracy of sensors, and the overall precision
of the stage assembly 10. Moreover, with the design illustrated and
described herein, the fluid distribution network 28 can be used to
inhibit the transfer of heat from the coil units 40 of the
conductor array 36 to the surrounding environment.
[0062] The type of circulation fluid 30 that is utilized within the
fluid distribution network 28 can be varied. For example, in
certain embodiments, the circulation fluid 30 can be water or
another appropriate cooling fluid. Additionally, the circulation
fluid 30 can also be referred to as a coolant.
[0063] As provided herein, during use of the stage assembly 10, the
device 16 is moved by the stage mover 18. Typically, during use of
the stage assembly 10, more current is directed to certain of the
coil units 40 as compared to other coil units 40. For example,
certain coil units 40 are primarily used to move the device 16,
e.g., a wafer, during the scanning portion of an exposure. These
coil units 40 will generate more heat and, thus, will require more
cooling. As provided herein, the fluid distribution network 28 is
uniquely designed to provide more cooling to certain coil units 40
and/or groups of coil units 40. The design of the fluid
distribution network 28 is discussed in more detail below.
[0064] The control system 22 is electrically connected to, and
directs and controls electrical current to the coil units 40 of the
stage mover 18 to precisely position the device 16. Further, the
control system 22 is electrically connected to and controls the
fluid distribution network 28 to accurately control the temperature
of the reaction assembly 20 and the conductor units 40. The control
system 22 can include one or more processors and/or circuits.
[0065] The design of the countermass assembly 26 can be varied
pursuant to the teachings provided herein to suit the specific
design requirements of the stage assembly 10. In one embodiment,
the countermass assembly 20 includes (i) a fluid distribution plate
assembly 48, (ii) a support frame 50, (iii) a plate attachment
assembly 51; and (iv) one or more countermasses 52.
[0066] The fluid distribution plate assembly 48 supports the coil
units 40 and also functions as a manifold to direct the circulation
fluid 30 between the fluid distribution network 28 and the coil
units 40. Thus, in certain embodiments, the fluid distribution
plate assembly 48 provides structural support for the coil units 40
and is used with the fluid distribution network 28 for thermal
control of the coil units 40. With this design, (i) reaction forces
from the coil units 40 are transferred to the distribution plate
assembly 48, then the plate attachment assembly 51, and
subsequently to the support frame 50 and the countermass weights
52; and (iii) the circulation fluid 30 travels between the coil
units 40 and the fluid distribution network 28 through the
distribution plate assembly 48.
[0067] In certain embodiments, the fluid distribution plate
assembly 48 is designed to enable the fluid distribution network 28
to be effectively decoupled from the physical structure of the
stage assembly 10 to more effectively manage the thermal strain
that may otherwise exist within the countermass assembly 26. In
certain embodiments, the fluid distribution plate assembly 48 is
the only part of the countermass assembly 26 that is used with the
fluid distribution network 28 for thermal control of the coil units
40. Stated in another fashion, the only part of the countermass
assembly 26 in which the fluid 30 flows is the distribution plate
assembly 48. Thus, in these embodiments, (i) the fluid distribution
plate assembly 48 is the only part of the countermass assembly 26
that is subjected to potential thermal deformation caused by the
circulation fluid 30; and (iii) the other components (e.g. the
support frame 50, the plate attachment assembly 51, and the
countermasses 52) of the countermass assembly 26 are not subjected
to potential thermal deformation caused by the circulation fluid
30. This minimizes the potential for thermal stain of the
countermass assembly 26 that can adversely influence the position
of the stage 14.
[0068] Moreover, in certain embodiments, the mass of the fluid
distribution plate assembly 48 is relatively small when compared to
the other components (e.g. the support frame 50, the plate
attachment assembly 51, and the countermasses 52) of the
countermass assembly 26. In this embodiment, when the circulation
fluid 30 only flows through the fluid distribution plate assembly
48 of the countermass assembly 26, the fluid distribution network
28 is substantially decoupled from the physical structure of the
countermass assembly 26 to more effectively manage the thermal
strain that may otherwise exist within the countermass assembly 26.
In alternative, non-exclusive embodiments, the circulation fluid 30
only flows through five, ten, fifteen, or twenty percent of the
mass of the countermass assembly 26.
[0069] In the embodiment illustrated in FIG. 1, the fluid
distribution plate assembly 48 is generally rectangular plate
shaped and rigid. In certain embodiments, the fluid distribution
plate assembly 48 can be made as a modular unit that includes a
plurality of substantially similar fluid distribution plates 48A.
As a non-exclusive example, the fluid distribution plate assembly
48 can include eleven fluid distribution plates 48A that are
secured together in a side-by-side manner so as to provide a
supporting mechanism to support the plurality of coil units 40. In
this embodiment, each fluid distribution plates 48A is generally
rectangular plate shaped and supports twenty-four separate coil
units 40 (two rows of twelve coil units 40). Additionally, in this
embodiment, each distribution plate 48A extends from one side of
the distribution plate assembly 48 to the other side of the
distribution plate assembly 48 in the X-direction (i.e. the shorter
dimension as illustrated in the Figures), and the distribution
plates 248 are positioned side-by-side in the Y-direction (i.e. the
longer dimension as illustrated in the Figures).
[0070] Alternatively, the fluid distribution plate 48A can have a
different shape or design. Still alternatively, the distribution
plate assembly 48 can be made as single plate.
[0071] The support frame 50 supports the other components of the
countermass assembly 26. In FIG. 1, the support frame 50 is
generally rectangular plate shaped and rigid. Further, the support
frame 50 is positioned adjacent to the stage base 12. In certain
embodiments, the circulation fluid 30 does not flow through (or
contact) the support frame 50.
[0072] The plate attachment assembly 51 is rigid and supports and
rigidly couples the fluid distribution plate assembly 48 to the
support frame 50, while allowing space for the fluid distribution
network 28 to access a bottom of the fluid distribution plate
assembly 48. In certain embodiments, the circulation fluid 30 does
not flow through (or contact) the plate attachment assembly 51.
[0073] The one or more countermass weights 52 are coupled to the
distribution plate assembly 48 and/or the support frame 50 to
provide a greater mass to the reaction assembly 20 so as to
minimize or otherwise limit any movement of the reaction assembly
20 in reaction to the movement of the stage 14 (illustrated in FIG.
1) by the stage mover 18. For example, in one embodiment, the
countermass weights 52 can comprise tungsten blocks that are
coupled to an end of the distribution plate assembly 48 and/or the
support frame 50. Alternatively, the countermass weights 52 can be
made from another suitable material, and/or can be positioned in a
different manner relative to the distribution plate assembly 48
and/or the support frame 50. In certain embodiments, the
circulation fluid 30 does not flow through (or contact) the one or
more countermass weights 52.
[0074] Additionally, as noted above, in certain embodiments, the
countermass weights 52 can have sufficient mass such that the
overall mass of the reaction assembly 20 versus the mass of the
stage 14 can be between approximately 10:1 and 30:1. Alternatively,
the mass of the reaction assembly 20 versus the mass of the stage
14 can be greater than 30:1 or less than 10:1.
[0075] FIG. 2A is a simplified, non-exclusive side view of one coil
unit 40, a portion of the distribution plate assembly 48, and a
portion of the fluid distribution network 28. The design of each of
these components can be varied pursuant to the teachings provided
herein.
[0076] In FIG. 2A, the coil unit 40 is generally rectangular
shaped. In this non-exclusive embodiment, moving from the bottom to
the top, the coil unit 40 includes (i) a lower body circulation
plate 240A that is substantially rectangular plate shaped and
includes one or more fluid passageways 240B, e.g. microchannels,
(illustrated in phantom); (ii) a coil set 240C that includes one or
more X coils and/or one or more Y coils; (iii) an upper body
circulation plate 240D that is substantially rectangular plate
shaped and includes one or more fluid passageways 240E (illustrated
in phantom); and (iv) an upper surface circulation plate 240F that
is substantially rectangular plate shaped and includes one or more
fluid passageways 240G (illustrated in phantom). With this design,
(i) the body fluid source 32 (illustrated in FIG. 1) directs the
fluid 30 (illustrated in FIG. 1) through the body circulation
plates 240A, 240D to remove the bulk of heat generated by the coil
set 240C, and (ii) the surface fluid source 34 (illustrated in FIG.
1) directs the fluid 30 (illustrated in FIG. 1) through the surface
circulation plate 240F to provide a thermal shield for the coil
unit 40 and to maintain the surface temperature of each conductor
unit 40 at the desired temperature to inhibit the transfer of heat
from each conductor unit 40.
[0077] The design of the coil set 240C and the number of conductors
in each coil set 240C can be varied to suit the design requirements
of the stage mover 16 (illustrated in FIG. 1). For a three phase
planar motor, each coil set 240C includes three adjacent racetrack
shaped coils that are aligned side by side.
[0078] In FIG. 2A, the coil unit 40 is mounted on a top surface
248A of the distribution plate assembly 48. As illustrated in FIG.
2A, one or more sealers 254 (e.g., O-rings) can be positioned
between the coil unit 40 and the distribution plate assembly 48 to
connect one or more distribution fluid passageways 248B
(illustrated in phantom) in the distribution plate assembly 248 to
the coil unit 40. With this design, the coil unit 40 can be urged
against the distribution plate assembly 48 to seal the distribution
fluid passageways 248B in the distribution plate assembly 48 to the
desired fluid passageways (not shown) in the coil unit 40.
[0079] The distribution plate assembly 48 is generally rectangular
shaped and includes the top surface 248A, an opposed bottom surface
248C and a plurality of distribution fluid passageways 248B that
connect the fluid distribution network 28 to the coil units 40.
Additionally, the distribution plate assembly 48 can include a
separate unit aperture 248D (illustrated in phantom) for each coil
unit 40. For example, the unit aperture 248D can be a generally
rectangular shaped opening that extends between the top surface
248A and the bottom surface 248C that facilitates the attachment of
the coil units 40 and electrical connections to the coil units 40.
In certain embodiments, a portion of the coil unit 40 extends
through the corresponding unit aperture 248D.
[0080] Only a very small portion of the fluid distribution network
28 is illustrated in FIG. 2A. Importantly, the fluid distribution
network 28 is positioned directly adjacent to the bottom surface
248C of the distribution plate assembly 48. Further, the fluid
distribution network 28 is directly attached to the distribution
fluid passageways 248B in the distribution plate assembly 48. With
this design, the circulation fluid 30 (illustrated in FIG. 1) flows
only through the fluid distribution network 28 and a small portion
of the distribution plate assembly 48, and not the rest of the
countermass assembly 26 (illustrated in FIG. 1).
[0081] FIG. 2B is a perspective view of the coil unit 40 including
the lower body circulation plate 240A, the coil set 240C, the upper
body circulation plate 240D, and the upper surface circulation
plate 240F. Additionally, FIG. 2B illustrates that the coil unit 40
includes (i) a body plate inlet 240H that transfers the supply
circulation fluid 30 (illustrated in FIG. 1) received from the body
fluid source 32 (illustrated in FIG. 1) via the fluid distribution
network 28 (illustrated in FIG. 2A) and the distribution plate
assembly 48 (illustrated in FIG. 2A) to the body circulation plates
240A, 240D; (ii) a body plate outlet 2401 that transfers the return
circulation fluid 30 received from the body circulation plates
240A, 240D to the body fluid source 32 via the distribution plate
assembly 48 and the fluid distribution network 28; (iii) a surface
plate inlet 240J that transfers the supply circulation fluid 30
received from the surface fluid source 34 via the fluid
distribution network 28 and the distribution plate assembly 48 to
the surface circulation plate 240F; and (iv) a surface plate outlet
240K that transfers the return circulation fluid 30 received from
the surface circulation plate 240F to the surface fluid source 34
via the distribution plate assembly 48 and the fluid distribution
network 28.
[0082] FIG. 3A is a top plan view of the distribution plate
assembly 48 of FIG. 2A. In this embodiment, the distribution plate
assembly 48 defines a plurality of coil sites 348A that are each
designed to receive, retain, and direct fluid 30 (illustrated in
FIG. 1) to one of the coil units 40 (illustrated in FIG. 1). In
this embodiment, the distribution plate assembly 48 defines two
hundred and sixty-four coil sites 348A. Alternatively, the
distribution plate assembly 48 can be designed to have more than or
fewer than two hundred and sixty-four coil sites 348A.
[0083] As illustrated in FIG. 3A, for each coil site 348A, the
distribution plate assembly 48 includes four distribution fluid
passageways 248B and a separate unit aperture 248D. In this
embodiment, the fluid distribution plate assembly 48 is a modular
unit that includes eleven fluid distribution plates 48A that are
secured together in a side-by-side manner so as to provide a
supporting mechanism to support the plurality of coil units 40.
[0084] As noted above, in certain applications, different areas of
the stage mover 18 (illustrated in FIG. 1) are used more often than
others, thus generating more heat during the movement of the stage
14 (illustrated in FIG. 1). Accordingly, differing amounts of heat
can be generated near each of the distribution plate 48A, and,
thus, each of the distribution plate 48A can require a differing
amount of cooling (which can be controlled in any suitable manner,
some of which are noted herein below). For example, in certain
applications, the distribution plates 48A can be designated as low
use, medium use, or high use, depending on the required usage of
the adjacent coil units 40 during movement of the stage 14.
[0085] FIG. 3B is a top plan view of one of the distribution plates
48A of FIG. 3A. In this embodiment, each fluid distribution plates
48A is generally rectangular plate shaped and defines twenty-four
separate each coil site 348A arranged in two rows of twelve. As
provided above, for each coil unit 40, the four distribution fluid
passageways 248B can be referred to as (i) a body inlet passageway
348B that is in fluid communication with the body plate inlet 240H
(illustrated in FIG. 2B) of the coil unit 40; (ii) a body outlet
passageway 348C that is in fluid communication with the body plate
outlet 2401 (illustrated in FIG. 2B) of the coil unit 40; (iii) a
surface inlet passageway 348D that is in fluid communication with
the surface plate inlet 240J (illustrated in FIG. 2B) of the coil
unit 40; and (iv) a surface outlet passageway 348E that is in fluid
communication with the surface plate outlet 240K (illustrated in
FIG. 2B) of the coil unit 40.
[0086] In this embodiment, (i) the body inlet passageway 348B and
the surface inlet passageway 348D extend completely through the
distribution plate 48A, and (ii) the body outlet passageway 348C
and the surface outlet passageway 348E extend only partly through
the distribution plate 48A.
[0087] FIG. 3B also illustrates that each distribution plate 48A
includes (i) a body longitudinal passageway 348F (illustrated in
phantom) that is in fluid communication with the body outlet
passageways 348C; and a spaced apart surface longitudinal
passageway 348G (illustrated in phantom) that is in fluid
communication with the surface outlet passageways 348E. Further,
the longitudinal passageways 348F, 348G extend along the
distribution plate 48A. With this design, (i) the fluid 30
(illustrated in FIG. 1) that enters the body outlet passageways
348C is transferred to the body longitudinal passageway 348F, and
(ii) the fluid 30 that enters the surface outlet passageways 348E
is transferred to the surface longitudinal passageway 348G.
[0088] Thus, in certain embodiments, (i) the fluid 30 that has been
circulated in each body circulation plate 240A, 240D (illustrated
in FIG. 2A) is returned to the common body longitudinal passageway
348F; and (ii) the fluid 30 that has been circulated in each
surface circulation plate 240F (illustrated in FIG. 2A) is returned
to the common surface longitudinal passageway 348G. This simplifies
the pluming for the returning fluid 30. With this design, for each
distribution plate 48A, (i) the common body longitudinal passageway
348F functions as a manifold that receives and collects the
circulation fluid 30 exiting the body circulation plates 240A, 240D
of each coil unit 40; and (ii) the common surface longitudinal
passageway 348G functions as a manifold that receives and collects
the circulation fluid 30 exiting the surface circulation plate 240F
of each coil unit 40.
[0089] In certain embodiments, one or more of the passageways 348B,
348C, 348D, 348E can include one or more flow regulators (not
illustrated) that regulate the volume and rate of fluid flow to the
individual coil units 40. Additionally and/or alternatively, such
flow regulators can be included within the structure of the coil
units 40 themselves. In one non-exclusive embodiment, one or more
of the passageways 348B, 348C, 348D, 348E can be sized and shaped
to function as a flow regulator that is sized to provide the
desired flow rate based on the planned movement of the mover 18.
With this design, the coil units 40 that are used more will be
affiliated with flow regulators having larger diameter channels
(orifices), and coil units 40 that are used less will be affiliated
with flow regulators having smaller diameter channels (orifices).
Thus, one or more of the passageways 348B, 348C, 348D, 348E can be
sized to suit the flow (cooling) requirements of the respective
coil units 40 with the projected usage of the mover 18. Moreover,
in one embodiment, the passageways 348B, 348C, 348D, 348E can be
sized during the design phase of the mover 18 based on the
projected usage of the mover 18 to provide the appropriate flow
rate to respective coil units 40.
[0090] As a non-exclusive example, four different sizes can be used
for the passageways 348B, 348C, 348D, 348E. In this design, (i) the
first (largest) diameter can be used for coil units 40 that are
used the most; (ii) the second (next largest) diameter can be used
for coil units 40 that are used the second most; (iii) the third
(largest) diameter can be used for coil units 40 that are used the
third most; and (iv) the fourth (largest) diameter can be used for
coil units 40 that are used the least. It should be noted that more
than four or fewer than four channel diameters can be used.
[0091] Alternatively, one or more of the flow regulators can be an
adjustable valve that is controlled to adjust and/or regulate the
volume and rate of fluid flow depending on the specific cooling
requirements for each of the individual coil units 40. In various
applications, the control system 22 (illustrated in FIG. 1) can be
utilized to provide the necessary and desired regulation of the
valves to provide the desired and selective cooling of the
individual coil units 40.
[0092] As noted above, by providing the relatively short plate
passageways 348B, 348C, 348D, 348E, 348F, 348G which are the only
fluid paths through the physical structure of the stage assembly 10
(illustrated in FIG. 1), the fluid distribution network 28
(illustrated in FIG. 1) can be more effectively decoupled from the
physical structure of the stage assembly 10, so as to more
effectively manage the thermal strain that may otherwise exist
within the stage assembly 10, e.g., within the stage mover 18
(illustrated in FIG. 1).
[0093] FIG. 3C is a bottom plan view of the portion of the
distribution plate assembly 48A of FIG. 3B, including the body
inlet passageway 348B, the surface inlet passageway 348D, the body
longitudinal passageway 348F (illustrated in phantom), and the
surface longitudinal passageway 348G (illustrated in phantom).
[0094] FIG. 3C also illustrates that, in this non-exclusive
embodiment, (i) the body longitudinal passageway 348F includes four
outlet passageways 349A that are used to connect the body
longitudinal passageway 348F to the body fluid source 32
(illustrated in FIG. 1); and (ii) the surface longitudinal
passageway 348G includes two outlet passageways 349B that are used
to connect the surface longitudinal passageway 348G to the surface
fluid source 34 (illustrated in FIG. 1).
[0095] FIG. 3D is a cut-away view of the distribution plate 48A
taken on line 3D-3D in FIG. 3C that illustrates the first
transverse passageway 348E, the second transverse passageway 348F,
one outlet passageways 349A, and one outlet passageway 349B
(illustrated in phantom).
[0096] In certain embodiments, the distribution plate 48A can be
formed from multiple plate members that can be fusion bonded
together. In one embodiment, each of the plate members can be
formed from a stainless steel material. Alternatively, one or more
of the plate members can be formed from another suitable
material.
[0097] FIG. 4A is a bottom view of the distribution plate 48A, and
a portion of the fluid distribution network 28 positioned adjacent
to the bottom surface 248C of the distribution plate 48. As
provided herein, the majority of the fluid distribution network 28
is positioned below, near and/or substantially adjacent to the
bottom surface 248C of the distribution plate assembly 48. With
this design, the circulation fluid 30 (illustrated in FIG. 1) does
not flow through the bulk of the countermass assembly 26.
[0098] In this embodiment, for each distribution plate 48A, the
fluid distribution network 28 includes a separate, adjacent conduit
assembly 460 that is positioned directly adjacent to the bottom
surface 248C of the distribution plate 48A. In one embodiment, the
adjacent conduit assembly 460 provides a path below the
distribution plate 48A and near and/or substantially adjacent to
the bottom surface 248C for directing the circulation fluid 30
(illustrated in FIG. 1) into the distribution plate 48A. For
example, the adjacent conduit assembly 460 can include (i) a body
supply conduit 462 that is in fluid communication with the body
inlet passageway 348B (illustrated in FIG. 3C) of each coil site
348A of the distribution plate 48A; and (ii) a surface supply
conduit 464 that is in fluid communication with the surface inlet
passageway 348D (illustrated in FIG. 3C) of each coil site 348A of
the distribution plate 48A.
[0099] With this design, the adjacent conduit assembly 460 is
designed to broadly distribute the circulation fluid 30 for the
coil sites 348A substantially adjacent to the distribution plate
48A prior to the circulation fluid 30 being directed through the
distribution plate 48A in order to provide the desired cooling of
the coil units 40 (illustrated in FIG. 1). By effectively
distributing the circulation fluid 30 below the distribution plate
48A (i.e. not within the distribution plate assembly 48A), the
fluid distribution network 28 can be more effectively decoupled
from the physical structure of the countermass assembly 26
(illustrated in FIG. 1), so as to more effectively manage the
thermal strain that may otherwise exist.
[0100] As provided herein, the adjacent conduit assembly 460
functions as a manifold for the cool inlet circulation fluid 30
into the distribution plate 48A. More specifically, in this
embodiment, (i) the body supply conduit 462 is used as a manifold
to distribute the inlet circulation fluid 30 of each coil site
348A; and (ii) the surface supply conduit 464 is used as a manifold
to distribute the inlet circulation fluid 30 of each coil site
348A. It should be noted that (i) the circulation fluid 30
distributed by the body supply conduit 462 is directed to the body
circulation plates 240A, 240D (illustrated in FIG. 2A) of each coil
unit 40; and (ii) the circulation fluid 30 distributed by the
surface supply conduit 462 is directed to the surface circulation
plate 240F (illustrated in FIG. 2A) of each coil unit 40.
[0101] It should be noted that the adjacent conduit assembly 460
does not route the heated circulation fluid 30 that has exited each
coil unit 40. Thus, because only the adjacent conduit assembly 460
of the fluid distribution network 28 is illustrated in FIG. 4A, (i)
the four outlet passageways 349A that are in fluid communication
with the body longitudinal passageway 348F (illustrated in FIG. 3C)
are still open; and (ii) the two outlet passageways 349B that are
in fluid communication with the surface longitudinal passageway
348G (illustrated in FIG. 3C) are still open. Thus, in this
embodiment, the adjacent conduit assembly 460 does not route the
returning fluid 30 from the coil units 40.
[0102] With this design, the adjacent conduit assembly 460 provides
a stand alone means for distribution of the circulation fluid 30
(illustrated in FIG. 1) below, near and/or substantially adjacent
to the bottom surface 248C of the individual distribution plate
48A. Stated in another fashion, an individual and separate adjacent
conduit assembly 460 is utilized to effectively distribute the
circulation fluid 30 substantially adjacent to the bottom surface
248C of each distribution plate 48A prior to the circulation fluid
30 being directed through the distribution plate 48A.
[0103] FIG. 4B is a bottom view of the adjacent conduit assembly
460 including the body supply conduit 462 and the surface supply
conduit 464 from FIG. 4A. In this embodiment, the body supply
conduit 462 includes a main body conduit 462A and a plurality of
substantially parallel and spaced apart, branch body conduits 462B
that cantilever away from and that are in fluid communication with
the main body conduit 462A. In this embodiment, each branch body
conduit 462B (or the main body conduit 462A near the branch)
provides circulation fluid 30 to two coil sites 348A. Thus, the
number of branch body conduits 462B is equal to the number of pairs
of coil sites 348A for the distribution plate 48A. In FIG. 4B, the
body supply conduit 462 includes twelve branch body conduits 462B.
Moreover, in this embodiment, the main body conduit 462A includes
three spaced apart body conduit inlets 462C to receive the supply
circulation fluid 30 (illustrated in FIG. 1) from the body fluid
source 32 (illustrated in FIG. 1).
[0104] Somewhat similarly, in this embodiment, the surface supply
conduit 464 includes a main surface conduit 464A and a plurality of
substantially parallel and spaced apart, branch surface conduits
464B that cantilever away from and that are in fluid communication
with the main surface conduit 464A. In this embodiment, each branch
surface conduit 464B (or the main surface conduit 464A near the
branch) provides circulation fluid 30 to two coil sites 348A. Thus,
the number of branch surface conduits 464B is equal to the number
of pairs of coil sites 348A for the distribution plate 48A. In FIG.
4B, the surface supply conduit 464 includes twelve branch surface
conduits 464B. Moreover, in this embodiment, the surface body
conduit 464A includes two spaced apart surface conduit inlets 464C
to receive the supply circulation fluid 30 (illustrated in FIG. 1)
from the body fluid source 34 (illustrated in FIG. 1).
[0105] It should be noted that in this embodiment, with reference
to FIGS. 4A and 4B, each of the distribution plates 48A includes
eleven, separate fluid connection openings, namely four separate
body outlet passageways 349A, two separate surface outlet
passageways 349B, three body conduit inlets 462C, and two surface
conduit inlets 464C (4+2+3+2=11). As a result thereof, the rest of
the fluid distribution network 28 must provide fluid connections
for the eleven, separate fluid connection openings for each
distribution plate 48A.
[0106] FIG. 4C is a top view of the adjacent conduit assembly 460
of FIG. 4B. Additionally, FIG. 4D is an enlarged cut-away
perspective view of a portion of the adjacent conduit assembly 460
from FIG. 4C. As shown in this embodiment, (i) the body supply
conduit 462 include a separate body conduit outlet 462D for each
coil site 348A serviced (e.g. twenty four in this example); and
(ii) the surface supply conduit 464 include a separate surface
conduit outlet 464D for each coil site 348A serviced (e.g. twenty
four in this example). For each coil site 348A, (i) the body
conduit outlet 462D is in fluid communication with the
corresponding body inlet passageway 348B (illustrated in FIG. 3C)
of the distribution plate 48A; and (ii) the surface conduit outlet
464D is in fluid communication with the corresponding surface inlet
passageway 348D (illustrated in FIG. 3C) of the distribution plate
48A.
[0107] It should be noted that (i) half of the branch body conduits
462B include two body conduit outlets 462D, and (ii) half of the
branch body conduits 462B include only one body conduit outlet
462D, with the other body conduit outlets 462D being positioned in
the main body conduit 462A near the respective branch body conduit
462B. Similarly, (i) half of the branch surface conduits 464B
include two surface conduit outlets 464D, and (ii) half of the
branch surface conduits 464B include only one surface conduit
outlet 464D, with the other surface conduit outlets 464D being
positioned in the surface body conduit 464A near the respective
branch surface conduit 464B.
[0108] It should be understood that in certain embodiments, that
the body supply conduit 462 and/or the surface supply conduit 464
can include one or more flow regulators (not illustrated) that
individually (or as a group) regulate the volume and rate of the
circulation fluid 30 to one or more of the coil sites 348A.
[0109] As provided above, the design of the fluid distribution
network 28 can be varied to suit the specific requirements of the
stage assembly 10 (illustrated in FIG. 1) with which the fluid
distribution network 28 is utilized. FIG. 5A is a perspective view
of another portion of the fluid distribution network 28. In one
embodiment, the portion of the fluid distribution network 28
illustrated in FIG. 5A is used to connect in fluid communication
the (i) the body fluid source 32 (illustrated in FIG. 1) to the
body supply conduit 462 (illustrated in FIG. 4A) for each
distribution plate 48A to supply the body circulation fluid 30
(illustrated in FIG. 1) to each coil unit 40 (illustrated in FIG.
1); (ii) the outlet passageways 349A (illustrated in FIG. 3C) for
each distribution plate 48A to the body fluid source 32 to return
the body circulation fluid 30 from each coil unit 40; (iii) the
surface fluid source 34 (illustrated in FIG. 1) to the surface
supply conduit 464 (illustrated in FIG. 4A) for each distribution
plate 48A to supply the surface circulation fluid 30 (illustrated
in FIG. 1) to each coil unit 40 (illustrated in FIG. 1); and (iv)
the outlet passageways 349B (illustrated in FIG. 3C) for each
distribution plate 48A to the surface fluid source 34 to return the
surface circulation fluid 30 from each coil unit 40.
[0110] In one embodiment, the portion of the fluid distribution
network 28 illustrated in FIG. 5A is positioned below and adjacent
to the body supply conduit 462 and the surface supply conduit 464
for each distribution plate 48A. With this design, the fluid
distribution network 28 is substantially thermally decoupled from
the rest of the countermass assembly 26.
[0111] In the non-exclusive embodiment illustrated in FIG. 5A, the
fluid distribution network 28 includes (i) a first distribution hub
570 (also sometimes referred to as a "first gorgon"), (ii) a second
distribution hub 572 (also sometimes referred to as a "second
gorgon") that is a spaced apart from and that is a mirror image of
the first distribution hub 570; and (iii) a distribution conduit
array 574 (also sometimes referred to as "qanats") that is in fluid
communication with the distribution hubs 570, 572. In this
embodiment, (i) the distribution hubs 570, 572 are connected to and
are in fluid communication with the fluid sources 34, 36; and (ii)
the distribution conduit array 574 is in fluid communication with
the eleven, separate fluid connection openings, namely four
separate body outlet passageways 349A, two separate surface outlet
passageways 349B, three body conduit inlets 462C, and two surface
conduit inlets 464C (see FIGS. 4A and 4B) for each distribution
plate 48A. As provided above, in the embodiment illustrated in FIG.
3A, the distribution plate assembly 48 includes eleven separate
distribution plates 48A. Further, each distribution plate 48A
includes eleven separate fluid connection openings. Thus, in this
embodiment, the distribution conduit array 574 is designed provide
a separate fluid connection 576 to the one hundred and twenty-one
different fluid connection openings of the distribution plate
assembly 48. In FIG. 5A, the distribution conduit array 574
includes eleven separate, substantially equally spaced apart and
substantially parallel, distribution conduits 578 and each
distribution conduit 578 includes eleven separate fluid connections
576 to provide fluid connections to the one hundred and twenty-one
different fluid connection openings of the distribution plate
assembly 48.
[0112] Each of the eleven separate fluid connections 576 of each of
the distribution conduits 578 is connected in fluid communication
to a different one of the distribution plates 48A. Stated in
another fashion, for each distribution plate 48A, each distribution
conduits 578 provides a single separate fluid connection 576. Thus,
in this design, the distribution conduits 578 are positioned
transverse to the long axis of each distribution plate 48A. As a
result thereof, each of the distribution conduits 578 extends over
each of the distribution plates 48A.
[0113] It should be noted that with the present design, the fluid
distribution network 28 can easily be scaled to fit a distribution
plate assembly 48 that is sized differently than provided
herein.
[0114] FIG. 5B is a top view of the first distribution hub 570, the
second distribution hub 572 and the distribution conduit array 574.
Additionally, one of the eleven side-by-side distribution plates
48A and its corresponding adjacent conduit assembly 460 is
illustrated in phantom for reference. As provided above, each
distribution conduit 578 is in fluid communication once via the
eleven separate fluid connections 576 to each distribution plate
48A.
[0115] In this embodiment, as provided above, the distribution
conduit array 574 includes eleven distribution conduits 578 that
are substantially parallel to one another, and each of the
distribution conduits 578 extends along (or parallel to) a first
axis, e.g., the Y axis (transverse to the distribution plates 48A);
and the distribution conduits 578 are spaced apart from one another
along (or parallel to) a second axis, e.g., the X axis.
Alternatively, the fluid distribution network 28 can be designed to
include greater than eleven or less than eleven distribution
conduits 578, and/or the distribution conduits 578 can have a
different positioning and/or orientation relative to one
another.
[0116] As provided herein, the fluid distribution network 28 is in
fluid communication with the fluid sources 34, 36 to provide the
necessary and desired fluid path for (i) the inlet body circulation
fluid 30 (illustrated in FIG. 1) from the body fluid source 32 that
is to be delivered to body circulation plates 240A, 240D of each
coil unit 40; (ii) the returning body circulation fluid 30 from the
body circulation plates 240A, 240D of each coil unit 40 to the body
fluid source 32; (iii) the inlet surface circulation fluid 30 from
the surface fluid source 34 that is to be delivered to surface
circulation plate 240F of each coil unit 40; and (iv) the returning
surface circulation fluid 30 from the surface circulation plate
240F of each coil unit 40 to the surface fluid source 34.
[0117] In FIG. 5B, the first distribution hub 570 and the second
distribution hub 572 cooperate to be in fluid communication twice
with each distribution conduit 578. Further, in the non-exclusive
embodiment illustrated in FIG. 5B, the fluid distribution network
28 is designed and plumed so that (i) three of the distribution
conduits 578 (labeled 578B1) carry inlet body circulation fluid 30
from the body fluid source 32; (ii) four of the distribution
conduits 578 (labeled 578BR) carry returning body circulation fluid
30 from the distribution plates 48A; (iii) two of the distribution
conduits 578 (labeled 578S1) carry inlet surface circulation fluid
30 from the surface fluid source 34; and (iv) two of the
distribution conduits 578 (labeled 578SR) carry returning surface
circulation fluid 30 from the distribution plates 48A. With this
embodiment, the eleven distribution conduits 578 can each be
coupled once for each of the distribution plates 48A at the eleven,
separate fluid connection openings, namely four separate body
outlet passageways 349A, two separate surface outlet passageways
349B, three body conduit inlets 462C, and two surface conduit
inlets 464C (see FIGS. 4A and 4B).
[0118] The arrangement of the distribution conduits 578 can vary.
In the non-exclusive embodiment illustrated in FIG. 5B, moving from
the top to bottom, the distribution conduits 578 are arranged as
follows: (i) the first distribution conduit 578 is labeled 578BR
because it is carrying returning body circulation fluid 30; (ii)
the second distribution conduit 578 is labeled 578SS because it is
carrying inlet (supply) surface circulation fluid 30; (iii) the
third distribution conduit 578 is labeled 578SR because it is
carrying returning surface circulation fluid 30; (iv) the fourth
distribution conduits 578 is labeled 578BS because it is carrying
inlet (supply) body circulation fluid 30; (v) the fifth
distribution conduit 578 is labeled 578BR because it is carrying
returning body circulation fluid 30; (vi) the sixth distribution
conduit 578 is labeled 578BS because it is carrying inlet (supply)
body circulation fluid 30; (vii) the seventh distribution conduit
578 is labeled 578BR because it is carrying returning body
circulation fluid 30; (viii) the eighth distribution conduit 578 is
labeled 578BS because it is carrying inlet (supply) body
circulation fluid 30; (ix) the ninth distribution conduit 578 is
labeled 578SR because it is carrying returning surface circulation
fluid 30; (x) tenth distribution conduit 578 is labeled 578SS
because it is carrying inlet (supply) surface circulation fluid 30;
and (xi) the eleventh distribution conduit 578 is labeled 578BR
because it is carrying returning body circulation fluid 30;
[0119] Further, the first distribution hub 570 is connected (i)
twice to the first distribution conduit 578, the second
distribution conduit 578, the third distribution conduit 578, the
fourth distribution conduits 578, and the fifth distribution
conduit 578; and (i) once to the sixth distribution conduit
578.
[0120] Somewhat similarly, the second distribution hub 572 is
connected (i) once to the sixth distribution conduit 578 and (i)
twice to the seventh distribution conduit 578, the eighth
distribution conduit 578, the ninth distribution conduit 578, the
tenth distribution conduits 578, and the eleventh distribution
conduit 578.
[0121] It should be noted that fluid distribution network 28 can
include one or more valves or regulars (not shown) that can be used
to regulate flow.
[0122] FIG. 6A is a bottom perspective view, FIG. 6B is a top view,
and is an inverted side view of the distribution conduit array 574.
As provided above each distribution conduit 578 includes eleven,
spaced apart, separate fluid connections 576, with one fluid
connector from each distribution conduit 578 being connected each
distribution plate 48A or corresponding adjacent conduit assembly
460. Additionally, in this embodiment, each distribution conduit
578 includes one or more hub connectors 680 for fluid connection to
the respective distribution hub 570, 572. In the specific
illustrated embodiment, each distribution conduit 578 includes two
space apart hub connectors 680, which can function as either an
inlet to or an outlet from the respective distribution conduit 578
depending on whether the individual distribution conduit 578 is
part of the fluid supply trip or the fluid return trip.
[0123] FIG. 6C illustrates the size and positioning of the hub
connectors 680 and the fluid connections 576 along the length of
one of the distribution conduits 578.
[0124] FIG. 7A is a bottom perspective view, and FIG. 7B is a
bottom view of the distribution hubs 570, 572 of the fluid
distribution network 28. In this embodiment, the first distribution
hub 570 includes (i) a first manifold 782 having a plurality of
manifold openings 784 that are connected to and that are in fluid
communication with the fluid sources 34, 36, and (ii) eleven, first
manifold conduits 786 that are in fluid communication with the
first manifold 782. Similarly, the second distribution hub 572
includes (i) a second manifold 788 having a plurality of manifold
openings 790 that are connected to and that are in fluid
communication with the fluid sources 34, 36, and (ii) eleven,
second manifold conduits 792 that are in fluid communication with
the second manifold 786.
[0125] The number of manifold openings 784, 790, and manifold
conduits 786, 792 can be varied to suit the requirements of the
system. In one embodiment, the first distribution hub 570 include
eleven manifold openings 784, and eleven manifold conduits 786; and
the second distribution hub 572 include eleven manifold openings
790, and eleven manifold conduits 792.
[0126] The fluid distribution network 28 is designed and plumed so
that (i) three of the first manifold openings 784 and three of the
first manifold conduits 786 carry inlet body circulation fluid 30
from the body fluid source 32; (ii) four of the first manifold
openings 784 and four of the first manifold conduits 786 carry
returning body circulation fluid 30 from the distribution plates
48A; (iii) two of the first manifold openings 784 and two of the
first manifold conduits 786 carry inlet surface circulation fluid
30 from the surface fluid source 34; (iv) two of the first manifold
openings 784 and two of the first manifold conduits 786 carry
returning surface circulation fluid 30 from the distribution plates
48A; (v) three of the second manifold openings 790 and three of the
second manifold conduits 792 carry inlet body circulation fluid 30
from the body fluid source 32; (vi) four of the second manifold
openings 790 and four of the second manifold conduits 792 carry
returning body circulation fluid 30 from the distribution plates
48A; (vii) two of the second manifold openings 790 and two of the
second manifold conduits 792 carry inlet surface circulation fluid
30 from the surface fluid source 34; and (viii) two of the second
manifold openings 790 and two of the second manifold conduits 792
carry returning surface circulation fluid 30 from the distribution
plates 48A
[0127] FIG. 8A is a perspective view of a connector 894 that can be
used to connect a portion of the fluid distribution network 28
(illustrated in FIG. 1) to the distribution plate 48A (illustrated
in FIG. 1). Additionally, FIG. 8B is a perspective view of a
portion of the distribution plate 48A and the connector 894. In one
embodiment, the connector 894 can be a hollow bolt that extends
into and partially through a plate aperture 848A to provide the
desired feed-through for connection of the fluid conduits.
[0128] As illustrated the connector 894 can be annular-shaped, with
a substantially circular cross-section, and having an upper section
894A and a lower section 894B that is slightly smaller in outer
circumference than the upper section 894A. Additionally, the plate
aperture 848A can also have a substantially circular cross-section,
and have an upper portion 848B through which the entire connector
894 can fit, and a lower portion 848C through which only the lower
section 894B of the connector 894 can fit. With this design, the
connector 894 can effectively sit on a ledge within the plate
aperture 848A in order to provide the desired feed-through
connection with the conduits.
[0129] In certain embodiments, the orifice of the connector 894 can
be sized to regulate the volume and rate of fluid flow between the
distribution plates 48A. In this embodiment, the larger diameter
orifices can be used for distribution plates 48A that are used more
and that require more cooling, while smaller diameter orifices are
used for distribution plates 48A that are used less and that
require less cooling. Thus, the orifices can be sized to suit the
flow (cooling) requirements of the respective distribution plate
48A. Moreover, the orifices can be sized during the design phase of
the mover 18 based on the projected usage of the mover 18 to
provide the appropriate flow rate to respective distribution plates
48A.
[0130] FIG. 9 is a schematic illustration of a precision assembly,
namely an exposure apparatus 934 useful with the present invention.
The exposure apparatus 934 includes an apparatus frame 987, an
illumination system 988 (irradiation apparatus), an optical
assembly 989 (lens assembly), a reticle stage assembly 990, a wafer
stage assembly 991, a measurement system 992, and a control system
993. The design of the various components of the exposure apparatus
934 can be varied to suit the specific requirements of the exposure
apparatus 934. In certain applications, the various stage
assemblies, as described in detail herein, can be used as the wafer
stage assembly 991. Alternatively, with the disclosure provided
herein, the stage assemblies provided herein can be modified for
use as the reticle stage assembly 990.
[0131] The exposure apparatus 934 is particularly useful as a
lithographic device that transfers a pattern (not shown) of an
integrated circuit from a reticle 994 onto a semiconductor wafer
995. The exposure apparatus 934 mounts to a mounting base 924,
e.g., the ground, a base, or floor or some other supporting
structure.
[0132] There are a number of different types of lithographic
devices. For example, the exposure apparatus 934 can be used as a
scanning type photolithography system that exposes the pattern from
the reticle 994 onto the wafer 995 with the reticle 994 and the
wafer 995 moving synchronously. Alternatively, the exposure
apparatus 934 can be a step-and-repeat type photolithography system
that exposes the reticle 994 while the reticle 994 and the wafer
995 are stationary.
[0133] However, the use of the exposure apparatus 934 and stage
assemblies provided herein is not limited to a photolithography
system for semiconductor manufacturing. The exposure apparatus 934,
for example, can be used as an LCD photolithography system that
exposes a liquid crystal display device pattern onto a rectangular
glass plate or a photolithography system for manufacturing a thin
film magnetic head. Further, the present invention can also be
applied to a proximity photolithography system that exposes a mask
pattern by closely locating a mask and a substrate without the use
of a lens assembly. Additionally, the present invention provided
herein can be used in other devices, including other semiconductor
processing equipment, elevators, machine tools, metal cutting
machines, inspection machines and disk drives.
[0134] The apparatus frame 987 is rigid and supports the components
of the exposure apparatus 934. The design of the apparatus frame
987 can be varied to suit the design requirements of the rest of
the exposure apparatus 934. The apparatus frame 987 illustrated in
FIG. 9 supports the optical assembly 989, the reticle stage
assembly 990, the wafer stage assembly 991, and the illumination
system 988 above the mounting base 924.
[0135] The illumination system 988 includes an illumination source
996 and an illumination optical assembly 997. The illumination
source 996 emits a beam (irradiation) of light energy. The
illumination optical assembly 997 guides the beam of light energy
from the illumination source 996 to the optical assembly 989. The
beam of light energy selectively illuminates different portions of
the reticle 994 and exposes the wafer 995. In FIG. 9, the
illumination source 996 is illustrated as being supported above the
reticle stage assembly 990. Alternatively, the illumination source
996 can be secured to one of the sides of the apparatus frame 987
and the energy beam from the illumination source 996 can be
directed to above the reticle stage assembly 990 with the
illumination optical assembly 997.
[0136] The illumination source 996 can be a g-line source (436 nm),
an i-line source (365 nm), a KrF excimer laser (248 nm), an ArF
excimer laser (193 nm), a F.sub.2 laser (157 nm), or an EUV source
(13.5 nm). Alternatively, the illumination source 996 can generate
charged particle beams such as an x-ray or an electron beam. For
instance, in the case where an electron beam is used, thermionic
emission type lanthanum hexaboride (LaB.sub.6) or tantalum (Ta) can
be used as a cathode for an electron gun. Furthermore, in the case
where an electron beam is used, the structure could be such that
either a mask is used or a pattern can be directly formed on a
substrate without the use of a mask.
[0137] The optical assembly 989 projects and/or focuses the light
passing through the reticle 994 to the wafer 995. Depending upon
the design of the exposure apparatus 934, the optical assembly 989
can magnify or reduce the image illuminated on the reticle 994. The
optical assembly 989 need not be limited to a reduction system. It
could also be a 1.times. or magnification system.
[0138] The reticle stage assembly 990 holds and positions the
reticle 994 relative to the optical assembly 989 and the wafer 995.
Similarly, the wafer stage assembly 991 holds and positions the
wafer 995 with respect to the projected image of the illuminated
portions of the reticle 994.
[0139] The measurement system 992 monitors movement of the reticle
994 and the wafer 995 relative to the optical assembly 989 or some
other reference. With this information, the control system 993 can
control the reticle stage assembly 990 to precisely position the
reticle 994 and the wafer stage assembly 991 to precisely position
the wafer 995. For example, the measurement system 992 can utilize
multiple laser interferometers, encoders, autofocus systems, and/or
other measuring devices.
[0140] The control system 993 is connected to the reticle stage
assembly 990, the wafer stage assembly 990, and the measurement
system 992. The control system 993 receives information from the
measurement system 992 and controls the stage assemblies 990, 991
to precisely position the reticle 994 and the wafer 995. The
control system 993 can include one or more processors and
circuits.
[0141] As described above, a photolithography system according to
the above described embodiments can be built by assembling various
subsystems, including each element listed in the appended claims,
in such a manner that prescribed mechanical accuracy, electrical
accuracy, and optical accuracy are maintained. In order to maintain
the various accuracies, prior to and following assembly, every
optical system is adjusted to achieve its optical accuracy.
Similarly, every mechanical system and every electrical system are
adjusted to achieve their respective mechanical and electrical
accuracies. The process of assembling each subsystem into a
photolithography system includes mechanical interfaces, electrical
circuit wiring connections and air pressure plumbing connections
between each subsystem. Needless to say, there is also a process
where each subsystem is assembled prior to assembling a
photolithography system from the various subsystems. Once a
photolithography system is assembled using the various subsystems,
a total adjustment is performed to make sure that accuracy is
maintained in the complete photolithography system. Additionally,
it is desirable to manufacture an exposure system in a clean room
where the temperature and cleanliness are controlled.
[0142] Semiconductor devices can be fabricated using the above
described systems, by the process shown generally in FIG. 10A. In
step 1001 the device's function and performance characteristics are
designed. Next, in step 1002, a mask (reticle) having a pattern is
designed according to the previous designing step, and in a
parallel step 1003 a wafer is made from a silicon material. The
mask pattern designed in step 1002 is exposed onto the wafer from
step 1003 in step 1004 by a photolithography system described
hereinabove in accordance with the present invention. In step 1005
the semiconductor device is assembled (including the dicing
process, bonding process and packaging process), finally, the
device is then inspected in step 1006.
[0143] FIG. 10B illustrates a detailed flowchart example of the
above-mentioned step 1004 in the case of fabricating semiconductor
devices. In FIG. 10B, in step 1011 (oxidation step), the wafer
surface is oxidized. In step 1012 (CVD step), an insulation film is
formed on the wafer surface. In step 1013 (electrode formation
step), electrodes are formed on the wafer by vapor deposition. In
step 1014 (ion implantation step), ions are implanted in the wafer.
The above mentioned steps 1011-1014 form the preprocessing steps
for wafers during wafer processing, and selection is made at each
step according to processing requirements.
[0144] At each stage of wafer processing, when the above-mentioned
preprocessing steps have been completed, the following
post-processing steps are implemented. During post-processing,
first, in step 1015 (photoresist formation step), photoresist is
applied to a wafer. Next, in step 1016 (exposure step), the
above-mentioned exposure device is used to transfer the circuit
pattern of a mask (reticle) to a wafer. Then in step 1017
(developing step), the exposed wafer is developed, and in step 1018
(etching step), parts other than residual photoresist (exposed
material surface) are removed by etching. In step 1019 (photoresist
removal step), unnecessary photoresist remaining after etching is
removed.
[0145] Multiple circuit patterns are formed by repetition of these
preprocessing and post-processing steps.
[0146] While a number of exemplary aspects and embodiments of a
stage assembly 10 and a fluid distribution network 28 have been
discussed above, those of skill in the art will recognize certain
modifications, permutations, additions and sub-combinations
thereof. It is therefore intended that the following appended
claims and claims hereafter introduced are interpreted to include
all such modifications, permutations, additions and
sub-combinations as are within their true spirit and scope.
* * * * *