U.S. patent application number 11/282259 was filed with the patent office on 2006-04-06 for supercritical fluid technology for cleaning processing chambers and systems.
Invention is credited to Cem Basceri, Gurtej S. Sandhu.
Application Number | 20060070637 11/282259 |
Document ID | / |
Family ID | 34116357 |
Filed Date | 2006-04-06 |
United States Patent
Application |
20060070637 |
Kind Code |
A1 |
Basceri; Cem ; et
al. |
April 6, 2006 |
Supercritical fluid technology for cleaning processing chambers and
systems
Abstract
The invention includes a method of cleaning a processing chamber
by introducing supercritical fluid into the processing chamber. A
residue over an internal chamber surface is contacted with the
supercritical fluid to remove the residue from the surface. The
invention also includes a method of removing deposited material
from internal surfaces of a processing system. A cleaning agent
comprising carbon dioxide is provided in liquid phase or
supercritical phase into at least a portion of the processing
system. A material deposited on an internal surface of the
processing system is contacted with the cleaning agent to
solubilize at least a portion of the deposited material and the
solubilized fraction is removed from the system. The invention
further includes a processing system which includes a supercritical
fluid source in selective fluid communication with a processing
chamber configured to selectively flow supercritical fluid into the
chamber during a chamber cleaning process.
Inventors: |
Basceri; Cem; (Boise,
ID) ; Sandhu; Gurtej S.; (Boise, ID) |
Correspondence
Address: |
WELLS ST. JOHN P.S.
601 W. FIRST AVENUE, SUITE 1300
SPOKANE
WA
99201
US
|
Family ID: |
34116357 |
Appl. No.: |
11/282259 |
Filed: |
November 18, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10636028 |
Aug 6, 2003 |
|
|
|
11282259 |
Nov 18, 2005 |
|
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Current U.S.
Class: |
134/22.1 ;
118/70; 134/104.1; 134/166R; 134/169R; 134/22.18; 134/34 |
Current CPC
Class: |
B08B 7/0021 20130101;
B08B 9/08 20130101; C23C 16/4407 20130101 |
Class at
Publication: |
134/022.1 ;
134/022.18; 134/034; 134/104.1; 134/166.00R; 134/169.00R;
118/070 |
International
Class: |
B08B 3/02 20060101
B08B003/02 |
Claims
1-23. (canceled)
24. A processing system comprising: a reactor having a processing
chamber; a supercritical fluid source in selective fluid
communication with the processing chamber and configured for
selectively flowing supercritical fluid during a chamber-cleaning
process; and a recovery vessel in fluid communication with the
processing chamber.
25. The processing system of claim 24 further comprising a
cold-trap, wherein the system is configured to selectively flow
supercritical fluid into the cold trap.
26. The system of claim 25 wherein the cold trap is disposed in
fluid receiving relation relative to the processing chamber and in
fluid providing relation relative to the recovery vessel.
27. The system of claim 24 wherein the recovery vessel is in fluid
communication with the supercritical fluid source for recycling of
the supercritical fluid.
28. The system of claim 24 wherein at least some of any solutes
present in the supercritical fluid are removed in the recovery
vessel.
29. The system of claim 24 wherein the processing chamber is a
deposition chamber.
30. The system of claim 29 further comprising at least one line in
fluid communication with the deposition chamber, the at least one
line being utilized during deposition processes and being selected
from a feed line and an exhaust line, wherein the supercritical
fluid passes through at least a portion of the at least one line
during the chamber-cleaning process.
31. The system of claim 24 further comprising a co-solvent
source.
32. The system of claim 31 wherein a co-solvent is introduced into
the deposition chamber form the co-solvent source subsequent to
initiating flow of supercritical fluid into the processing
chamber.
33. The system of claim 31 wherein a co-solvent is dispersed within
the supercritical fluid prior to initiating flow of the
supercritical fluid into the processing chamber.
34. The system of claim 31 wherein a co-solvent is introduced into
the processing chamber prior to initiating flow of the
supercritical fluid into the processing chamber.
35. The system of claim 24 wherein the system is a semiconductor
processing system.
36. The system of claim 24 wherein the chamber is selected from a
PVD chamber, a CVD chamber, an ALD chamber, a pulsed CVD chamber, a
furnace chamber and a PECVD chamber.
Description
RELATED PATENT DATA
[0001] This patent resulted from a divisional application of U.S.
patent application Ser. No. 10/636,028, filed Aug. 6, 2003.
TECHNICAL FIELD
[0002] The invention pertains to methods of cleaning a processing
chamber. In particular applications, the invention pertains to
methods of cleaning semiconductor processing chambers using a
supercritical fluid. The invention also pertains to removing
deposited material from internal surfaces of processing systems.
The invention further pertains to a processing system.
BACKGROUND OF THE INVENTION
[0003] A variety of systems are utilized in materials processing
and fabrication technologies such as, for example, semiconductor
processing. Exemplary processing systems include deposition systems
such as various types of physical vapor deposition systems,
chemical vapor deposition systems, furnaces, etc. Many of these
systems include one or more processing chambers, various processing
equipment and processing tools, associated interconnects, feed
and/or exhaust lines, and other system components that may become
contaminated during a processing event. Such contamination can be
due to formation of residue materials such as one or more reagent,
product or byproduct involved in or produced by the processing
event. The presence of residue material on internal surfaces of the
processing system can affect processing efficiency or precision,
and can in some instances result in contamination of the material
or device being processed.
[0004] Conventional system cleaning techniques often utilize a
solvent or solvent system that is expensive, environmentally
unfriendly, and/or inefficient. In some instances, systems are
configured to include special components such as heated lines
and/or cold traps in an attempt to reduce contamination of system
components or surfaces by residue materials. Additionally, due to
the intricate nature of many processing tools, equipment and
internal regions of various processing systems, some areas are not
highly accessible to conventional solvents, other cleaning agents
or alternative techniques. Accordingly, conventional cleaning
methods can be cost prohibitive and unreliable.
[0005] It would be desirable to develop alternative methods for
cleaning processing systems, system components and associated tools
and equipment.
SUMMARY OF THE INVENTION
[0006] In one aspect the invention encompasses a method of cleaning
a processing chamber. A supercritical fluid is provided into a
processing chamber which has a residue material over at least one
internal chamber surface. The residue material is contacted with
the supercritical fluid to remove at least some of the residue from
the internal surface.
[0007] In one aspect the invention encompasses a method of removing
deposited material from internal surfaces of a processing system. A
cleaning agent comprising carbon dioxide is provided into at least
a portion of the processing system. The carbon dioxide can be
provided in liquid phase or supercritical phase. A material
deposited on an internal surface of at least a portion of the
processing system is contacted with the cleaning agent to
solubilize at least a portion of the deposited material. The
solubilized fraction is subsequently removed from the system.
[0008] In one aspect, the invention encompasses a processing system
which includes a supercritical fluid source in selective fluid
communication with a processing chamber. The system is configured
to selectively flow supercritical fluid into the chamber during a
chamber cleaning process. The system also contains a recovery
vessel in fluid communication with the processing chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Preferred embodiments of the invention are described below
with reference to the following accompanying drawings.
[0010] FIG. 1 is a diagrammatic, cross-sectional view of an
exemplary apparatus system which can be subjected to cleaning
methodology of the present invention.
[0011] FIG. 2 is a diagrammatic, cross-sectional view of a portion
of the system shown in FIG. 1 at a preliminary processing stage of
a method of the present invention.
[0012] FIG. 3 is a view of the FIG. 1 system portion shown at a
processing stage subsequent to that of FIG. 2.
[0013] FIG. 4 is a diagrammatic, cross-sectional view of a second
exemplary fragment of system 10 shown in FIG. 1, at a preliminary
processing stage of a method of the present invention.
[0014] FIG. 5 is a view of the FIG. 4 system fragment shown at a
processing stage subsequent to that of FIG. 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] This disclosure of the invention is submitted in furtherance
of the constitutional purposes of the U.S. Patent Laws "to promote
the progress of science and useful arts" (Article 1, Section
8).
[0016] In particular applications, the invention encompasses a
process of cleaning one or more surfaces of semiconductor
processing systems. The cleaning process can include exposing a
surface of the processing system to a supercritical fluid. As is
known to persons of ordinary skill in the art, a supercritical
fluid is defined as any substance that is above its critical
temperature (T.sub.c) and critical pressure (P.sub.c). T.sub.c is
the highest temperature at which a gas can be converted to a liquid
by an increase in pressure, and P.sub.c is the highest pressure at
which a liquid can be converted to a traditional gas by an increase
in the temperature of the liquid. The critical region for a
particular substance is the region on a phase diagram for a given
substance where both temperature and pressure are at or above their
corresponding critical values.
[0017] In the critical region, a substance exists in a single phase
which possesses properties of both a gas and a liquid.
Supercritical fluids differ from traditional liquids in several
aspects. For example, the solvent power of a supercritical fluid
will typically increase with density at a given temperature.
Additionally, supercritical fluids have very low effective
viscosity and surface tension allowing penetration into very small
areas and features. In particular applications, the cleaning
processes of the invention can utilize a liquid cleaning agent that
is near the critical point of the agent. When a liquid cleaning
agent is utilized, the liquid can preferably be at a temperature
greater than or equal to about 90% of T.sub.c and at a pressure
greater than or equal to about 90% of P.sub.c. More preferably,
when a liquid cleaning agent is utilized the agent is at a
sufficient temperature and pressure to assume some of the solvent,
surface tension and/or diffusivity properties the agent exhibits in
the supercritical state.
[0018] In particular applications of the present invention, the
supercritical fluid can have at least one surfactant and/or at
least one co-solvent dispersed and/or dissolved therein. For
purposes of interpreting this disclosure and the claims that
follow, the term "supercritical fluid" is utilized to refer
specifically to a portion of composition that is in a supercritical
state (i.e., is utilized to refer to the supercritical component of
a composition). Typically, the materials dispersed and/or dissolved
within the supercritical fluid will not be in a supercritical state
and accordingly will not be part of the supercritical fluid.
However, it is noted that in particular applications one or more of
the materials dispersed within a supercritical fluid can themselves
be in a supercritical state. In such applications the dispersed
materials that are in the supercritical state will be part of the
supercritical fluid.
[0019] The supercritical fluid can, in particular aspects of the
invention, comprise one or more of CO.sub.2, NH.sub.3,
C.sub.3H.sub.8, N.sub.2O, C.sub.2H6, CH.sub.4, H.sub.2O and Ar. In
some instances, the supercritical fluid can consist essentially of,
or consist of one or more of these substances. Other exemplary
materials that can be formed into supercritical fluids which may be
useful for purposes of the present invention include an alcohol
having from 1 to 5 carbon atoms, for example, ethanol and/or
methanol, isooctane, hexane, heptane, butane, propane, ethene,
propene, dimethyl ether, tetrafluoromethane, difluoromethane,
tetrafluoroethane, xenon, pentafluoroethane, sulfur hexafluoride,
CFC-12, HCFC-22, HCFC-123, HFC-116, and HFC-134a.
[0020] In particular applications, a cleaning agent according to
the invention can preferably comprise a supercritical fluid which
comprises, consist essentially of, or consist of CO.sub.2. In some
applications the agent can comprise supercritical CO.sub.2 with
various additional components or "co-agents" dispersed or dissolved
therein. Such co-agents can include, for example, a co-solvent
and/or a surfactant. An advantage of utilizing CO.sub.2 as opposed
to other supercritical fluids is that CO.sub.2 has a relatively low
critical temperature of about 31.degree. C. Carbon dioxide also has
a convenient supercritical pressure range of from about 73
atmospheres (atm). Additional advantages of utilizing supercritical
CO.sub.2 include its ready availability, relative non-toxicity, and
lower expense as compared to alternative solvents or cleaning
technologies.
[0021] A cleaning agent consisting essentially of or consisting of
a given supercritical fluid, such as CO.sub.2, can be utilized to
dissolve certain substances such as, for example, many organic
compounds. However, in particular instances, it can be advantageous
to increase the ability of a particular supercritical fluid to
dissolve one or more materials by utilizing a co-solvent and/or a
surfactant. In particular instances, the supercritical fluid can
act as a carrier medium to carry co-solvents to areas for cleaning
to occur. For example, the ability of supercritical CO.sub.2 to
dissolve or remove ionic materials can be increased by utilizing a
more polar co-solvent in conjunction with the supercritical
CO.sub.2. An exemplary polar co-solvent can be water. Alternative
solvents are available for use as co-solvent in conjunction with a
supercritical fluid according to methodology of the present
invention as will be understood by those skilled in the art.
[0022] Optionally, the co-solvent/supercritical fluid mixture
described above can additionally contain one or more surfactants. A
variety of surfactants are available which can be utilized in the
cleaning agent of the present invention. In particular
applications, the cleaning agent of the invention can include a
supercritical fluid combined with one or more surfactant in the
absence of any additional co-solvent. The supercritical fluid
portion of a cleaning mixture according to the invention can
advantageously carry dispersed or dissolved co-agents into areas
that would be relatively inaccessible to liquid or conventional
solvents.
[0023] An exemplary system 10 which can be utilized for purposes of
the present invention is discussed with reference to FIG. 1. System
10 can be, for example, a processing system utilized during
processing of materials or during device fabrication. System 10 can
comprise a processing chamber 12 used for performing one or more
steps in a processing event. Chamber 12 is not limited to a
particular form of processing and can be a chamber utilized for one
or more techniques including but not limited to material
deposition, etching, annealing, photolithography, ion implantation,
or chemical mechanical polishing. In particular applications,
chamber 12 can be a deposition chamber utilized for processes
including physical vapor deposition (PVD), chemical vapor
deposition (CVD), atomic layer deposition (ALD), pulsed-CVD, plasma
enhanced CVD (PECVD), or high density plasma deposition (HDP). In
other instances, chamber 12 can be a furnace chamber or other batch
tool. In particular embodiments of the invention, system 10 can be
utilized for semiconductor processing system and chamber 12 can be
a semiconductor processing chamber.
[0024] Chamber 12 can have various internal surfaces over which
various unwanted residue materials can be deposited during the
semiconductor processing steps performed therein. Such internal
surfaces can comprise, for example, wall surfaces 14 and/or
surfaces comprised by one or more system components internal to
chamber 12 such as a surface of a heater 15, a surface of a
substrate holder 16 and a surface of a disperser 18. Internal
components 15, 16 and 18 are not limited to a particular
configuration and can be, for example, any component utilized as a
heater 15, as a substrate holder 16 (for example to hold one or
more semiconductor wafers) or as a disperser 18 during
semiconductor processing. Such internal features can be integral or
removable.
[0025] In addition to the internal surfaces discussed above, the
invention encompasses placement of additional processing equipment
or tools into the chamber specifically for the cleaning process.
Accordingly, system 10 can be utilized for cleaning within chamber
12, surfaces that were not within chamber 12 during the deposition
or other processing event. For example, a semiconductor wafer
holder which held one or more wafers during processing within an
alternate processing chamber can be cleaned by placing such holder
into chamber 12 during the cleaning process.
[0026] Processing system 10 can comprise, for example, a cleaning
agent source 20. In applications where the cleaning agent will be
utilized in a supercritical phase, source 20 can comprise the
supercritical fluid phase of the agent and the agent can be
provided into chamber 12 through inlet 22 in supercritical form.
Alternatively, source 20 can provide the cleaning agent into
chamber 12 in liquid form or gas form and a cleaning agent 20 can
be converted to its supercritical phase within chamber 12. In
applications where cleaning agent 20 will be utilized in a liquid
or near supercritical form, source 20 can be a liquid or can
alternatively be a gas which can be converted into a liquid by an
appropriate increase in pressure within chamber 12 relative to
source 20.
[0027] In applications where a co-solvent and/or a surfactant will
be utilized during cleaning, system 10 can comprise a co-agent
source 26 for providing the co-solvent and/or surfactant. Although
FIG. 1 shows system 10 as comprising a single co-agent source, it
is to be understood that the invention contemplates embodiments
having two or more co-agent sources (not shown) or an absence of
any co-agent source (not shown). Source 26 can provide at least one
co-agent selected from the group consisting of co-solvents and
surfactants. Exemplary co-solvents and surfactants utilized in
system 10 can be any of those agents discussed above.
[0028] Co-agent 26 can be combined with agent 20 prior to flowing
cleaning agent into chamber 12, or alternatively can be provided
independently of agent 20. Co-agent 26 can be provided through
common inlet 22, as shown in FIG. 1 or alternatively can be
provided through an independent inlet (not shown). When provided
independently, co-agent 26 can be provided simultaneously with
agent 20, can be introduced into chamber 12 prior to agent 20, or
in particular instances can be introduced subsequent to agent
20.
[0029] In some applications of the invention, co-agent 26 can be
utilized as a pre-treatment substance. For example, one or more
co-agent can be independently provided into chamber 12, and can
contact and/or react with materials on surfaces internal to system
10 prior to any flowing of agent 20. Agent 20 can then be provided
within a portion or all of the internal areas of system 10 to
interact or mix with the co-agent. The mixture of agent and
co-agent can subsequently be removed from the internal areas of the
system along with any materials dissolved or dispersed therein.
[0030] Whether or not cleaning agent 20 is utilized in conjunction
with a surfactant and/or a co-solvent, agent 20 can be introduced
into chamber 12 in gas phase, in liquid phase or in supercritical
fluid phase. Where agent 20 is introduced into chamber 12 in a
non-supercritical phase and where cleaning of chamber 12 will
utilize the supercritical fluid phase, temperature and pressure
conditions of chamber 12 can be provided such that agent 20 is
converted to the supercritical phase within chamber 12. In
particular instances, it can be preferable that agent 20 be flowed
or injected into chamber 12 in supercritical phase.
[0031] Processing system 10 can comprise one or more reagent inlets
24 and feed lines 25 for introduction of one or more reagents
utilized during semiconductor processing or other processing
events. As indicated in FIG. 1, inlet 24 can be configured such
that one or more reagents are provided into chamber 12 through
disperser 18. Disperser 18 is not limited to a particular type of
disperser and can be, for example, a shower head type disperser.
System 10 can further comprise additional internal features such as
heater 15 and substrate holder 16. It is to be understood that the
internal features, as well as the inlet and outlet configuration
shown in FIG. 1 represents an exemplary apparatus configuration.
The invention additionally encompasses utilizing cleaning methods
of the present invention for processing chambers having alternate
configurations and additional or different internal features. As
discussed above, chamber 12 can additionally be utilized to clean
items that are not internal components of system 10 by placing such
items within chamber 12 for the cleaning event.
[0032] System 10 can be configured such that the cleaning fluid
introduced into chamber 12 contacts at least a portion of an
internal surface of inlet 24 and/or feed line 25. Additionally, in
particular applications system 10 can be configured such that the
cleaning agent contacts at least a portion of an internal surface
of exhaust outlet 30 and/or an internal surface of exhaust line 31.
In embodiments where system 10 comprises additional feed lines,
inlets, outlets, and/or exhaust lines, the system can be configured
such that the cleaning agent contacts at least a portion of one or
more internal surfaces comprised by any of these features.
[0033] As shown in FIG. 1, system 10 can comprise a cold trap 28
for utilization during the processing function of system 10. System
10 can further comprise a pump 32 in fluid communication with trap
28. Conventional processing systems can utilize a cold trap to
recover the various reactants and/or byproducts from the processing
stage. For example, during particular depositions processing, a
cold trap can be provided to condense and/or collect one or more
exhaust materials after passing through an exhaust line which is
maintained at a sufficiently hot temperature to inhibit
condensation of material prior to reaching the cold trap. In
particular applications of the present invention, system 10 can be
configured such that the cleaning agent passes into cold trap 28.
In applications where the cleaning agent comprises a supercritical
fluid, cold trap 28 can preferably be maintained at a temperature
and a pressure sufficient to maintain the supercritical fluid phase
of the agent during cleaning.
[0034] The cleaning agent introduced into chamber 12 can pass
through outlet 30 and exhaust line 31 into cold trap 28 as shown in
FIG. 1. Alternatively, cold trap 28 can be exposed to the cleaning
agent independently from other apparatus components by providing
the agent directly through a trap feed line 29 or through multiple
feed lines (not shown). Independent cleaning of trap 28 can
comprise introduction of the cleaning agent into cold trap 28 can
comprise separate simultaneous or sequential addition of agent 20
and optional co-agent(s), or can comprise providing a mixture of
agent 20 and one or more co-agents as discussed above with respect
to introducing cleaning agent into chamber 12.
[0035] The cleaning agent can be exhausted from cold trap 28 and
can optionally be provided to a recovery vessel 34. In embodiments
where the cleaning agent comprises a supercritical fluid, it can be
preferable to maintain the supercritical phase for the duration of
the existence of the cleaning agent within chamber 12 and/or cold
trap 28 to minimize or avoid having materials dissolved therein
fall out of solution and deposit within the chamber and/or the cold
trap. Once the cleaning agent carrying materials dissolved from
internal surfaces of chamber 12 and/or cold trap 28 reaches
recovery vessel 34, the supercritical fluid can be released from
the supercritical state to remove and or separate solutes and/or
other contaminants dispersed within the cleaning agent. The
cleaning agent can optionally be separated into its components
(agent(s) and co-agent(s)), each of which can optionally be
recycled back to corresponding sources 20 and 26.
[0036] In particular applications, cold trap 28 which is disposed
between chamber 12 and pump 32 in FIG. 1 can be eliminated from
system 10 (not shown). Because the cleaning methods of the present
invention allow removal of residue material from internal surfaces
of tubing or lines, it can be possible to eliminate cold traps from
at least some apparatuses. Accordingly, in an absence of cold trap
28 the cleaning agent can be exhausted from chamber 12 (preferably
in supercritical phase) and can be provided to recovery vessel 34
without passing through a cold trap. It is to be noted that the
invention additionally encompasses exhausting the cleaning agent
from chamber 12 into 34 bypassing cold trap 28, even in those
systems which include the cold trap.
[0037] Cleaning methods of the present invention can be utilized to
clean internal surfaces of one or more components of system 10
between each consecutive processing event or after a number of
individual events have been performed. Additionally, cleaning
methods of the present invention can be combined or alternated with
conventional cleaning techniques.
[0038] Cleaning of various internal surfaces of system 10 is
further described with reference to FIGS. 2-5. Referring initially
to FIG. 2, an internal surface such as chamber wall surface 14 can
be exposed to various reactants, products, byproducts and/or
contaminants during processing events that occur within chamber 12.
In particular instances, one or more materials 36 can be deposited
onto surface 14. Material 36 can be organic material, inorganic
material, or a combination of organic and inorganic materials.
Exemplary substances which can be comprised by material 36 include
a photoresist, a metallic material, a low-k dielectric, an oxide
material, a nitride material, a hydrocarbon material, a carbide
material, a polymer material, a chloride material, a fluoride
material or a hydroxide material. In particular applications,
material 36 can comprise one or more of aluminum oxide, copper, a
copper-comprising material, TiN, Ta.sub.2O.sub.5, barium strontium
titanate (BST), lead zirconate titanate (PZT), strontium bismuth
titanate (SBT), NH.sub.4Cl, TiCl.sub.4, hafnium oxide, zirconium
oxide, WN.sub.x, W, Pt, a platinum/rhodium alloy, ruthenium,
ruthenium oxide, iridium, iridium oxide, HfN, Ta, TaN, aluminum
nitride and Si.sub.xN.sub.y, for example (where x and y are not
limited to any particular value).
[0039] Upon completion of the processing event, or alternatively
after completion of a series of processing events, one or more
portions of system 10 can be subjected to the cleaning process
described above. During the cleaning process, material 36 can be
contacted by the cleaning agent which can remove some or all of
material 36 from surface 14 as shown in FIG. 3. For chamber
cleaning purposes, it can be preferable to remove processed wafers
from chamber 12 prior to initiating the cleaning treatment. However
it is to be noted that processing equipment such as, for example,
substrate holder 16 as shown in FIG. 1 can be retained within
chamber 12 during the cleaning process. Additional processing
equipment may be retained within chamber 12 or can be introduced
into chamber 12 prior to initiating the cleaning process (not
shown).
[0040] As discussed above, internal surfaces of system 10
components that are external to chamber 12 can also be cleaned
utilizing methods of the present invention. Referring to FIG. 4, a
line 38 having an internal surface 40 can acquire a rescue material
42 over surface 40. Line 38 can be, for example, a feed line or an
exhaust line and material 42 can be one or more of a reactant, a
product, a byproduct or a contaminant of the processing event.
Exemplary substances which can be comprised by material 42 include
any of those substances indicated above with respect to residue
material 36. In a given system, material 42 can be the same or can
differ from material 36 shown in FIG. 2. Material 42 can be
contacted with the cleaning agent during cleaning processes as
described above. Such contact can remove some or all of material 42
from surface 40 as shown in FIG. 5.
[0041] After contacting residue material with the cleaning agent of
the invention, the agent can be vented from the system as described
above. It can be particularly advantageous to utilize supercritical
fluids for cleaning processes according to methods of the invention
due to the relative ease of removal of such supercritical fluids
from the system. Conventional methods of cleaning systems equipment
and/or processing chambers can typically utilize water and or other
solvents that are difficult to eliminate entirely from the
system.
[0042] In compliance with the statute, the invention has been
described in language more or less specific as to structural and
methodical features. It is to be understood, however, that the
invention is not limited to the specific features shown and
described, since the means herein disclosed comprise preferred
forms of putting the invention into effect. The invention is,
therefore, claimed in any of its forms or modifications within the
proper scope of the appended claims appropriately interpreted in
accordance with the doctrine of equivalents.
* * * * *