U.S. patent application number 10/624397 was filed with the patent office on 2005-01-27 for multi-staged heating system for fabricating microelectronic devices.
Invention is credited to Ivanov, Igor C., Zhang, Weiguo.
Application Number | 20050016201 10/624397 |
Document ID | / |
Family ID | 34080002 |
Filed Date | 2005-01-27 |
United States Patent
Application |
20050016201 |
Kind Code |
A1 |
Ivanov, Igor C. ; et
al. |
January 27, 2005 |
Multi-staged heating system for fabricating microelectronic
devices
Abstract
A system is provided which is adapted to transport a fluid from
a plurality of serially coupled tanks to a chamber configured to
process microelectronic wafers. The system further includes a
plurality of temperature controllers positioned such that the
chamber and the tanks are characterized into at least three zones
based upon the adaptations of the controllers to maintain the fluid
within each zone within a distinct temperature range. A method is
also provided which includes storing a fluid within a preliminary
temperature range, transporting the fluid to an intermediate tank
and controlling the fluid temperature within the intermediate tank
to be within a transitional temperature range distinct from the
preliminary temperature range. The method further includes
delivering the fluid to a process chamber and controlling the fluid
temperature within the process chamber to be within a process
temperature range distinct from the preliminary and transitional
temperature ranges.
Inventors: |
Ivanov, Igor C.; (Dublin,
CA) ; Zhang, Weiguo; (San Jose, CA) |
Correspondence
Address: |
DAFFER MCDANEIL LLP
P.O. BOX 684908
AUSTIN
TX
78768
US
|
Family ID: |
34080002 |
Appl. No.: |
10/624397 |
Filed: |
July 22, 2003 |
Current U.S.
Class: |
62/434 ; 62/185;
62/65 |
Current CPC
Class: |
H01L 21/67248 20130101;
H01L 21/6715 20130101; C23C 18/1619 20130101; C23C 18/1676
20130101; H01L 21/67023 20130101 |
Class at
Publication: |
062/434 ;
062/065; 062/185 |
International
Class: |
F25D 013/04; F25D
017/02 |
Claims
What is claimed is:
1. A system, comprising: a chamber configured to process one or
more wafers for the fabrication of microelectronic devices; a
plurality of reservoirs serially coupled to the chamber via a
plurality of intervening pipes, wherein the system is adapted to
transport a fluid used to process the wafers from the plurality of
reservoirs to the chamber; one or more devices adapted to maintain
the fluid supplied to the chamber within a first temperature range;
and one or more additional devices adapted to maintain the fluid
residing in a first set of the plurality of reservoirs within a
second temperature range distinct from the first temperature range,
wherein a second set of the plurality of reservoirs are used to
maintain the fluid residing therein within a third temperature
range distinct from the first and second temperature ranges.
2. The system of claim 1, wherein the chamber is configured to
conduct an electroless deposition process.
3. The system of claim 1, wherein the system is further adapted to
transport the fluid from the chamber to one or more of the
plurality of reservoirs.
4. The system of claim 1, wherein the system is further adapted to
circulate the fluid between at least two of the plurality of
reservoirs.
5. The system of claim 1, wherein the first temperature range is
higher than the second temperature range.
6. The system of claim 1, wherein the second temperature range is
higher than the third temperature range.
7. The system of claim 1, wherein the first temperature range is
lower than the second temperature range, and wherein the second
temperature range is lower than the third temperature range.
8. The system of claim 1, wherein the first temperature range
comprises temperatures between approximately 42.degree. C. and
approximately 50.degree. C.
9. The system of claim 1, wherein the second temperature range
comprises temperatures between approximately 70.degree. C. and
approximately 95.degree. C.
10. The system of claim 1, wherein the third temperature range
comprises temperatures between approximately 95.degree. C. and
approximately 110.degree. C.
11. The system of claim 1, further comprising one or more different
devices adapted to maintain the fluid residing in the second set of
the plurality of reservoirs within the third temperature range.
12. The system of claim 1, further comprising one or more
additional process chambers coupled to at least one of the
plurality of reservoirs.
13. A system, comprising: a chamber configured to process one or
more wafers for the fabrication of microelectronic devices; a
plurality of tanks serially coupled to the chamber and adapted to
store a fluid used to process the wafers; and a plurality of
temperature controllers positioned within the system such that the
chamber and the plurality of tanks are characterized into at least
three different zones based upon adaptations of the temperature
controllers to maintain the fluid within distinct temperature
ranges in the respective zones while processing the wafers.
14. The system of claim 13, wherein the plurality of temperature
controllers are positioned such that the at least three different
zones are arranged in ascending order based upon their respective
temperature ranges, and wherein the zone comprising the chamber has
the highest temperature range.
15. The system of claim 13, wherein the plurality of temperature
controllers are positioned such that the at least three different
zones are arranged in descending order based upon their respective
temperature ranges, and wherein the zone comprising the chamber has
the lowest temperature range.
16. The system of claim 13, wherein one of the plurality of
temperature controllers is arranged within the chamber.
17. The system of claim 13, wherein one of the plurality of
temperature controllers is coupled to a fluid inlet of the
chamber.
18. The system of claim 13, wherein one of the plurality of
temperature controllers is coupled to one of a plurality of pipes
configured to transport the fluid from the plurality of tanks to
the chamber.
19. The system of claim 13, wherein one of the plurality of
temperature controllers is arranged within one of the plurality of
tanks.
20. The system of claim 13, wherein at least one of the plurality
of temperature controllers comprises an infrared heater.
21. A method, comprising: storing a fluid used to process
microelectronic topographies within a storage tank of a
microelectronic fabrication apparatus within a preliminary
temperature range; transporting the fluid from the storage tank to
an intermediate tank of the microelectronic fabrication apparatus;
controlling the temperature of the fluid within the intermediate
tank to be within a transitional temperature range distinct from
the preliminary temperature range; delivering the fluid from the
intermediate tank to a process chamber of the microelectronic
fabrication apparatus; and controlling the temperature of the fluid
within the process chamber to be within a process temperature range
distinct from the preliminary and transitional temperature
ranges.
22. The method of claim 21, wherein the step of transporting the
fluid from the storage tank to the intermediate tank comprises
circulating the fluid between the storage tank and intermediate
tank.
23. The method of claim 21, further comprising recirculating the
fluid from the chamber to at least one of the intermediate and
storage tanks.
24. The method of claim 21, wherein the steps of controlling the
temperature within the intermediate tank or process chamber
comprises heating the fluid.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention generally relates to a system and a method
for fabricating microelectronic devices and, more specifically, a
system and a method for controlling the temperature of a fluid used
to process a microelectronic topography prior to and during a
fabrication step.
[0003] 2. Description of the Related Art
[0004] The following descriptions and examples are not admitted to
be prior art by virtue of their inclusion within this section.
[0005] Electroless plating is a process for depositing materials on
a catalytic surface from an electrolyte solution without an
external source of current. An advantage of an electroless
deposition process is that it can be selective, i.e., the material
can be deposited only onto areas that demonstrate appropriate
chemical properties. In addition, electroless deposition techniques
are favorable for depositing materials into deep holes within the
topography that cannot be uniformly covered by other deposition
techniques, such as sputtering and evaporation, for example. As
such, an electroless deposition process may be advantageous for
depositing a metal using a damascene process. One common drawback
of existing electroless deposition processes and apparatuses is,
however, low deposition rates. For example, a typical electroless
deposition process does not exceed 100 nm/min. The deposition rate
of an electroless process is generally dependent on the material to
be deposited and, therefore, may be much lower than 100 nm/min in
some cases. For instance, the deposition rate of a
cobalt-tungsten-phosphorus layer may be less than approximately 20
nm/min.
[0006] In general, the deposition rate of an electroless process
may depend on characteristics of the activated areas, such as
profiles of the exposed surfaces. In some embodiments, the
deposition rate of an electroless process may further depend on the
temperature of the solution used to deposit the material. In
particular, the deposition rate of an electroless process may
generally increase with increases in temperature of the deposition
solution. Many electroless deposition solutions, however, tend to
decompose at high temperatures, leading to significant
non-uniformities in the deposited material. In particular, the
decomposition of a solution may cause the deposition rate of an
electroless deposition process to vary across a topography or may
halt the deposition process entirely.
[0007] In either case, the deposition solution needs to be
replenished in order to prevent such a disruption in the deposition
process. More specifically, the deposition solution needs to be
replenished periodically due to the consumption of the components
within the solution. Such a replenishment process, however, may
cause non-uniformities in the deposition process. In particular,
the replenishment of a solution within a process chamber may cause
the temperature of the solution to fluctuate, causing the
deposition rate to vary. In some cases, such temperature
fluctuation issues are resolved by replenishing the chamber with a
solution which is stored at the desired process temperature.
Storing the solution at the desired process temperature prior to
introducing it into the chamber, however, may undesirably advance
the decomposition of the solution, resulting in a shortened
processing life. Consequently, the solution, in such an embodiment,
may need to be replenished at a high flow rate. As a result, a vast
of amount of solution may be used, increasing production and waste
disposal costs of the process.
[0008] As such, it would be advantageous to develop a system and a
method for delivering a fluid into a chamber used to process a
microelectronic topography without disrupting the rate of the
fabrication step. More specifically, it would be beneficial to
develop a system and a method which prepare a fluid for delivery
into a chamber by regulating the temperature of the fluid at
different stages prior to being introduced into the chamber. In
particular, it would be advantageous to have a system and a method
which minimize the temperature fluctuation of the fluid within the
chamber upon replenishment of the fluid, while also minimizing the
variation of components within the fluid. Such a system and method
may be particularly advantageous for processes associated with an
electroless deposition process.
SUMMARY OF THE INVENTION
[0009] The problems outlined above may in large part be addressed
by a system and a method for delivering a fluid into a chamber that
is used to process microelectronic topographies. In particular, a
system and a method are provided which control the temperature of a
fluid used to process a microelectronic topography prior to and
during a fabrication step of the topography. In general, the system
may include a chamber configured to process one or more wafers for
the fabrication of microelectronic devices. In some cases, the
chamber may be particularly configured to conduct an electroless
deposition process, including but not limited to any processes
performed prior to, during, or subsequent to an electroless
deposition process. In particular, the chamber may be configured to
conduct etching, activating, depositing, rinsing and/or cleaning
steps associated with an electroless deposition process. In other
cases, the chamber may additionally or alternatively be configured
to conduct processes other than steps associated with an
electroless deposition process.
[0010] In any case, the system may further include a plurality of
reservoirs adapted to store a fluid used to process wafers in the
chamber. Such a plurality of reservoirs may be serially coupled to
the chamber via a plurality of intervening pipes such that the
system may be adapted to transport the fluid from the plurality of
reservoirs to the chamber. In some cases, the system may be further
adapted to transport the fluid from the chamber to one or more of
the plurality of reservoirs. In addition or alternatively, the
system may be adapted to circulate the fluid between at least two
of the plurality of reservoirs. In some embodiments, the system may
include one or more additional process chambers coupled to at least
one of the plurality of reservoirs.
[0011] In any case, the system may include a plurality of
temperature controllers positioned such that the chamber and the
plurality of reservoirs are characterized into at least three
different zones based upon adaptations of the temperature
controllers to maintain the fluid within distinct temperature
ranges in the respective zones while processing the wafers. In
particular, the system may include one or more devices adapted to
maintain the fluid supplied to the chamber within a first
temperature range, while another set of devices may be adapted to
maintain the fluid residing in a first set of the plurality of
reservoirs within a second temperature range. In addition, a second
set of the plurality of reservoirs, distinct from the first set,
may be used to maintain the fluid residing therein within a third
temperature range. Additional sets of the reservoirs may be used to
characterize other temperature zones of the system as well,
depending on the design specifications of the apparatus. In other
cases, however, the system may be specifically adapted to only
characterize three different zones. In any case, the plurality of
temperature controllers may be positioned such that the different
zones are arranged in ascending order based upon their respective
temperature ranges. In such an embodiment, the zone in which the
chamber is included may have the highest temperature range.
Alternatively, the plurality of temperature controllers may be
positioned such that the different zones may be arranged in
descending order based upon their respective temperature ranges. In
such an embodiment, the zone in which the chamber is included may
have the lowest temperature range.
[0012] In any case, the temperature ranges of the different zones
of the system may be distinct from each other. In some embodiments,
the temperature range of the zone including the process chamber may
be higher than the temperature range of the zone including the
first set of reservoirs. In addition or alternatively, the
temperature range including the first set of reservoirs may be
higher than the temperature range of the zone including the second
set of reservoirs. In yet other embodiments, the temperature range
of the zone including the process chamber may be lower than the
temperature range of the zone including the first set of
reservoirs, which may be lower than the temperature range of the
zone including the second set of reservoirs. In any case, the
system may, in some embodiments, be used for an electroless
deposition process, as noted above. In such an embodiment, an
exemplary temperature range for the zone farthest away from the
process chamber may be between approximately 42.degree. C. and
approximately 50 .degree. C., while the temperature range for the
zone arranged directly adjacent to the zone including the process
chamber may include temperatures between approximately 70.degree.
C. and approximately 95.degree. C. An exemplary temperature range
for the zone including the process chamber may include temperatures
between approximately 95.degree. C. and approximately 115.degree.
C. Other temperature ranges, however, may be used for the different
respective temperature ranges, depending on the design
specifications of the fabrication step and the operating parameters
of the fluid.
[0013] The temperature controllers may be arranged in a variety of
locations within the system in order to achieve the
characterization of distinct zones of temperature ranges. For
example, in some embodiments, one or more of the temperature
controllers may be arranged within and/or about the process
chamber. In addition or alternatively, one or more of the
temperature controllers may be coupled to a fluid inlet of the
chamber. In yet other embodiments, one or more of the temperature
controllers may be arranged within one of the plurality of
reservoirs or within one of a plurality of pipes configured to
transport the fluid from the plurality of reservoirs to the
chamber. In any case, the plurality of temperature controllers may
include any type of mechanism with which to control the temperature
of a fluid. For example, in some cases, the temperature controllers
may include a heater or more specifically, an infrared heater. In
other embodiments, the temperature controllers may additionally or
alternatively include a cooler.
[0014] A method for delivering a fluid to a chamber configured to
process wafers for the fabrication of microelectronic devices is
also contemplated herein. In particular, a method is provided which
includes storing a fluid, used to process microelectronic
topographies, within a storage tank of a microelectronic
fabrication apparatus. Such a step may include controlling the
temperature of the fluid within a preliminary temperature range.
The method may further include transporting the fluid from the
storage tank to an intermediate tank of the microelectronic
fabrication apparatus. In some cases, the step of transporting the
fluid from the storage tank to the intermediate tank may include
circulating the fluid between the storage tank and intermediate
tank. In other cases, the transportation of the fluid may be simply
include delivering the fluid from the storage tank to the
intermediate tank without a recirculation loop back to the storage
tank. In either embodiment, the method may include controlling the
temperature of the fluid within the intermediate tank to be within
a transitional temperature range which is distinct from the
preliminary temperature range of the storage tank.
[0015] As noted above, the method may include delivering the fluid
to a process chamber of the microelectronic fabrication apparatus.
In particular, the method may include transporting the fluid from
the intermediate tank to the process chamber. In some cases, the
method may include recirculating the fluid from the chamber to at
least one of the intermediate and storage tanks. In other
embodiments, however, the fluid from the chamber may be disposed.
In either case, the method may include controlling the temperature
of the fluid within the process chamber to be within a process
temperature range which is distinct from the preliminary and
transitional temperature ranges of the storage and intermediate
tanks, respectively. In general, the steps of controlling the
temperature within the intermediate tank or process chamber may
include heating and/or cooling the fluid.
[0016] There may be several advantages to using the system and
methods described herein. For example, a system is provided which
is configured to deliver a fluid into a chamber used to process a
microelectronic topography without substantially altering the
temperature of the fluid within the chamber. In this manner, a
system and method are provided which allows a fluid to be
introduced into a processing chamber without disrupting the rate of
fabrication of a microelectronic device. For instance, a deposition
solution for an electroless deposition process may be replenished
without having the temperature of the solution vary within the
chamber. As a result, a substantially uniform layer may be
deposited. In addition, the system and method described herein may
advantageously minimize the amount of fluid used to process the
topography by optimizing the temperature and time the fluid is
heated prior to being introduced in the chamber. Consequently,
material and waste disposal costs associated with the process may
be reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Other objects and advantages of the invention will become
apparent upon reading the following detailed description and upon
reference to the accompanying drawings in which:
[0018] FIG. 1a depicts a schematic diagram of a microelectronic
fabrication system in a storage mode of operation;
[0019] FIG. 1b depicts a schematic diagram of the microelectronic
fabrication system illustrated FIG. 1a in a pre-process mode of
operation;
[0020] FIG. 1c depicts a schematic diagram of the microelectronic
fabrication system illustrated FIG. 1a in process mode of
operation; and
[0021] FIG. 2 depicts a flow chart of a method for delivering a
fluid to a process chamber of the system illustrated in FIGS.
1a-2c.
[0022] While the invention is susceptible to various modifications
and alternative forms, specific embodiments thereof are shown by
way of example in the drawings and will herein be described in
detail. It should be understood, however, that the drawings and
detailed description thereto are not intended to limit the
invention to the particular form disclosed, but on the contrary,
the intention is to cover all modifications, equivalents and
alternatives falling within the spirit and scope of the present
invention as defined by the appended claims.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] Turning now to the drawings, an exemplary embodiment of a
system configured to prepare a fluid for optimum use within a
microelectronic fabrication chamber is illustrated in FIGS. 1a-1c.
In particular, FIGS. 1a-1c illustrate a system adapted to control
the temperature of a fluid used to process a microelectronic
topography prior to and during a fabrication step of the
topography. Such an adaptation may be used to minimize the thermal
fluctuations of the fluid within the chamber such that the reaction
rate at which the fabrication step is conducted may be maximized
and the uniformity of the process may be substantially stable. In
addition, the adaptation of the system may be used to optimize the
life of the fluid such that material and waste disposal costs may
be minimized.
[0024] As shown in FIGS. 1a-1c, the system is designated, as a
whole, by reference numeral 20 and includes process chamber 22. In
general, process chamber 22 may be configured to process one or
more wafers for the fabrication of microelectronic devices. More
specifically, process chamber 22 may be configured to conduct one
or more processing steps, such as depositing, etching, activating,
polishing, cleaning, rinsing, drying, or any combination of such
processes associated with the fabrication of microelectronic
devices. As such, process chamber 22 may be adapted to produce
conditions which may be necessitated by one or more steps of a
fabrication process. In particular, process chamber 22 may be
adapted to generate environments with pressures below, at, or above
atmospheric pressure as well as temperatures ranging between
approximately -20.degree. C. and approximately 800.degree. C. In
addition, process chamber 22 may be adapted to process a
microelectronic topography with a fluid in any state of matter
known to be used in the microelectronic fabrication industry for a
respective process step. As such, process chamber 22 may be adapted
to treat a microelectronic topography with a liquid, gas, or
plasma, including gases in a standard state or an excited state
(i.e., a photon-activated gas state).
[0025] In a preferred embodiment, process chamber 22 may be used
for processes associated with an electroless deposition process,
including any processes performed prior to, during, and/or
subsequent to an electroless deposition process. For example, in
some cases, process chamber 22 may be used to activate a surface of
a microelectronic topography such that a layer may be subsequently
deposited using an electroless deposition solution within process
chamber 22 or within a different process chamber. In addition or
alternatively, process chamber 22 may be used for polishing,
rinsing, and/or cleaning an electrolessly deposited layer as well
as depositing a cap layer upon the electrolessly deposited layer.
In yet other embodiments, process chamber 22 may simply be used for
electroless deposition of a layer. In any case, process chamber 22
may be additionally or alternatively used for processes not
associated with an electroless deposition process as well.
[0026] In general, process chamber 22 may have a plurality of
components arranged therein and coupled thereto. For example,
process chamber 22 may include a substrate holder, a plurality of
inlets and outlets, and a loading port as well as any other
components which may be used to process a microelectronic
topography. Such a plurality of components is not illustrated in
FIGS. 1a-1c to simplify the drawing illustrations. In general, the
system and method described herein are not restricted by the
configuration of process chamber 22. As such, any process chamber
configured for the fabrication of microelectronic devices may be
included within system 20. Exemplary configurations of process
chambers that may be used for process chamber 22 are described in
U.S. patent application Ser. Nos. 10/103,015; 10/242,331;
10/369,878; 10/247,895; and 10/299,074, which are incorporated by
reference as if fully set forth herein.
[0027] As shown in FIGS. 1a-1c, system 20 may further include
intermediate tank/s 24 and storage tank/s 26 serially coupled to
process chamber 22. In general, intermediate tank/s 24 and storage
tank/s 26 may be adapted to store a fluid used to process a
microelectronic topography within process chamber 22. As noted
above, process chamber 22 may be used for any microelectronic
fabrication process, including but not limited to, depositing,
etching, activating, polishing, cleaning, rinsing, drying, or any
combination of such processes. As such, intermediate tank/s 24 and
storage tank/s 26 may be adapted to store any fluid, including a
liquid or a gas, which is used for the fabrication of a
microelectronic device. In some cases, the fluid stored within
include intermediate tank/s 24 and storage tank/s 26 may be
associated with processes that treat a microelectronic topography
prior to, during, and/or subsequent to an electroless deposition
process. For example, the fluid may be an electroless deposition
solution. In other embodiments, the fluid may used for the
treatment of a wafer prior to or subsequent to an electroless
deposition process. In yet other cases, the fluid stored within
include intermediate tank/s 24 and storage tank/s 26 may be used
for processes other than those associated with an electroless
deposition process.
[0028] In general, intermediate tank/s 24, storage tank/s 26 and
process chamber 22 may each include one or more reservoirs. In
particular, process chamber 22 may include one or more reservoirs
coupled in parallel to intermediate tank/s 24. In this manner,
intermediate tank/s 24 and storage tank/s 26 may be used to supply
a fluid to a single process chamber or a plurality of process
chambers. In cases in which one or both of intermediate tank/s 24
and storage tank/s 26 include a plurality of reservoirs, the
reservoirs may either be serially coupled to each other or may be
arranged in parallel. Alternatively stated, intermediate tank/s 24
may, in some embodiments, include a plurality of reservoirs coupled
in series or in parallel to each other. Similarly, storage tank/s
24 may additionally or alternatively include a plurality of
reservoirs coupled in series or in parallel. In yet other
embodiments, one or both of intermediate tank/s 24 and storage
tank/s 26 may include a single reservoir. In any case, system 20
may include one or more other "sets" of intermediate and storage
tanks serially coupled to each other such that other fluids may be
supplied to one or more process chambers of system 20 in a manner
similar to the method described below in reference to intermediate
tank/s 24 and storage tank/s 26. As used herein, a "set" of
intermediate and storage tanks may generally refer to one or more
storage tanks serially coupled to one or more intermediate tanks
for the delivery of a particular fluid to one or more process
chambers.
[0029] In any case, the primary distinction between intermediate
tank/s 24 and storage tank/s 26 are their adaptations to maintain
the fluid residing therein within two distinct temperature ranges
as described in more detail below. Another matter of distinction
between intermediate tank/s 24 and storage tank/s 26, however, may
also be the volume of fluid each is configured to hold. In
particular, storage tank/s 26 maybe configured to hold a larger
volume of liquid than intermediate tank/s 24 in some embodiments.
For example, in some cases, storage tank/s 26 may be adapted to
hold between approximately 30 liters and approximately 100 liters
of fluid, while intermediate tank/s 24 may be adapted to store
between approximately 10 liters and approximately 30 liters.
Although intermediate tank/s 24 and storage tank/s 26 may be
adapted for larger or smaller volumes of fluid depending on the
design specifications of the system, the relative amounts of fluid
storage tank/s 26 and intermediate tank/s 24 are adapted to hold
preferably decrease with the proximity of the tanks to process
chamber 22 in such an embodiment. Consequently, in some
embodiments, one or both of intermediate tank/s 24 and/or storage
tank/s 26 may have a plurality of reservoirs of different volumes
serially arranged in order of their volumes. In other embodiments,
however, one or both of intermediate tank/s 24 and/or storage
tank/s 26 may have a plurality of reservoirs having substantially
similar volumes as each other. In yet other cases, intermediate
tank/s 24 may not be configured to hold a smaller amount of fluid
than storage tank/s 26, but rather may be configured to store a
similar amount of fluid.
[0030] In any case, process chamber 22 is preferably configured to
hold a smaller volume of fluid than intermediate tank/s 24. For
example, in the aforementioned embodiment in which fluid volumes
for intermediate tank/s 24 and/or storage tank/s 26 are recited,
process chamber 22 may be adapted to hold approximately 2 liters or
less of fluid. In other cases, process chamber 22 may be adapted to
hold larger or smaller volumes of fluid, depending on the design
specifications of the device. In any case, scaling down the
reservoir volumes between storage tank/s 24 and process chamber 22
may be advantageous for minimizing the advancement of fluid
decomposition as described in more detail below. In particular,
changing the temperature of relatively small volumes of fluid will
generally be easier to accomplish the process of changing the
temperature of the fluid to a desired temperature for the
fabrication process in process chamber 22 while minimizing the
advancement of the fluid decomposition.
[0031] As shown in FIGS. 1a-1c, intermediate tank/s 24 and storage
tank/s 26 may be serially coupled to process chamber 22 by
intervening pipes 28. As noted above, intermediate tank/s 24 and
storage tank/s 26 may be adapted to store a fluid used to process a
microelectronic topography. Intervening pipes 28, on the other
hand, may be used to transport the fluid between storage tank/s 26,
intermediate tank/s 24, and process chamber 22 via pumps 30. It is
noted that although pipes 28 may be adapted to store some of the
fluid during certain moments of the process, tank/s 24 and 26 are
clearly distinct from pipes 28 in that the tanks are configured to
store a considerable larger amount of fluid than pipes 28. In
particular, tank/s 24 and 26 may be distinguished as reservoirs,
while pipes 28 may be distinguished as passageways. It is further
noted that system 20 may be adapted to provide fluids other than
the fluid stored in intermediate tank/s 24 and storage tank/s 26 to
process chamber 22 in some embodiments. In particular, system 20
may be adapted to supply a plurality of fluids either
simultaneously or sequentially into process chamber 22.
Consequently, system 20 may include a plurality of reservoirs and
supply lines other than intermediate tank/s 24, storage tank/s 26,
and intervening pipes 28 for supplying fluids to process chamber
22. Such a plurality of other reservoirs and supply lines are not
illustrated FIGS. 1a-1c in order to simply the drawing
illustrations.
[0032] Similarly, FIGS. 1a-1c do not illustrate other components
that may enhance the operation of system 20 in order to simplify
the drawing illustrations. For example, in some embodiments, system
20 may include filters with which remove foreign matter from the
fluid. In general, filters may be arranged within any portion of
system 20, including intermediate tank/s 24, storage tank/s 26
and/or pipes 28. Alternatively, system 20 may not include filters.
In either case, system 20 may sometimes include process control
devices, such as temperature and/or pressure gauges, within pipes
28, storage tank/s 26, intermediate tank/s 24, and/or process
chamber 22. In addition, system 20 may be adapted to control the
flow rate and time at which a fluid is transferred between tank/s
24 and 26 and/or supplied to process chamber 22. As such, pipes 28
may include solenoid valves in some cases. Operation of the
solenoid valves as well as other components within system 20 may be
controlled through central processing unit (CPU) 46 as described in
more detail below.
[0033] In general, fluid supplied to process chamber 22 may be
removed through exhaust ports of the chamber. In some embodiments,
the outlet ports may discharge the fluid to a waste stream to be
disposed. In other embodiments, however, one or more of the outlet
ports may serve to recycle the process fluid back to intermediate
tank/s 24 and/or storage tank/s 26 as described in more detail
below. In this manner, the fluid may be reused such that material
and disposal costs may be minimized. In some cases, the
recirculation line may include a filter such that tank/s 24 and/or
26 are not contaminated with particles removed from process chamber
22. For example, in some embodiments, the recirculation line may
include a magnetic filter such that magnetic materials may be
removed from the recirculated fluid. Other types of filters,
however, may also or alternatively be included in the recirculation
line from process chamber 22 to intermediate tank/s 24 and/or
storage tank/s 26. The inclusion of a magnetic filter may be
particularly advantageous in embodiments in which the size of
magnetic particles is sufficiently low to allow them to flow
through non-magnetic filter mediums. In some embodiments, the
inclusion of a magnetic filter may be beneficial for embodiments in
which an electroless deposition solution is recirculated from
process chamber 22. In particular, a magnetic filter may be used to
remove particulate metal from the recirculated fluid, which may
otherwise serve as a catalyst to consume the components of the
fluid, reducing the life of the solution. Another advantage of
using a magnetic filter is that particles may be removed without
affecting the fluid flowrate through the recirculation line.
[0034] As noted above, system 20 may be configured to control the
temperature of a fluid prior to and during the fabrication step of
a microelectronic device within process chamber 22. In particular,
system 20 may include temperature controllers 36 positioned such
that process chamber 22, intermediate tank/s 24, and storage tank/s
26 are characterized into at least three different zones based upon
the adaptations of temperature controllers 36 to maintain the fluid
within distinct temperature ranges in the respective zones while
processing the wafers. More specifically, one or more of
temperature controllers 36 may be positioned to maintain the fluid
supplied to process chamber 22 within a first temperature range,
while another set of temperature controllers 36 may be positioned
to maintain the fluid residing in intermediate tank/s 24 within a
second temperature range distinct from the first temperature range.
In addition, storage tank/s 26 may be used to maintain the fluid
residing therein within a third temperature range distinct from the
first and second temperature ranges. In this manner, temperature
controllers 36 may be positioned such that process chamber 22,
intermediate tank/s 24, and storage tank/s 26 are respectively
characterized into zones 40, 42, and 44 as shown in FIG. 1a.
[0035] As used hereinafter, the term "zone" may generally refer to
a region of system 20 having components such as reservoirs and
adjoining pipes that are configured to maintain a fluid within a
particular temperature range. As such, "zone 44," as used herein,
may generally refer to the zone including process chamber 22, while
"zone 40" may generally refer to the zone farthest away from
process chamber 22 and including at least a portion of storage
tank/s 26 and "zone 42" may refer to a zone in between zones 40 and
44 and including at least a portion of intermediate tank/s 24. In
some embodiments, temperature controllers 36 may be positioned to
characterize system 20 to have more than three zones. More
specifically, storage tank/s 26 and intermediate tank/s 24 may be
configured into more than two zones, particularly in embodiments in
which one or both of storage tank/s 26 and intermediate tank/s 24
include a plurality of reservoirs. Embodiments in which system 20
includes more than three distinct zones may be particularly
advantageous for cases in which the fluid has a relatively large
temperature differential to overcome from the storage tank arranged
farthest from process chamber 22 to the process chamber. In
particular, a system with more than three distinct zones may offer
a manner with which to more easily and more efficiently change the
temperature of the fluid for treatment of a topography in process
chamber 22. On the contrary, in some embodiments, it may be
advantageous for system 20 to be limited to three zones in order to
simplify the configuration of the system and the number of
components and controls necessary to operate such a system.
[0036] In general, temperature controllers 36 may be arranged in a
variety of locations within system 20 in order to achieve the
characterization of zones 40, 42, and 44 and any zones in between
zones 40, 42, and 44. For example, in some embodiments, one or more
of temperature controllers 36 may be arranged within and/or about
process chamber 22. In particular, one or more of temperature
controllers 36 may be incorporated into any component arranged
within process chamber 22, such as a wafer chuck configured to hold
one or more wafers or a fluid inlet of the chamber. In addition or
alternatively, one or more of temperature controllers 36 may be
coupled to the exterior of process chamber 22. In any case, one or
more of temperature controllers 36 may further be arranged within
intermediate tank/s 24 and/or within one or more of the intervening
pipes as shown in FIGS. 1a-1c. In particular, one or more
temperature controllers 36 may be arranged within intermediate
tank/s 24 and/or the intervening pipes within zones 42 and 44 and
any zones in between zones 40, 42, and 44. In some cases, one or
more of temperature controllers 36 may be additionally arranged
within storage tanks/ 26 and/or within one or more of the
intervening pipes within zone 40. In other embodiments, however,
temperature controllers 36 may not be positioned within zone 40. In
particular, the temperature of the fluid within storage tank/s 26
and adjoining pipes may alternatively be maintained by the
environment in which system 20 is arranged.
[0037] In any case, temperature controllers 36 may, in some
embodiments, be positioned such that zones 40, 42, and 44 and any
zones in between zones 40, 42, and 44 are arranged in ascending
order based upon their respective temperature ranges. In such an
embodiment, zone 44 including process chamber 22 may have the
highest temperature range. More specifically, the temperature range
of zone 44 may be higher than the temperature range of zone 42 and
the temperature range of zone 42 may be higher than zone 40. In
this manner, temperature controllers 36, in such an embodiment, may
be adapted to heat the fluid in stages as it traverses between
storage tank/s 26, intermediate tank/s 24 and process chamber 22.
The adaptation to heat the fluid residing within process chamber
22, intermediate tank/s 24 and sometimes storage tank/s 26 may, in
some embodiments, be advantageous for improving the reaction rate
of the fabrication process conducted within process chamber 22. For
example, in an embodiment in which an electroless deposition
process is conducted within process chamber 22, heating the
deposition solution may advantageously increase the deposition rate
of the process. Reaction rates of other microelectronic fabrication
processes may benefit from heating as well.
[0038] In an alternative embodiment, temperature controllers 36 may
be positioned such that the zones 40, 42, and 44 and any zones in
between zones 40, 42, and 44 are arranged in descending order based
upon their respective temperature ranges. In such an embodiment,
zone 44 may have the lowest temperature range. More specifically,
the temperature range of zone 44 may be lower than the temperature
range of zone 42 and the temperature range of zone 42 may be lower
than the temperature range of zone 40. Consequently, temperature
controllers 36, in such an embodiment, may be adapted to cool the
fluid in stages as it traverses between storage tank/s 26,
intermediate tank/s 24 and process chamber 22. Similar to the
adaptation to heat a fluid, the adaptation to cool the fluid
residing within process chamber 22, intermediate tank/s 24 and
sometimes storage tank/s 26 may, in some embodiments, be
advantageous for improving the fabrication process conducted in
process chamber 22.
[0039] In other embodiments, temperature controllers 36 may be
positioned such that the zones 40, 42, and 44 and any zones in
between zones 40, 42, and 44 are arranged in neither ascending or
descending order but rather, in a random order based upon their
respective temperature ranges. In such an embodiment, the
temperature ranges of each zone is still preferably distinct, but
the temperature range of zone 44 may be higher or lower than the
temperature range of zone 42 and the temperature range of zone 42
may respectively be lower or higher than the temperature range of
zone 44. Such mixed order of temperature ranges may be advantageous
for processes in which the chemical composition of a fluid is
altered at a particular temperature, but may be used at a lower or
higher temperature after such an alteration.
[0040] In any case, temperature controllers 36 may include any type
of mechanism with which to control the temperature of a fluid. For
example, in some cases, temperature controllers 36 may include
heaters and in some embodiments, specifically infrared heaters. An
infrared heater may specifically offer a manner with which to
efficiently and uniformly heat a fluid. In other embodiments,
temperature controllers 36 may include coolers. In yet other cases,
temperature controllers 36 may include heaters and coolers. For
example, as noted above, in some embodiments it may be advantage to
heat a fluid to a desired temperature to enhance the deposition
rate of the fabrication process. In such an embodiment, however, it
also may be beneficial to be able to cool the fluid such that
deposition process may be immediately terminated, allowing more
control over the amount deposited upon the substrate. In addition
or alternatively, the fluid within process chamber 22, as described
in more detail below, may, in some embodiments, be recirculated
back to one or both of intermediate tank/s 24 and storage tanks 26
during or subsequent to a fabrication process. In such an
embodiment, it may be advantageous to have a temperature controller
coupled to the recirculation pipe such that the temperature of the
fluid may be cooled back to the temperature specified for the zone
to which it is returning. In any case, temperature controllers 36
may be adapted to monitor the temperature of a fluid and,
therefore, may further include thermocouples in some
embodiments.
[0041] In general, the temperature ranges for zones 40, 42, and 44
and any zones in between zones 40, 42, and 44 may depend on the
fabrication step to be conducted, the operating parameters of the
fluid and the design specifications of the system. For example,
exemplary temperature ranges for a deposition solution for an
electroless deposition process may be approximately 42.degree. C.
to approximately 50.degree. C. for zone 40, approximately
70.degree. C. to approximately 95.degree. C. for zone 42, and
approximately 95.degree. C. to approximately 115.degree. C. for
zone 44. Other temperature ranges, however, may be maintained for
the different respective zones as well. For example, in some
embodiments, an electroless deposition solution may be maintained
at or near room temperature in zone 44 in order to maximize the
uniformity of the deposition. It is noted that although zones 40,
42, and 44 and any zones in between zones 40, 42, and 44 are
distinguished by their different temperature ranges, the
temperature ranges of the zones may or may not overlap. In
particular, the reference of "distinct temperature ranges" merely
refers to different breadths of temperatures and/or higher or lower
ranges of temperatures of the different zones.
[0042] As noted above, controlling the temperature of a fluid to be
within different temperature ranges at different stages within
system 20 may be advantageous for preparing the fluid for optimum
use within process chamber 22. In particular, maintaining a fluid
in zone 40 within a temperature range which does not substantially
advance the life and/or change the composition of the fluid may be
advantageous for storing the fluid. In addition, maintaining the
fluid in zone 44 within a temperature range which improves the
reaction rate and/or uniformity of the fabrication step conducted
within process chamber 22 may be advantageous for enhancing the
fabrication of microelectonic devices. Furthermore, maintaining the
fluid in zone 42 within a temperature range in between the storage
temperature range and the desired process temperature range of
respective zones 40 and 44 may allow the fluid to be more easily
altered to the desired process temperature upon replenishing the
fluid within process chamber 22 without substantially advancing the
life of the fluid. In particular, the temperature of the fluid may
be altered to the desired temperature range more efficiently than
in an embodiment in which the temperature of the fluid is directly
converted from its storage temperature to the desired process
temperature. As a result, temperature fluctuations of the fluid
within process chamber 22 may be minimized or prevented entirely.
Moreover, maintaining the fluid at such an intermediate temperature
may prolong the life of the fluid since the amount of time the
fluid is at such a temperature is reduced as compared to an
embodiment in which a fluid is stored at the desired process
temperature prior to being introduced into process chamber 22.
[0043] In some cases, system 20 may further include central
processing unit (CPU) 46 configured to control operation of system
20. In particular, system 20 may include a dedicated
microprocessor-based controller or a general-purpose computer to
automate the operations of system 20. Consequently, the method
described in reference to FIG. 2 below may, in some embodiments, be
a computer-implemented method. As described below, CPU 46 may be
used to control a variety of components within system 20. In
general, CPU 46 may be coupled to the components of system 20 which
it is configured to control. Such individual connections to the
components, however, are not illustrated FIGS. 1a-1c to simplify
the illustrations of system 20. Rather, CPU 46 is shown coupled to
system 20 by a dotted line to show a general connection to the
components included within system 20.
[0044] In some cases, CPU 46 may be configured to control the
operation of temperature controllers 36. In particular, CPU 46 may
be configured to regulate the use of temperature controllers 36
such that the temperature of the fluid within zones 40, 42, and 44
and any zones in between zones 40, 42, and 44 may be adjusted to be
within the specified temperature ranges of the zones. CPU 46 may be
adapted to control the operations of process chamber 22 as well,
including but not limited to the loading and unloading of wafers
within the chamber, the temperature and pressure of the chamber, as
well as the introduction and disposal of fluids from the
chamber.
[0045] In some cases, CPU 46 may be configured to control the
opening and closing of the valves along intervening pipes 28. In
this manner, the routing of the fluid between tanks 24 and 26 and
process chamber 22 may be controlled. For instance, CPU 46 may
include a carrier medium with program instructions for managing the
use of solenoid valves on pipes 28 such that the fluid may be
routed between tanks 24 and 26 and process chamber 22 based upon
the use of the fluid within process chamber 22. For example, upon
starting the operation of system 20, CPU 46 may include program
instructions with which to supply zone 42 with fluid from zone 40.
Subsequently, CPU 46 may send a command to supply zone 44 with the
fluid from zone 42. During such a sequence, CPU 46 may also send
instructions to one or more of the temperature controllers 36 to
maintain the temperature of the fluid within the temperature range
specified for the respective zones. In some cases, CPU 46 may also
send commands to regulate the flow of fluid through the outlet
ports of process chamber 22. In turn, CPU 46 may be used to
regulate the replenishment of fluid within process chamber 22 as
well. Moreover, CPU 46 may be used to manage the recirculation of
fluid within and between the reservoirs of system 20 as described
in more detail below.
[0046] As shown in FIGS. 1a-1c, system 20 may, in some embodiments,
be configured to circulate the fluid between storage tank/s 26 and
intermediate tank/s 24. In particular, system 20 may include
intervening pipes 28 and valves 48 configured to circulate the
fluid within storage tank/s 26 and intermediate tank/s 24
independently and between each other. Such a recirculation
adaptation may, in some embodiments, be advantageous for keeping
the composition of the fluid within a particular zone homogenized.
In addition or alternatively, recirculating the fluid within a
particular zone may aid in maintaining the fluid within a specified
temperature range. For example, in an embodiment in which a tank
within the zone does not include a temperature controller but an
adjoining pipe does, the fluid may have to be recirculated within
the zone to maintain it within its specified temperature range. In
yet other cases, the tank within the zone may include a temperature
controller with which to regulate the fluid temperature. In either
case, system 20 may be additionally or alternatively adapted to
transport the fluid from process chamber 22 to intermediate tank/s
24 and storage tank/s 26. In particular, system 20 may be adapted
to return the fluid from process chamber 22 back to preceding
reservoirs for storage, particularly when the fluid has not
decomposed or still has an adequate process life. The determination
of whether the state of the fluid is suitable to be recycled may
involve using analytical tests to evaluate the fluid or may be
based on historical data of the system.
[0047] In any case, system 20 may be adapted to change the position
of valves 48 based upon the mode of operation of the system.
Exemplary positions of valves 48 simulating the different modes of
operation for system 20 are illustrated in FIGS. 1a-1c. In
particular, FIG. 1a illustrates an exemplary configuration of
valves 48 in a position to circulate the fluid within storage
tank/s 26 without having the fluid delivered to intermediate tank/s
24 or process chamber 22. Alternatively, the fluid may be stored
stagnantly in storage tank/s 26. In either case, such a mode of
operation of system 20 may be suitable for embodiments in which
process chamber 22 is not in operation or when process chamber 22
is being serviced.
[0048] A different mode of operation is illustrated in FIG. 1b in
which the fluid is transported from storage tank/s 26 to
intermediate tank/s 24. Such a mode of operation may be referred to
as the "pre-process" stage or, more specifically, the stage at
which the fluid is prepared for delivery to process chamber 22 but
not yet delivered. Consequently, the mode of operation may likely
occur prior to conducting a fabrication process within process
chamber 22. In some embodiments, the fluid may be recirculated back
to storage tank/s 26 from intermediate tank/s 24 during such a mode
of operation. In other embodiments, however, the valve on the
recirculation pipe between intermediate tank/s 24 and storage
tank/s 26 (i.e., the line having the arrow directed back to storage
tank/s 26) may be closed. In either case, the valve on the pipe
connecting the delivery and recirculation pipes between
intermediate tank/s 24 and storage tank/s 26 may be closed or open,
depending on whether the fluid within storage tank/s 26 is
circulated during such a mode of operation.
[0049] In some embodiments, the routing of fluid between storage
tank/s 26 and intermediate tank/s may be controlled by volume
sensors within intermediate tank/s 24. More specifically, the
position of valves 48 may depend on the volume contained within
intermediate tank/s 24 and/or process chamber 22. For example, in
an embodiment in which the level sensor within intermediate tank/s
24 indicates a low volume of fluid, the valve on the delivery pipe
between intermediate tank/s 24 and storage tank/s 26 may be open,
while the pipe connecting the delivery and recirculation pipes
between intermediate tank/s 24 and storage tank/s 26 may be closed.
Once the fluid within intermediate tank/s 24 reaches a particular
volume, the positions of such valves may be reversed such that the
flow of fluid from storage tank/s 26 to intermediate tank/s 24 is
terminated and is instead recirculated in and out of storage tank/s
26. In an alternative embodiment, the fluid within storage tank/s
26 may not be recirculated upon reaching a particular volume within
intermediate tank/s 24. In any case, if the level sensor within
intermediate tank/s 24 indicates a high volume of fluid, the valve
on the recirculation pipe between intermediate tank/s 24 and
storage tank/s 26 may be opened. A similar level sensor may be used
to control flow between intermediate tank/s 26 and process chamber
22 as well, however, in other embodiments the fluid flow between
intermediate tank/s 26 and process chamber 22 may be based on the
degradation of the fluid during the fabrication process as
described in more detail below.
[0050] Another mode of operation for system 20 may be when the
fluid is delivered from intermediate tank/s 24 to process chamber
22 such that a fabrication step may be performed within the
chamber. Such a mode of operation is illustrated in FIG. 1c by
having the valve on the delivery pipe between the intermediate
tank/s 24 and process chamber 22 open. In general, the fluid may be
delivered from intermediate tank/s 24 to process chamber 22 just
prior to or at the start of the fabrication process and during
times in which the fluid within process chamber 22 is being
replenished. As such, in some embodiments, the valve on the
delivery pipe between the intermediate tank/s 24 and process
chamber 22 may be closed during the "processing" mode of system 20.
In other embodiments, however, the fluid within process chamber 22
may be continually replenished. In some embodiments, the rate of
replenishment and/or the position of the valve on the delivery pipe
between the intermediate tank/s 24 and process chamber 22 may be
based on the degradation of the fluid during the fabrication
process. In particular, the routing of fluid between intermediate
tank/s 24 and process chamber 22 may depend on the life of the
fluid affecting the reaction rate of the process. The determination
of whether the life of the fluid is suitable to for the fabrication
may involve using analytical tests to evaluate the fluid during the
fabrication process or may be based on historical data of the
system. In any case, the valve on the pipe connecting the delivery
and recirculation pipes between intermediate tank/s 24 and
processing chamber 22 may be closed or open, depending on whether
the fluid within intermediate tank/s 24 is circulated during such a
mode of operation.
[0051] As described above, in some embodiments, the fluid may be
routed back to intermediate tank/s 24 and/or storage tank/s 26 upon
terminating fabrication step in process chamber 22. In particular,
the fluid may be recycled back to intermediate tank/s 24 and/or
storage tank/s 26 if the components within the fluid are still
active to process a microelectronic topography. Such a
recirculation is illustrated in FIG. 1c by having the valves on the
recirculation pipes between process chamber 22, intermediate tank/s
24 and storage tank/s 26 (i.e., the lines having the arrow directed
back to intermediate tank/s and storage tank/s 26, respectively)
open. Although FIGS. 1a-1c illustrate the recirculation pipe from
process chamber 22 routed back to intermediate tank/s 24 first and
then to storage tank/s 26, system 20 may alternatively have a
recirculation pipe from process chamber 22 routed directly back to
storage tank/s 26 or just to intermediate tank/s 24. In any case,
system 20 may be adapted to alter the temperature of the fluid upon
recycling the fluid from process chamber 22. In particular, system
20 may include a temperature controller on the recycling line from
the process chamber such that the temperature of the fluid may be
returned to the temperature of the fluid in the tank to which it is
returning. In this manner, the life of a fluid which tends to
degrade while maintained at a elevated temperature may be
preserved. For example, the life of an electroless deposition
solution may be preserved. In other embodiments, however, the valve
on the recirculation pipe between intermediate tank/s 24 and
process chamber 22 may be closed.
[0052] A method for delivering a fluid to a process chamber of the
microelectronic fabrication apparatus is illustrated in FIG. 2. In
particular, the method may include step 70 in which a fluid, used
to process microelectronic topographies, is stored within a storage
tank of a microelectronic fabrication apparatus. Such a step may
include controlling the temperature of the fluid within a
preliminary temperature range. More specifically, microelectronic
fabrication apparatus may employ one or more temperature
controllers with which to control the temperature of the fluid
within the storage tank within a preliminary temperature range. In
yet other embodiments, the environment in which the microelectronic
fabrication apparatus is operated may be adapted to maintain the
fluid within the storage tank within a preliminary temperature
range. For example, the microelectronic fabrication apparatus may
be operated in a temperature controlled environment which has a
substantially similar operating range as the preliminary
temperature range. In any case, the preliminary temperature range
may preferably include temperatures which do not substantially
degrade the life of the fluid as compared to other temperatures at
which the fluid may be maintained. For example, in an embodiment in
which the fluid is an electroless deposition solution, the
preliminary temperature range may include temperatures between
approximately 42.degree. C. and approximately 50.degree. C. Higher
or lower and larger or smaller ranges of temperatures, however, may
be used for the preliminary temperature range, depending on the
fabrication process to be conducted and the operating parameters of
the fluid and the design specifications of the system.
[0053] As shown in step 72, the method may further include
transporting the fluid from the storage tank to an intermediate
tank of the microelectronic fabrication apparatus. In some cases,
step 72 may include circulating the fluid between the storage tank
and intermediate tank. In other cases, the transportation of the
fluid may be simply include delivering the fluid from the storage
tank to the intermediate tank without a recirculation loop back to
the storage tank. In either embodiment, the method may include step
74 in which the temperature of the fluid within the intermediate
tank is controlled to be within a transitional temperature range
which is distinct from the preliminary temperature range of the
storage tank. In some cases, the transitional temperature range may
be higher than the preliminary temperature range. Alternatively,
the transitional temperature range may be lower than the
preliminary temperature range. In either case, the transitional
temperature range is preferably smaller than the preliminary
temperature range such that fluctuations of the fluid temperature
within the process chamber may be minimized. In addition, the
transitional temperature range preferably includes temperatures
which are between the preliminary temperature range and the
processing temperature range described in more detail below. In
this manner, the fluid to be more easily altered to the desired
process temperature range upon replenishing the fluid within
process chamber 22 without substantially advancing the life of the
fluid.
[0054] Step 76 includes transporting the fluid from the
intermediate tank to the process chamber. In some cases, step 76
may include recirculating the fluid from the chamber to at least
one of the intermediate and storage tanks. In other embodiments,
however, the fluid from the chamber may be disposed of after using
it to process wafers within the process chamber. In either case,
the method may further include step 78 in which the temperature of
the fluid is controlled within the process chamber to be within a
process temperature range which is distinct from the preliminary
and transitional temperature ranges of the storage and intermediate
tanks, respectively. In some embodiments, the process temperature
range may be higher than the transitional temperature range.
Alternatively, the process temperature range may be lower than the
transitional temperature range. In either case, the process
temperature range is preferably smaller than the transitional
temperature range such that fluctuations of the fluid temperature
within the process chamber may be minimized or prevented. In
addition, the process range is preferably optimized to include
temperatures which offer a high reaction rate as well as a uniform
treatment process.
[0055] It will be appreciated to those skilled in the art having
the benefit of this disclosure that this invention is believed to
provide a system and a method for controlling the temperature of a
fluid used to process a microelectronic topography prior to and
during the fabrication step of the topography. Further
modifications and alternative embodiments of various aspects of the
invention will be apparent to those skilled in the art in view of
this description. For example, although the system and method
provided herein are frequently described in reference to process
steps conducted prior to, during, and subsequent to an electroless
deposition process, the system and method are not necessarily
restricted to such processes. In addition, the system and method
described herein may be used for any fluid in which the temperature
is preferably heated and/or cooled prior to and during a step of a
microelectronic fabrication process. Accordingly, this description
is to be construed as illustrative only and is for the purpose of
teaching those skilled in the art the general manner of carrying
out the invention. It is to be understood that the forms of the
invention shown and described herein are to be taken as the
presently preferred embodiments. Elements and materials may be
substituted for those illustrated and described herein, parts and
processes may be reversed, and certain features of the invention
may be utilized independently, all as would be apparent to one
skilled in the art after having the benefit of this description of
the invention. Changes may be made in the elements described herein
without departing from the spirit and scope of the invention as
described in the following claims.
* * * * *