POWDER PARTICLE COATING USING ATOMIC LAYER DEPOSITION CARTRIDGE
FIELD OF THE INVENTION
The present invention generally relates to deposition reactors. More particularly,
but not exclusively, the invention relates to such deposition reactors in which
material is deposited on surfaces by sequential self-saturating surface reactions.
BACKGROUND OF THE INVENTION
Atomic Layer Epitaxy (ALE) method was invented by Dr. Tuomo Suntola in the
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.
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 at 250 - 300 °C
resulting in only about 1% non-uniformity over a substrate wafer.
One interesting application of ALD technique is coating of small particles. It may
be desirable, for example, to deposit a thin coating on particles to alter the surface
properties of these particles while maintaining their bulk properties.
SUMMARY
According to a first example aspect of the invention there is provided a method
comprising:
receiving an atomic layer deposition (ALD) cartridge into a receiver of an ALD
reactor by a quick coupling method, said ALD cartridge configured to serve as an
ALD reaction chamber; and
processing surfaces of particulate material within said ALD cartridge by sequential
self-saturating surface reactions.
In certain example embodiments, a bottom-to-top flow causes the particulate
material particles to whirl forming fluidized bed within the ALD cartridge. In certain
other embodiments, fluidized bed is not formed depending on certain factors, such
as the flow rate and the weight of the particles. The particulate material may be
powder or more coarse material, such as diamonds or similar.
The receiver may be arranged in an ALD reactor body so that the ALD cartridge is
received into the ALD reactor body. The ALD body may form the receiver. The
receiver may form part of the ALD reactor body (it may be its integral part) or it
may be a fixed receiver integrated to the ALD reactor body, or to an ALD reactor
or processing chamber structure. In case of an integrated receiver, the receiver
may be integrated into an ALD processing chamber lid.
In certain example embodiments, the quick coupling method comprises twisting
the ALD cartridge until a locking member locks the ALD cartridge into its correct
place. In certain example embodiments, the quick coupling method comprises
using form locking that locks the ALD cartridge into its correct place. In certain
example embodiments, the quick coupling method is a combination of these
methods.
In certain example embodiments, the method comprises:
feeding vibrating gas into the ALD cartridge to hinder the formation of
agglomerates within said particulate material.
Vibrating gas may be fed during ALD processing. The vibrating gas may be fed
during both precursor exposure periods and purge periods.
In certain example embodiments, the method comprises:
using a flow channel separate from precursor in-feed lines to feed vibrating
inactive gas into the ALD cartridge during ALD processing.
In many of the example embodiments, percussion may be used in addition to or
instead of the vibrating gas.
In certain example embodiments, the method comprises:
conducting reaction residue via at least one outlet conduit into exhaust, said at
least one outlet conduit being arranged inside the ALD cartridge body.
Instead of one outlet conduit, there may be two outlet conduits, or more.
In certain example embodiments, the method comprises:
loading said particulate material via a loading channel arranged inside the ALD
cartridge body.
Instead of a pre-filled ALD cartridge, particulate material to be coated may be
loaded into the ALD cartridge via a loading channel. The loading channel may be
arranged at the bottom section of the ALD cartridge. Alternatively, the ALD
cartridge may be loaded from the top via a loading channel arranged at the top
section of the ALD cartridge. Alternatively, in certain example embodiments, the
ALD cartridge is loaded by removing a removable lid or cover forming the top
section of the ALD cartridge in those embodiments.
In certain example embodiments, the method comprises:
processing particulate material in a plurality of compartments arranged on top of
each other, each compartment having been separated from an adjacent
compartment by a filter plate. The filter plate(s) may be sinter filter(s).
In certain example embodiments, gases are fed into the ALD cartridge from the
bottom of the ALD cartridge.
According to a second example aspect of the invention there is provided an atomic
layer deposition (ALD) reactor comprising:
a receiver configured to receive and ALD cartridge into the ALD reactor by a quick
coupling method, said ALD cartridge configured to serve as an ALD reaction
chamber; and
in-feed line(s) configured to feed precursor vapor into said ALD cartridge to
process surfaces of particulate material within said ALD cartridge by sequential
self-saturating surface reactions.
In certain example embodiments, the receiver is the ALD reactor body itself sized
and shaped so as to receive the ALD cartridge by quick coupling. In other
embodiments, the receiver is implemented as a certain form or a certain part
arranged in the ALD reactor body configured to receive the ALD cartridge.
The quick coupling method causes that (flow) conduits inside the ALD reactor and
cartridge bodies are in alignment with each other. For example, the said form or
part in the ALD reactor body may be sized and shaped so that the respective
conduits arranged in the ALD cartridge and ALD reactor body set in alignment with
each other.
In certain example embodiments, said receiver is configured to receive said ALD
cartridge by a twisting method in which the ALD cartridge is twisted until a locking
member locks the ALD cartridge into its correct place.
In certain example embodiments, said receiver is configured to receive said ALD
cartridge by a form locking method locking the ALD cartridge into its correct place.
In certain example embodiments, the ALD comprises a vibration source in a flow
channel configured to feed vibrating gas into the ALD cartridge to hinder the
formation of agglomerates within said particulate material. The vibrating gas may
be inactive gas.
In certain example embodiments, the ALD reactor comprises:
an outlet conduit inside the ALD reactor body configured to receive reaction
residue from an outlet conduit arranged inside the ALD cartridge body.
In certain example embodiments, the ALD reactor comprises:
a loading channel inside the ALD reactor body configured to conduct particulate
material into a loading channel arranged inside the ALD cartridge body.
In certain example embodiments, the ALD reactor comprises or is configured to
form a gas spreading space (or volume) before (i.e., upstream) an inlet filter of the
ALD cartridge. The gas spreading space may be below the inlet filter. The gas
spreading space may be next to the inlet filter.
In certain example embodiments, the ALD reactor comprises a microfilter tube in
the end of a precursor vapor in-feed line. In certain example embodiments, the gas
spreading space is arranged around the microfilter tube.
According to a third example aspect of the invention there is provided a removable
atomic layer deposition (ALD) cartridge configured to serve as an ALD reaction
chamber and comprising a quick coupling mechanism configured to attach to an
ALD reactor body of an ALD reactor by a quick coupling method, the ALD
cartridge being configured to process surfaces of particulate material within said
ALD cartridge by sequential self-saturating surface reactions once attached to the
ALD reactor body by the quick coupling method.
In certain example embodiments, the removable ALD cartridge comprises:
an outlet conduit inside the ALD cartridge body configured to conduct reaction
residue via the ALD reactor body into exhaust.
In certain example embodiments, the removable ALD cartridge is a cylindrical
cartridge. Accordingly, the basic shape of the removable ALD cartridge in certain
example embodiments is a cylindrical form. In certain example embodiments, the
removable ALD cartridge is a conical cartridge. Accordingly, the basic shape of the
removable ALD cartridge in certain example embodiments is a conical form. In
certain example embodiments, the removable has both cylindrical part and a
conical part. The conical part may be at the bottom.
The ALD cartridge may be downwards tapering. Alternatively, the ALD cartridge
may be of uniform width.
In certain example embodiments, the removable ALD cartridge comprises or is
configured to receive a plurality of filter plates on top of each other to form a
plurality of particulate material coating compartments therebetween. In certain
example embodiments, each of the compartments has space to accommodate an
amount of particulate material to be coated.
According to a fourth example aspect of the invention there is provided an
apparatus comprising the ALD reactor of the second example aspect and the ALD
cartridge of the third aspect. The apparatus thereby forms a system. The system
comprises an ALD reactor with a removable ALD reaction chamber cartridge.
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
corresponding embodiments may apply to other example aspects as well. Any
appropriate combinations of the embodiments may be formed.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described, by way of example only, with reference to the
accompanying drawings, in which:
Fig. 1 shows a deposition reactor and method for coating particles in
accordance with an example embodiment;
Fig. 2 shows flow vibrations in accordance with an example
embodiment;
Fig. 3 shows a method for causing flow vibrations in accordance with
an example embodiment;
shows a deposition reactor and method for coating particles in
accordance with an alternative embodiment;
show different example embodiments to feed gases and particles
into a cartridge reaction chamber;
shows a production line for coating particles in accordance with
an example embodiment;
shows a deposition reactor and method for coating particles in
accordance with yet another example embodiment;
shows a rough example of a quick coupling method in
accordance with an example embodiment;
shows a rough example of another quick coupling method in
accordance with an example embodiment;
shows a deposition reactor and method for coating particles in
accordance with yet another example embodiment;
shows a deposition reactor and method for coating particles in
accordance with yet another example embodiment; and
shows a deposition reactor and method for coating particles in
accordance with yet another example embodiment.
DETAILED DESCRIPTION
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 introductory 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 substrate is
located within a reaction space. The reaction space is typically heated. The basic
growth mechanism of ALD relies on the bond strength differences between
chemical adsorption (chemisorption) and physical adsorption (physisorption). ALD
utilizes chemisorption and eliminates physisorption during the deposition process.
During chemisorption a strong chemical bond is formed between atom(s) of a solid
phase surface and a molecule that is arriving from the gas phase. Bonding by
physisorption is much weaker because only van der Waals forces are involved.
Physisorption bonds are easily broken by thermal energy when the local
temperature is above the condensation temperature of the molecules.
The reaction space of an ALD reactor comprises all the typically heated surfaces
that can be exposed alternately and sequentially to each of the ALD precursor
used for the deposition of thin films or coatings. A basic ALD deposition cycle
consists of four sequential steps: pulse A, purge A, pulse B and purge B. Pulse A
typically consists of metal precursor vapor and pulse B of non-metal precursor
vapor, especially nitrogen or oxygen precursor vapor. Inactive gas, such as
nitrogen or argon, and a vacuum pump are used for purging gaseous reaction by
products and the residual reactant molecules from the reaction space during purge
A and purge B. A deposition sequence comprises at least one deposition cycle.
Deposition cycles are repeated until the deposition sequence has produced a thin
film or coating of desired thickness.
In a typical ALD process, precursor species form through chemisorption a
chemical bond to reactive sites of the heated surfaces. Conditions are typically
arranged in such a way that no more than a molecular monolayer of a solid
material forms on the surfaces during one precursor pulse. The growth process is
thus self-terminating or saturative. For example, the first precursor can include
ligands that remain attached to the adsorbed species and saturate the surface,
which prevents further chemisorption. Reaction space temperature is maintained
above condensation temperatures and below thermal decomposition temperatures
of the utilized precursors such that the precursor molecule species chemisorb on
the substrate(s) essentially intact. Essentially intact means that volatile ligands
may come off the precursor molecule when the precursor molecules species
chemisorb on the surface. The surface becomes essentially saturated with the first
type of reactive sites, i.e. adsorbed species of the first precursor molecules. This
chemisorption step is typically followed by a first purge step (purge A) wherein the
excess first precursor and possible reaction by-products are removed from the
reaction space. Second precursor vapor is then introduced into the reaction space.
Second precursor molecules typically react with the adsorbed species of the first
precursor molecules, thereby forming the desired thin film material or coating. This
growth terminates once the entire amount of the adsorbed first precursor has been
consumed and the surface has essentially been saturated with the second type of
reactive sites. The excess of second precursor vapor and possible reaction by
product vapors are then removed by a second purge step (purge B). The cycle is
then repeated until the film or coating has grown to a 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
microprocessor.
In certain example embodiments as described in the following, thin conformal
coatings are provided onto the surfaces of various particulate materials. The size
of the particles depends on the particular material and the particular application.
Suitable particle sizes typically range from the nanometer range up to the
micrometer range. A wide variety of particulate materials can be used. The
composition of a base particle and that of the coating is typically selected together
so that the surface characteristics of the particle are modified in a way that is
desirable for a particular application. The base particles preferably have some
functional group on the surface that participates in an ALD reaction sequence that
creates the coating.
Fig. 1 shows a deposition reactor and method for coating particles in accordance
with an example embodiment. The deposition reactor comprises a removable
cartridge 110 . The cartridge 110 is attached to a reactor body 12 1 . In an
embodiment, the cartridge 110 is attached to the reactor body 12 1 by quick
coupling, for example, by twisting it into a locked position. The interface formed
between the cartridge 110 and reactor body 12 1 is sealed by a cartridge seal 116 .
However, in other embodiments, the seal 116 may be omitted.
Figs. 8 and 9 roughly show certain principles of quick coupling methods which can
be applied in attaching the cartridge (here: 8 10, 9 10) into the reactor body (here:
821 , 921 ) .
The example embodiment shown in Fig. 8 shows a form locking method. The
reactor body 821 comprises a receiver 822 configured to receive an attachment
part 823 of the cartridge 810. The receiver 822 is formed and shaped so that
depressions 847b and 848b arranged therein fit into corresponding protrusions
847a and 848a arranged into the attachment part 823 (or vice versa) locking the
cartridge 810 into its correct position. In its correct position, corresponding flow
conduits (835a and 835b as well as 836a and 836b in this embodiment) used in
ALD processing become set in alignment with each other. The receiver 822 can be
used in feeding in gases into the cartridge via the attachment part 823 from the
bottom.
The example embodiment shown in Fig. 9 shows a twisting method for attaching
the cartridge 9 10 into the reactor body 921 . The reactor body 921 comprises a
receiver 922 configured to receive the cartridge 9 10 . The receiver 922 is roundshaped
and comprises a thread 924 onto which the cartridge 9 10 can be twisted.
The receiver 922 further comprises a stopping part 958b which stops the twisting
movement of the cartridge 910 at a point where the stopping part 958b touches a
corresponding stopping part 958a arranged in the cartridge 9 10 (for example in a
round-shaped flow channel 926 of the cartridge 9 10). In this position,
corresponding flow conduits 940a and 940b machined into the reactor and
cartridge body parts set in alignment with each other. The conduits herein may be
gas flow conduits, or conduits used in feeding particulate material into the
cartridge (as shows for example in connection with Fig. 6 in the following
description).
In certain example embodiments, other quick coupling methods, for example,
methods containing both form locking and twisting can be used. In the preceding
and other embodiments, pushing and locking methods using levers or springloaded
levers (not shown) attached to the reactor body or to the cartridge can be
used in addition or instead.
Returning to Fig. 1, the interface between the cartridge 110 and the reactor body
12 1 is indicated by the dotted line 152. This is also the line at which the cartridge
110 can be detached from the reactor body 121 after ALD processing.
The cartridge 110 comprises a cartridge body 112 that forms a hollow space,
namely a reaction chamber 111, inside the cartridge 110 . The reaction chamber
111 comprises particles to be coated, herein referred to as powder or powder
particles. The cartridge 110 further comprises a top 113 which can be detached
from the cartridge body 112 at line 15 1 for powder loading and unloading purpose.
Accordingly, in an example embodiment, the cartridge 110 is loaded with powder
elsewhere (pre-filled cartridge), then attached into the reactor body 12 1 for coating
the powder particles, then detached from the reactor body 12 1, and then used or
unloaded elsewhere, when needed.
The cartridge 110 comprises a first particle filter 114 (inlet filter 114) on the inlet
side of the cartridge 110 and a second particle filter 115 (outlet filter 115) on the
outlet side of the cartridge 110 . The inlet filter 114 may be more coarse than the
outlet filter 115 (the outlet filter 115 more fine than the inlet filter 114).
In accordance with ALD technique, precursor A via the in-feed line 13 1 and
precursor B via the in-feed line 132 are controlled to flow alternately into the
reaction chamber 111. Precursor A and B exposure periods are separated by
purge steps. The gases flow into the reaction chamber 111 through a hallway 133
and the inlet filter 114. The flow causes the powder particles to whirl forming a
fluidized bed 105 into the reaction chamber 111 enabling the desired coating to be
grown onto the powder particles. A coating of desired thickness is obtained by
repeating a required number of ALD cycles. The residual reactant molecules and
reaction by-products (if any) and carrier/purge gas are controlled to flow through
the outlet filter 115 via a channel 134 within the cartridge top part 113 into outlet
conduits 135 and 136. The outlet conduits 135 and 136 have been arranged into
the cartridge body 112 by for example machining them by a suitable method. The
outlet conduits 135 and 136 continue in the reactor body part 12 1 in which the
gases flow via channel 137 into an exhaust line.
During operation, the bottom and mid portions of the vertical reaction chamber 111
shown in Fig. 1 may be considered to form a fluidized zone in which the coating
reactions occur. The upper portion of the reaction chamber 111 close the outlet
filter 115 may be considered to form a disengaging zone in which the powder
particles separate from the gases and drop down back to the fluidized zone.
It has been observed that the powder particles in fluidized beds tend to stick to
each other forming larger particle blocks, agglomerates. In order to hinder the
formation of agglomerates, a vibrating gas flow is used in certain example
embodiments. In these embodiments, a gas flow that vibrates is fed into the
reaction chamber. Which gas flow is chosen to vibrate depends on the
implementation. Certain alternatives are discussed later in this description in
connection with Figs. 5A - 5D.
Fig. 2 shows flow vibrations in accordance with an example embodiment. The flow
pressure against time is varied to cause a vibrating flow. Fig. 3 shows a method
for causing flow vibrations in accordance with an example embodiment. In this
method, an incoming gas flow 301 is forced over and into a cavity 302 causing
vibrations into the outgoing gas flow 303. The phenomenon is based on Helmholtz
resonance. The outgoing vibrating gas flow 303 is guided into the reaction
chamber in order to hinder the formation of agglomerates.
Fig. 4 shows a deposition reactor and method for coating particles in accordance
with an alternative embodiment. The deposition reactor shown in Fig. 4 basically
corresponds to the deposition reactor shown in Fig. 1. However, there are some
differences as will become evident in the following. The deposition reactor
comprises a removable cartridge 410. The cartridge 410 is attached to a reactor
body 421 . In an embodiment, the cartridge 4 10 is attached to the reactor body 421
by quick coupling, for example, by twisting it into a locked position. Unlike in the
example embodiment shown in Fig. 1, in the embodiment shown in Fig. 4, the
cartridge seal 116 between the cartridge 410 and the reactor body 421 may be
omitted, especially if the interface 152 between the cartridge 4 10 and the reactor
body 421 is a metal against metal or a ceramic against ceramic interface or
similar. Then there is much tight contact surface avoiding the need for using a
separate seal. Also, when ALD processing is operated in low pressure, the need
for using a separate seal reduces.
The cartridge 4 10 comprises a cartridge body 112 that forms a hollow space, a
reaction chamber 111, inside the cartridge 4 10. The reaction chamber 111
comprises the powder particles to be coated. In an example embodiment, the
powder particles are loaded into the reaction chamber 111 via a separate loading
channel 441 . The powder can be blown by an inactive gas flow through the
loading channel 441 into the reaction chamber 111. In the embodiment shown in
Fig. 4, the loading channel 441 has been arranged into the cartridge body 112 so
that its other end is in fluid communication with (or leads to) the bottom portion of
the reaction chamber 111. The loading channel 441 has been arranged into the
cartridge body 112 by for example machining it by a suitable method. In the
embodiment shown in Fig. 4, the loading channel 441 continues in the reactor
body part 421 , and the direction of the powder flow during loading is from the
reactor body part 421 via the cartridge body 112 into the reaction chamber 111.
The other end of the loading channel may be connected to a powder source or a
loading cartridge or similar. Nitrogen, for example, can be used as the inactive
gas.
After ALD processing, the coated powder particles are unloaded out of the
reaction chamber 111 via an unloading channel 442. The powder can be blown by
an inactive gas flow through the unloading channel 442 into a remote cartridge or
container. In the embodiment shown in Fig. 4, the unloading channel 442 has
been arranged into the cartridge body 112 so that its other end is in fluid
communication with the bottom portion of the reaction chamber 111. The
unloading channel 442 continues in the reactor body part 421 , and the direction of
the powder flow during unloading is from the reaction chamber 111 via the
cartridge body 112 into the reactor body part 421 . The other end of the unloading
channel can be connected to the remote cartridge or container. The inactive gas
blowing the coated powder particles can be guided into the reaction chamber 111
via the loading channel 441 so that it exits the reaction chamber via the unloading
channel 442 drawing the coated powder particles with it.
The cartridge 4 10 for the purpose of the embodiment of Fig. 4 may be a single part
cartridge or a two-part cartridge. Whilst a removable cartridge top 113 is not
needed for loading and unloading, the part 113 can be useful for a cartridge
cleaning purpose. In a single part cartridge embodiment, the top 113 and the rest
of the cartridge 4 10 form a single inseparable piece.
The rest of the operational and structural features of the embodiment shown in
Fig. 4 correspond to those of the embodiment shown in Fig. 1.
Fig. 5 shows different example embodiments to feed gases and powder particles
into the cartridge reaction chamber 111. The example embodiment shown in Fig.
5A shows an embodiment similar to the one shown in Fig. 1. Accordingly, the
precursors typically carried by carrier gas are fed into the reaction chamber 111
from the bottom through the hallway 133 and inlet filter 114. The powder particles
are fed elsewhere from the top beforehand. In the embodiment where the vibrating
gas flow is used, the gas flow causing vibrations during ALD processing can be
the gas flow travelling along either in-feed line 13 1 or 132 (Fig. 1) or both. Or a
separate channel for vibrating inactive gas flow can be used in addition or instead
(as shown in Figs. 5B and 5D in the following).
The example embodiment shown in Fig. 5C shows an embodiment similar to the
one shown in Fig. 4 . Accordingly, the precursors typically carried by carrier gas are
fed into the reaction chamber 111 from the bottom through the hallway 133 and
inlet filter 114. The powder particles are fed along the loading channel 441 from
the bottom and unloaded along the unloading channel 442. In the embodiment
where the vibrating gas flow is used, the gas flow causing vibrations during ALD
processing can be the gas flow travelling along either the in-feed line 13 1 or 132
(Fig. 1) or both. Alternatively, or in addition, a vibrating inactive gas flow is
controlled to flow during ALD processing along the loading channel 441 into the
reaction chamber 111. During ALD processing there can be a small inactive gas
flow towards the reaction chamber 111 in the channel 441 and/or 442 when the
channel in question is not used for vibrating gas supply.
In the example embodiment shown in Fig. 5B there is a separate inlet 575 for
vibrating inactive gas from the bottom, whereas precursors A and B, typically
carried by carrier gas, are fed into the cartridge reaction chamber 111 via inlet 531
and 532, respectively.
In the example embodiment shown in Fig. 5D there is the separate inlet 575 for
vibrating inactive gas from the bottom, but the embodiment also comprises the
loading and unloading channels 441 and 442 for loading and unloading the
powder particles. Alternatively, or in addition to the vibrating gas flowing via inlet
575, a vibrating inactive gas flow can be controlled to flow during ALD processing
along the loading channel 441 and/or unloading channel 442 into the reaction
chamber 111. During ALD processing there can be a small inactive gas flow
towards the reaction chamber 111 in the channel 441 and/or 442 when the
channel in question is not used for vibrating gas supply.
Fig. 6 shows an example layout for a powder coating production line. The
production line comprises a triple-cartridge system. The first cartridge 110a is a
loading cartridge detachably attached into a first body 621a. The powder particles
to be coated are blown by inactive gas via loading channel 640a into an ALD
processing cartridge 110b detachable attached into an ALD reactor body 621 b.
Coated powder particles are blown by inactive gas via unloading channel 640b
into a third cartridge 110c detachable attached into a third body 621 c . The third
cartridge 110c therefore is the cartridge for the end product. Once detached from
the body 621 c, the third cartridge 110c can be transported to the place of use.
Fig. 7 shows a deposition reactor and method for coating particles in accordance
with yet another example embodiment. The deposition reactor comprises a
processing chamber 760 and a lid 770 which can be pressed against a processing
chamber top flange 771 . The processing chamber 760 houses in its reaction
space 765 a cartridge reaction chamber 7 10 filled with powder particles to be
coated.
The cartridge reaction chamber 7 10 is coupled to the processing chamber lid 770.
In the embodiment shown in Fig. 7, the cartridge reaction chamber 7 10 is coupled
to the processing chamber lid 770 by in-feed lines 781 and 782. The cartridge
reaction chamber 7 10 therefore can be loaded into the reaction chamber 760 by
lowering the processing chamber lid 770 carrying the cartridge reaction chamber
7 10 . The lid 770 comprises a lifting mechanism 775 with the aid of which the lid
770 can be raised and lowered. When the lid 770 is raised it raises at line 750 so
that the cartridge reaction chamber 7 10 and pipelines 781 and 782 coupled
thereto raise simultaneously.
The cartridge reaction chamber 7 10 is attached to processing chamber structures
by quick coupling at a fitting part 791 . In an example embodiment, the cartridge
reaction chamber 7 10 can be twisted to lock into the fitting part 791 or twisted to
open.
Similarly as in foregoing embodiments, the cartridge reaction chamber 7 10
comprises an inlet filter 714 on its bottom side and an outlet filter 715 on its top
side. During ALD processing, precursor A via in-feed line 13 1 and precursor B via
the in-feed line 132 are controlled to flow alternately into the cartridge reaction
chamber 7 10 . In the embodiment shown in Fig. 7, the in-feed lines 13 1 and 132
travel via the processing chamber lid 770 and have been marked by reference
numerals 781 and 781 inside the processing chamber 760.
Precursor A and B exposure periods are separated by purge steps. The gases
flow into the cartridge reaction chamber 7 10 alternately from the in-feed lines 781
and 782 through a hallway 133 and the inlet filter 714 from the bottom. The flow
causes the powder particles to whirl forming a fluidized bed 705 into the cartridge
reaction chamber 7 10 enabling the desired coating to be grown onto the powder
particles. A coating of desired thickness is obtained by repeating a required
number of ALD cycles. From the cartridge reaction chamber 7 10 the gases flow
through the outlet filter 715 from the top into the reaction space 765 of the
surrounding processing chamber 760 and therefrom into an exhaust line 737.
The cartridge reaction chamber 7 10 is connected to the ground 780 to prevent
static electricity generated by the movement and collisions of powder particles
from being excessively accumulated into the cartridge reaction chamber 7 10 . The
connection to the ground is also applicable in foregoing embodiments.
The vibrating gas supply into the cartridge reaction chamber 7 10, if implemented,
can be implemented via the existing pipelines/in-feed lines.
Fig. 10 shows a deposition reactor and method for coating particles in accordance
with yet another example embodiment. The deposition reactor comprises a
receiver 10 11 within a processing chamber 1003. The receiver 10 11 is configured
to receive a removable cartridge 1020 into the processing chamber 1003 by a
quick coupling method, such as a form-locking method or similar.
The deposition reactor comprises a processing chamber lid 1001 which lies on a
processing chamber top flange 1002 during operation. The cartridge 1020 can be
loaded into the processing chamber 1003 from the top of the processing chamber
1003 when the processing chamber lid 1001 is raised aside.
The cartridge 1020 shown in this embodiment is a cylindrical reaction chamber
comprising therein a plurality of filter plates 1030 set on top of each other to form a
plurality of compartments therebetween, each compartment having space to
accommodate an amount of particulate material to be coated. In the embodiment
shown in Fig. 10 there are three filter plates and two compartments therebetween
(although in other embodiments there may be less compartments, that is, only a
single compartment, or more, that is three or more compartments). The filter plates
1030 lie on filter supports 1032 arranged into the sidewall of the cartridge 1020.
The filter plates 1030 allow precursor vapor and inactive gas to flow therethrough,
but do not allow the particulate material to go through. In practice, one or more of
the filter plates 1030 may be sinter filters.
The lowest of the filter plates 1030 functions as an inlet filter. The uppermost of the
filter plates 1030 functions as an outlet filter. In the embodiment shown in Fig. 10,
a first compartment is formed between the lowest filter plate and the next (i.e.,
second) filter plate. A second compartment is formed between that (i.e., second)
filter plate and the uppermost (i.e., third) filter plate. The first compartment
accommodates a first amount of particulate material 1041 to be coated. The
second compartment accommodates a second amount of particulate material
1042 to be coated. The particulate material in the first compartment may be the
same of different particulate material compared to the particulate material in the
second compartment.
The cartridge 1020 comprises a lid 1021 which closes the cartridge on the top.
One or more of the filter plates 1030 and the particulate material can be loaded
from the top of the cartridge 1020 when the lid 1021 is moved aside.
In the embodiment shown in Fig. 10, the cartridge 1020 further comprises in its top
part an aperture 1007 in the cartridge sidewall leading to an exhaust channel
1008. The exhaust channel 1008 travels outside of the cartridge 1020 and leads
into an exhaust guide 1009 of the deposition reactor. In the continuation of the
exhaust guide 1009 the deposition reactor comprises an exhaust valve 1010
through which gases are pumped to a vacuum pump (not shown).
The deposition reactor further comprises in-feed lines to feed precursor vapor
and/or inactive gas into the processing chamber as required by the ALD process.
In Fig. 10 a first in-feed line configured to feed precursor vapor of a first precursor
and/or inactive gas is denoted by reference numeral 1005, and a second in-feed
line configured to feed precursor vapor of a second precursor and/or inactive gas
is denoted by reference numeral 10 15 . In-feed of precursor vapor and inactive gas
is controlled by a first in-feed valve 1004 in the first in-feed line 1005 and by a
second in-feed valve 1014 in the second in-feed line 10 15 .
Below the inlet filter the cartridge 1020 comprises a gas spreading space 1006. In
certain embodiments, the gas spreading space 1006 helps to cause a uniform
bottom-to-top flow of precursor vapor within the cartridge 1020. In an alternative
embodiment, the gas spreading space 1006 is formed by the deposition reactor by
a suitable structure. In such an embodiment, the inlet filter may form the bottom of
the cartridge 1020.
The upper drawing of Fig. 10 shows the deposition reactor in operation during the
exposure period of second precursor. The mixture of precursor vapor of the
second precursor and inactive gas (here: N2) flows via the second in-feed line
10 15 into the gas spreading space 1006, whilst only inactive gas flows into the gas
spreading space 1006 via the first in-feed line 1005. The flow continues from the
gas spreading space 1006 into the compartments causing the particulate material
particles to whirl forming fluidized beds within the compartments (depending on
certain factors, such as the flow rate and the weight of the particles). The gas flow
exits the cartridge 1020 via the aperture 1007 into the exhaust channel 1008.
Vibrating gas flow may be used similarly as presented in the foregoing.
The lower drawing of Fig. 10 together with the upper drawing of Fig. 10 shows that
the route of the exhaust channel 1008 outside of the cartridge 1020 may be such
that the exhaust channel 1008 first travels along the side of the cartridge 1020,
and then along the center axis of the (cylindrical) cartridge 1020 below the
cartridge 1020 to obtain flow symmetry.
The lower drawing of Fig. 10 also shows a processing chamber heater 1051 and
heat reflectors 1053 around the cartridge 1020 within the processing chamber
1003. Furthermore, the lower drawing of Fig. 10 shows the in-feed lines 1005 and
10 15 as well as the heater 1051 travelling through processing chamber
feedthroughs 1052. After passing through the feedthroughs 1052 in a vertical
direction, the in-feed lines 1005 and 10 15 take a turn and continue in a horizontal
direction into the gas spreading space 1006.
Fig. 11 shows a deposition reactor and method for coating particles in accordance
with yet another example embodiment. This embodiment has certain similarities
with the embodiments shown in Fig. 7 and Fig. 10 concerning which a reference is
made to the description of Fig. 7 and Fig. 10 .
The left-hand drawing of Fig. 11 is an assembly drawing. The right-hand drawing
shows the deposition reactor in operation during the exposure period of second
precursor. The deposition reactor comprises a processing chamber 1110. The
processing chamber 1110 is closed by a processing chamber lid 110 1 from the
top. The processing chamber lid 1101 lies on a processing chamber top flange
1102 during operation.
The deposition reactor comprises a first precursor source and a second precursor
source. The deposition reactor further comprises in-feed lines to feed precursor
vapor and/or inactive gas into the processing chamber as required by the ALD
process. In Fig. 11 a first in-feed line configured to feed precursor vapor of the first
precursor and/or inactive gas is denoted by reference numeral 1105, and a second
in-feed line configured to feed precursor vapor of the second precursor and/or
inactive gas is denoted by reference numeral 1115 . In-feed of precursor vapor and
inactive gas is controlled by a first in-feed valve 1104 in the first in-feed line 1105
and by a second in-feed valve 1114 in the second in-feed line 1115 .
A receiver 1131 is configured to receive a removable cartridge 1120 into the
processing chamber 1110 by a quick coupling method, such as a form-locking
method or similar.
The receiver 113 1 is integrated to the processing chamber lid 110 1 . The first infeed
line 1105 goes through the processing chamber top flange 1102, takes a turn
in the processing chamber lid 1101 and travels within the processing chamber lid
110 1 (although in some other embodiments, the first in-feed line only travels within
the processing chamber lid). Similarly, the second in-feed line 1115 goes through
the processing chamber top flange 1102 on the opposite side, takes a turn in the
processing chamber lid 1101 and travels within the processing chamber lid 1101
(although in some other embodiments, the second in-feed line only travels within
the processing chamber lid). The first and second in-feed lines 1105 and 1115 turn
downwards and travel into the receiver 113 1 attaching the receiver 1131 thereby
into the processing chamber lid 110 1 . In other words, the in-feed lines 1105 and
1115 carry the receiver 3 1.
The receiver 113 1 comprises supports 1132 arranged into the sidewall(s) of the
receiver 1 3 1. The cartridge 1120 when loaded into its place in the receiver 113 1
is supported by the supports 1132.
The cartridge 1120 shown in this embodiment is a cylindrical reaction chamber
comprising a cylindrical body (or cylindrical wall), an inlet filter 112 1 at the bottom
and an outlet filter 112 1 on the top. The inlet filter 112 1 and/or the outlet filter 1122
may be sinter filters. Alternatively, the cartridge 1120 may comprise one or more
filter plates in between to form compartments within the cartridge 1120 as in the
embodiment of Fig. 10 . At least the outlet filter 1122 may be removable to enable
loading of particulate material 1140 to be coated into the cartridge 1120.
The deposition reactor comprises and exhaust guide 1107. In the continuation of
the exhaust guide 1107 the deposition reactor comprises an exhaust valve 1108
through which gases are pumped to a vacuum pump 1109.
The first in-feed line 1105 ends at a microfilter tube 116 1 arranged in or in
connection with the receiver 3 1. Similarly, the second in-feed line 1115 ends at
a microfilter tube which may be the same microfilter tube 1161 or another
microfilter tube, for example a microfilter tube parallel to the microfilter tube 1161 .
Upon loading the cartridge 1120 its place in the receiver 113 1 a confined volume
115 1 around the microfilter tube(s) 116 1 is formed. This confined volume is
located right below the cartridge 1120 (or below its inlet filter 1121 ) and it functions
as a gas spreading space 115 1 during operation. In certain embodiments, the gas
spreading space 1151 helps to cause a uniform bottom-to-top flow of precursor
vapor within the cartridge 1120.
As mentioned, the right-hand drawing of Fig. 11 shows the deposition reactor in
operation during the exposure period of second precursor. The mixture of
precursor vapor of the second precursor and inactive gas (here: N2) flows along
the second in-feed line 1115 via the microfilter tube 1161 into the gas spreading
space 1151 , whilst only inactive gas flows into the gas spreading space 1151 via
the first in-feed line 1105. The flow continues from the gas spreading space 1151
into the cartridge reaction chamber causing the particulate material particles to
whirl forming fluidized beds within the cartridge (depending on certain factors,
such as the flow rate and the weight of the particles). The gas flow exits the
cartridge 1120 via the outlet filter 1122 through the top of the cartridge 1120 into
the processing chamber volume 1110 . From the processing chamber 1110 the
gases flow into the exhaust guide 1107 at the bottom and through the exhaust
valve 1108 into the vacuum pump 1109.
Vibrating gas flow may be used similarly as presented in the foregoing to hinder
the formation of agglomerates within the particulate material 1140.
Fig. 12 shows a deposition reactor and method for coating particles in accordance
with yet another example embodiment. The embodiment of Fig. 12 basically
otherwise corresponds to the one presented in Fig. 11 except that the first and
second in-feed lines 1205 and 12 15 do not travel within the processing chamber
lid 1201 but merely within the processing chamber top flange 1102, and the
receiver 1231 in not integrated to the processing chamber lid 1101 but to the
processing chamber top flange 1202.
The first in-feed line 1205 penetrates into the processing chamber top flange 1202,
takes a turn and travels within the processing chamber top flange 1202. Similarly,
the second in-feed line 121 5 penetrates into the processing chamber top flange
1202, takes a turn and travels within the processing chamber top flange 1202. The
first and second in-feed lines 1205 and 1215 turn downwards and travel into the
receiver 1231 attaching the receiver 1231 thereby into the processing chamber top
flange 1202. In other words, the in-feed lines 1205 and 12 15 carry the receiver
1231 .
A gas spreading space 1251 forms similarly as the gas spreading space 115 1 in
the embodiment of Fig. 11. Vibrating gas flow may be used similarly as presented
in the foregoing to hinder the formation of agglomerates within the particulate
material 1140.
The receiver 1231 in this embodiment, and also in certain other embodiments, is a
fixed receiver integrated to the processing chamber structure, while in the
embodiment of Fig. 11 the receiver 113 1, although also being a fixed receiver and
integrated to the processing chamber structure, was a movable receiver moving
together with the processing chamber lid 1 0 1.
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 carrying
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
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
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 comprising:
receiving an atomic layer deposition (ALD) cartridge into a receiver of an
ALD reactor by a quick coupling method, said ALD cartridge configured to
serve as an ALD reaction chamber; and
processing surfaces of particulate material within said ALD cartridge by
sequential self-saturating surface reactions.
The method of claim 1, wherein said quick coupling method is selected from a
group consisting of: a twisting method in which the ALD cartridge is twisted
until a locking member locks the ALD cartridge into its correct place, and a
form locking method locking the ALD cartridge into its correct place.
The method of claim 1 or 2, comprising:
feeding vibrating gas into the ALD cartridge to hinder the formation of
agglomerates within said particulate material.
4 . The method of any preceding claim, comprising:
using a flow channel separate from precursor in-feed lines to feed vibrating
inactive gas into the ALD cartridge during ALD processing.
The method of any preceding claim, comprising:
conducting reaction residue via at least one outlet conduit into exhaust, said
at least one outlet conduit being arranged inside the ALD cartridge body.
6 . The method of any preceding claim, comprising:
loading said particulate material via a loading channel arranged inside the
ALD cartridge body.
7 . The method of any preceding claim, comprising:
processing particulate material in a plurality of compartments arranged on
top of each other, each compartment having been separated from an adjacent
compartment by a filter plate.
8 . An atomic layer deposition (ALD) reactor comprising:
a receiver configured to receive and ALD cartridge into the ALD reactor by a
quick coupling method, said ALD cartridge configured to serve as an ALD
reaction chamber; and
in-feed line(s) configured to feed precursor vapor into said ALD cartridge to
process surfaces of particulate material within said ALD cartridge by
sequential self-saturating surface reactions.
9 . The ALD reactor of claim 8, wherein said receiver is configured to receive said
ALD cartridge by a twisting method in which the ALD cartridge is twisted until a
locking member locks the ALD cartridge into its correct place.
10 . The ALD reactor of claim 8, wherein said receiver is configured to receive said
ALD cartridge by a form locking method locking the ALD cartridge into its
correct place.
11.The ALD reactor of any preceding claim 8-10, wherein the ALD comprises a
vibration source in a flow channel configured to feed vibrating gas into the ALD
cartridge to hinder the formation of agglomerates within said particulate
material.
12 . The ALD reactor of any preceding claim 8-1 1, comprising:
an outlet conduit inside the ALD reactor body configured to receive reaction
residue from an outlet conduit arranged inside the ALD cartridge body.
13 . The ALD reactor of any preceding claim 8-1 2, comprising:
a loading channel inside the ALD reactor body configured to conduct
particulate material into a loading channel arranged inside the ALD cartridge
body.
14. The ALD reactor of any preceding claims 8-1 3, wherein the ALD reactor is
configured to form a gas spreading space before an inlet filter of the ALD
cartridge.
15 . A removable atomic layer deposition (ALD) cartridge configured to serve as an
ALD reaction chamber and comprising a quick coupling mechanism configured
to attach to an ALD reactor body of an ALD reactor by a quick coupling
method, the ALD cartridge being configured to process surfaces of particulate
material within said ALD cartridge by sequential self-saturating surface
reactions once attached to the ALD reactor body by the quick coupling
method.
16 . The removable ALD cartridge of claim 15, comprising:
an outlet conduit inside the ALD cartridge body configured to conduct
reaction residue via the ALD reactor body into exhaust.
17 . The removable ALD cartridge of claim 15 or 16, comprising:
a plurality of filter plates on top of each other to form a plurality of particulate
material coating compartments therebetween.
18 . The removable ALD cartridge of any preceding claim 15-1 7, comprising
a gas spreading space below an inlet filter.
19 . An apparatus comprising the ALD reactor of any preceding claim 8-14 and the
ALD cartridge of any preceding claim 15-1 7 .