Protecting an interior of a gas container with an ALD coating
FIELD OF THE INVENTION
5
The present invention generally relates to atomic layer deposition (ALD). More
particularly, the invention relates to providing protective coating by means of ALD.
BACKGROUND OF THE INVENTION
10
This section illustrates useful background information w~thout admission of any
technique described herein representative of the state of the art.
Atomic Layer Epitaxy (ALE) method was invented by Dr. Tuomo Suntola in the
15 early 1970's. Another generic name for the method is Atomic Layer Deposition
(ALD) and it is nowadays used instead of ALE. ALD is a special chemical
deposition method based on the sequential introduction of at least two reactive
precursor species to at least one substrate.
20 Thin films grown by ALD are dense, pinhole free and have uniform thickness. For
example, in an experiment aluminum oxide has been grown by thermal ALD from
trimethylaluminum (CH3)3AI, also referred to as TMA, and water resulting in only
about 1% non-uniformity over a substrate wafer.
25 One interesting application of ALD technique is providing protective coatings on
surfaces.
SUMMARY
30 According to a first example aspect of the invention there is provided a method of
protecting a gas conta~nerin terior, the method comprlslng:
providing an inlet and exhaust man~fold comprising a port assembly attachable to
a port of the gas container;
exposing the gas container interior to sequential self-saturating surface reactions
by sequential inlet of reactive gases via said port assembly and said port into the
gas container interior; and
pumping reaction residue via said port and said port assembly out from the gas
5 container.
The gas container may be, for example, a gas bottle or a gas cylinder. The
sequential self-saturating surface reactions (according to ALD) produce the
desired protective coating within the gas container interior. Accordingly, the gas
10 container interior may be coated by using ALD so that all surfaces within the gas
container whlch see the reactive gases end up coated.
In certain example embodiments, the method comprises attaching said port
assembly to said port of the gas container. Said port of the gas container may be a
15 gas container mouth. The gas container mouth may be threaded.
In certain example embodiments, the method comprises pumping reactlon residue
and purge gas from the gas container interior by a vacuum pump attached to an
exhaust side of the inlet and exhaust manifold. The vacuum pump may provide
20 one or more of the following effects: It may be used to pump the gas container
interlor into vacuum. It may be configured to pump reaction residue from the gas
container via the port assembly.
The gas container may be used as the reaction chamber for ALD reactions.
25 Accordingly, in certain example embodiments, the gas container is used as a
reaction vessel sealed by the port assembly. The sequential self-saturating
surface reactions are thereby limlted to occur within the gas container interior.
In certain example embodiments, the gas container whose inner walls are coated
30 forms a hot wall reaction chamber heated by an external heater.
In certain example embodiments, both gas inlet and gas exhaust occurs via a
same port or opening of the gas container. In certain example embodiments, the
inlet and exhaust manifold hermetically connected to the gas container opens
directly into the gas container and allows alternate supply of the precursors
needed for performing an ALD process, purging the inner volume of the gas
container with an inert gas and evacuation of the precursors, gaseous reaction
5 products and purge gas from the gas container.
In certain example embodiments, the gas container is closable (or closed) by the
inlet and exhaust manifold.
10 In certain example embodiments, said port assembly comprises a sealing part. In
certain example embodiments, the sealing part is detachably attachable to the gas
container mouth in the place of a gas container stop valve. The sealing part, in
certain example embodiments, comprises a tapered thread. In certain example
embodiments, the tapered thread is configured to fit to a counter thread in the gas
15 container mouth. The sealing part may be twisted into the gas container mouth to
seal the gas container mouth. In certain example embodiments, there is a sealing
tape, such as Teflon tape between the tapered thread and the threaded gas
container mouth to improve sealing. In certain example embodiments, at least one
in-feed line and an exhaust line pass through the sealing part. In certain example
20 embodiments, said port assembly comprises a fitting part detachably attachable to
the sealing part. The fitting part may form a (cylindrical) continuation of the sealing
part. In certain example embodiments, when the fitting part is detached from the
sealing part, the sealing part is twistable to tighten against the gas container
mouth. Depending on the implementation, the fitting part may allow the sealing
25 part to twist also when attached to the fitting part. In certain example
embodiments, at least one in-feed line and an exhaust line pass both through the
sealing part and the fitting part. In certain example embodiments, an interface
between the sealing part and the fitting part is airtight when the fitting part has
been attached to the sealing part. In certain example embodiments, there is an
30 airtight feedthrough at an opposite end of the fitting part for at least one of an infeed
and an exhaust line to pass through.
In embodiments, in which the gas container is placed into a chamber of a reactor
for deposition, such as a reaction or vacuum chamber, the sealing by the port
assembly prevents a coating from being deposited onto the chamber walls. This
reduces the need to clean the chamber walls.
5 In certain example embodiments, the gas container is used as a reaction vessel
sealed by a sealing part comprised by the port assembly.
In certain example embodiments, said sealing part comprises a tapered thread
detachably attachable to said port of the gas container in the place of a stop valve.
10
In certain example embodiments, said port assembly comprises a fitting part
attachable to the sealing part allowlng the sealing part to twist to tighten against
said port of the gas container.
15 In certain example embodiments, the method comprises:
guiding inactive purge gas into an intermediate space between the gas container
and a surrounding chamber wall, and
pumping said inactive purge gas out from the intermediate space.
20 An over pressure generated by guiding the inactive purge gas into the
intermediate space further improves the sealing effect of the port assembly. The
intermediate space In an embodiment is kept in a vacuum pressure by a vacuum
pump which is in fluid communication with the intermediate space. By arranging a
material flow from the intermediate space through an exhaust conduit to a pump,
25 such as the vacuum pump, any precursor material ended up into the intermediate
space can be removed.
The inlet and exhaust manifold provides at least one in-feed line and an exhaust
line. Precursor vapor is discharged from said at least one in-feed line at a
30 discharge point within the gas container. The exhaust line begins at an exhaust
point within the gas container. In certain example embodiments, the discharge
point (i.e., a gas discharge point) within the gas container IS arranged at a different
level than the exhaust point (i.e., a gas exhaust point). The discharge point in
certain example embodiments resides at the bottom (or bottom section) of the gas
container the exhaust point being in the top (or top section). In other example
embodiments, the discharge point resides in the top (or top section) of the gas
container interior the exhaust point being at the bottom (or bottom section)
5
In certain example embodiments, the inlet and exhaust manifold comprises one or
more in-feed lines with their controlling elements controlled by a computerimplemented
control system.
10 In certain example embodiments, the inlet and exhaust manifold comprises ALD
reactor in-feed equipment. In certain example embodiments, the in-feed
equipment comprises in-feed l~ne(s) and at least the desired precursor and
inactive gas flow controlling elements, such as valve(s), mass flow controller(s) or
similar, and their control system.
15
The control system may be implemented for example by software in a laptop
computer or similar. Accordingly, in certain example embodiments, the inlet and
exhaust manifold comprises one or more in-feed lines with their controlling
elements controlled by a computer-implemented control system. Suitable
20 replaceable precursor and Inactive gas sources may be attached to the in-feed
equipment.
According to a second example aspect of the invention there is provided an
apparatus for protecting a gas container interior, comprising:
25 an inlet and exhaust manifold comprising a port assembly attachable to a port of
the gas container, the apparatus being configured to expose the gas container
interior to sequential self-saturating surface reactions by sequential inlet of
reactive gases via said port assembly and said port into the gas container interior;
and
30 a pump configured to pump reaction residue via said port and said port assembly
out from the gas container.
In certain example embodiments, a gas discharge point provided by the inlet and
exhaust manifold is arranged at a different level than a gas exhaust point provided
by the inlet and exhaust manifold. The different levels here typically mean different
heights.
5 In certain example embodiments, the inlet and exhaust manifold comprises
precursor vapor and purge gas in-feed lines and their controlling elements. The
pump may attached to the exhaust side of the inlet and exhaust manifold. The
pump may be a vacuum pump.
10 In certain example embodiments, the inlet and exhaust manifold comprises a gas
container-specific port assembly configured to attach the inlet and exhaust
manifold into said port of the gas container thereby forming a fluid communication
path between the inlet and exhaust manifold and the gas container interior.
Similarly, a fluid communication path between the gas container interior and the
15 pump is formed.
In certain example embodiments, the port assembly comprises a sealing part
attachable to the port of the gas container.
20 In certain example embodiments, the sealing part comprises a tapered thread
In certain example embodiments, the apparatus comprises:
a chamber surrounding the gas container and an inactive gas in-feed line
configured to guide inactive purge gas into an intermediate space between the gas
25 container and a surrounding chamber wall.
The apparatus comprising the inlet and exhaust man~foldm ay be mobile so that it
can be moved to meet the user's needs. In certain example embodiments, the inlet
and exhaust manifold comprises a separate inlet manifold and a separate exhaust
30 manifold both being able to simultaneously couple to the gas container port and
designed to work together in a gas container interior protecting method.
Different non-binding example aspects and embodiments of the present invention
have been illustrated in the foregoing. The above embodiments are used merely to
explain selected aspects or steps that may be utilized in implementations of the
present invention. Some embodiments may be presented only with reference to
certain example aspects of the invention. It should be appreciated that
5 corresponding embodiments may apply to 'other example aspects as well. Any
appropriate combinations of the embodiments may be formed.
BRIEF DESCRIPTION OF THE DRAWINGS
10 The invention will now be described, by way of example only, with reference to the
accompanying drawings, in which:
Fig. 1 shows a schematic view of an apparatus and its use for
protecting a gas container interior in accordance with an example
15 embodiment;
Figs. 2A-2B show alternative in-feed arrangements in accordance with certain
example embodiments;
Fig. 3 shows another example embodiment;
Figs. 4A-4B show a sealing arrangement in accordance with certain example
20 embodiments; and
Fig. 5 shows a method in accordance with an example embodiment.
DETAILED DESCRIPTION
25 In the following description, Atomic Layer Deposition (ALD) technology is used as
an example. The basics of an ALD growth mechanism are known to a skilled
person. As mentioned in the ~ntroductory portion of this patent application, ALD is
a special chemical deposition method based on the sequential introduction of at
least two reactive precursor species to at least one substrate. The at least one
30 substrate is exposed to temporally separated precursor pulses in a reaction vessel
to deposit material on the substrate surfaces by sequential self-saturating surface
reactions. In the context of this application, the at least one substrate comprises
the interior (inner surface) of a gas container, for example a gas bottle. Further, in
the context of this application, the term ALD comprises all applicable ALD based
techniques and any equivalent or closely related technologies, such as, for
example MLD (Molecular Layer Deposition) technique.
5 A basic ALD deposition cycle consists of four sequential steps: pulse A, purge A,
pulse B and purge 8. Pulse A consists of a first precursor vapor and pulse B of
another precursor vapor. Inactive gas and a vacuum pump are typically used for a
purging gaseous reaction by-products and the residual reactant molecules from
the reaction space during purge A and purge B. A deposition sequence comprises
10 at least one deposition cycle. Deposition cycles are repeated until the deposition
sequence has produced a thin film or coating of desired thickness. Deposition
cycles can also be more complex. For example, the cycles can include three or
more reactant vapor pulses separated by purging steps. All these deposition
cycles form a timed deposition sequence that is controlled by a logic unit or a
15 micro~rocessor.
In certain example embodiments as described in the following, there is provided a
method and apparatus for protecting a gas container (such as a gas cylinder, or
gas bottle) interior with a protective coating. The gas container here is a pressure
20 vessel. The gas container itself forms a reaction chamber (or a reaction space),
and there is typically no separate substrate, but the surfaces of the gas container
interior form a substrate (substrate here meaning the material on which a process
is conducted). All these surfaces can be coated by an ALD process in which
precursor vapors are sequentially inlet via an inlet and exhaust manifold into the
25 gas container interior. The reaction residue is pumped out from the gas container
interior via an exhaust side of the inlet and exhaust manifold. The gas container
can be optionally heated before and/or during ALD processing by a heater placed
around the gas container.
30 Fig. 1 shows the method and related apparatus in certain example embodiments.
The apparatus used to protect the interior of a gas container 10 comprises an inlet
and exhaust manifold 20. The apparatus may be a mobile apparatus. A mobile
apparatus may be conveniently moved into the proximity of gas containers to be
protected, if needed.
The inlet and exhaust manifold 20 is configured to be detachably attached to a gas
container port 11. Fig. 1 shows the inlet and exhaust manifold 20 attached by a
5 port assembly 24 to the gas container port I I . The port assembly 24 may be a gas
container-specific part. The port assembly comprises a sealing arrangement (not
shown) to seal the interface between the gas container port 11 and the port
assembly 24. In an example implementation, the port assembly comprises a seal
(not shown) which tightens against its counter surface in the gas container port 11.
10
The inlet and exhaust manifold 20 comprises ALD reactor in-feed equipment 70.
The in-feed equipment 70 comprises the required in-feed lines and their controlling
elements. Attached to the port assembly 24 in Fig. 1 is a first precursor vapor infeed
line 41, a second precursor in-feed line 42 and a purge gas in-feed line 43.
15 The first precursor in-feed line 41 originates from a first precursor source 21, the
second precursor in-feed line 42 from a second precursor source 22, and the
purge gas in-feed line 43 from a purgelinactive gas source 23. The in-feed lines
41-43 extend, travelling through the port assembly 24 and gas container port 11,
from the sources 21-23 to the interior of the gas container 10. The in-feed lines 41-
20 43 end at respective discharge points. An exhaust line 32 begins at an exhaust
point within the gas container interior. The discharge points should reside in a
different level than the exhaust point to effectively obtain uniform deposition. In the
embodiment shown in Fig. 1 the discharge points of the in-feed lines 41-43 are at
the bottom section of the gas container 10 the exhaust point being in the top
25 section.
The in-feed line controlling elements comprise flow and timing controlling
elements. A first precursor in-feed valve 61 and mass (or volume) flow controller
51 in the first precursor in-feed line 41 control the timing and flow of first precursor
30 pulses. Correspondingly, a second precursor in-feed valve 62 and mass (or
volume) flow controller 52 in the second precursor in-feed line 42 control the timing
and flow oT second precursor pulses. Finally, a purge gas in-feed valve 63 and
mass (or volume) flow controller 53 control the timing and flow of purge gas.
In the embodiment shown in Fig. 1, the operation of the in-feed equipment 70 is
controlled by a control system. Fig. 1 shows a control connection 72 between the
in-feed equipment 70 and a control system 71. The control system 71 may be
5 implemented for example by software in a laptop computer or similar.
In certain example embodiments, the ALD process within the gas container interior
is performed in a vacuum pressure. The inlet and exhaust manifold 20 comprises
a vacuum pump 33. In certain example embodiments, the vacuum pump 33 is
10 located in the end of the exhaust line 32 provided by the inlet and exhaust
manifold 20. The vacuum pump 33 can be optionally controlled by the control
system 71 via an optional electrical connection 73 (which is between the control
system 71 and the vacuum pump 33). In certain example embodiments, the gas
container is heated by an external heater (not shown).
15
In operation, the vacuum pump 33 pumps the interior of the gas container 10 into
vacuum. Precursor vapor of the first precursor and second precursor are
sequentially discharged into the gas container interior from the discharge points of
the first and second precursor in-feed lines 41 and 42, respectively. In the purge
20 steps, inactive purging gas is discharged into the gas container interior from the
discharge point of the purge gas in-feed line 43. The arrows 15 depict the flow
direction of precursor vapor and purge gas within the gas container from the
respective discharge points towards the exhaust point (via which they are pumped
into the exhaust line 32). The desired thickness of protective coating onto the gas
25 container inner surface is obtained by repeating deposition cycles as needed.
Further referring to Flg. 1, it should be noted that in other embodiments, the inlet
and exhaust manifold 20 may be arranged differently. Instead of separate in-feed
llnes at least part of the in-feed lines may be in common. The valve types may
30 vary. The flow controlling element locations may vary, etc. For example, three-way
valves may be used instead of two-way valves, immediately reflecting changes in
in-feed llne routing Concerning the precursor sources and purge gas, their
selection depends on the implementation and desired coating. The gas container
10 can be heated by an optional heater 16 from the outside of the gas container
10. The heater may be a helical coil heater arranged around the gas container 10.
The operation of the heater can be optionally controlled be the control system 71
over a connection.
5
Applicable coatings depending on the application are, for example, metal oxides,
such as aluminum oxide, titanium oxide, tantalum oxide, and tungsten carbide,
and their combinations, but the coatings are not limited to these materials.
10 Figs. 2A and 2B show two alternative embodiments for the placement of in-feed
and exhaust lines within the gas container 10. The gas container 10 has an inner
wall shape allowing free movement of low-pressure gases.
Fig. 2A corresponds to the arrangement shown in Fig. 1. Accordingly, the in-feed
15 lines 41-43 and exhaust line 32 travel through the gas container port 11. The infeed
lines 41-43 end at respective discharge points. The exhaust line 32 begins at
an exhaust point. The discharge points of the in-feed lines 41-43 are at the bottom
section of the gas container 10 the exhaust point being in the top section. The
direction of gas flow is shown by the arrows 15.
20
In the preferred embodiment shown in Fig. 28, the exhaust line to the contrary
begins at the bottom section of the gas container 10 whereas the discharge points
of the in-feed lines 41-43 are in the top section. The in-feed lines 41-43 and
exhaust line 32 travel through the gas container port 11. The in-feed lines 41-43
25 end at respective discharge points. The exhaust line 32 begins at an exhaust
point. The direction of gas flow is shown by the arrows 15.
Fig. 3 shows a method and apparatus for protecting a gas container interior in
accordance with another example embodiment. This embodiment basically
30 corresponds to the embodiment shown in Fig. I, however, disclosing certain
further features.
Fig. 3 shows pressure vessel, such as a chamber 30 surrounding the gas
container 10. The chamber 30 may be, for example, a vacuum chamber or ALD
reaction chamber generally used in the field of ALD. The gas container 10 is
loaded into the chamber 30 via a loading hatch 31, or s~milar, and is attached by
its port 11 to the port assembly 24. The in-feed lines 41-43 are passed into the
5 chamber 30 through a feedthrough 36 arranged into the chamber 30 wall. The
exhaust line 32 is passed out from the chamber 30 through a feedthrough 46
arranged into the chamber 30 wall. The location of the feedthroughs 36 and 46
depend on the implementation. The feedthroughs 36 and 46 may even be
implemented by a single feedthrough. The feedthroughs 36 and 46 are sealed.
10
The basic operation concerning the deposition of a protective coating with~n the
gas container 10 is similar to that described in connection with Fig. I.
The embodiment shown in Fig. 3 optionally comprises a purge gas in-feed conduit
15 44 through which inactive purge gas is guided (discharged) into an intermediate
space 40 between the gas container 10 and a surrounding chamber 30 wall. The
purge gas flows to the conduit 44, for example, along a branch 43a divided from
the purge gas in-feed line 43.
20 The intermediate space 40 is pumped by the vacuum pump 33 via an exhaust
conduit 45 arranged on the opposite side of the intermediate space 40. The
exhaust pump 33 is in fluid communication with the intermediate space 40 through
an exhaust line 47 extending from the exhaust conduit 45 to the exhaust pump 33.
The exhaust lines 32 and 47 may join at some point on the way to the exhaust
25 pump 33.
The pumping causes a flow within the intermediate space 40 that conducts any
precursor material ended up into the intermediate space 40 into the exhaust line
47. An over pressure generated by guiding the inactive purge gas into the
30 intermediate space 40 further improves the sealing effect of the port assembly 24.
The arrows 35 depict the flow direction within the intermediate space 40.
Fig. 4A shows a sealing arrangement in accordance with an example embodiment.
The gas container 410 comprises a gas container port 411 which is here a mouth
of the gas container. An inlet and exhaust manifold comprises a port assembly
comprising a sealing part 424. The sealing part is detachably attachable, by for
example twisting, to the gas container mouth 411 in the place of a gas container
5 stop valve. For this purpose, the sealing part 424 is a tapered thread part. The
tapered thread of the sealing part is configured to fit to a counter thread (not
shown) in the gas container mouth 411 to tighten and seal the gas container
mouth 41 1. As mentioned, the sealing part 424 can be, for example, twisted into
the gas container mouth to seal the gas container mouth.
10
In certain example embodiments, there is sealing tape 425, such as Teflon tape
around the tapered thread between the tapered thread and the threaded gas
container mouth 41 1 to improve sealing as illustrated in Fig. 48 which is an
enlargement of certain parts of Fig. 4A.
15
Figs. 4A and 4B show two in-feed lines 441 and 443 as well as an exhaust line
432 arranged similarly as in the preferred Fig. 28. Accordingly, the gas discharge
point is in the very proximity of the gas container mouth and the exhaust point at
the opposite end of the gas container (i.e., at the bottom). The in-feed lines and
20 exhaust line pass through the sealing part 424 extending through the sealing part
into an interior of the gas container 410. In certain example embodiments, the port
assembly further comprises a fitting part 426 detachably attachable to the sealing
part. The fitting part 426 forms a (cylindrical) continuation of the sealing part 424.
In certain example embodiments, when the fitting pat? 426 is detached from the
25 sealing part 424, the sealing part 424 is twistable to tighten against the gas
container mouth 41 1. Depending on the implementation, the fitting part 426 may
allow the sealing part 424 to twist also when attached to the fitting part 426. The
in-feed lines 441 and 443 as well as the exhaust line 432 pass both through the
sealing part 424 and the fitting part 426. The interface between the sealing part
30 424 and the fitting part 426 is airtight when the fitting part 426 has been attached
to the sealing part 424. In certain example embodiments, there is an airtight
feedthrough at an end opposite to the sealing part end of the fitting part 426 (as
depicted in the upper section of Fig. 4A) for at least one of an in-feed line 441,443
and an exhaust line 432 to pass through. An airtight feedthrough here means
basically a feedthrough at which gas can flow between the inside of a part and the
outside of a part 426 only through a pipeline. An airtight interface, similarly, means
an interface at which gas can flow from the part (for example, fitting part 426) on a
5 first side of the interface to the part (for example, sealing part 424) on the other
side only through the interface.
In embodiments, in which the fitting part is omitted, the feedthrough(s) are
preferably arranged in the (upper) end of the sealing part 424.
10
As to the general operation of the embodiments shown in Figs. 4A and 48, a
reference is made also to the embodiments shown in Figs. 1 to 3.
Fig. 5 shows a method in accordance with an example embodiment. In step 81, an
15 inlet and exhaust manifold is attached to a gas confainer. ALD processing is
performed in step 82. The ALD processing comprises exposing the gas container
interior to sequential self-saturating surface reactions and pumping reaction
residue out from the gas container. Finally, in step 83, the inlet and exhaust
manifold is detached from the gas container.
20
Without limiting the scope and interpretation of the patent claims, certain technical
effects of one or more of the example embodiments disclosed herein are listed in
the following: A technical effect is protecting gas container interior by a conformal
protective coating. Another technical effect is coating only the inside of the gas
25 container the outside being not coated. Another technical effect is reduced
cleaning need of a surrounding chamber.
It should be noted the some of the functions or method steps discussed in the
preceding may be performed in a different order andior concurrently with each
30 other. Furthermore, one or more of the above-described functions or method steps
may be optional or may be combined.
The foregoing description has provided by way of non-limiting examples of
particular implementations and embodiments of the invention a full and informative
description of the best mode presently contemplated by the inventors for carrylng
out the invention. It IS however clear to a person skilled in the art that the invention
is not restricted to details of the embodiments presented above, but that it can be
5 implemented in other embodiments using equivalent means without deviating from
the characteristics of the invention.
Furthermore, some of the features of the above-disclosed embodiments of this
invention may be used to advantage without the corresponding use of other
10 features. As such, the foregoing description should be considered as merely
illustrative of the principles of the present invention, and not in limitation thereof.
Hence, the scope of the invention is only restricted by the appended patent claims.

Claims
1. A method of protecting a gas container interior, the method comprising:
providing an inlet and exhaust manifold comprising a port assembly
5 attachable to a port of the gas container;
exposing the gas container interior to sequential self-saturating surface
reactions by sequential inlet of reactive gases via said port assembly and said
port into the gas container interior; and
pumping reaction residue via said port and said port assembly out from the
10 gas container.
2. The method of claim 1, comprising attaching said port assembly to said port of
the gas container.
15 3. The method of claim I or 2, comprising pumping reaction residue and purge
gas from the gas container interior by a vacuum pump attached to an exhaust
side of the inlet and exhaust manifold.
4. The method of any preceding claim, wherein a gas discharge point within the
20 gas container is arranged at a different level than a gas exhaust point.
5. The method of any preceding claim, wherein the gas container IS used as a
reaction vessel sealed by a sealing part comprised by the port assembly.
25 6. The method of claim 5, wherein said sealing part comprises a tapered thread
detachably attachable to said port of the gas container in the place of a stop
valve.
7. The method of clalm 5 or 6, wherein sald port assembly comprises a fltting
30 part attachable to the sealing part allowing the sealing part to twist to tighten
agalnst sald port of the gas container.
8. The method of any preceding claim, comprising:
guiding inactive purge gas into an intermediate space between the gas
container and a surrounding chamber wall, and
pumping said inactive purge gas out from the intermediate space.
5 9. The method of any preceding claim, wherein the inlet and exhaust manifold
comprises one or more in-feed lines with their controlling elements controlled
by a computer-implemented control system.
10. An apparatus for protecting a gas container interior, comprising:
10 an inlet and exhaust man~foldc omprising a port assembly attachable to a
port of the gas container, the apparatus being configured to expose the gas
container interior to sequential self-saturating surface reactions by sequential
inlet of reactive gases via said port assembly and said port into the gas
container interior; and
15 a pump configured to pump reaction residue via said port and said port
assembly out from the gas container.
11. The apparatus of claim 10, wherein a gas discharge point provided by the inlet
and exhaust manifold is arranged at a different level than a gas exhaust point
20 provided by the inlet and exhaust manifold.
12. The apparatus of claim 10 or 11, wherein the inlet and exhaust manifold
comprises precursor vapor and purge gas in-feed lines and their controlling
elements.
25
13. The apparatus of any of claims'l0-12, wherein the inlet and exhaust manifold
comprises a gas container-specific port assembly configured to attach the inlet
and exhaust manifold into said port of the gas container thereby forming a fluid
communication path between the inlet and exhaust manifold and the gas
30 container interior.
14. The apparatus of any of claims 10-13, comprising:
a chamber surrounding the gas container and an inactive gas in-feed line
configured to guide inactive purge gas into an intermediate space between the
gas container and a surrounding chamber wall.
15. The apparatus of any of claims 10-14, wherein the port assembly comprises a
5 sealing part attachable to the port of the gas container.
16. The apparatus of claim 15, wherein the sealing part comprises a tapered
thread.
10 17. The apparatus of claims 10-16, wherein the apparatus is mobile.