U.S. patent application number 11/173962 was filed with the patent office on 2007-01-25 for integrated pump apparatus for semiconductor processing.
This patent application is currently assigned to The BOC Group, Inc.. Invention is credited to Neil Geoffrey Bellenie, Peter John Holland, Graeme Huntley, Richard Lewington, Michael James Percy, David Clinton Wong.
Application Number | 20070020115 11/173962 |
Document ID | / |
Family ID | 37679224 |
Filed Date | 2007-01-25 |
United States Patent
Application |
20070020115 |
Kind Code |
A1 |
Huntley; Graeme ; et
al. |
January 25, 2007 |
Integrated pump apparatus for semiconductor processing
Abstract
The invention relates to an integrated pump apparatus for use in
semiconductor processing. The apparatus may include a
turbomolecular pump and a dry pump positioned no more than about 20
centimeters away from each other. The turbomolecular pump and dry
pump may share at least one of a common housing and a common
controller. The apparatus may also include at least one of an
abatement device and a cryogenic water pump.
Inventors: |
Huntley; Graeme;
(Bridgwater, GB) ; Bellenie; Neil Geoffrey;
(Pleasanton, CA) ; Holland; Peter John;
(Pleasanton, CA) ; Percy; Michael James; (Lewes,
GB) ; Lewington; Richard; (Hayward, CA) ;
Wong; David Clinton; (Wisborough Green, GB) |
Correspondence
Address: |
Ira Lee Zebrak;The BOC Group, Inc.
Legal Services-IP
575 Mountain Ave.
Murray Hill
NJ
07974
US
|
Assignee: |
The BOC Group, Inc.
|
Family ID: |
37679224 |
Appl. No.: |
11/173962 |
Filed: |
July 1, 2005 |
Current U.S.
Class: |
417/199.1 ;
417/423.4 |
Current CPC
Class: |
F04D 19/046 20130101;
F04D 29/403 20130101; F04D 29/522 20130101 |
Class at
Publication: |
417/199.1 ;
417/423.4 |
International
Class: |
F04B 23/08 20060101
F04B023/08 |
Claims
1. An apparatus for use in semiconductor processing, comprising: a
turbomolecular pump; and a dry pump, wherein the turbomolecular
pump and the dry pump are coupled together so as to position the
turbomolecular pump and the dry pump no more than about 20
centimeters from one another.
2. The apparatus of claim 1, wherein the turbomolecular pump and
the dry pump are coupled together so as to position the
turbomolecular pump and the dry pump no more than about 10
centimeters from one another.
3. The apparatus of claim 1, wherein the turbomolecular pump and
the dry pump are coupled together so as to position the
turbomolecular pump and the dry pump no more than about 0.5
centimeters from one another.
4. The apparatus of claim 1, wherein the apparatus comprises at
least one of a common housing associated with both of the pumps and
a common controller associated with both of the pumps.
5. The apparatus of claim 1, further comprising a semiconductor
processing tool associated with the turbomolecular pump and the dry
pump, wherein the turbomolecular pump, the dry pump, and the
semiconductor processing tool are disposed in a single room of a
facility where semiconductors are processed.
6. The apparatus of claim 1, wherein a boundary between the
turbomolecular pump and the dry pump is not externally
discernable.
7. The apparatus of claim 1, wherein the apparatus includes only
one electrical connection configured to provide electrical power
input to both of the pumps.
8. The apparatus of claim 1, wherein the apparatus includes only
one fluid connection configured to provide fluid to at least one of
the pumps.
9. The apparatus of claim 1, wherein the apparatus includes only
one cooling water connection configured to provide cooling water to
at least one of the pumps.
10. The apparatus of claim 1, wherein the apparatus includes only
one nitrogen connection configured to provide nitrogen to at least
one of the pumps.
11. The apparatus of claim 1, wherein the apparatus includes only
one clean dry air connection configured to provide clean dry air to
at least one of the pumps.
12. The apparatus of claim 1, wherein the apparatus comprises a
common controller, and wherein the common controller controls both
the turbomolecular pump and the dry pump.
13. The apparatus of claim 1, wherein the apparatus comprises a
common controller, wherein the apparatus further comprises a
cryogenic water pump, and wherein the common controller is
associated with the cryogenic water pump.
14. The apparatus of claim 13, wherein a common controller controls
the turbomolecular pump, the dry pump, and the cryogenic water
pump.
15. The apparatus of claim 1, wherein the apparatus comprises a
common controller, wherein the apparatus further comprises an
abatement device, and wherein the common controller is associated
with the abatement device.
16. The apparatus of claim 15, wherein the common controller
controls the turbomolecular pump, the dry pump, and the abatement
device.
17. The apparatus of claim 1, wherein the apparatus comprises a
common housing and a common controller.
18. An apparatus for use in semiconductor processing, comprising: a
turbomolecular pump; and a dry pump coupled to the turbomolecular
pump, wherein the apparatus comprises at least one of a common
housing associated with both of the pumps and a common controller
associated with both of the pumps.
19. The apparatus of claim 18, wherein the apparatus comprises the
common housing, and wherein the common housing includes only one
electrical connection configured to provide electrical power input
to both of the pumps.
20. The apparatus of claim 18, wherein the apparatus comprises the
common housing, and wherein the common housing includes only one
fluid connection configured to provide fluid to at least one of the
pumps.
21. The apparatus of claim 18, wherein the apparatus comprises the
common housing, and wherein the common housing includes only one
water connection configured to provide water to at least one of the
pumps.
22. The apparatus of claim 18, wherein the apparatus comprises the
common housing, and wherein the common housing includes only one
nitrogen connection configured to provide nitrogen to at least one
of the pumps.
23. The apparatus of claim 18, wherein the apparatus comprises the
common housing, and wherein the common housing includes only one
clean dry air connection configured to provide clean dry air to at
least one of the pumps.
24. The apparatus of claim 18, wherein the apparatus comprises the
common controller, and wherein the common controller controls both
the turbomolecular pump and the dry pump.
25. The apparatus of claim 18, wherein the apparatus comprises the
common controller, wherein the apparatus further comprises a
cryogenic water pump, and wherein the common controller is also
associated with the cryogenic water pump.
26. The apparatus of claim 25, wherein the common controller
controls the turbomolecular pump, the dry pump, and the cryogenic
water pump.
27. The apparatus of claim 18, wherein the apparatus comprises the
common controller, wherein the apparatus further comprises an
abatement device, and wherein the common controller is also
associated with the abatement device.
28. The apparatus of claim 27, wherein the common controller
controls the turbomolecular pump, the dry pump, and the abatement
device.
29. The apparatus of claim 18, wherein the apparatus comprises the
common housing and the common controller.
30. The apparatus of claim 18, further comprising a semiconductor
processing tool associated with the turbomolecular pump and the dry
pump, wherein the turbomolecular pump, the dry pump, and the
semiconductor processing tool are disposed in a single room of a
facility where semiconductors are processed.
31. The apparatus of claim 18, wherein a boundary between the
turbomolecular pump and the dry pump is not externally
discernable.
32. An apparatus for use in semiconductor processing, comprising: a
turbomolecular pump; a dry pump coupled to the turbomolecular pump;
a semiconductor processing tool associated with the turbomolecular
pump and the dry pump, wherein the turbomolecular pump, the dry
pump, and the semiconductor processing tool are disposed in a
single room of a facility where semiconductors are processed.
33. The apparatus of claim 32, wherein the boundary between the
turbomolecular pump and the dry pump is not externally
discernable.
34. The apparatus of claim 1, wherein the turbomolecular pump and
the dry pump share a common facility distribution path.
35. The apparatus of claim 18, wherein the turbomolecular pump and
the dry pump share a common facility distribution path.
Description
FIELD OF THE INVENTION
[0001] The invention relates to an integrated pump apparatus for
use in semiconductor processing. The apparatus may include a
turbomolecular pump and a dry pump positioned no more than about 20
centimeters away from each other. The turbomolecular pump and dry
pump may share at least one of a common housing and a common
controller. The apparatus may also include at least one of an
abatement device and a cryogenic water pump.
BACKGROUND OF THE INVENTION
[0002] Semiconductor wafers are used to form a number of different
types of devices. For example, wafers, or portions of wafers, may
be used to form memory devices, microprocessor unit devices, or
combinations of the two devices. The devices may be very small,
(e.g., on the order of only one Micron), and thus these devices are
often manufactured in large batches. In some instances, a single
wafer may have hundreds of devices manufactured on it.
[0003] In order to manufacture a device on a wafer, a number of
discrete steps are performed. Although the number of steps may vary
greatly depending on the type and complexity of the device, a
typical manufacturing process may include anywhere between 100 and
300 individual steps between the initial step of providing an
initial substrate and the finals step of extracting individual
devices from the wafer and installing them in personal computers,
telephones, mobile phones, or other electronic equipment.
[0004] Some of the steps in semiconductor wafer processing may
include etching away selected material, depositing selected
materials, and performing selective ion implantation in the silicon
wafer. Many of these steps are performed by tools especially
designed for the particular step, but several steps may also be
performed by a single tool. Because these steps may be performed in
a variety of locations, the wafer may often be moved. For example,
the wafer may be placed in and taken out of ion implanter tools,
transported by cassettes, placed in and taken out of deposition
tools, and placed in and taken out of etch tools, etc.
[0005] As mentioned above, etching is one form of processing that
may be performed on a wafer. The wafer may be etched a number of
different times at a number of different levels for a number of
different reasons. For example, one type of etching step includes
placing a photoresist type material over an area of the wafer. The
photoresist on the wafer may be then be exposed to a light source
with a specific wavelength and a specific pattern. The exposure of
the photoresist to the light source may alter the chemical
composition of the exposed area such that the photoresist either
"hardens" so that when a chemical is applied the "hardened"
photoresist remains, or "softens" so that when a chemical is
applied the "softened" photoresist is removed. In either case, a
desired photoresist pattern remains on the wafer. Using this
remaining photoresist as a mask, chemical substances may be applied
to the wafer so as to etch away or remove exposed portions of the
wafer. Thus, a desired pattern may be "etched" into the silicon
wafer.
[0006] The devices and/or patterns that are etched into the wafer
often have dimensions that are on the order of one micron. Because
the dimensions being dealt with are so small, etching processes are
especially susceptible to contaminants. For example, foreign
molecules may become lodged in the channels etched into the wafers,
and the existence of such flaws may prevent a device or portions of
the device from working properly. Accordingly, in order to minimize
these flaws, much attention is paid to the method by which the
etching is performed, specifically by working to minimize the
number of contaminants in the system.
[0007] The most common method of controlling the etching is by
etching in a vacuum chamber using a plasma. The vacuum chamber is,
by definition, kept at a low pressure, for example, between
pressures of about 10.sup.-3 millibar and about 10.sup.-1 millibar.
The plasma used to etch the wafers may include the addition of any
number of substances, such as fluorocarbons or perflourocarbons,
which within the plasma may be broken up into smaller portions,
such as fluorine and fluorine radicals. These smaller portions
react with the exposed portions of the wafer and "etch away" that
portion of the wafer through the formation of volatile reactant
by-products. Other substances may be used depending on the
substrate to be etched. Performing this procedure under vacuum
substantially prevents contaminants from entering the system, as
the chemicals present are normally only those specifically
introduced into the system and the reduced pressure may moderate
the reaction rate as the molecular density may be lower.
[0008] In a number of current etching procedures, a large number of
reactants are run past the wafer at high speeds, for example, on
the order of thousands of liters per second. This runs contrary to
the desire to minimize the number of contaminants by keeping the
pressure in the vacuum chamber low. What results is a desire to
pass etching substances through the vacuum chamber at high speeds,
but low pressures, and thus specialized pumps are often
desired.
[0009] Currently, there are two discrete, completely separate,
unintegrated pumps used in conjunction with each other to provide a
high flow rate of etching substance at low pressures. The pumps
have, among things, separate housings, separate controllers,
separate electrical connections, and separate fluid connections,
and are located long distances away from one another in different
rooms of a wafer processing facility.
[0010] In some current configurations, an inlet of a first pump is
bolted to the bottom of the vacuum chamber and receives the
substances from the vacuum chamber that are flowing at the low
pressures. The first pump then gradually increases the pressure of
the substance flow from the molecular level (at the inlet) to about
the transition level (at the outlet). The substance flow is then
sent through a tube or pipe to a second pump which is located in
another room, for example, a basement of the wafer processing
facility. The second pump is currently located in another room of
the wafer processing facility for several reasons, most prominent
of which are its size, the amount of noise it generates, and its
maintenance. The flow path (e.g. tube) connecting the pumps is
typically between 5 and 15 meters in length, with a minimum length
of 3 meters and a maximum length of 20 meters. The second pump
gradually increases the pressure of the substance flow from about
the transition level (at the inlet) to about atmospheric pressure
(at the outlet). The second pump then exhausts the substance
flow.
[0011] There are some drawbacks associated with the current dual
pump arrangement. For example, having the second pump in a room
separate from the first pump is often an inefficient use of space.
In addition, there are efficiency losses associated with flowing
the substances through a long tube connecting the pumps.
Accordingly, alternative arrangements and/or configurations of
multiple pumps are desired.
SUMMARY OF THE INVENTION
[0012] In the following description, certain aspects and
embodiments of the invention will become evident. It should be
understood that the invention, in its broadest sense, could be
practiced without having one or more features of these aspects and
embodiments. It should also be understood that these aspects and
embodiments are merely exemplary.
[0013] One aspect, as embodied and broadly described herein, may
relate to an apparatus for use in semiconductor processing. The
apparatus may include a turbomolecular pump and a dry pump, and the
turbomolecular pump and the dry pump may be coupled together so as
to position the turbomolecular pump and the dry pump no more than
about 20 centimeters from one another.
[0014] In a further aspect, an apparatus for use in semiconductor
processing may include a turbomolecular pump and a dry pump coupled
to the turbomolecular pump. The apparatus may include at least one
of a common housing associated with both of the pumps and a common
controller associated with both of the pumps.
[0015] Still another aspect may relate to an apparatus that may
include a turbomolecular pump, a dry pump coupled to the
turbomolecular pump, and a semiconductor processing tool associated
with the turbomolecular pump and the dry pump. The turbomolecular
pump, the dry pump, and the semiconductor processing tool may be
disposed in a single room of a facility where semiconductors are
processed.
[0016] Various aspects may include one or more optional features.
For example, the turbomolecular pump and the dry pump may be
coupled together so as to position the turbomolecular pump and the
dry pump no more than about 10 centimeters from one another; the
turbomolecular pump and the dry pump may be coupled together so as
to position the turbomolecular pump and the dry pump no more than
about 0.5 centimeters from one another; the apparatus may include
at least one of a common housing associated with both of the pumps
and a common controller associated with both of the pumps; the
apparatus may include a semiconductor processing tool associated
with the turbomolecular pump and the dry pump; the turbomolecular
pump, the dry pump, and the semiconductor processing tool may be
disposed in a single room of a facility where semiconductors are
processed; the boundary between the turbomolecular pump and the dry
pump may not be externally discernable; the apparatus may include
only one electrical connection configured to provide electrical
power input to both of the pumps; the apparatus may include only
one fluid connection configured to provide fluid to at least one of
the pumps; the apparatus may include only one cooling water
connection configured to provide cooling water to at least one of
the pumps; the apparatus may include only one nitrogen connection
configured to provide nitrogen to at least one of the pumps; the
apparatus may include only one clean dry air connection configured
to provide clean dry air to at least one of the pumps; the
apparatus may include a common controller; the common controller
may control both the turbomolecular pump and the dry pump; the
apparatus may include a cryogenic water pump; the common controller
may be associated with the cryogenic water pump; the common
controller may control the turbomolecular pump, the dry pump, and
the cryogenic water pump; the apparatus may include an abatement
device; the common controller may be associated with the abatement
device; and the common controller may control the turbomolecular
pump, the dry pump, and the abatement device.
[0017] Aside from the structural relationships discussed above, the
invention could include a number of other forms such as those
described hereafter. It is to be understood that both the foregoing
description and the following description are exemplary only.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The accompanying drawings, which are incorporated in and
constitute a part of this specification. The drawings illustrate
several embodiments of the invention and, together with the
description, serve to explain some principles of the invention. In
the drawings:
[0019] FIG. 1 is a schematic view of an embodiment of an apparatus
in accordance with the present invention;
[0020] FIG. 2 is a schematic view of another embodiment of the
apparatus;
[0021] FIG. 3 is a schematic view of a further embodiment of the
apparatus;
[0022] FIG. 4 is a schematic view of yet another embodiment of the
apparatus;
[0023] FIG. 5 is a schematic view of a further embodiment of the
apparatus;
[0024] FIG. 6 is a schematic view of still another embodiment of
the apparatus;
[0025] FIG. 7 is a schematic view of a still further embodiment of
the apparatus;
[0026] FIG. 8 is an exploded perspective view of part of the
apparatus of FIG. 6;
[0027] FIGS. 8A and 8B are perspective views of portions of yet
another embodiment of the apparatus;
[0028] FIGS. 8C and 8D are schematic views of the portions of FIGS.
8A and 8B;
[0029] FIG. 9 is a schematic view of a yet further embodiment of
the apparatus; and
[0030] FIG. 10 is a schematic view of yet another embodiment of the
apparatus.
DESCRIPTION OF THE EMBODIMENTS
[0031] Reference will now be made in detail to some possible
embodiments of the invention, examples of which are illustrated in
the accompanying drawings. Wherever possible, the same reference
numbers are used in the drawings and the description to refer to
the same or like parts.
[0032] FIGS. 1-8 depict exemplary embodiments of an apparatus for
use in semiconductor processing. The apparatus 1 may include a
turbomolecular pump 10 and a dry pump 30.
[0033] The turbomolecular pump 10 may be a pump configured to
provide turbomolecular flow of a substance such that molecules of
the substance are more likely to collide with at least one interior
wall 15 (FIGS. 1 and 2) of the pump rather than into other
substance molecules. The turbomolecular pump 10 may have an inlet
11 to receive a flow of the substance at a first pressure and an
outlet 12 to expel the substance flow at a second pressure. As
shown in FIG. 2, the turbomolecular pump 10 may include blades 13
that rotate together to transition substance flow from an input
pressure on the order of about 10.sup.-1 to 10.sup.-3 millibar
(e.g., such as when the input flow passing through inlet 11 is from
an etching tool) or less (e.g., a pressure as low as about
10.sup.-8 millibar, such as, for example, when the input flow
passing through inlet 11 is from a tool or other structure
associated with an application other than etching, for example,
physical vapor deposition ("PVD") to an output pressure on the
order of about 1 to 10 millibar. The blades 13 may be disposed in
the turbomolecular pump 10 using mechanical bearings, or the blades
13 may be magnetically levitated within the turbomolecular pump 10.
The blades 13 may also be connected by a central shaft. For
example, as shown in FIG. 10, blades 13 may be disposed on a shaft
113. A top portion of shaft 113 closer to inlet 11 may be suspended
by magnetic bearings, and a bottom portion of shaft 113 closer to
outlet 12 may be suspended by mechanical bearings. In various
embodiments, however, shaft 113 may be suspended by any number of
bearings of any type and in any combination (e.g., two mechanical
bearings or two magnetic bearings).
[0034] Adjacent blades 13 may be spaced from one another by an
intervening stator 14. The stators 14 may remain substantially
stationary during the pumping process, and may be fixed to an outer
cylinder that surrounds the blades 13.
[0035] The molecules entering the pump 10 may have a substantially
random motion. These molecules may then land on a rotating blade 13
and pick up the blade's 13 velocity such that on leaving the blade
13, the molecule has the velocity of the blade 13 as well as the
blade's intrinsic thermal velocity. Thus, compression may be
generated by a combination of blades 13 providing a higher
transmission probability downwards rather than upwards due to the
angle of blades 13 and the relative blade velocity. Stationary
stator 14 is also configured such that it generates compression
through a combination of the relative gas velocity and the stator
14 providing a higher transmission probability downwards as
compared to upwards due to the angle of the stator blade. The
stator 14 may have a relative velocity from the reference of the
molecule such that equal pumping may be provided by stator 14 and
blade 13.
[0036] Additional details concerning exemplary configurations of a
turbomolecular pump 10 with blades 13 and stators 14, and its
various components, are set forth in U.S. Pat. Nos. 6,109,864 and
6,778,969, which are both incorporated herein by reference in their
entirety.
[0037] Each of the blades 13, intervening stators 14, and/or other
portions of the turbomolecular pump 10 may be configured to
efficiently move substances at low pressures. Turbomolecular pumps
typically operate with inlet pressures between 10.sup.-1 millibar
to 10.sup.-8 millibar and corresponding outlet pressures from 10
millibar to 1 millibar or less depending on flow and the size of
the pump downstream. One or more of blades 13 and intervening
stators 14 may rotate at relatively high speeds, for example, up to
twenty-thousand revolutions-per-minute or more.
[0038] The turbomolecular pump 10 may include a molecular drag
portion 17. The molecular drag portion 17 may be disposed before
and/or after the blades 13 and stators 14. The molecular drag
portion 17 may include two co-axial hollow cylinders 18, 19. One or
more of the cylinders 18, 19 may have a helical thread 20 provided
on the surface facing the other cylinder 18, 19. In operation, one
or more of the cylinders 18, 19 may rotate at relatively high
speeds, for example, up to twenty-thousand revolutions-per-minute
or more. Accordingly, at low pressures the molecules may strike the
surface of the rotating helical thread 20, giving the molecules a
velocity component and tending to cause the molecules to have the
same direction of motion as the surface against which they strike.
The molecules may be urged through the molecular drag portion 17 in
this manner and exit the molecular drag portion 17 at a higher
pressure than that at which they entered. Further details regarding
exemplary molecular drag portions and their various components can
be found in U.S. Pat. No. 5,772,395, which is incorporated herein
by reference in its entirety.
[0039] Molecular drag portion 17 may have an alternate
configuration, for example, as shown in FIG. 9. Molecular drag
portion 17 may have several stationary cylinders 18 having a
helical thread 20 and several rotating cylinders 19. Rotating
cylinders 19 may be connected, may rotate at substantially the same
rotational speed, and/or may be disposed on the same shaft 113 as
blades 13. Each stationary cylinder 18 and surface of rotating
cylinder 19 facing its respective stationary cylinder may comprise
a separate molecular drag portion 17. Some molecular drag portions
17 may include a surface of a stationary cylinder 18 having a
helical thread 20 facing radially outward and also facing a
substantially flat radially inward surface of a rotating cylinder
19. Some molecular drag portions 17 may have the opposite
configuration. Each stationary cylinder 18 may have helical threads
20 on its radially outward surface and/or its radially inward
surface. Each rotating cylinder 19 may face a surface of a
stationary cylinder 18 having helical threads 20 on its radially
outward surface and/or its radially inward surface.
[0040] Each molecular drag portion 17 may be in flow communication
with other molecular drag portions 17. Each molecular drag portion
17 may be disposed radially inward or outward from other molecular
drag portions 17. Each molecular drag portion 17 may have a
different configuration. For example, the helical threads 20 in
each molecular drag portion 17 may have a different length than
helical threads 20 in other molecular drag portions 17. Molecular
drag portions 17 may be disposed radially outward from
turbomolecular pump 10. Each molecular drag portion 17 may be
configured to increase a pressure of the substance while the
substance flows through the molecular drag portion 17, and then
exhaust the substance to a more radially outer molecular drag
portion 17 until the substance is exhausted by the final molecular
drag portion 17 to the dry pump 30.
[0041] The dry pump 30 may be a pump configured to provide
transition flow and/or viscous flow of the substance such that
molecules of the substance are more likely to collide with each
other rather than at least one interior wall 35 (FIG. 1) of the
pump. The dry pump 30 may have an inlet 31 to receive a substance
flow at a first pressure and an outlet 32 to expel the substance
flow at a second pressure. One exemplary type of dry pump 30 may
include rotating blades 33 (FIG. 2), typically having a different
geometry than those of a turbomolecular pump, such that they are
suitable for operating at higher pressures with intervening stators
34 which may be configured to transition substance flow from an
input pressure on the order of about 1 to 10 millibar or less
(e.g., a pressure as low as about 0.1) to atmospheric pressure on
the order of about 1000 millibar. The blades 33 may be disposed in
the dry pump 30 using bearings, and/or the blades 33 may be
disposed on a rotary shaft. The stators 34 may be fixed to a
cylindrical housing that surrounds the blades 33. The blades 33 and
stators 34 may operate similar to the blades 13 and stators 14
described above with respect to turbomolecular pump 10, in that the
dry pump 30 may cause an increase in the pressure of the substance
passing into the dry pump 30 via the inlet 31 before the substance
exits the dry pump 30 via the outlet 32. Examples of dry pumps and
their various components are disclosed in U.S. Pat. Nos. 6,244,841,
6,705,830, 6,709,226, 6,755,611 B1, which are all incorporated
herein by reference in their entirety. Other suitable examples of
dry pumps include a screw pump as disclosed in U.S. Pat. Nos.
6,129,534, 6,200,116, 6,379,135, and 6,672,855, which are
incorporated herein by reference in their entirety.
[0042] Dry pump 30 may have an alternate configuration, for
example, as shown in FIGS. 8A, 8B, 8C, 8D, and 9. In the alternate
configuration, dry pump 300 may include a regenerative rotor 350
and a regenerative stator 370.
[0043] As shown in FIG. 8A, regenerative rotor 350 may include a
plurality of substantially circular protrusions 351 extending from
a surface of regenerative rotor 350. Protrusions 351 may have a
plurality of blades 352 extending therefrom. A cross-section of
protrusion 351 and blade 352 is shown in FIG. 8D.
[0044] As shown in FIG. 8B, regenerative stator 370 may include a
plurality of protrusions 371 defining a plurality of channels 372
therebetween. Adjacent channels 372 may be connected via
intervening channels 373. A cross-section of protrusion 371 and
channel 372 is shown in FIG. 8D. Each channel 372 may include a
first portion 372a and a second portion 372b. First portion 372a
may be slightly wider than a width of protrusion 351, for example,
to prevent the flow of a substance therebetween. Thus, in
operation, any substance may be substantially contained in second
portion 372b. Second portion 372b may have any suitable
cross-sectional shape to accommodate substance flow, for example, a
curved or oval-like shape.
[0045] As shown in FIGS. 8C and 9, each blade 352 may be placed in
one of channels 372 such that protrusion 351 is disposed in first
portion 372a, and that blade 352 extends into second portion 372.
Each set of blades 352 and channels 372 may include a corresponding
inlet 391 and outlet 392 which may or may not be the same as
intervening channels 373.
[0046] In operation, blade 352 may rotate relative to channel 372.
A substance may enter second portion 372b of channel 372 via inlet
391. Blade 352 may then cause the substance to flow in the same
direction as the rotation of blade 352, for example, in a
substantially oval-like and/or spiral-like pattern. The substance
may then exit second portion 372b of channel 372 via outlet 392.
The substance may then be sent to another blade 352 and channel 372
combination, or may be exhausted from pump 1.
[0047] As shown in FIG. 9, dry pump 30 may have a plurality of
blade 352 and channel 372 combinations. Each combination of blades
352 and channels 372 may be disposed radially inward and/or outward
from other combinations of blades 352 and channels 372. Rotor 350
may be disposed on the same shaft 106 as blades 104 and cylinders
202. Each combination of blades 352 and channels 372 may exhaust
the substance from an outer combination to a combination disposed
radially inward. The inner-most combination may exhaust the
substance out of the pump 1, for example, to the atmosphere.
[0048] In some examples, the turbomolecular pump 10 may be coupled
to the dry pump 30 such that the turbomolecular pump 10 and the dry
pump 30 are positioned no more than about 20 centimeters from one
another. In such a configuration, the outlet 12 of the
turbomolecular pump 10 may be connected to the inlet 31 of the dry
pump 30 such that the outlet 12 and inlet 31 are in flow
communication with each other so as to pass the substance pumped
from the turbomolecular pump 10 into the dry pump 30.
[0049] In one exemplary embodiment, as shown in FIG. 1, the outlet
12 of the turbomolecular pump 10 may be connected to the inlet 31
of the dry pump 30 by a tube 50 that is no more than 20 centimeters
in length. In some examples, the tube 50 may have a length of less
than about 20 centimeters. For example, the length may be less than
about 10 centimeters or less than about 0.5 centimeters.
[0050] In another exemplary embodiment, as shown in FIG. 2, the
turbomolecular pump 10 may be directly connected to the dry pump 30
such that the outlet 12 of the turbomolecular pump 10 directly
contacts the inlet 31 of the dry pump 30. In such an embodiment,
the distance between the end of the blade 13 immediately preceding
the outlet 12 of the turbomolecular pump 10 and the beginning of
the blade 33 immediately following the inlet 31 of the dry pump 30
may be no more than about 20 centimeters. In various embodiments,
the distance between pumping elements 13, 33 may be less than about
20 centimeters, less than about 10 centimeters, or less than about
0.5 centimeters.
[0051] As shown in FIGS. 1 and 2, the turbomolecular pump 10 and
the dry pump 30 may share a common housing 80 and the boundary
between the two pumps may not be externally discernable (i.e., a
person viewing the exterior of the apparatus with unassisted vision
would not be able to visualize the boundary between the pumps 10
and 30). Each of the pumps 10, 30 may have its own respective
driving motor so as to rotate the sets of blades or other mechanism
13 and 33 at different speeds.
[0052] FIGS. 4-7 depict exemplary embodiments of apparatuses 1 each
including an abatement device 60. The abatement device 60 may be
configured to convert a substance gas flow, which may be at least
partially toxic and/or chemically volatile, and/or include a global
warming gas, etc., into a form that is more manageable, stable,
and/or benign. Some examples of different types of abatement
devices 60 include plasma-type abatements, burning type abatements,
abatements with electrically heated surfaces, etc.
[0053] In one example of an abatement process, the abatement device
60 may receive a substance flow including perfluorocarbons ("PFCs")
via at least one of the turbomolecular pump 10 and the dry pump 30.
The abatement device 60 may then take the PFCs and break them up
into hydrogen flouride ("HF"). While HF may be more hazardous than
PFCs, unlike PFCs, HF may be readily dissolved in water. Thus
dissolved, the HF may now be more easily handled and/or disposed.
More details concerning this type of abatement is disclosed in U.S.
Pat. No. 6,530,977, which is incorporated herein by reference in
its entirety.
[0054] Another example of abatement device 60 is disclosed in U.S.
Pat. No. 6,358,485, which is incorporated herein by reference in
its entirety. In such an abatement device, a gas stream containing
trimethylvinylsilane (TMVS) is exposed to a gas stream containing
copper oxide and/or manganese oxide, which chemically combine to
form a non-toxic byproduct. This non-toxic byproduct may then be
readily and more easily disposed.
[0055] In another example of an abatement process, the abatement
device 60 may receive a substance flow including fluorine via at
least one of the turbomolecular pump 10 and the dry pump 30. The
abatement device 60 may take the fluorine and burn it (or otherwise
heat it and provide a hydrogen atom source) so as to form HF. The
HF may then be dissolved in water and disposed of.
[0056] In yet a further example of an abatement process, the
abatement device 60 may receive a substance flow including
pyrophoric gas(es) (e.g., silane) via at least one of the
turbomolecular pump 10 and the dry pump 30. The abatement device 60
may take the pyrophoric gas(es) and mix it with air heated to at
least 300 degrees Celsius. Such mixing may reduce the amount of
pyrophoric gas(es) that exits the abatement device, thus making the
substance flow safer and easier to handle. More details concerning
an example of this type of abatement are disclosed in U.S. Pat. No.
6,530,977, which is incorporated herein by reference in its
entirety.
[0057] The abatement device 60 may be positioned at any location so
as to receive substance passing to, or flowing from, either or both
of the pumps 10, 30. If the abatement device 60 operates more
efficiently at lower pressures, the abatement device 60 may be
positioned downstream from the turbomolecular pump 10 and upstream
from the dry pump 30, as shown in FIG. 5. If the abatement device
operates more efficiently at higher pressures the abatement device
60 may be positioned downstream from both of the turbomolecular
pump 10 and the dry pump 30, as shown in FIGS. 4, 6, and 7.
[0058] FIGS. 5 and 7 depict exemplary embodiments of an apparatus
10 including a cryogenic water pump 70. The cryogenic water pump 70
may be configured to receive the substance flow from a vacuum
processing chamber 2 (partially shown in FIG. 5 in schematic form)
and remove water at a very high efficiency. It may also be used to
remove from the substance flow other desired material(s), such as
lower vapor pressure precursors used within the semiconductor
process (although in some example, it may possibly be more
desirable to pump such materials through the turbomolecular pump
and drypump.
[0059] In some examples, the vacuum processing chamber 2 may be
associated with a semiconductor wafer processing arrangement where
very low levels of water vapor may be used and/or created. For
example, when a vacuum is created in the vacuum processing chamber
2, water molecules may be collected on the inner surfaces of the
chamber 2. When the substance flow exits the vacuum chamber 2, it
may be desirable to substantially prevent any of the water vapor
from reentering the vacuum processing chamber 2.
[0060] The cryogenic water pump 70 may remove the water vapor from
the substance flow by causing the water vapor to freeze and become
trapped on cryogenically cooled surfaces of the cryogenic water
pump 70. If the temperature of the surfaces of the cryogenic water
pump 70 is lowered enough, the cryogenic water pump 70 may also
trap other materials on its surface, for example lower vapour
pressure precursors used within the semiconductor process. If the
temperature is lowered further, then gases like carbon dioxide and
argon may be trapped, although these gases may be more commonly
handled downstream from the turbomolecular pump and/or the dry
pump. Avoiding oxygen condensation may also be desirable, hence the
use of a cryogenic pump for water but turbomolecular pump for
gases.
[0061] As shown in FIGS. 5 and 7, the cryogenic water pump 70 may
be mounted onto the top of the turbomolecular pump 10 such that an
outlet of the cryogenic water pump 70 ends where the inlet of the
turbomolecular pump 10 begins. In other examples, the top section
of the turbomolecular pump 10 may house the cryogenic water pump 70
such that the cryogenic water pump 70 is not externally
discernable. In some examples, there may be a valve between the two
pumps 30, 70.
[0062] FIGS. 6-8 depict exemplary embodiments of an apparatus 1
with common portions and/or connections. The common housing 80 may
be associated with both the turbomolecular pump 10 and the dry pump
30. The common housing 80 may also be associated with the abatement
device 60 and/or the cryogenic water pump 70. The common housing 80
may be configured such that the boundaries between the
turbomolecular pump 10, the dry pump 30, the abatement 60, and/or
the cryogenic water pump 70 are not externally discernable.
[0063] As shown in FIG. 7, the turbomolecular pump 10, the dry pump
30, the abatement device 60, and/or the cryogenic water pump 70 may
be disposed in a single room 3 of a semiconductor processing
facility.
[0064] As shown in FIGS. 6 and 7, the turbomolecular pump 10, the
dry pump 30, the abatement device 60, and/or the cryogenic water
pump 70 may have a common controller 90 that controls each of the
turbomolecular pump 10, the dry pump 30, the abatement 60, and/or
the cryogenic water pump 70. The common controller 90 may be
connected to the turbomolecular pump 10, the dry pump 30, the
abatement 60, and/or the cryogenic water pump 70 by a controller
connection 91.
[0065] In some examples, rather than having a wired connection, a
wireless link may provide communication between the common
controller 90 and the turbomolecular pump 10, the dry pump 30, the
abatement 60, and/or the cryogenic water pump 70.
[0066] The turbomolecular pump 10, the dry pump 30, the abatement
60, and/or the cryogenic water pump 70 may share common
connections. For example, the turbomolecular pump 10, the dry pump
30, the abatement 60, and/or the cryogenic water pump 70 may share
a common power connection 100 (FIG. 6). The power connection 100
may provide electrical power to the turbomolecular pump 10 and the
dry pump 30 so as to power motors associated with the respective
mechanisms of the turbomolecular pump 10 and the dry pump 30. This
connection may also be fed through the remote controller cabinet 90
to condition power before being directed to the turbomolecular pump
10 and the dry pump 30.
[0067] As shown in FIG. 8, the turbomolecular pump 10 and the dry
pump 30 may share common water distribution route 101. As the
turbomolecular pump 10 and the dry pump 30 operate, they generate
heat due to compression of the substance (e.g., when the substance
is a gas) and cause the substance flow in the pumps 10, 30 to
increase in temperature. In order to moderate the temperature of
each of the pumps 10, 30, water may be introduced into, circulated
through, and removed from the pumps 10, 30 so as to remove heat. In
an exemplary embodiment, water may enter at least one of the pumps
10, 30 via one of the common water distribution route 101 at about
20.degree. C. and leave at least one of the pumps at about
30-35.degree. C. via the other water distribution route 101.
[0068] The turbomolecular pump 10 and the dry pump 30 may share a
common nitrogen distribution route 102. Nitrogen may be used to
protect certain elements of the pumps 10, 30 from contamination.
For example, the pumps 10, 30 may each have a motor and bearing
arrangement, and the nitrogen may be used to keep potentially
corrosive process materials away from the bearings or other
portions in the motors of the pumps 10, 30.
[0069] Nitrogen may additionally (or alternatively) be used to
dilute gas flowing through at least one of the pumps 10, 30. For
example, if a very light gas, such as hydrogen or helium, is being
pumped through the pumps 10, 30, the light gas may move around very
quickly, and thus may have a tendency to flow undesirably backwards
through the turbomolecular pump 10 and the dry pump 30. By adding
nitrogen, the density of the chemical flow may be increased and the
backwards flow of the light gas species may be substantially
reduced and/or eliminated.
[0070] Nitrogen may additionally (or alternatively) be used to
substantially prevent condensation within at least one of the pumps
10, 30. For example, water may condense out of the substance flow
as the substance flow is brought up to atmospheric pressure. By
adding nitrogen to the substance flow, the water within the
substance flow passing through at least one of the pumps 10, 30 may
be diluted, and thus condensation of the water may be substantially
limited or prevented by keeping the water in the vapor phase. In
addition to limiting condensation of water, nitrogen may be used to
limit condensation of other materials, such as, for example,
silicon fluoride and silicon bromide.
[0071] Nitrogen may additionally (or alternatively) be used to
dilute a flammable material so that it no longer has a flammable
concentration.
[0072] As shown in FIG. 8, the turbomolecular pump 10 and the dry
pump 30 may also share a common clean dry air (CDA) distribution
route 103. The clean dry air may be substituted for nitrogen in
some instances or be used to operate any pneumatic systems (e.g.,
valves).
[0073] The invention may have several advantages. For example, the
invention may operate at a greater efficiency than pumps positioned
at further distances relative to each other. In another example,
conductance losses present during the use of pumps positioned at
further distances relative to each other may be minimized and/or
substantially eliminated, for example, due to a reduction in the
length of the substance flow paths. In another example, the
invention may take up less space than pumps positioned at further
distances relative to each other and require less energy, important
advantages in an industry where space and power consumption is at a
premium. In a further example, because the exhaust from the
apparatus may be greater than or equal to about 100 millibar,
double containment of the apparatus may not be necessary as any
sub-atmospheric leaks may be inwards.
[0074] It will be apparent to those skilled in the art that various
modifications and variations can be made to the structure described
herein. This, it should be understood that the invention is not
limited to the subject matter discussed in the specification and
shown in the drawings. Rather, the present invention is intended to
include modifications and variations.
* * * * *