FIELD OF THE INVENTION
The present invention generally relates to deposition reactors. More particularly,
the invention relates to atomic layer deposition reactors in which material is
deposited on surfaces by sequential self-saturating surface reactions.
j O 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
15 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
20 trimethylaluminum (CH3)3AI, also referred to as TMA, and water at 250 - 300 "C
resulting in only about 7 % non-uniformity over a substrate wafer.
Until now the ALD industry has mainly concentrated on depositing material on one
or more rigid substrates. In recent years, however, an increasing interest has been
25 shown towards roll-to-roll ALD processes in which material is deposited on a
substrate web unwound from a first roll and wound up around a second roll after
deposition.
SUMMARY
30
According to a first example aspect of the invention there is provided a method
comprising:
I
I driving a substrate web into a reaction space of an atomic layer deposition reactor;
and
exposing the reaction space to temporally separated precursor pulses to deposit
material on said substrate web by sequential self-saturating surface reactions.
5 In certain example embodiments, material is deposited on a substrate web and the
material growth is controlled by the speed of the web. In certain example
embodiments, the substrate web is moved along a straight track through a
processing chamber and a desired thin film coating is grown onto the substrate
surface by a temporally divided ALD process. In certain example embodiments,
10 each of the phases of an ALD cycle is carried out in one and the same reaction
space of a processing chamber. This is in contrast to e.g. spatial ALD in which
different phases of a deposition cycle are performed in different reaction spaces.
In certain example embodiments, the whole reaction space may be alternately
15 exposed to precursor pulses. Accordingly, the exposure of the reaction space to a
precursor pulse of a first precursor may occur in the exactly same space (or same
volume of a processing chamber) as the exposure to a precursor pulse of a
second (another) precursor. The ALD process in the reaction space is temporally
divided (or time-divided) in contrast to e.g. spatial ALD which requires a reaction
20 space to be spatially divided. The substrate web may be continuously moved or
periodically moved through the reaction space. The material growth occurs when
the substrate web is within the reaction space and is alternately exposed to
precursor vapor pulses to cause sequential self-saturating surface reactions to
occur on the substrate web. surface. When the substrate web is outside the
25 reaction space in the reactor, substrate web surface is merely exposed to inactive
gas, and ALD reactions do not occur.
The reactor can comprise a single processing chamber providing said reaction
space. In certain example embodiments, the substrate web is driven from a
30 substrate web source, such as a source roll, into the processing chamber (or
reaction space). The substrate web is processed by ALD reactions in the
processing chamber and driven out of the processing chamber to a substrate web
destination, such as a destination roll. When the substrate web source and
destination are rolls, a roll-to-roll atomic layer deposition method is present. The
substrate web may be unwound from a first roll, driven into the processing
chamber, and wound up around a second roll after deposition. Accordingly, the
substrate web may be driven from a first roll to a second roll and exposed to ALD
5 reactions on its way. The substrate web may be bendable. The substrate web may
also be rollable. The substrate web may be a foil, such as a metal foil.
In certain example embodiments, the substrate web enters the reaction space
from or via a first confined space. The first confined space may be an excess
10 pressure volume. From the reaction space the substrate web may be driven into a
second confined space. The second confined space may be an excess pressure
volume. It may be the same or another volume as the first confined space. The
purpose of the confined space(s) may simply be to prevent precursor
vaporlreactive gases from flowing to the outside of the processing chamber via the
15 substrate web route. In a roll-to-roll scenario, the rolls may reside in the confined
space or not. The reactor may form part of a production line with processing units
in addition to the ALD reactor (or module). Especially then the rolls may reside
outside of the confined space@) further away in suitable point of the production
line.
2 0
In certain example embodiments, the method comprises:
inputting the substrate web from an excess pressure volume into the reaction
space via a slit maintaining a pressure difference between said volume and the
reaction space.
25
The excess pressure herein means that although the pressure in the excess
pressure volume is a reduced pressure with regard to the ambient (or room)
pressure, it is a pressure higher compared to the pressure in the reaction space.
Inactive gas may be fed into the excess pressure volume to maintain said
30 pressure difference. Accordingly, in certain example embodiments, the method
comprises:
feeding inactive gas into the excess pressure volume.
In certain example embodiments, the slit (input slit) is so thin that the substrate
web just hardly fits to pass through. The excess pressure volume may be a
volume in which the first (or source) roll resides. In certain example embodiments,
both the first and second roll reside in the excess pressure volume. The excess
pressure volume may be denoted as an excess pressure space or compartment.
The slit may operate as a flow restrictor, allowing inactive gas to flow from said
excess pressure volume to the reaction space (or processing chamber), but
substantially preventing any flow in the other direction (i.e., from reaction space to
the excess pressure volume). The slit may be a throttle. The slit may operate as a
constriction for the inactive gas flow.
In certain example embodiments, the reactor comprises constriction plates forming
said slit. The constriction plates may be two plates placed next to each other so
I that the substrate web just hardly fits to pass through. The plates may be parallel ~ I 15 plates so that the space between the plates (slit volume) becomes elongated in ~ I the web moving direction.
The substrate web may be unwound from the first roll, ALD processed in a
processing chamber providing the reaction space, and wound up on the second
20 roll.
1 The ALD processed substrate,web may output from the reaction space via a
second slit (output slit). The structure and function of the second slit may
correspond to that of the first mentioned slit. The second slit may reside on the
25 other side of the reaction space compared to the first mentioned slit.
In certain example embodiments, the thickness of deposited material is controlled
by the speed of the web. In certain example embodiments, the speed of the web is
adjusted by a control unit. The thickness of deposited material may be directly
30 determined by the speed of the web. The web may be driven continuously from
said first roll' onto the second roll. In certain example embodiment, the web is
driven continuously at constant speed. In certain example embodiment, the web is
driven by a stop and go fashion. Then the substrate web may be stopped for a
deposition cycle, moved upon the end of the cycle, and stopped for the next cycle,
and so on. Accordingly, the substrate web may be moved from time to time at
predetermined time instants.
I
I 5 In certain example embodiments, the method comprises:
I 1 conveying inactive gas into the volume(s) in which the first and second roll reside.
Accordingly, the gas in thislthese volume(s) may consist of inactive gas. The
inactive gas may be conveyed into said volume(s) from a surrounding volume. For
example, inactive gas may be conveyed into a reaction chamber accommodating
1 10 the rolls and surrounding the actual processing chamber from a vacuum chamber
that, in turn, surrounds the reaction chamber.
In certain example embodiments, the precursor vapor flow direction in the reaction
space is along the moving direction of the substrate web. The substrate web
comprises two surfaces and two edges. The precursor vapor may flow along at
least one of said surfaces.
In certain example embodiments, the method comprises feeding precursor vapor
into the reaction space at the substrate web input end of the reaction space and
arranging exhaust of gases at the substrate web output end of the reaction space.
Precursor vapor of a first and a second (another) precursor may be alternately
conducted into the substrate web input end of the reaction space.
In certain example embodiments, the precursor vapor flow direction in the reaction
space is traverse compared to the moving direction of the substrate web. The
substrate web comprises two surfaces and two edges. The traverse precursor
vapor flow direction may be along at least one of said surfaces.
In certain example embodiments, the method comprises:
feeding precursor vapor into the reaction space at a side of the reaction space and
arranging exhaust of gases at an opposite side of the reaction space.
In certain example embodiments, the method comprises:
alternately feeding precursor vapor of a first precursor into the reaction space at a
first side of the reaction space and precursor vapor of a second (another)
precursor at the first side or a second (opposite) side of the reaction space, and
arranging exhaust of gases at the middle area of the reaction space or at the
5 substrate web output end of the reaction space.
I
In certain example embodiments, the method comprises:
integrating the first and second roll into a reaction chamber lid.
1 10 The atomic layer deposition reactor may be reactor with nested chambers. In ~
certain example embodiments, the reactor comprises a first chamber (a vacuum
chamber, or a first pressure vessel) surrounding and housing a second chamber
(a reaction chamber, or a second pressure vessel). The reaction chamber houses
the first and second roll, and inside the reaction chamber may be formed a third
1 5 chamber (the processing chamber) providing said reaction space. In certain
example embodiments, the processing chamber is integrated into the reaction
chamber lid.
The reactor may be loaded and unloaded from the top of the reactorlreaction
20 chamber. In certain example embodiments, the reaction chamber lid (which may
be a dual lid system providing also a lid to the vacuum chamber) is raised into an
upper position for loading. The first roll and second roll are attached to the lid. The
lid is lowered so that the reaction chamber (and vacuum chamber) closes. Feeding
of gases into the reaction space may occur from precursorlinactive gas sources
25 via the reaction chamber lid.
In certain example embodiments, the method comprises:
driving said substrate web straight through said reaction space.
30 In other embodiments, the web may be arranged to follow a longer track within the
reaction space to enable larger capacity.
In certain example embodiments, the method comprises:
using a narrow processing chamber that is, in its lateral direction, as wide as the
substrate web.
Especially when the processing chamber is not substantially wider than the
5 substrate web, material may be deposited on a single side of the substrate web,
since the substrate itself prevents gases from flowing onto the other side of the
web. The substrate web, said slit(s) and the processing chamber may all be
substantially equal in width. Basically, embodiments in which the substrate web
travels close to the processing chamber wall (in the direction of desired material
10 growth) suit well for single-sided deposition, whereas embodiments in which the
substrate travels in the center area of the processing chamberlreaction space suit
well for double-sided deposition.
In certain example embodiments, the method comprises feeding inactive gas into I
I
I 15 a space between a backside of the substrate web and processing chamber wall to
form a shielding volume. The shielding volume is formed against deposition on the
backside of the substrate web, the backside thus being the surface of the
substrate web that is not to be coated.
20
In certain example embodiments, the reactor comprises separate precursor vapor
in-feed openings for both surfaces of the substrate web.
I
According to a second example aspect of the invention there is provided an
25 apparatus comprising:
a driving unit configured to drive a substrate web into a reaction space of an
atomic layer deposition reactor; and
a precursor vapor feeding part configured to expose the reaction space to
temporally separated precursor pulses to deposit material on said substrate web
30 by sequential self-saturating surface reactions.
The apparatus may be an atomic layer deposition (ALD) reactor. The ALD reactor
may be a standalone apparatus or a part of a production line. The driving unit may
be configured to drive the substrate web from a first roll via the reaction space to a
second roll. The driving unit may be connected to the second (destination) roll. In
certain example embodiments, the driving unit comprises a first drive that is
connected to the first (source) roll and a second drive that is connected to the
5 second (destination) roll, respectively. The driving unit may be configured to rotate
the roll(s) at a desired speed.
In certain example embodiments, a precursor vapor feeding part comprises a
plurality of shower heads arranged inside the reaction space to deliver precursor
10 vapor into the reaction space. In certain example embodiments, a reaction
chamber lid forms a precursor vapor feeding part.
In certain example embodiments, the apparatus comprises:
an input slit for inputting the substrate web from an excess pressure volume into
15 the reaction space.
In certain example embodiments, the slit is for maintaining a pressure difference
between said volume and the reaction space. In certain example embodiments,
the apparatus comprises constriction plates forming said slit.
20
In certain example embodiments, the apparatus comprises:
a channel configured to convey inactive gas into the excess pressure volume.
In certain example embodiments, said channel is from a vacuum chamber via
25 reaction chamber wall or lid into the reaction chamber.
In certain example embodiments, the apparatus comprises:
a precursor vapor in-feed opening at the substrate web input end of the reaction
space and exhaust at the substrate web output end of the reaction space.
30
In certain example embodiments, the apparatus comprises:
a precursor vapor in-feed opening or openings at a side of the reaction space and
exhaust at an opposite side of the reaction space.
The apparatus may have a precursor vapor in-feed opening or openings at a side
of the reaction space substantially throughout the reaction space in its longitudinal
direction.
5 The directions of the reaction space may be defined as follows: substrate web
moving direction, direction of desired material growth (a direction perpendicular to
the substrate web moving direction), and a traverse direction (a direction
perpendicular to both the substrate web moving direction and the direction of
desired material growth). Said longitudinal direction of the reaction space means a
10 direction parallel to the substrate web moving direction.
In certain example embodiments, the apparatus comprises:
a reaction chamber lid configured to receive the first and second roll.
In an example embodiment, the reaction chamber lid comprises roll holders
15 integrated to it for receiving the first and second roll.
In certain example embodiments, the reaction chamber lid comprises an
attachment or an attachment mechanism to which the first and second roll can be
attached. The beginning portion of the substrate web may be drawn through the
20 processing chamber onto the second roll before the lid is lowered.
In certain example embodiments, the apparatus comprises:
a narrow processing chamber that is, in its lateral direction, as wide as the input
slit. Said lateral direction means said traverse direction. The apparatus may further
25 comprise a control unit configured to control the operation of the reactor, such as
timing of the precursor pulses and purge periods. The control unit may also control
the operation of the driving unit. In certain example embodiments, the control unit
adjusts the speed of the substrate web to control thickness of desired material
growth.
30
According to a third example aspect of the invention there is provided an
apparatus comprising:
means for driving a substrate web into a reaction chamber of an atomic layer
I
I deposition reactor; and
means for exposing the reaction space to temporally separated precursor pulses
I
to deposit material on said substrate web by sequential self-saturating surface
reactions.
5
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
10 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
I 15
I
The invention will now be described, by way of example only, with reference to the 1
accompanying drawings, in which:
Fig. 1 shows a side view of a deposition reactor in a loading phase in
20 accordance with an example embodiment;
Fig. 2 shows the deposition reactor of Fig. 1 in operation during a purge
step in accordance with an example embodiment;
Fig. 3 shows the deposition reactor of Fig. 1 in operation during a
I precursor exposure period in accordance with an example i
25 embodiment;
Fig. 4 shows a top view of a thin processing chamber of the deposition
I reactor of Fig. 1 and a cross section at an input slit in accordance I
I I with an example embodiment; i
I Fig. 5 shows the deposition reactor of Fig. 1 after ALD processing has I
I I 30 been finished in accordance with an example embodiment;
I Fig. 6 shows a single drive system in accordance with an example 1
I
embodiment; 1
Fig. 7 shows a side view of a deposition reactor in a loading phase in
1
1
Fig. 8
5 Fig.9
Fig. 10
Fig. 12
Fig. 13
Fig. 14
20
Fig. 15
Fig. 16
25
Fig. 17
Fig. 18
30
Fig. 19
Fig. 20
accordance with another example embodiment;
shows the deposition reactor of Fig. 7 in operation during a
precursor exposure period in accordance with an example
embodiment;
shows a side view of a deposition reactor in accordance with a
generic example embodiment;
shows the deposition reactor of Fig. 9 in operation during a
precursor exposure period in accordance with an example
embodiment;
shows a top view of the deposition reactor of Fig. 9 during the
precursor exposure period of Fig. 7 in accordance with an
example embodiment;
shows the deposition reactor of Fig. 9 in operation during another
precursor exposure period in accordance with an example
embodiment;
shows a deposition reactor with constriction plates in accordance
with an example embodiment;
shows thickness of deposited material in the function of distance
traveled within a reaction space in accordance with an example
embodiment;
shows a deposition reactor with precursor vapor in-feed at the
substrate web input end of the processing chamber in
accordance with an example embodiment;
shows a top view of the type of deposition reactor of Fig. 15 in
accordance with an example embodiment;
shows a deposition reactor with precursor vapor in-feed at the
side of the processing chamber in accordance with an example
embodiment;
shows a top view of the type of deposition reactor of Fig. 17 in
accordance with an example embodiment;
shows an alternative construction in accordance with an example
embodiment;
shows a top view of a deposition reactor in accordance with yet
Fig. 21
Fig. 22
Fig. 23
Fig. 24
Fig. 26
another example embodiment;
shows a top view of a deposition reactor for deposition of multiple
rolls at a time in accordance with an example embodiment;
shows a thin reactor structure in accordance with an example
embodiment;
shows a thin reactor structure for deposition of multiple rolls in
accordance with an example embodiment;
shows double-sided coating in accordance with an example
embodiment;
shows a specific detail for single-sided coating in accordance
with an example embodiment; and
shows a rough block diagram of a deposition reactor control
system in accordance with an example embodiment.
15 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
20 a special chemical deposition method based on the sequential introduction of at
least two reactive precursor species to at least one substrate. The substrate, or
the moving substrate web in this case, 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
25 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.
30
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 typically 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.
10 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
15 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
20 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
25 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
30 reactive sites. The excess of second precursor vapor and possible reaction byproduct
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.
5 Fig. 1 shows a side view of a deposition reactor in a loading phase in accordance
with an example embodiment. The deposition reactor comprises vacuum chamber
wall(s) 111 to form a vacuum chamber 110. The vacuum chamber I10 is a
pressure vessel. It can be in the form of a cylinder or any other suitable shape.
The vacuum chamber 110 houses a reaction chamber 120, which is another
10 pressure vessel. The reaction chamber 120 be in the form of a cylinder or any
other suitable shape. The vacuum chamber 110 is closed by a vacuum chamber
lid 101. In an example embodiment, the vacuum chamber lid 101 is integrated to a
reaction chamber lid I02 as shown in Fig. 1 thereby forming a lid system (here: a
dual-lid system). A processing chamber 130 comprising processing chamber walls
131 has been attached to the reaction chamber lid 102 by fastener(s) 185.
Between the reaction chamber lid 102 and the vacuum chamber lid 101, the lid
system comprises heat reflectors 171 .
A first (source) roll 151 of substrate web 150 is attached to a first roll axis 143. The
roll axis (or roll 151) can be rotated by a first drive 141 attached to the roll axis
143. The drive 141 is located outside of the vacuum chamber 110. It is attached to
the lid system by a fastener 147. There is a lead-through in the lid system (both in
the vacuum chamber lid I01 and in the reaction chamber lid 102) via which the roll
axis 143 penetrates into the reaction chamber 120. In the bottom of the reaction
25 chamber 120, there is an attachment 145 for attaching the roll axis 143 to the
reaction chamber 120. The roll 151 can be attached to the roll axis 143 by an
appropriate attachment 106. The roll axis 143 and the attachment 106 form a roll
holder.
30 A second (destination) roll 152 is attached to a second roll axis 144. The roll axis
(or roll 152) can be rotated by a second drive 142 attached to the roll axis 144.
The drive 142 is located outside of the vacuum chamber 110. It is attached to the
lid system by a fastener 148. There is a lead-through in the lid system (both in the 1
vacuum chamber lid 101 and in the reaction chamber lid 102) via which the roll
axis 144 penetrates into the reaction chamber 120. In the bottom of the reaction
chamber 120, there is an attachment 146 for attaching the roll axis 144 to the
reaction chamber 120. Similarly, as the roll 151, the roll 152 can be attached to the
5 roll axis by an appropriate attachment 107. The roll axis 144 and the attachment
107 therefore form another roll holder.
In the vacuum chamber 110 around the reaction chamber 120 (or in the reaction
chamber 120 around the processing chamber 130 in some embodiments), the
10 deposition reactor comprises a heater 175 for heating the reaction space formed
within the processing chamber 130. At the side, between the vacuum chamber
wall I I I and reaction chamber wall 121, the vacuum chamber 110 comprises heat
reflectors 172.
I
I 15 The deposition reactor comprises an upper interface flange 104 attached to a
reaction chamber top flange 103. A seal 181 is placed between the vacuum
I chamber lid 101 and the upper interface flange 104 to seal the top part of the
I
I vacuum chamber 110. The reaction chamber 120 comprises a reaction chamber
I top flange 105. Upon lowering the lid system the reaction chamber lid 102 sets on
20 the reaction chamber top flange 105, thereby closing the reaction chamber 120.
The deposition reactor further comprises a vacuum pump 160 and an exhaust line
161, which during operation is in fluid communication from the processing
chamber 130 to the vacuum pump 160.
25
The deposition reactor is loaded with the lid system in its upper position. The
source roll 151 with bendable or rollable substrate web is attached into the roll axis
143. A first end of the substrate web 150 is brought through the processing
chamber 130 to the destination roll 152 and attached thereto. The lid system is
30 subsequently lowered to close the chambers. In an embodiment, the processing
chamber 130 comprises a protruding channel at the bottom. The protruding
channel passes through an opening in the reaction chamber 120 and forms the
beginning of the exhaust line 161 when the lid system has been lowered as
depicted in Fig. 2.
I
I Moreover, Fig. 2 shows the deposition reactor of Fig. 1 in operation during a purge ~ step in accordance with an example embodiment. The substrate web I50 enters
5 the processing chamber (reaction space) 130 via a slit 291 arranged into the
processing chamber wall 131. lnactive gas flows into the processing chamber 130
via reaction chamber lid 102. It flows from an inlet 135 into an expansion volume
136. The gas spreads within the expansion volume 136 and flows through a flow
distributor 137 (such as a perforated plate or a mesh) into the reaction space of I
10 the processing chamber 130. The inactive gas purges the substrate web surface
l
and flows as a top-to-bottom flow into the exhaust line 161 and finally to the
vacuum pump 160. The substrate web 150 is output from the reaction space 130 i
,
via a slit 292 arranged into the processing chamber wall 131. The output substrate I
1 I
I web is wound around the destination roll 152.
I I
I
I I 5
I
The reaction chamber 120 has at least one opening to the vacuum chamber 110. I
I I
In the example embodiment shown in Fig. 2, a first opening 201 is arranged at the
lead-through at which the roll axis 143 penetrates through the reaction chamber lid I
102. There is an inlet of inactive gas into the vacuum chamber (outside of the
20 reaction chamber 120). This inactive gas flows through the opening 201 from an
I
I
intermediate space 215 (between the vacuum chamber and reaction chamber) to
the reaction chamber 120 into the confined space where the rolls 151 and 152
reside. This flow is depicted by arrow 21 1. Similarly, a second opening 202 is
arranged at the lead-through at which the roll axis 144 penetrates through the
25 reaction chamber lid 102. lnactive gas flows from the intermediate space 215 to
the reaction chamber 120 into the confined space where the rolls 151 and 152
reside. This flow is depicted by arrow 21 2.
The slits 291 and ,292 function as throttles maintaining a pressure difference
30 between the reaction space of the processing chamber 130 and the surrounding
volume (such as the confined space in which the rolls 151 and 152 reside). The
pressure within the confined space is higher than the pressure within the reaction
I space. As an example, the pressure within the reaction space may be 1 mbar I
while the pressure within the confined space is for example 5 mbar. The pressure
difference forms a barrier preventing a flow from the reaction space into the
confined space. Due to the pressure difference, however, flow from the other
direction (that is, from the confined space to the reaction space through the slits
5 291 and 292 is possible). As to the inactive gas flowing from the inlet 135 (as well
as precursor vapor during precursor vapor pulse periods), this flow therefore
practically only sees the vacuum pump 160. In Fig. 2 the flow from the reaction
chamber (confined space) to the reaction space is depicted by the arrows 221 and
222.
10
Fig. 3 shows the deposition reactor of Fig. 1 in operation during a precursor
exposure period in accordance with an example embodiment. Precursor vapor of a
first precursor flows into the processing chamber 130 via reaction chamber lid 102.
It flows from the inlet 135 into the expansion volume 136. The gas spreads within
15 the expansion volume 136 and flows through the flow distributor 137 into the
reaction space of the processing chamber 130. The precursor vapor reacts with
the reactive sites on substrate web surface in accordance with ALD growth
mechanism.
20 As mentioned in the preceding, the pressure difference between the reaction
space and the confined space where the rolls 151 and 152 are located forms a
barrier preventing a flow from the reaction space into the confined space. The
precursor vapor does therefore not substantially enter the space where the rolls
I51 and 152 are. Due to the pressure difference, however, flow from the other
25 direction (that is, from the confined space to the reaction space through the slits
291 and 292) is possible.
Inactive gas, gaseous reaction by-products (if any) and residual reactant
molecules (if any) flow into the exhaust line 161 and finally to the vacuum pump
30 160.
A deposition sequence is formed of one or more consecutive deposition cycles,
each cycle consisting of at least a first precursor exposure period (pulse A)
I followed by a first purge step (purge A) followed by a second precursor exposure
period (pulse B) followed by a second purge step (purge B). The thickness of
grown material is determined by the speed of the web. The substrate web is driven
I by the drives 141 and 142. During a single deposition cycle the substrate web
5 moves a certain distance d. If the total length of the reaction space is Dl the
number of layers deposited on the substrate web basically becomes D/d. When
the desired length of substrate web has been processed, the lid system is raised
and the deposited roll is unloaded from the reactor. Figure 5 shows the end
position in a deposition process in which the source roll 151 has become empty
10 and the destination roll 152 full with deposited coating.
The upper drawing of Fig. 4 shows a top view of the processing chamber 130 in an
example embodiment. The processing chamber 130 is a thin processing chamber
with said slits 291 and 292 arranged into the processing chamber walls 131. The
15 moving substrate web 150 is input into the (narrow) reaction space via slit 291 and
output via slit 292. The flow of precursor vapor from the reaction space to the
outside of the reaction space is prevented firstly by the narrowness of the slits and
secondly by the maintained pressure difference.
20 The lower drawing of Fig. 4 shows a cross section of the processing chamber 130
at the input slit 291 (line b) in accordance with an example embodiment. In the
longitudinal direction of the slit the substrate web 150 is substantially matched with
the length of the slit 291 (the substrate web 150 is as wide as the slit 291 is long).
25 In certain example embodiments, the drives 141 and 142 rotate the rolls 151 and
152 in the same direction during the whole deposition sequence. In these example
embodiments, it is actually enough to have one drive, namely the second drive
142. In certain other example embodiments, the roll direction of the rolls 151 and
152 is changed in the middle of the deposition sequence. In these embodiments,
30 in the end of the deposition sequence it is the first roll 151 that is full and the
second roll 152 empty.
Fig. 6 shows a single drive system in accordance with an example embodiment.
I The substrate web is driven by the drive 142. The roll axis 643 (basically
I
corresponding to roll axis 143 in Fig. 1) is attached to the fastener 147. Otherwise
as to the structural and functional features of the embodiment of Fig. 6 a reference
is made to Figs. 1-5 and their description.
5
Fig. 7 shows a side view of a deposition reactor in a loading phase in accordance
with another example embodiment, and Fig. 8 shows the deposition reactor of Fig.
7 in operation during a precursor exposure period in accordance with an example
embodiment. As to the basic structural and functional features of the embodiments
10 of Figs. 7 and 8 a reference is made to the embodiments described in the
foregoing with reference to Figs. 1-6 and related description.
In the embodiments shown in Fig. 7 and 8, a drive 741 is located below the
I
I
vacuum chamber. A driving mechanism 742 of drive 741 penetrates into the
I 15 reaction chamber through a vacuum chamber wall 711 and a reaction chamber
wall 721 by a vacuum and reaction chamber lead-through. An end part 744 or the
I second roll axis fits into a counterpart 746 of the driving mechanism 742.
A first precursor in-feed line 771. penetrates through the vacuum chamber wall 71 1
20 by a vacuum chamber lead-through 772. And a second precursor in-feed line 781
penetrates through the vacuum chamber wall 711 by a vacuum chamber leadthrough
782. The vacuum chamber lid 701 is integrated to the reaction chamber lid
702 by a connecting part 791. The first and second precursor in-feed lines 771 and
781 go through the reaction chamber top flange 705 and continue inside of the
25 reaction chamber lid 702 as depicted by reference numerals 773 and 783. The infeed
lines 771 and 781 open to the processing chamber 730.
The route of the second precursor during the second precursor exposure period as
shown in Fig. 8 is via the second precursor in-feed line 781 into the reaction space
30 of the processing chamber 730. Via the first precursor in-feed line 771 into the
processing chamber only an inactive gas flow is maintained. The route of the
gases out of the reaction space is the route to the vacuum pump 760 due to the
barrier formation at substrate web input and output slits as described in the
foregoing.
Fig. 9 shows a side view of a deposition reactor in accordance with another
example embodiment. The deposition reactor comprises a first precursor source
5 913, which is for example a TMA (trimethylaluminium) source, and a second
precursor source 914, which is for example a Hz0 (water) source. In this and in
other embodiments, the water source can be replaced by an ozone source. A first
pulsing valve 923 controls the flow of precursor vapor of the first precursor into a
first precursor in-feed line 943. A second pulsing valve 924 controls the flow of
10 precursor vapor of the second precursor into a second precursor in-feed line 944.
The deposition reactor further comprises a first inactive gas source 903. For
example nitrogen N2 can be used as the inactive gas is many embodiments. The
1 first inactive gas source 903 is in fluid communication with the first precursor in- 1
15 feed line 943. The first inactive gas source 903 is further in fluid communication
with a confined space 920a that contains a first roll core 963 having bendable I
substrate web wound thereon to form a first (source) substrate web roll 953. ~
The deposition reactor further comprises a second inactive gas source 904. 1
20 However, the inactive gas sources 903 and 904 may be implemented as a single 1
source in some example embodiments. The second inactive gas source 904 is in I
fluid communication with the second precursor in-feed line 944. The second ~
inactive gas source 904 is further in fluid communication with a confined space I
920b that contains a second roll core 964 having bendable substrate web to be I
25 wound thereon to form a second (destination) substrate web roll 954. I
I
The deposition reactor further comprises a processing chamber providing a
reaction space 930 with the length of a. The in-feed lines 943 and 944 enter the
processing chamber and continue in the processing chamber as shower head
30 channels 973 and 974, respectively. In the example embodiment of Fig. 9 the
showerhead channels 973 and 974 are horizontal channels. The shower head
channels 973 and 974 reach from one end to the other end of the processing
chamber (or reaction space). On their length the shower head channels 973 and
974 have apertures 983 and 984, respectively, which function as shower heads for
in-feed gases (such as precursor vapor andlor inactive gas).
The deposition reactor further comprises a vacuum pump 960 and an exhaust line
5 961, which during operation is in fluid communication from the reaction space 930
to the vacuum pump 960.
Moreover, Fig. 9 shows the deposition reactor in operation during a purge step in
accordance with an example embodiment. The substrate web 950 enters the
I 0 processing chamber (reaction space 930) via a slit or narrow passage 993
arranged between the confined space 920a and the reaction space 930. The
pulsing valves 923 and 924 are closed. lnactive gas flows into the processing
chamber via in-feed lines 943 and 944 and into the reaction space 930 via
apertures 983 and 984. The inactive gas purges the substrate web 950 surface
15 and flows as a horizontal flow into the exhaust line 961 and finally to the vacuum
pump 960. The substrate web 950 is output from the reaction space 930 via a slit
or narrow passage 994 arranged between the confined space 920b and the
reaction space 930. The output substrate web is wound around the second roll
core 964 to form the destination roll 954.
20
The slits 993 and 994 function as throttles maintaining a pressure difference
between the reaction space 930 and the confined space in which the rolls 953 and
954 are located. Inactive gas flows via confined space in-feed channels 933 and
934 into the confined spaces 920a and 920b, respectively. The pressure within the
25 confined space(s) 920a and 920b is higher than the pressure within the reaction
space 930. As an example, the pressure within the reaction space 930 may be 1
mbar while the pressure within the confined space(s) 920a and 920b is for
example 5 mbar. The pressure difference forms a barrier preventing a flow from
the reaction space 930 into the confined space(s) 920a and 920b. Due to the
30 pressure difference, however, flow from the other direction (that is, from the
confined space(s) 920a and 920b to the reaction space 930 through the slits 993
and 994 is possible). As to the inactive gas flowing via shower heads 983 and 984
(as well as precursor vapor during precursor vapor pulse periods), these flows
therefore practically only see the vacuum pump 960.
The track of the substrate web 950 can be arranged close to a processing
chamber wall 931. If the substrate web is in the lateral direction is substantially as
5 wide as the reaction space or processing chamber 930 and the substrate web is
impermeable with regard to the used precursors it is possible, depending on the
implementation, to deposit material on a single side (down side) of the substrate
web.
10 Fig. 10 shows the deposition reactor of Fig. 9 in operation during a precursor
exposure period in accordance with an example embodiment. The pulsing valve
924 is opened. Precursor vapor of H20 precursor flows into the processing
chamber via in-feed line 944 and into the reaction space 930 via apertures 984.
The precursor vapor fills the reaction space 930 and reacts with the reactive sites
15 on substrate web surface in accordance with ALD growth mechanism. Since the
pulsing valve 923 is closed, only inactive gas flows into the reaction space via
apertures 983. lnactive gas, gaseous reaction by-products (if any) and residual
reactant molecules (if any) flow as a horizontal flow into the exhaust line 961 and
finally to the vacuum pump 960.
20
As mentioned in the preceding, the pressure difference between the reaction
space 930 and the confined space(s) 920a and 920b where the rolls 953 and 954
are located forms a barrier at the slits 993 and 994. The precursor vapor flow is in
that way prevented from flowing from the reaction space 930 into the confined
25 space(s) 920a and 920b. Due to the pressure difference, however, flow from the
other direction (that is, from the confined space(s) 920a and 920b to the reaction
space through the slits 993 and 994) is possible. lnactive gas is fed via the in-feed
channels 933 and 934 into the confined spaces 920a and 920b, respectively. The
pressure difference is maintained by the throttle function caused by the slits 993
30 and 994.
Fig. I 1 shows a top view of the deposition reactor of Figs. 9 and 10 during the Hz0
precursor exposure period in accordance with an example embodiment. Visible in
Fig. 11 are the doors 1141a and 1141 b through which the source and destination
rolls 953 and 954, respectively, can be loaded to and unloaded from the deposition
reactor. Visible are also roll axis 1105a and 11 05b of the respective rolls 953 and
954. The deposition reactor comprises one or more drives (not shown in Fig. 11)
5 connected to the roll axis 1105a andlor 1105b to rotate the rolls 953 and 954. The
arrows 1104 depict precursor vapor flow from the shower head channel 974 to a
collecting channel 962. The form and place of the collecting channel depends on
the implementation. In the embodiment shown in Fig. 11 the collecting channel is
located at the side of the reaction space. The collecting channel 962 in Fig. I 1 it
10 extends substantially throughout the total length a of the reaction space. The
collecting channel is in fluid communication with the exhaust line 961 leading to
the vacuum pump 960. The arrows 1 103 depict inactive gas flow from the shower
head channel 973 to the collecting channel 962 and therefrom to the exhaust line
961.
15
Fig. 12 shows the deposition reactor of Figs. 9-1 I in operation during the exposure
period of the other precursor in accordance with an example embodiment. The
pulsing valve 923 is opened. Precursor vapor of TMA precursor flows into the
processing chamber via in-feed line 943 and into the reaction space 930 via
20 apertures 983. The precursor vapor fills the reaction space 930 and reacts with the
reactive sites on substrate web surface in accordance with ALD growth
mechanism. Since the pulsing valve 924 is closed, only inactive gas flows into the
reaction space via apertures 984. Inactive gas, gaseous reaction by-products (if
any) and residual reactant molecules (if any) flow as a horizontal flow into the
25 exhaust line 961 and finally to the vacuum pump 960.
A deposition sequence is formed of one or more consecutive deposition cycles,
each cycle consisting of at least a first precursor exposure period (pulse A)
followed by a first purge step (purge A) followed by a second precursor exposure
30 period (pulse B) followed by a second purge step (purge B). Herein, if for example
aluminum oxide AI2O3 is the deposited material the TMA precursor may be the first
precursor (pulse A) and the water precursor may be the second precursor (pulse
The thickness of grown material is determined by the speed of the web. As an
example, the length a of the reaction space 930 may be 100 cm. The deposition
cycle may consist of a TMA pulse of 0.1 s, N2 purge of 0.3 s, H20 pulse of 0.1 s,
5 and N2 purge of 0.5 s. The total cycle period therefore is 1 s. If it is estimated that
a monolayer of A1203 is around 0.1 nm the following applies:
If the speed of the web is 1 cmlcycle there will be I00 cycles; this will take I .66
min, and a 10 nm coating of A1203 will be deposited.
10 If the speed of the web is 0.5 cmlcycle there will be 200 cycles; this will take 3.33
min, and a 20 nm coating of A1203 will be deposited.
If the speed of the web is 0.1 cmlcycle there will be I000 cycles; this will take
16.66 min, and a I00 nm coating of A1203 will be deposited.
15 Figs. 9-12 are simplified figures so they do not show for example any heaters and
other typical parts or elements that the deposition reactor may contain, and the
use of which is known as such.
Fig. 13 shows the deposition reactor of Figs. 9-12 with constriction plates in
20 accordance with an example embodiment. As described in the foregoing, the
substrate web was input into the reaction space and output from the reaction
space via slits. The embodiment of Fig. 13 shows constriction plates forming said
slits. In the embodiment of Fig. 13 there are two constriction plates 1301 a and
1301 b placed next to each other at the interface between the confined space 920a
25 and the reaction space 930. The substrate web 950 just hardly fits to pass through
between the plates. Similarly, at the interface between the reaction space 930 and
the confined space 920a there is another pair of constriction plates 1302a and
1302b. The constriction plates may be parallel plates so that the space between
the plates (slit volume) becomes elongated in the web moving direction.
30
As to the other structural and functional features of the embodiment of Fig. 13 a
reference is made to the embodiments described in the foregoing with reference to
Figs. 9-1 2 and related description.
I Fig. 14 roughly shows the thickness of deposited material in the function of
I distance traveled within a reaction space in accordance with an example
embodiment. In this example, the substrate web enters the reaction space via the
5 input slit formed by the constriction plates 1301 a, b similarly as shown in the
I embodiment of Fig. 13. The thickness of deposited material gradually grows as
indicated by the curve and different colors in Fig. 13 when the substrate web
travels towards the output slit formed by the constriction plates 1302a, b. If the
average speed of the web is I cmlcycle and the length of the reaction space is
10 100 cm, the thickness in the end is 10 nm in this example. The growth curve in
Fig. 13 indicates that the substrate web has been moved 10 cm in every 10 cycles.
However, in other embodiments it is possible to move the substrate web after
every cycle. Or the movement of the substrate web may continuous movement.
15 The in-feed of precursor vapor into the reaction space can be with or without
shower head channels from one or both of the sides of the reaction space. In
alternative embodiments, the in-feed of precursor vapor can be by in-feed head(s)
from the substrate web input end of the reaction space, or alternatively from both
the substrate web input and output ends of the reaction space. Depending on the
20 embodiment, the exhaust line and a possible collecting channel can be
conveniently arranged on the other side of the reaction space than the in-feed, at
the substrate web output end of the reaction space, or at the middle area of the
reaction space.
25 Fig. 15 shows a deposition reactor with precursor vapor in-feed at the substrate
web input end of the processing chamber in accordance with an example
embodiment. The reactor comprises a processing chamber providing a reaction
space 1530. A source roll 1553 resides in a first confined space 1520a, and a
destination roll 1554 in a second confined space 1520b.
30
A first pulsing valve 1523 controls the flow of precursor vapor of a first precursor
from a first precursor source 1513, and a second pulsing valve 1524 controls the
flow of precursor vapor of a second precursor from a second precursor source
1514. A first inactive gas source 1503 is in fluid communication with a confined
space 1520a that contains a first (source) substrate web roll 1553. A second
inactive gas source 1504 is in fluid communication with a confined space 1520b
that will contain a second (destination) substrate web roll 1554. However, the
5 inactive gas sources 1503 and 1504 may be implemented as a single source in
I some example embodiments, and they may also be in fluid communication with
I precursor vapor in-feed lines.
A substrate web I550 is driven from the source roll 1553 into the reaction space
10 1530 via an input slit 1593 at the substrate web input end of the reaction space
1530. The 'track of the substrate web, follows the upper wall of the processing
chamber. However, other routes and constructions are possible. ALD deposition
occurs in the reaction space 1530. The substrate web is driven from the reaction
space 1530 onto the destination roll 1554 via an output slit 1594 at the substrate
15 web output end of the reaction space 1530.
The first and second confined spaces 1520a,b are excess pressure volumes
compared to the pressure in the reaction space 1530. The excess pressure is
maintained by the slits I593 and 1594 as well as by feeding inactive gas into the
20 excess pressure volumes from the inactive gas source(s) 1503 and 1504.
Precursor vapor of the second precursor is fed into the reaction space at the
substrate web input end during the second precursor exposure period, as depicted
in Fig. 15. The precursor vapor is fed by an in-feed head 1601, as better depicted
25 by Fig. 16, where Fig. 16 shows a top view of the type of deposition reactor of Fig.
I 5 during the second precursor vapor exposure period in accordance with an
example embodiment. The in-feed head 1601 may extend substantially throughout
the total width of the reaction space 1530. During a first precursor exposure
period, precursor vapor of the first precursor is fed by a corresponding in-feed
30 head 1602 at the substrate web input end. During the second precursor exposure
period, however, merely inactive gas in guided from the in-feed head I602 into the
reaction space 1530. During the second precursor exposure period, the precursor
vapor of the second precursor flows (as indicated by arrows I61 1) along the
substrate web surface in the substrate web moving direction into an exhaust line
1561 at the substrate web output end of the reaction space 1530. Similarly,
inactive gas from the in-feed head 1602 flows (as indicated by arrows 161 2) along
the substrate web moving direction into the exhaust line 1561 at the substrate web
5 output end of the reaction space 1530. In certain example embodiments, the
deposition reactor comprises a collecting channel 1662 at the substrate web
output end of the reaction space 1530. The collecting channel 1662 in Fig. I 6
extends substantially throughout the total width of the reaction space 1530. The
collecting channel 1662 is in fluid communication with the exhaust line 1561
10 leading to the vacuum pump 1560, and it collects the gases evacuating from the
reaction space 1530 leading them into the exhaust line I561 and finally to the
vacuum pump 1560.
Fig. 16 also shows doors 1141a and 1141b in opposite ends of the deposition
15 reactor via which the source and destination rolls 1553, 1554 may be loaded and
unloaded.
Fig. 17 shows a deposition reactor with precursor vapor in-feed at the side of the
processing chamber in accordance with an example embodiment. The reactor
20 comprises a processing chamber providing a reaction space 1730. A source roll
I753 resides in a first confined space 1720a, and a destination roll I754 in a
second confined space 1720b.
A first pulsing valve 1723 controls the flow of precursor vapor of a first precursor
25 from a first precursor source 1713, and a second pulsing valve 1724 controls the
flow of precursor vapor of a second precursor from a second precursor source
1714. A first inactive gas source 1703a is in fluid communication with a confined
space 1720a that contains a first (source) substrate web roll 1753 and with an infeed
'line from the first precursor source 1713. A second inactive gas source 1703b I
30 is in fluid communication with the confined space 1720a and with an in-feed line
from the second precursor source 171 4. A third inactive gas source 1704 is in fluid
communication with a confined space 1720b that will contain a second
(destination) substrate web roll 1754. However, the inactive gas sources 1703a
and b, or 1703a and b as well as 1704 may be implemented as a single source in
some example embodiments.
A substrate web 1750 is driven from the source roll 1753 into the reaction space
5 1730 via an input slit 1793 at the substrate web input end of the reaction space
1730. The track of the substrate web follows the lower wall of the processing
chamber. However, other routes and constructions are possible. ALD deposition
occurs in the reaction space 1730. The substrate web is driven from the reaction
space I730 onto the destination roll I754 via 'an output slit I794 at the substrate
10 web output end of the reaction space 1730.
The first 'and second confined spaces 1720a,b are excess pressure volumes
compared to the pressure in the reaction space 1730. The excess pressure is
maintained by the slits 1793 and 1794 as well as by feeding inactive gas into the
15 excess pressure volumes from the inactive gas source(s) 1703a,b and 1704.
Precursor vapor of the first precursor is fed into the reaction space 1730 from a
side of the reaction space 1730. The precursor vapor is fed via a showerhead
channel 1873, as better depicted by Fig. 18, where Fig. 18 shows a top view of the
20 type of deposition reactor of Fig. 17 during the first precursor vapor exposure
period in accordance with an example embodiment. The showerhead channel
I873 may extend substantially throughout the total length of the reaction space
1730. During a second precursor exposure period, precursor vapor of the second
precursor is fed by a corresponding showerhead channel 1874 from the opposite
25 side of the reaction space 1730. During the first precursor exposure period,
however, merely inactive gas in guided from the showerhead channel 1874 into
the reaction space 1730. During the first precursor exposure period, the precursor
vapor of the first precursor flows (as indicated by arrows 1703) along the substrate
web surface first in a traverse direction but the flow direction later turns towards
30 the collecting channel 1762 at the substrate web output end of the reaction space
1730 drawn by the vacuum pump 1760. Similarly, inactive gas from showerhead
channel 1874 flows (as indicated by arrows 1704) along the substrate web surface
first in a traverse direction but the flow direction later turns towards the collecting
channel 1762. The collecting channel 1762 in Fig. 18 extends substantially
throughout the total width of the reaction space 1730. The collecting channel 1762 ,
is in fluid communication with the exhaust line 1761 leading to the vacuum pump
1760, and it collects the gases evacuating from the reaction space I730 leading
5 them into the exhaust line 1761 and finally to the vacuum pump 1760.
Fig. 18 also shows doors 1141a and 1141 b in opposite ends of the deposition
reactor via which the source and destination rolls 1753, 1754 may be loaded and
unloaded.
I 0
As mentioned in the preceding the deposition reactor may be a standalone
apparatus or it may form part of a production line. Fig. 19 shows the deposition
reactor as a part of a production line.
15 A first pulsing valve 1923 of the deposition reactor controls the flow of precursor
vapor of a first precursor from a first precursor source 191 3, and a second pulsing
valve 1924 controls the flow of precursor vapor of a second precursor from a
second precursor source 1914. A first inactive gas source 1903 is in fluid
communication with a confined space 1920a. A second inactive gas source 1904
20 is in fluid communication with a confined space 1920b. However, the inactive gas
sources 1903 and 1904 may be implemented as a single source in some example
embodiments, and they may also be in fluid communication with precursor vapor
I in-feed lines.
25 A substrate web 1950 enters the processing chamber 1930 of the deposition
reactor from a previous processing stage via the first confined space 1920a and
via an input slit 1993 at the substrate web input side of the reactor. ALD deposition
occurs in the reaction space 1930. The substrate web is guided from the reaction
space 1530 to a following processing stage of the production line via an output slit
30 I994 and via the second confined space 1920b at the substrate web output side of
the reactor.
The first and second confined spaces 1920a,b are excess pressure volumes
compared to the pressure in the reaction space 1930. The excess pressure is
maintained by the slits 1993 and 1994 as well as by feeding inactive gas into the
excess pressure volumes from the inactive gas source(s) 1903 and 1904.
The in-feed of precursor vapor into the reaction space 1930 as well as evacuating
gases from the reaction space 1930 via an exhaust line 1961 to a vacuum pump
1960 may occur similarly as described in connection with the embodiment shown
in Figs. 15 and 16 and in related description.
In a yet another embodiment, the excess pressure volumes may be omitted. The
substrate web 1950 may enter the processing chamber 1930 without passing
through any first confined space 1920a. If required by the production process, in
this embodiment, an entry to the processing chamber and outlet from the
processing chamber simply should be tight enough with proper dimensioning or
sealing.
Fig. 20 shows a top view of a deposition reactor in accordance with yet another
example embodiment. The deposition reactor comprises first and second inactive
gas sources 2003 and 2004, and first and second precursor sources 2013 and
2014, as well as first and second pulsing valves 2023 and 2024. The inactive gas
sources 2003 and 2004 are in fluid communication with confined spaces (excess
pressure volumes) 2020a and 2020b where the rolls 2053 and 2054 reside. The
rolls can be loaded and unloaded through doors 2041a and 2041 b. The substrate
web 2050 is driven from roll-to-roll via the processing chamber 2030 and slits 2093
and 2094 (here: with constriction plates), and is ALD processed in the meantime in
the processing chamber 2030. As to the basic structural and functional features of
the embodiment of Fig. 20 a reference is therefore made to the preceding
embodiments described in the foregoing. A difference to the preceding
embodiments is in the showerhead channels (via which precursor vapor in-feed
occurs) within the reaction space. A first showerhead channel configured to feed
precursor vapor of the first precursor travels within the processing chamber 2030
in the direction of desired material growth. The first showerhead channel has at
least one aperture on both sides of the substrate web (in the direction of desired
material growth). Similarly, a second showerhead channel 2074 configured to feed
precursor vapor of the second precursor travels within the processing chamber
2030 in the direction of desired material growth. The second showerhead channel
2074 has at least one aperture 2084a,b on both sides of the substrate web. The
5 exhaust to the vacuum pump 2060 is at the middle area of the processing
chamber (or reaction space) 2030 on the bottom of the processing chamber.
Fig. 21 shows a top view of a deposition reactor for deposition of multiple rolls at a
time in accordance with an example embodiment. Each of the rolls have their own
10 separate entries into the processing chamber. The first and second showerhead
channels 2173 and 2174 travel within the processing chamber in the direction of
desired material growth. The showerhead channels have at least one aperture on
both sides of each of the substrate webs. Otherwise, as to the basic structural and
functional features of the embodiment of Fig. 21 a reference is made to what has
15 been presented in Fig. 20 and in related description.
Fig. 22 shows a thin reactor structure in accordance with an example embodiment.
The deposition reactor comprises first and second inactive gas sources (not
shown), and first and second precursor sources 2213 and 2214, as well as first
20 and second pulsing valves 2223 and 2224. The inactive gas sources are in fluid
communication (not shown) with confined spaces (excess pressure volumes)
2220a and 2220b where the rolls 2253 and 2254 reside. The substrate web 2250
is driven from roll-to-roll via a processing chamber 2230, and is ALD processed in
the meantime in the processing chamber 2230. Precursor vapor in-feed is at the
25 substrate web input end of the processing chamber 2230. An exhaust line 2261
directing towards a vacuum pump 2260 resides at the substrate web output end of
the processing chamber 2230. As to the basic'structural and functional features of
the embodiment of Fig. 22 a reference is therefore made to the preceding
embodiments described in the foregoing. A difference to the preceding
30 embodiments is in the processing chamber 2230. In this embodiment, a slit
extends from the first confined space 2220a all the way to the second confined
space 2220b. The slit therefore forms the thin processing chamber 2230.
Fig. 23 shows a thin reactor structure for deposition of multiple rolls in accordance
with an example embodiment. Each of the rolls have their own input slits 2393 into
the processing chamber 2330 as well as their own separate output slits 2394 out
from the processing chamber 2330. The source rolls reside in a first confined
5 space (excess pressure volume) 2320a and the destination rolls in a second
confined space (excess pressure volume) 232013. In the embodiment shown in Fig. I
23 the outer sides of the slits 2393 and 2394 forms the outer sides 2331 a, 2331 b
of the thin processing chamber wall. Otherwise, as to the basic structural and
functional features of the embodiment of Fig. 23 a reference is made to what has
10 been presented in Fig. 22 and in related description.
The preceding embodiments in which the substrate web travels close to the
processing chamber wall (in the direction of desired material growth) suit well for
single-sided deposition, whereas embodiments in which the substrate travels in
15 the center area of .the processing chamberlreaction space suit well for doublesided
deposition.
Fig. 24 shows double-sided coating in accordance with an example embodiment.
The deposition reactor shown in Fig. 24 basically corresponds to the deposition
20 reactor in Fig. 15. As to the features of Fig. 24 already known from Fig. 15 a
reference is made to Fig. 15 and related description. Contrary to the embodiment
of Fig. 15 in which the substrate web travels close to the upper wall of the
processing chamber, the substrate web in the embodiment of Fig. 24 travels along
the center area of the processing chamberlreaction space 1530. The deposition
25 reactor comprises precursor vapor in-feed heads 2475 of each precursor on both
sides of the substrate web surface for double-sided deposition.
In certain example embodiments, the placement of the track of the substrate web
within the processing chamber or reaction space is adjustable. The placement of
30 the track may be adjusted based on present needs. It may be adjusted for
example by adjusting the placement of the input and output slits in relation to the
processing chamber (or reaction space). As mentioned, for double-sided
deposition, the substrate web may travel in the center area of the processing
chamber, whereas for single-sided deposition the substrate web may travel close
to the processing chamber wall. Fig. 25 shows a deposition reactor and a specific
detail for single-sided deposition. The deposition reactor of Fig. 25 basically
I corresponds to the deposition reactor of Fig. 15. The substrate web 1550 travels
5 close to a first (here: upper) wall of the processing chamber. Inactive gas is fed
from an inactive gas source 2505 (which may be the same or different source as
I the source 1503 and/or 1504) into the space between the backside (i.e., the side
I or surface that ,is not to be coated) of the substrate web and the first wall. The
inactive gas fills the space between the backside of the substrate web and the first
10 wall. The inactive gas thereby forms a shielding volume. The other surface of the
substrate web is coated by sequential self-saturating surface reactions. The actual
1 reaction space is formed in the volume between the surface to be coated and a I
i
1 second wall (opposite to the first wall) of the processing chamber. Reactive gas I
1 does not substantially enter the shielding volume. This is partly due to the inactive I
15 gas flow into the shielding volume, and partly because of the substrate web itself I
I
prevents the flow to the backside of the substrate web from the other side of the I
web. 1
I
In an example embodiment, the deposition reactor (or reactors) described herein
20 is a computer-controlled system. A computer program stored into a memory of the
system comprises instructions, which upon execution by at least one processor of
the system cause the deposition reactor to operate as instructed. The instructions
may be in the form of computer-readable program code. Fig. 26 shows a rough
block diagram of a deposition reactor control system 2600. In a basic system
25 setup process parameters are programmed with the aid of software and
instructions are executed with a human machine interface (HMI) terminal 2606 and
downloaded via a communication bus 2604, such as Ethernet bus or similar, to a
control box 2602 (control unit). In an embodiment, the control box 2602 comprises
a general purpose programmable logic control (PLC) unit. The control box 2602
30 comprises at least one microprocessor for executing control box software
comprising program code stored in a memory, dynamic and static memories, I10
modules, AID and DIA converters and power relays. The control box 2602 sends
electrical power to pneumatic controllers of appropriate valves of the deposition
reactor. The control box controls the operation of the drive(s), the vacuum pump,
and any heater(s). The control box 2602 receives information from appropriate
sensors, and generally controls the overall operation of the deposition reactor. The
control box 2602 controls driving a substrate web in an atomic layer deposition
5 reactor from a first roll via a reaction space to a second roll. By adjusting the
speed of the web the control box controls the growth of deposited material, i.e.,
material thickness. The control box 2602 further controls exposing the reaction
space to temporally separated precursor pulses to deposit material on said
substrate web by sequential self-saturating surface reactions. The control box
10 2602 may measure and relay probe readings from the deposition reactor to the
HMI terminal 2606. A dotted line 2616 indicates an interface line between the
deposition reactor parts and the control box 2602.
Without limiting the scope and interpretation of the patent claims, certain technical
15 effects of one or more of the example embodiments disclosed herein are listed in
the following: A technical effect is a simpler structure compared to spatial roll-toroll
ALD reactors. Another technical effect is that the thickness of deposited
material is directly determined by the speed of the web. Another technical effect is
optimized consumption of precursors due to a thin processing chamber structure.
20
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
25 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.
~urthermore, some of the features of the above-disclosed embodiments of this
30 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.
I Hence, the scope of the invention is only restricted by the appended patent claims.

WE CLAIMS:-
1. A method comprising:
driving a substrate web into a reaction space of an atomic layer deposition
reactor ; and
exposing the reaction space to temporally separated precursor pulses to
deposit material on said substrate web by sequential self-saturating surface
reactions.
10 2. The method of claim I , comprising:
inputting the substrate web from an excess pressure volume into the
reaction space via a slit maintaining a pressure difference between said
volume and the reaction space.
15 3. The method of claim 2, wherein the reactor comprises constriction plates
forming said slit.
4. The method of any preceding claim, wherein the thickness of deposited
material is controlled by the speed of the web.
20
5. The method of any preceding claim 2-4, comprising:
feeding inactive gas into the excess pressure volume.
6. The method of any preceding claim, wherein the precursor vapor flow direction
25 in the reaction space is along the moving direction of the substrate web.
7. The method of claim 6, comprising:
feeding precursor vapor into the reaction space at the substrate web input
end of the reaction space and arranging exhaust of gases at the substrate web
30 output end of the reaction space.
8. The method of any preceding claim, wherein the precursor vapor flow direction
in the reaction space is traverse compared to the moving direction of the
substrate web.
9. The method of claim 8, comprising:
feeding precursor vapor into the reaction space at a side of the reaction
space and arranging exhaust of gases at an opposite side of the reaction
5 space.
10. The method of any preceding claim, comprising:
integrating the first and second roll into a reaction chamber lid.
10 1 I. The method of any preceding claim, comprising:
driving said substrate web straight through said reaction space.
12. An apparatus comprising:
a driving unit configured to drive a substrate web into a reaction space of an
15 atomic layer deposition reactor; and
a precursor vapor feeding part configured to expose the reaction space to
temporally separated precursor pulses to deposit material on said substrate
web by sequential self-saturating surface reactions.
20 13. The apparatus of claim 12, comprising:
an input slit for inputting the substrate web from an excess pressure volume
into the reaction space.
14. The apparatus of claim 13, comprising constriction plates forming said slit.
25
15. The apparatus of any preceding claim 12-1 4, comprising:
a channel configured to convey inactive gas into the excess pressure
volume.
30 16. The apparatus of any preceding claim 12-1 5, comprising:
a precursor vapor in-feed opening at the substrate web input end of the
reaction space and exhaust at the substrate web output end of the reaction
space.
17. The apparatus of any preceding claim 12-1 6, comprising:
a precursor vapor in-feed opening or openings at a side of the reaction
space and exhaust at an opposite side of the reaction space.
5 18. The apparatus of any preceding claim 12-1 7, comprising:
a reaction chamber lid configured to receive the first and second roll.
19. An apparatus comprising:
means for driving a substrate web into a reaction space of an atomic layer
10 deposition reactor; and
means for exposing the reaction space to temporally separated precursor
pulses to deposit material on said substrate web by sequential self-saturating
surface reactions.