U.S. patent application number 16/608945 was filed with the patent office on 2020-06-11 for apparatus with a valve and method of operation.
The applicant listed for this patent is Picosun Oy. Invention is credited to Marko PUDAS.
Application Number | 20200181774 16/608945 |
Document ID | / |
Family ID | 64016439 |
Filed Date | 2020-06-11 |
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United States Patent
Application |
20200181774 |
Kind Code |
A1 |
PUDAS; Marko |
June 11, 2020 |
APPARATUS WITH A VALVE AND METHOD OF OPERATION
Abstract
An apparatus includes, a reaction chamber to accommodate a
substrate to be processed, and a pulsing valve fluidly connected to
the reaction chamber. The pulsing valve has a reactive chemical
inlet to receive reactive chemical, a reaction chamber outlet to
mediate provided fluid connection of the pulsing valve to the
reaction chamber, a closure to control fluid flow from the reactive
chemical inlet in the pulsing valve to the reaction chamber outlet,
and an additional flow channel inlet or outlet to continuously
purge the closure through the additional flow channel during an
entire substrate processing cycle or sequence.
Inventors: |
PUDAS; Marko; (Espoo,
FI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Picosun Oy |
Espoo |
|
FI |
|
|
Family ID: |
64016439 |
Appl. No.: |
16/608945 |
Filed: |
May 2, 2018 |
PCT Filed: |
May 2, 2018 |
PCT NO: |
PCT/FI2018/050317 |
371 Date: |
October 28, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C23C 16/45589 20130101;
C23C 16/4408 20130101; C23C 16/45557 20130101; C23C 16/4405
20130101; C23C 16/45544 20130101; C23C 16/4557 20130101 |
International
Class: |
C23C 16/455 20060101
C23C016/455; C23C 16/44 20060101 C23C016/44 |
Foreign Application Data
Date |
Code |
Application Number |
May 2, 2017 |
FI |
PCT/FI2017/050336 |
Claims
1. An apparatus, comprising: a reaction chamber to accommodate a
substrate to be processed; a pulsing valve fluidly connected to the
reaction chamber, the pulsing valve comprising: a reactive chemical
inlet to receive reactive chemical; a reaction chamber outlet to
mediate provided fluid connection of the pulsing valve to the
reaction chamber; a closure to control fluid flow from the reactive
chemical inlet in the pulsing valve to the reaction chamber outlet;
and an additional flow channel inlet or outlet to continuously
purge the closure through the additional flow channel during an
entire substrate processing cycle or sequence.
2. The apparatus of claim 1, comprising the closure having an open
and closed configuration to open and close, respectively, or at
least partially close a route from the reactive chemical inlet to
the reaction chamber outlet.
3. The apparatus of claim 1, comprising the closure having only a
steady configuration, the apparatus being configured to adjust
fluid flow with the aid of flow controlling elements positioned in
flow channels in fluid communication with the pulsing valve.
4. The apparatus of claim 1, configured to purge, during the entire
substrate processing cycle or sequence, the entire surface area of
the closure exposed to processing gases.
5. The apparatus of claim 1, further comprising a vacuum chamber
surrounding the reaction chamber.
6. The apparatus of claim 5, comprising the pulsing valve within
the vacuum chamber on the outside of the reaction chamber in a
heated area defined by the vacuum chamber.
7. The apparatus of claim 1, wherein the flow direction of the
purge is along the surface of the closure.
8. The apparatus of claim 1, configured to purge the closure during
the entire substrate processing cycle or sequence.
9. The apparatus of claim 1, comprising a suction channel on the
reactive chemical inlet side of the closure to enable a reactive
chemical flow through the reactive chemical inlet to the suction
channel to purge the closure.
10. The apparatus of claim 9, configured to provide the suction
channel with suction during the entire substrate processing cycle
or sequence.
11. The apparatus of claim 1, the pulsing valve further comprising
a carrier gas inlet fluidly connected to the reaction chamber via
the reaction chamber outlet.
12. The apparatus of claim 11, configured to pulse reactive
chemical into a carrier gas flow flowing from the carrier gas inlet
towards the reaction chamber via the reaction chamber outlet.
13. The apparatus of claim 1, wherein the pulsing valve is embedded
into or forms part of a reaction chamber wall or lid.
14. The apparatus of claim 1, wherein the additional flow channel
resides within a flow channel providing the reactive chemical
inlet.
15. The apparatus of claim 1, wherein the additional flow channel
has a cross-sectional flow area that is less than 25% of the
cross-sectional flow area of a flow channel providing the reactive
chemical inlet.
16. The apparatus of claim 1, wherein a flow channel providing the
reactive chemical inlet resides within the additional flow
channel.
17. The apparatus of claim 1, wherein the flow path from the
carrier gas inlet to the reaction chamber is unrestricted.
18. The apparatus of claim 1, wherein the pulsing valve is
implemented without non-continuously purged gaps.
19. The apparatus of claim 1, the pulsing valve further comprising
a heating arrangement configured to operate the pulsing valve at an
elevated temperature.
20. A method, comprising: supplying reactive chemical through a
pulsing valve along a route extending from a reactive chemical
inlet to a reaction chamber outlet of the pulsing valve;
controlling the closing of the route by a pulsing valve closure;
and purging the closure continuously through an additional flow
channel during an entire substrate processing cycle or
sequence.
21. The method of claim 20, comprising: purging the closure at the
area of the reactive chemical inlet continuously by said reactive
chemical during the entire substrate processing cycle or sequence;
and purging the closure around that area continuously by carrier
gas.
22. (canceled)
23. A pulsing valve, comprising: a reactive chemical inlet to
receive reactive chemical; a reaction chamber outlet to fluidly
connect the pulsing valve to a reaction chamber; a closure to
control fluid flow from the reactive chemical inlet in the pulsing
valve to the reaction chamber outlet; and an additional flow
channel inlet or outlet to continuously purge the closure through
the additional flow channel during an entire substrate processing
cycle or sequence.
Description
FIELD
[0001] The aspects of the disclosed embodiments generally relate to
substrate processing methods and apparatus, in particular to
chemical deposition methods and deposition reactors. More
particularly, but not exclusively, the aspects of the disclosed
embodiments relate to atomic layer deposition (ALD) reactors with
pulsing valve(s) attached to a reaction chamber.
BACKGROUND
[0002] This section illustrates useful background information
without admission of any technique described herein representative
of the state of the art.
[0003] ALD is based on strictly separated pulses of gases.
Precursor gases that are released into a reaction chamber should
react with each other on a substrate surface. Any reaction in gas
phase is not preferred. The number of pulsing valves required to
feed in reactive chemical(s) depends on used technology. In the
case of photon-enhanced or plasma-assisted processes only a single
pulsing valve may be needed while in conventional processes a
plurality of pulsing valves are used. In order to achieve the
highest quality required for modern semiconductor products there
should not be mixing of precursor gases, in the gas phase, not even
in ppm scale. Any such mixing is likely to cause particle
formation, and is thus likely to cause damage on patterns on the
substrate.
[0004] The conventional approach to prevent the mixing of the gases
is to purge the reaction chamber and related gas lines a
sufficiently long time. However, as the ALD pulses may need
repeating thousands of times, and the purge time is directly
increasing the process time, having long purge times is not an
optimum solution. Also, certain precursor chemicals start to
decompose quickly in the used temperatures, and they cannot wait
for the next chemical pulse for a long time.
[0005] U.S. Pat. No. 9,029,244 B2 demonstrates a 4-way valve
solution for continuous purge gas flow where purge gas flows
continuously along a purge gas line into a reaction chamber via the
4-way valve. However, due to the used valve design, the 4-way
valve, when in closed state, contains a vertical cavity extending
from the by-passing purge gas line to a valve diaphragm. The space
formed by the cavity is sufficient to contain in it or absorb on
its walls an undesired amount of precursor chemicals. Fluid passing
by along the purge gas line will create turbulence in the described
cavity, and there is a risk that precursor chemical trapped within
the cavity is sucked by the by-passing purge gas flow towards the
substrate and cause undesirable particle formation on substrate
surface.
SUMMARY
[0006] It is an object of embodiments of the present disclosure to
provide an improved apparatus and method with no trapped precursor
chemical thereby avoiding undesired particle generation, while
enabling high pulsing speed, or at least to provide an alternative
to existing technology.
[0007] According to a first example aspect of the disclosed
embodiments there is provided an apparatus, comprising: [0008] a
reaction chamber to accommodate a substrate to be processed; [0009]
a pulsing valve fluidly connected to the reaction chamber (530,
1430), the pulsing valve comprising: [0010] a reactive chemical
inlet to receive reactive chemical; [0011] a reaction chamber
outlet to mediate provided fluid connection of the pulsing valve to
the reaction chamber; [0012] a closure to control fluid flow from
the reactive chemical inlet in the pulsing valve to the reaction
chamber outlet; and [0013] an additional flow channel inlet or
outlet to continuously purge the closure through the additional
flow channel during an entire substrate processing cycle or
sequence.
[0014] In certain example embodiments of the present disclosure the
reactive chemical inlet is denoted as "a reactive chemical
receiving inlet", and the reaction chamber outlet as "an outlet
towards the reaction chamber".
[0015] In certain example embodiments, the apparatus comprises the
closure having an open and closed configuration to open and close,
respectively, or at least partially close a route from the reactive
chemical inlet to the reaction chamber outlet.
[0016] In certain example embodiments, the apparatus comprises the
closure having only a steady configuration, the apparatus being
configured to adjust fluid flow with the aid of flow controlling
elements positioned in flow channels in fluid communication with
the pulsing valve. Accordingly, in these embodiments the "closure"
may be a stationary flow guiding element.
[0017] In certain example embodiments, the closure has an open and
closed configuration to open and close, respectively, the route
from the reactive chemical inlet to the reaction chamber
outlet.
[0018] In certain example embodiments, the apparatus is a substrate
processing apparatus, such as a vacuum deposition reactor, for
example, an atomic layer deposition reactor. The reaction chamber
may accommodate a substrate or a plurality of substrates, i.e., at
least one substrate to be processed.
[0019] In certain example embodiments, the apparatus is configured
to purge, during the entire substrate processing cycle or sequence,
the entire surface area of the closure exposed to processing gases.
In particular, this may be interpreted to contain all open (i.e.,
non-covered) areas of the closure that are exposed to a precursor
gas flow at least during certain periods of the deposition cycle or
sequence. These open areas include exposed areas that are not
contacted by any fixed part of the valve.
[0020] In certain example embodiments, the apparatus is configured
to purge the parts of the pulsing valve from which reactive
chemical can flow towards the reaction chamber.
[0021] In certain example embodiments, the apparatus is configured
to purge the closure during an entire substrate processing cycle.
In certain example embodiments, the apparatus is configured to
purge the closure during an entire substrate processing
sequence.
[0022] In certain example embodiments, the gas arrived at the
reactive chemical inlet may be reactive gas or reactive gas mixed
with (inactive) carrier gas or inactive gas only. Nitrogen as an
example can be used as the carrier and/or inactive gas.
[0023] In certain example embodiments, the additional flow channel
inlet or outlet is a waste channel outlet. In certain example
embodiments, the waste channel is routed from the pulsing valve,
bypassing the reaction chamber, to a particle trap and/or vacuum
pump.
[0024] In certain example embodiments, the apparatus further
comprises a vacuum chamber surrounding the reaction chamber. In
certain example embodiments, the reaction chamber is configured to
operate in vacuum conditions. Accordingly, in certain example
embodiments said vacuum chamber surrounding the reaction chamber
provides "another vacuum chamber".
[0025] In certain example embodiments, the apparatus comprises the
pulsing the pulsing valve within the vacuum chamber on the outside
of the reaction chamber in a heated area defined by the vacuum
chamber. Accordingly, in certain example embodiments, the pulsing
valve is a hot valve. Herein, the term hot valve means a valve that
is being heated, for example, by a surrounding gas or with the aid
of a heater. Heating may thus be implemented by means of a heating
arrangement included in the pulsing valve configured to operate the
pulsing valve at an elevated temperature (equals to the "hot
valve"), wherein the term "elevated temperature" is defined, within
the present disclosure, as a temperature above the ambient
temperature (i.e., higher than about 20 degrees Celsius). In some
instances, the pulsing valve can be operated at 22 degrees Celsius;
in some other instances--at 25 degrees Celsius.
[0026] In certain example embodiments, the additional flow channel
is a smaller channel, in terms of a cross-sectional flow area,
compared to a flow channel providing the reactive chemical
inlet.
[0027] In certain example embodiments, the flow direction of the
purge is along the surface of the closure.
[0028] In certain example embodiments, the apparatus is configured
to purge the closure during the entire substrate processing cycle
or sequence. In certain example embodiments, said "configured to"
means that the apparatus is programmed to operate as desired. In
certain example embodiments, the apparatus comprises a control
system enabling said programming by computer program code means. In
certain example embodiments, the apparatus is programmed to purge
the closure, during the entire substrate processing cycle or
sequence, by reactive chemical or by fluid flowing from the
reactive chemical inlet.
[0029] In certain example embodiments, the apparatus comprises a
suction channel on the reactive chemical inlet side of the closure
to enable a reactive chemical flow through the reactive chemical
inlet to the suction channel to purge the closure. In certain
example embodiments, the apparatus comprises a suction channel on
the reactive chemical inlet side of the closure to enable a
reactive chemical flow from the reactive chemical inlet to purge
the closure on its way from the reactive chemical inlet to the
suction channel.
[0030] In certain example embodiments, the apparatus is configured
(or programmed) to provide the suction channel with suction during
the entire substrate processing cycle or sequence.
[0031] In certain example embodiments, the pulsing valve further
comprising a carrier gas inlet fluidly connected to the reaction
chamber via the reaction chamber outlet. In certain example
embodiments, the pulsing valve comprises the carrier gas inlet in
fluid communication with the reaction chamber outlet. In certain
example embodiments, the flow path from the carrier gas inlet to
the reaction chamber is an unrestricted flow path.
[0032] In certain example embodiments, the apparatus is configured
to pulse reactive chemical into a carrier gas flow that is
configured to flow from the carrier gas inlet to the reaction
chamber outlet. In certain example embodiments, the apparatus is
configured to pulse reactive chemical into a carrier gas flow
flowing from the carrier gas inlet towards the reaction chamber via
the reaction chamber outlet.
[0033] In certain example embodiments, a reactive chemical flow
arriving at the reactive chemical inlet already is a mixture of
reactive chemical and carrier gas.
[0034] In certain example embodiments, there are means adopted to
modify pressure or flow rate of the reactive chemical or carrier
gas used to purge the closure. In certain example embodiments,
these include an outgoing flow control. In certain other
embodiments, these include an incoming flow control. In yet other
embodiments, these include an incoming and outgoing flow
control.
[0035] In certain example embodiments, the pulsing valve is
embedded into or forms part of a reaction chamber wall or lid.
[0036] In certain example embodiments, the additional flow channel
resides within a flow channel providing the reactive chemical
inlet.
[0037] In certain example embodiments, the additional flow channel
has a cross-sectional flow area that is less than 25% of the
cross-sectional flow area of a flow channel providing the reactive
chemical inlet.
[0038] In certain example embodiments, the waste channel has a
cross-sectional flow area that is less than 25% of the
cross-sectional flow area of a flow channel providing the reactive
chemical inlet.
[0039] In certain example embodiments, a flow channel providing the
reactive chemical inlet resides within the additional flow
channel.
[0040] In certain example embodiments, the flow path from the
carrier gas inlet to the reaction chamber is unrestricted.
[0041] In certain example embodiments, the pulsing valve is
implemented without non-continuously purged gaps.
[0042] In certain example embodiments, the pulsing valve further
comprising a heating arrangement configured to operate the pulsing
valve at an elevated temperature.
[0043] In certain example embodiments, the closure is of convex
form. In certain example embodiments, the closure is of convex form
in both in its closed and open configuration. In certain example
embodiments, the general convex form does not change in a
transition from the closed to the open configuration. For example,
the transition is performed without a deformation of the general
form, or the transition is performed without buckling of the
closure.
[0044] In certain example embodiments, the transition from the open
configuration to the closed configuration is actuated by an
actuating element. In certain example embodiments, the said
actuation is performed by mechanical actuation. In other
embodiments, other types of conventional actuation methods are
used.
[0045] In certain example embodiments, the transition from the open
configuration to the closed configuration is actuated by pushing
the closure against a sealing surface or ring defining or
surrounding an opening. In certain example embodiments, the valve
comprises an opening that the closure is configured to open and
close to open and close, respectively, the route from the reactive
chemical inlet to the reaction chamber outlet. In certain example
embodiments, the said opening is the opening defined or surrounded
by the sealing surface or ring.
[0046] In certain example embodiments, the transition from the open
configuration to the closed configuration is implemented by moving
the closure into a more convex form that in said open
configuration. In certain example embodiment, the closure then
contacts the edge(s) of the opening. In certain example
embodiments, said opening is an opening between a first flow
channel and a second flow channel, wherein the first flow channel
via the pulsing valve provides the reactive chemical inlet and
waste line outlet and the second flow channel via the pulsing valve
the inactive or carrier gas inlet and reaction chamber outlet. In
certain example embodiments, the gas flow within the second flow
channel is unrestricted. For example, there are no flow obstacles
within the channel on the way from the pulsing valve to the
reaction chamber wall or lid (nor in the pulsing valve).
[0047] In certain example embodiments, the flow channel guiding gas
to purge a center area of the closure (in its closed configuration)
is implemented without sharp changes in flow direction (within the
area of the pulsing valve). In certain example embodiments, the
changes in flow direction in that channel are gentle. In certain
example embodiments, the flow path in that flow channel is a curved
path without any angles. In certain example embodiments all changes
in flow directions within the pulsing valve are gentle, i.e.,
non-sharp. In certain example embodiments, all changes in flow
directions are less than 90 degrees, in certain example embodiments
less than 60 degrees, in certain example embodiments less than 45
degrees.
[0048] In certain example embodiments, the closure is attached to
or sealed against a valve body at an attachment point or area. In
certain example embodiment, the attachment is a fixed attachment.
In certain example embodiments the closure extends, in its moving
direction (the direction in which the closure or actuator moves in
the transition from the open configuration to the closed
configuration), in the closed configuration into a level that is
farther away than the level of the attachment point or area at
which the valve is attached to the valve body.
[0049] In certain example embodiments, said continuous purge of the
closure does not occur through the additional flow channel or does
not occur through the additional flow channel during the entire
substrate processing cycle or sequence. For example, when the
closure is in the open configuration, the purge in certain example
embodiments is implemented from the inlet(s) to the reaction
chamber outlet. In certain example embodiments, the additional flow
channel is closed or at least partially closed when the closure is
in the open configuration.
[0050] According to a second example aspect of the disclosed
embodiments there is provided a method, comprising: [0051]
supplying reactive chemical through a pulsing valve along a route
extending from a reactive chemical inlet to a reaction chamber
outlet of the pulsing valve; [0052] controlling the closing of the
route by a pulsing valve closure; and purging the closure
continuously through an additional flow channel during an entire
substrate processing cycle or sequence.
[0053] In certain example embodiments, the reactive chemical is
guided further to the reaction chamber via the reaction chamber
outlet of the pulsing valve.
[0054] In certain example embodiments, the continuous purge of the
closure is implemented via an additional flow channel inlet or
outlet. Accordingly, the direction of flow may be to (the direction
of) the additional flow channel or from (the direction of) the
additional flow channel.
[0055] In certain example embodiments, the method comprises:
purging the closure at the area of the reactive chemical inlet
continuously by said reactive chemical during the entire substrate
processing cycle or sequence; and purging the closure around that
area continuously by carrier gas.
[0056] In certain example embodiments, the method comprises: [0057]
providing the pulsing valve with a heating arrangement to operate
the pulsing valve at an elevated temperature.
[0058] Further example aspects and their embodiments are presented
as follows:
[0059] According to a third example aspect of the disclosed
embodiments there is provided a computer program product (or
computer program) comprising program code executable by at least
one processor in a control system of a substrate processing
apparatus, the program code, when executed by the at least one
processor, causing the substrate processing apparatus to perform
the method of the second aspect and/or any of its embodiments.
[0060] According to a fourth example aspect of the disclosed
embodiments there is provided a pulsing valve, comprising: [0061] a
reactive chemical inlet to receive reactive chemical; [0062] a
reaction chamber outlet to fluidly connect the pulsing valve to a
reaction chamber; [0063] a closure to control fluid flow from the
reactive chemical inlet in the pulsing valve to the reaction
chamber outlet; and [0064] an additional flow channel inlet or
outlet to continuously purge the closure through the additional
flow channel during an entire substrate processing cycle or
sequence.
[0065] In certain example embodiment, the closure has an open and
closed configuration to open and close, respectively, a route from
the reactive chemical inlet to the reaction chamber outlet.
[0066] According to a fifth example aspect there is provided an
apparatus, comprising: [0067] a reaction chamber to accommodate a
substrate to be processed; [0068] a flow guiding device fluidly
connected to the reaction chamber, the flow guiding device
comprising: [0069] a reactive chemical inlet; [0070] a reaction
chamber outlet; and [0071] a flow guiding element for routing
incoming gas from the reactive chemical inlet to the reaction
chamber outlet or to another outlet.
[0072] In certain example embodiments, the flow guiding device
comprises an inactive or carrier gas inlet. In certain example
embodiments, said another outlet is a waste line outlet. In certain
example embodiments, the apparatus comprises a control system
providing pressure-based control of flow rate from the reactive
chemical inlet to the reaction chamber outlet and to said another
outlet. In certain example embodiments, the control system
comprises a pressure changing device to cause a change in pressure
(within a pipeline). In certain example embodiments, the device
causing a change in pressure is positioned in a pipeline providing
said another outlet. In certain example embodiments, the apparatus
is programmed to maintain a flow from the reactive chemical inlet
to the reaction chamber outlet and to said another outlet and from
the inactive or carrier gas inlet to the reaction chamber outlet
during an entire substrate processing cycle or sequence.
[0073] In certain example embodiments, there is provided a pulsing
valve with a cylinder route for precursor to bypass a valve
membrane, and a waste line starting from a face of the membrane on
the side of a precursor line.
[0074] In certain example embodiments, there is provided a
deviation in which a line loops over a valve membrane having
therein a flow restrictor.
[0075] According to a sixth example aspect there is provided an
apparatus, comprising: [0076] a reaction chamber; [0077] a pulsing
valve attached to the reaction chamber, the pulsing valve
comprising: [0078] a reactive chemical inlet; [0079] a reaction
chamber outlet; and [0080] a closure having an open and closed
configuration to open and close, respectively, [0081] a route from
the reactive chemical inlet to the reaction chamber outlet, the
apparatus further comprising: [0082] an additional cleaning
chemical inlet at the reaction chamber side of the closure to purge
the closure.
[0083] In certain example embodiments, the closure provides a valve
output surface pointing to or towards the reaction chamber, and the
apparatus comprises the additional cleaning chemical inlet to purge
the valve output surface.
[0084] In certain example embodiments, the valve output surface is
the surface of the closure pointing to an output direction of the
reaction chamber outlet. Accordingly, in certain example
embodiments, the valve output surface is defined as a part of the
closure pointing towards the reaction chamber (reaction chamber
interior, or substrate). In certain example embodiments, the
closure is a closing member, such as a membrane, a diaphragm, or an
orifice plunger. In certain example embodiments, the closure or
closing member is of solid material. In other embodiments, the
closure is of non-solid material, such as fluid, or a combination
of solid and non-solid material. Accordingly, the closure may be
alternatively implemented by, for example, a drop of liquid metal
capable of closing the route from the reactive chemical inlet to
the reaction chamber outlet. In certain example embodiments, the
membrane (or other closure) is facing the substrate, or reaction
chamber interior. The expression membrane is to be considered
interchangeable with closure, and with its different forms, such as
plunger or fluid closure.
[0085] In certain example embodiments, the closure and/or valve
output surface is in a fluid-flowing-pass contact with a cleaning
chemical, or inert gas.
[0086] In certain example embodiments, the additional cleaning
chemical inlet points directly or at least obliquely to the closure
and/or valve output surface.
[0087] In certain example embodiments, the additional cleaning
chemical inlet points towards the closure and/or valve output
surface from the reaction chamber side of the closure.
[0088] In certain example embodiments, the reaction chamber outlet
provides a reaction chamber outlet channel towards the reaction
chamber. In certain example embodiments, the reaction chamber
outlet, or reaction chamber outlet channel, provides an opening
towards the reaction chamber. The reaction chamber outlet of the
pulsing valve in an example embodiment opens directly, without an
intermediate part, to an interior of the reaction chamber.
[0089] In certain example embodiments, the additional cleaning
chemical input is additional to the parts the pulsing valve would
typically have. Accordingly, in certain example embodiments, the
additional cleaning chemical input is additional to the reaction
chamber outlet and/or reaction chamber outlet channel.
[0090] In certain example embodiments, the apparatus comprises the
additional cleaning chemical inlet in a reaction chamber outlet
channel wall.
[0091] In certain example embodiments, the apparatus comprises a
pipe (cleaning chemical inlet pipe) extending towards the closure
and/or valve outlet surface within the reaction chamber outlet
channel, the pipe providing the additional cleaning chemical
inlet.
[0092] In certain example embodiments, inert purge gas is directed
to the proximity of the membrane with a pipe from the same space as
the reaction space.
[0093] In certain example embodiments, the apparatus is configured
to provide continuous purge of the closure and/or valve output
surface.
[0094] In certain example embodiments, the apparatus is configured
to provide purge along the closure and/or valve output surface.
[0095] In certain example embodiments, the flow direction of the
cleaning chemical is first perpendicular to or oblique with respect
to the closure and/or valve output surface, and upon hitting the
closure and/or valve output surface the flow direction turns in
parallel to the closure and/or valve output surface. When the
cleaning chemical subsequently exits into the direction of the
reaction chamber, also the remainder of the reaction chamber outlet
channel becomes purged.
[0096] In certain example embodiments, the apparatus comprises a
pulsing valve or other means, such as mass flow controller, to
change the cleaning chemical flow rate as needed. In certain
example embodiments, the cleaning chemical flow is synchronized
with reactive chemical pulses.
[0097] In certain example embodiments, the apparatus provides for a
first flow path via the pulsing valve to the reaction chamber, and
has a second flow path intersecting the first flow path at the
valve output surface to purge the valve output surface.
[0098] In certain example embodiments, the apparatus comprises a
heated outer chamber around the reaction chamber.
[0099] In certain example embodiments, the apparatus comprises the
pulsing valve in a heated intermediate space within the outer
chamber but on the outside of the reaction chamber.
[0100] In certain example embodiments, the pulsing valve comprises
a chemical waste line outlet.
[0101] In certain example embodiments, the apparatus provides a
route by-passing the closure from the reactive chemical inlet to
the waste line outlet that route being open in the closed
configuration of the closure.
[0102] In certain example embodiments, the apparatus is configured
to maintain a higher pressure in a chemical waste line beginning at
the waste line outlet compared to a pressure in the reaction
chamber.
[0103] In certain example embodiments, the closure is configured to
prevent reactive chemical from flowing into the chemical waste line
outlet when being in the open configuration.
[0104] In certain example embodiments, the chemical waste line
comprises a flow restrictor that may be a narrow passage or a
capillary.
[0105] In certain example embodiments, the apparatus comprises an
outlet other than the reaction chamber outlet. The other outlet may
be the afore-mentioned waste line outlet. In certain example
embodiments, the other outlet is connected to a same foreline, or
exhaust line, to which the reaction chamber is connected. In
certain example embodiments, the other outlet is connected to the
same foreline, via a trap (for chemical neutralization or
combustion) positioned before the connection to the foreline. In
certain example embodiments, the other outlet is connected to a
different foreline. In certain example embodiments, the other
outlet is connected to a precursor chemical recovery
arrangement.
[0106] In certain example embodiments, the pulsing valve is
embedded into or attached to a structure selected from a group
comprising: a structure leading to a reaction chamber, a reaction
chamber structure, a reaction chamber wall, and a reaction chamber
lid. In certain example embodiments, there are a plurality of
pulsing valves embedded into or attached to a plurality of
structures selected from a group comprising: a reaction chamber
structure, a reaction chamber wall, and a reaction chamber lid.
[0107] Accordingly, in certain example embodiments, the pulsing
valve is positioned inside or at least partly inside of the
reaction chamber structure or wall. In certain example embodiments,
a reaction chamber structure is a structure defining the reaction
chamber, such as a reaction chamber wall or lid.
[0108] In certain example embodiments, the apparatus comprises a
plurality of additional cleaning chemical inlets at the reaction
chamber side of the closure to purge the closure. In yet further
example embodiments, the closure is a non-completely closing member
thereby not closing the route from the reactive chemical inlet to
the reaction chamber outlet completely when being in closed
configuration.
[0109] In certain the pulsing valve connects to the reaction space
without there being a pipeline in between. In certain example
embodiments, the pulsing valve opens directly into the reaction
space defined by the reaction chamber. In certain example
embodiments, the pulsing valve reaction chamber outlet directly
connects to inside of the reaction space by an expansion volume, or
a passage widening towards the reaction space, and/or by a
showerhead. In certain example embodiments, the route from the
route from the pulsing valve to the reaction space is without
bends. In certain example embodiments, the pulsing valve is a
surface part of the reaction chamber (the reaction chamber defining
the reaction space accommodating at least one substrate).
[0110] In certain example embodiments, the apparatus is a substrate
processing apparatus. In certain example embodiments, the apparatus
is a deposition reactor. In certain example embodiments, the
apparatus is a chemical deposition reactor. In certain example
embodiments, the apparatus is an ALD reactor.
[0111] According to a seventh example aspect there is provided a
method, comprising: [0112] supplying reactive chemical through a
pulsing valve along a route extending from a reactive chemical
inlet to a reaction chamber outlet; [0113] controlling the closing
of the route by a pulsing valve closure; and [0114] supplying
cleaning chemical through an additional cleaning chemical inlet at
the reaction chamber side of the closure and purging the closure by
the cleaning chemical.
[0115] In certain example embodiments, the method comprises: [0116]
purging a valve output surface provided by the closure that is
pointing towards or directly to the reaction chamber, or substrate,
by cleaning chemical released from the additional cleaning chemical
inlet that is additional to the reaction chamber outlet.
[0117] In certain example embodiments, said supplying of cleaning
chemical comprises releasing cleaning chemical onto pulsing valve
output surface which cleaning chemical reacts with reactive
chemicals on the surface without producing solid particles.
[0118] In certain example embodiments, the additional cleaning
chemical inlet points directly or at least obliquely to the closure
and/or valve output surface.
[0119] In certain example embodiments, the method comprises
providing the additional cleaning chemical inlet in a reaction
chamber outlet channel wall.
[0120] In certain example embodiments, the method comprises:
supplying the cleaning chemical from a pipe extending towards the
closure and/or valve outlet surface within the reaction chamber
outlet channel, the pipe providing the additional cleaning chemical
inlet.
[0121] In certain example embodiments, the method comprises: [0122]
purging the closure and/or valve output surface continuously.
[0123] In certain example embodiments, the method comprises: [0124]
purging along the closure and along the reaction chamber outlet
channel wall.
[0125] In certain example embodiments, the method comprises: [0126]
heating an outer chamber around the reaction chamber.
[0127] In certain example embodiments, the method comprises: [0128]
providing a route by-passing the closure from the reactive chemical
inlet to a waste line outlet that route being open in the closed
configuration of the closure.
[0129] In certain example embodiments, the method comprises: [0130]
maintaining a higher pressure in a chemical waste line beginning at
the waste line outlet compared to a pressure in the reaction
chamber.
[0131] In certain example embodiments, the method comprises: [0132]
completely preventing or at least partly preventing reactive
chemical from flowing into the chemical waste line outlet when the
closure is in the open configuration.
[0133] In certain example embodiments, the method comprises: [0134]
performing ALD deposition within the reaction chamber.
[0135] According to an eighth example aspect there is provided a
valve for use in the apparatus of the sixth aspect and any of its
embodiments, the valve comprising: [0136] a reactive chemical
inlet; [0137] a reaction chamber outlet; and [0138] a closure
having an open and closed configuration to open and close,
respectively, a route from the reactive chemical inlet to the
reaction chamber outlet, the valve further comprising: [0139] an
additional cleaning chemical inlet at a downstream side of the
closure to purge the closure.
[0140] Different non-binding example aspects and embodiments 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 disclosure. Some embodiments may be
presented only with reference to certain example aspects. It should
be appreciated that corresponding embodiments apply to other
example aspects as well. Any appropriate combinations of the
embodiments may be formed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0141] The aspects of the disclosed embodiments will now be
described, by way of example only, with reference to the
accompanying drawings, in which:
[0142] FIG. 1 shows a pulsing valve with its closure in a closed
configuration in accordance with certain example embodiments;
[0143] FIG. 2 shows the pulsing valve of FIG. 1 with its closure in
an open configuration;
[0144] FIG. 3 shows a pulsing valve with its closure in a closed
configuration in accordance with certain other example
embodiments;
[0145] FIG. 4 shows the pulsing valve of FIG. 3 with its closure in
an open configuration;
[0146] FIG. 5 shows a pulsing valve attached to a reaction chamber
structure in accordance with certain example embodiments;
[0147] FIG. 6 shows a substrate processing apparatus in accordance
with certain example embodiments;
[0148] FIG. 7 shows a method according to certain example
embodiments;
[0149] FIG. 8 shows yet another example embodiment;
[0150] FIG. 9 shows a further example embodiment in which a closure
of a pulsing valve is purged;
[0151] FIG. 10 shows the pulsing valve of FIG. 9 with its closure
in an open configuration;
[0152] FIG. 11 shows a carrier gas route according to certain
example embodiments;
[0153] FIG. 12 shows yet another example embodiment in which a
closure of a pulsing valve is purged;
[0154] FIG. 13 shows the pulsing valve of FIG. 12 with its closure
in an open configuration;
[0155] FIG. 14 shows a further substrate processing apparatus in
accordance with certain example embodiments;
[0156] FIG. 15 shows a block diagram of a control system in
accordance with certain example embodiments;
[0157] FIG. 16 shows the substrate processing apparatus of FIG. 14
with certain modifications
[0158] FIG. 17 shows the substrate processing apparatus equipped
with certain flow control devices in accordance with certain
example embodiments;
[0159] FIG. 18 shows an alternative positioning within the
substrate processing apparatus;
[0160] FIG. 19 shows yet another example embodiment in which a
closure of a pulsing valve is purged;
[0161] FIG. 20 shows the pulsing valve of FIG. 19 with its closure
in an open configuration;
[0162] FIG. 21 shows certain details of a pulsing valve in
accordance with certain example embodiments;
[0163] FIG. 22 shows a further design of the valve of FIGS. 19 and
20;
[0164] FIG. 23 shows yet another embodiment; and
[0165] FIG. 24 shows a method according to certain example
embodiments.
DETAILED DESCRIPTION
[0166] In the following description, Atomic Layer Deposition (ALD)
technology is used as an example. However, the aspects of the
disclosed embodiments are not limited to ALD technology, but it can
be exploited in a wide variety of substrate processing apparatuses,
for example, in Chemical Vapor Deposition (CVD) reactors.
[0167] The basics of an ALD growth mechanism are known to a skilled
person. ALD is a special chemical deposition method based on the
sequential introduction of at least two reactive precursor species
to at least one substrate. It is to be understood, however, that
one of these reactive precursors can be substituted by energy when
using, for example, photon-enhanced ALD or plasma-assisted ALD, for
example PEALD, leading to single precursor ALD processes. For
example, deposition of a pure element, such as metal, requires only
one precursor. Binary compounds, such as oxides can be created with
one precursor chemical when the precursor chemical contains both of
the elements of the binary material to be deposited. Thin films
grown by ALD are dense, pinhole free and have uniform
thickness.
[0168] The at least one substrate is typically exposed to
temporally separated precursor pulses in a reaction vessel to
deposit material on the substrate surfaces by sequential
self-saturating surface reactions. In the context of this
application, the term ALD comprises all applicable ALD based
techniques and any equivalent or closely related technologies, such
as, for example the following ALD sub-types: MLD (Molecular Layer
Deposition) plasma-assisted ALD, for example PEALD (Plasma Enhanced
Atomic Layer Deposition) and photon-enhanced Atomic Layer
Deposition (known also as flash enhanced ALD).
[0169] A basic ALD deposition cycle consists of four sequential
steps: pulse A, purge A, pulse B and purge B. Pulse A consists of a
first precursor vapor and pulse B of another precursor vapor.
Inactive gas and a vacuum pump are typically used for 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. Deposition cycles can also be
either simpler or more complex. For example, the cycles can include
three or more reactant vapor pulses separated by purging steps, or
certain purge steps can be omitted. All these deposition cycles
form a timed deposition sequence that is controlled by a logic unit
or a microprocessor.
[0170] A reaction space is a defined volume within a reaction
chamber. The desired chemical reactions occur in the reaction
space. Basic ALD inlet tools through which chemicals are flown into
the reaction space are generally knows as shower heads. The inlet
of precursor chemical can be from the top, or cross flow, where the
chemical is inlet from at least one side.
[0171] FIG. 1 shows a pulsing valve with its closure in a closed
configuration in accordance with certain example embodiments. The
pulsing valve 100 comprises a valve body 110 having an inlet 101
for reactive chemical, such as a precursor chemical, and an outlet
104 towards a reaction chamber (not shown in FIG. 1). A closure 111
comprised by the pulsing valve has an open and closed configuration
to open and close, respectively, a route from the reactive chemical
inlet 101 to the reaction chamber outlet 104. FIG. 1 shows the
closure 111 in its closed configuration.
[0172] A surface of the closure 111 pointing towards the reaction
chamber is defined as a valve output surface 112. The pulsing valve
100 further comprises an additional cleaning chemical inlet 103 at
the reaction chamber side of the closure 111 to purge the closure
111, especially the valve output surface 112, to prevent or
minimize material growth thereon thus providing a cleaning effect.
The same effect is achieved on side walls of the outlet (or outlet
channel, or opening) 104 when the cleaning chemical exits along the
side walls towards the reaction chamber. In certain example
embodiments, the cleaning chemical inlet 103 is implemented through
the side wall of the outlet 104. A cleaning chemical inlet pipe or
channel travelling within the valve body passes through the side
wall and points towards the closure 111 and/or valve output surface
112.
[0173] The cleaning chemical can be the same gas that is used as
the purging gas in the reaction chamber during process stage.
Cleaning chemical is led to inlet 103 via a route that is separate
from the routes the other chemicals use. In certain example
embodiments, the cleaning chemical route has pulsing control, mass
flow control, and/or valve control to change and/or limit the flow
of cleaning chemical with respect to pulses in process stage.
[0174] The pulsing valve 100 further comprises an optional chemical
waste line outlet 102. A route by-passing the closure 111 is formed
from the reactive chemical inlet 101 to the waste line outlet
102.
[0175] The pulsing valve 100 may be attached to and/or sealed with
a reaction chamber structure of a substrate processing apparatus at
its attaching surface 115.
[0176] FIG. 2 shows the pulsing valve 100 with its closure 111 in
an open configuration. The reactive chemical flows from the
reactive chemical inlet 101 to the reaction chamber outlet 104.
[0177] FIG. 3 shows a pulsing valve with its closure in a closed
configuration in accordance with certain other example embodiments.
The pulsing valve 300 comprises a valve body 110 having an inlet
101 for reactive chemical, such as a precursor chemical, and an
outlet 104 towards a reaction chamber (not shown in FIG. 3). A
closure 111 comprised by the pulsing valve has an open and closed
configuration to open and close, respectively, a route from the
reactive chemical inlet 101 to the reaction chamber outlet 104.
FIG. 3 shows the closure 111 in its closed configuration.
[0178] A surface of the closure 111 pointing towards the reaction
chamber is, again, defined as a valve output surface 112. The
pulsing valve 300 further comprises an additional cleaning chemical
inlet 303 at the reaction chamber side of the closure 111 to purge
the closure 111, especially the valve output surface 112, to
prevent or minimize material growth thereon thus providing a
cleaning effect. The same effect is achieved on side walls of the
outlet (or outlet channel, or opening) 104 when the cleaning
chemical exits along the side walls towards the reaction chamber.
In certain example embodiments, the cleaning chemical inlet 103 is
implemented as a separate pipeline extending within the outlet 104
towards the closure 111 and/or valve output surface 112.
[0179] The pulsing valve 300 further comprises an optional chemical
waste line outlet 102. A route by-passing the closure 111 is formed
from the reactive chemical inlet 101 to the waste line outlet
102.
[0180] The pulsing valve 300 may be attached to a reaction chamber
structure of a substrate processing apparatus at its attaching
surface 115. As to the operation of the pulsing valve 300 a
reference is made to the preceding description in connection with
pulsing valve 100.
[0181] FIG. 4 shows the pulsing valve 300 with its closure 111 in
an open configuration. The reactive chemical flows from the
reactive chemical inlet 101 to the reaction chamber outlet 104.
[0182] FIG. 5 shows a pulsing valve attached to a reaction chamber
structure in accordance with certain example embodiments. The
pulsing valve 100 (300) may form part of the surface of the
reaction chamber. In certain example embodiments, the reaction
chamber structure 520 comprises a recess into which the pulsing
valve 100 (300, similarly) is embedded. The pulsing valve 100 (300)
may be tightened against the structure 520 at the attaching surface
115. In certain example embodiments, the pulsing valve is attached
to a reaction chamber wall. In certain example embodiments, the
pulsing valve is attached to a reaction chamber side wall. FIG. 5
specifically shows an embodiment in which the pulsing valve is
embedded into reaction chamber upper wall, or lid.
[0183] In certain example embodiments, the pulsing valve forms an
integral part of the reaction chamber. In other example
embodiments, the pulsing valve is attached to a pipe or other
structure leading to a reaction chamber.
[0184] FIG. 5 further shows by arrows certain routing alternatives
to implement a route of the cleaning chemical inlet pipe (or
channel). The pipe can for part of the valve structure and/or the
reaction chamber lid and/or wall structure, or it can be a separate
pipe attached to or through the reaction chamber lid/wall. The
route can extend in parallel of the reaction chamber lid or wall
structure on the outside of the structure, and/or it can penetrate
through the structure into the reaction chamber side of the
structure, and/or it can extend within the lid or wall structure
and/or within the valve body. The other pipings, such as the
reactive chemical in-feed piping, can be implemented similarly.
[0185] FIG. 6 shows a substrate processing apparatus in accordance
with certain example embodiments. The substrate processing
apparatus 500 comprises a reaction chamber 530 configured to house
a substrate 600 within a reaction space 521 defined by the reaction
chamber 530. In certain example embodiments, the apparatus
comprises an outer chamber 540 surrounding the reaction chamber 530
thereby closing an intermediate space 522 in between the reaction
chamber 530 and the outer chamber 540. In certain example
embodiments, the intermediate space 522 is heated by a heater 545
positioned in the space 522.
[0186] A reactive chemical in-feed line 501 (which may contain a
plurality of pipes) extends from a reactive chemical source (not
shown) via the intermediate space (if any) to the reactive chemical
inlet (see FIGS. 1-4, inlet 101) of the pulsing valve 100. A
chemical waste line 502 extends from the chemical waste line outlet
(see FIGS. 1-4, outlet 102) of the pulsing valve 100 via the
intermediate space (if any) to exhaust. The waste line 502 in
certain example embodiments joins to an exhaust line 555 that
extends from the reaction chamber 530 to a vacuum pump (not
shown).
[0187] The pulsing valve 100 has similar structure and operation as
described in connection of FIGS. 1 and 2. Accordingly, the pulsing
valve 100 comprises a valve body having an inlet for reactive
chemical, and an outlet towards the reaction chamber 530. A closure
comprised by the pulsing valve has an open and closed configuration
to open and close, respectively, a route from the reactive chemical
inlet to the reaction chamber outlet. The pulsing valve 100 further
comprises the additional cleaning chemical inlet at the reaction
chamber side of the closure to purge the closure. The pulsing valve
100 further comprises the optional chemical waste line outlet. A
route by-passing the closure is formed from the in-feed line 501
via the reactive chemical inlet to the waste line 502 via the waste
line outlet.
[0188] Although there is only one pulsing valve shown in FIG. 6 it
is clear that there may be a plurality of pulsing valves with
similar structural and operational features, and/or one or more
other pulsing valves with different known structures. Instead of
the pulsing valve 100, the pulsing valve(s) 300 described in
connection with FIGS. 3 and 4 may be used. The pulsing valve(s) may
be positioned at the side wall of the reaction chamber 530, as
illustrated by reference numeral 100', or they may be positioned at
the lid structure or upper wall 520, or both at the side wall and
at the lid structure/upper wall 520. In certain example
embodiments, at least one pulsing valve can be positioned inside of
the reaction chamber 530. In certain example embodiments, all of
the one or more pulsing valves are positioned at the side wall and
the reaction chamber is open from the top to receive energy needed
in surface reactions at the substrate surface from the top, wherein
the energy may be in the form of plasma or photons, for
example.
[0189] In certain example embodiments, the reaction chamber 530
comprises a hatch 531 at its side wall for loading and unloading
substrates. The structure 520 may be a fixed chamber upper wall or
a removable lid. In certain example embodiments, the structure 520
is a removable lid. The substrate or substrates 600 are loaded from
the top side of the reaction chamber by lifting the lid 520. A
preferred position of the pulsing valve(s) is then at the side
wall. In the event the removable lid has pulsing valve(s) at the
lid, the pipings 501 and 502 can be designed to connect and
disconnect if needed, for example at line 560 in
[0190] FIG. 6. In certain example embodiments, the reaction chamber
520 is lowered, for example, by a bellows structure 570 to form a
substrate loading route in between the chamber 530 and lid 520. A
similar arrangement has been described in a co-pending
international application PCT/FI2017/050071 filed by the same
application. This enables loading from the side of the reaction
chamber.
[0191] FIG. 7 shows a method according to certain example
embodiments. In step 701, reactive chemical is supplied to a
reaction chamber via a pulsing valve for deposition. The supply of
reactive chemical to the reaction chamber is interrupted in step
702. The valve output surface is purged by cleaning chemical, and
the purging by cleaning chemical is continued in step 703.
[0192] In certain example embodiments, a reactive chemical pulse
into the reaction chamber is followed by a cleaning chemical
period. The cleaning chemical may be gas or fluid. In certain
example embodiments, the cleaning chemical flows continuously. In
certain example embodiments, the flow rate of cleaning chemical is
reduced at least during a part of a precursor chemical pulse. In
certain example embodiments, the cleaning chemical flows at an
elevated rate during a period in which precursor vapor is not
released into the reaction chamber via the pulsing valve in
question.
[0193] The cleaning chemical can refer here to a gas or fluid,
which can push fluid atoms or molecules away from a space, and/or
which can remove them from surfaces. The cleaning chemical can be
neutral, such as argon gas Ar, or nitrogen gas N2, or reactive,
such as heated gas, or ionized or radical gas. It can be any such
gas which does not react with the reactive chemical, or it can be
any such gas which reacts with the chemical to be cleaned in a way
that it does not produce solid species (or in some cases neither
liquid species, which would react with the substrate). In certain
example embodiments, the cleaning gas can be helium gas He. Some or
all of the gases can be considered as carrier gases.
[0194] In certain or all foregoing embodiments, the following
applies: [0195] chemical flowing into the inlet 101 may consist of
pure precursor (or reactive) chemical, or a mixture of precursor
chemical and carrier gas; [0196] the flow and mixing of reactive
gas to carrier gas can be controller with mass flow controller or
valves synchronized with the whole process, or with any
synchronization down to duration of a step of the deposition cycle,
such as presented, for example, in U.S. Pat. No. 8,211,235 assigned
to the same assignee; [0197] the pulsing valve 100 or 300 may
contain a flow restrictor, such as a capillary, in the optional
waste line 502 within the valve area; [0198] the valve 100 or 300
may be a 3-way valve or a 4-way valve in which a fluid flow hits
the closure 111; [0199] the fluid flow may be released from the
additional cleaning chemical inlet positioned at a side of the
valve (as in FIGS. 1 and 2), and/or the additional cleaning
chemical inlet may be provided by a cleaning chemical inlet pipe
coming from the outside of valve body (as in FIGS. 3 and 4); [0200]
the cleaning chemical inlet pipe may be heated, which heat may me
higher than the reaction chamber heat; [0201] the cleaning chemical
inlet pipe may be provided with pre-heated gas; [0202] the provided
reaction chamber outlet channel (or opening) 104 towards the
reaction chamber may be the only inlet to the reaction chamber
(i.e., there are no other gas inlets to the reaction chamber)--this
outlet channel may provide all chemicals needed in the reactions
within the reaction chamber; [0203] the pulsing valve may be
oriented such that the closure 111 faces (or sees) the reaction
space (or substrate surface); [0204] the opening may expand from
the closure surface towards the reaction chamber--the expansion may
be in the form of a conical opening; [0205] the pulsing valve may
form part of the reaction chamber (or reaction vessel)
structure--the reaction chamber structure may be a reaction chamber
lid [0206] the pressure in the intermediate space 522 pressure may
be 1000-0.1 mBar, preferably 100-1 mBar, more preferably 20-2 mBar.
[0207] the reaction chamber pressure may be ambient to 1 .mu.Bar,
more preferably 10-0.01 mBar, most preferably 1-0.1 mBar. [0208]
the reaction chamber pressure can be varied with the aid of
modifying the vacuum in foreline (exhaust line) 555 leading out
from the chamber 530, or by a total gas flow to the reaction space
521, and possibly intermediate space 522; [0209] the reaction
chamber pressure referred here can be synchronized with the whole
process, or any synchronization down to duration of a step of the
deposition cycle may be applied
[0210] FIG. 8 shows yet another example embodiment. The closure 111
can be configured to close the waste line outlet 102', or at least
partly close the waste line outlet 102', or decrease the flow to
the waste line, while the route from the reactive chemical inlet
101 to the reaction chamber outlet 104 is opened. The waste line
outlet 102' may be positioned at the other side of the closure 111
so that when the closure 111 moves away from the reaction chamber
outlet 104 it pushes against the waste line outlet (opening)
102'.
[0211] Yet in other embodiments, in a slightly modified valve
design, the closure 111 will close the reactive chemical inlet
(opening) 101 while it closes the passage to the reaction chamber,
e.g., by pushing against the inlet 101. This is in order to
evacuate reactive gas from the space above the closure 111 into the
waste line. This is especially applicable if the closure 111 is not
able to completely block the reactive chemical flow into the
reaction chamber past the closure (i.e., when the closure 111 is
not completely closing). The pressure in the space above the
closure 111 is then lower compared to the pressure inside the
reaction chamber and residual reactive chemical flows into the
direction of the waste line.
[0212] The description concerning any particular preceding
embodiment is directly applicable to other disclosed embodiments.
This applies both with regard to the structure and operation of the
disclosed apparatus.
[0213] Without limiting the scope and interpretation of the patent
claims, certain technical effects of one or more of the example
embodiments disclosed herein are listed in the following. A
technical effect is providing a minimum amount of trapped precursor
chemical thereby avoiding undesired particle generation, while
enabling high pulsing speed, for example, more than one pulse and
purge per second. Another technical effect is a mechanically
smaller pulsing valve implementation, for example, less than 10
cm.sup.3, such as 4 cm.sup.3. Another technical effect is a
cleaning effect by purging reactive material away from surfaces.
Undesired gas phase reactions of material adsorbed on solid
surfaces of the pulsing valve structure and pulsing valve outlet
can be minimized.
[0214] It should be noted that some of the functions or method
steps discussed in the preceding may be performed in a different
order and/or concurrently with each other. Furthermore, one or more
of the above-described functions or method steps may be optional or
may be combined.
[0215] In the foregoing drawings 1-4, and 8 a space inside the
valve 100 or 300 where the closure 111 is moved should in each case
be consider to be a closed volume.
[0216] What has been described in the preceding concerning the
embodiments shown in FIGS. 1-8 generally apply also for the
following embodiments. Also, what will be described in connection
with any of the following embodiments generally apply to the other
followings embodiments as well as for the embodiments shown and
described in the preceding.
[0217] FIG. 9 shows a further example embodiment in which a closure
of a pulsing valve is purged. The pulsing valve 900 comprises a
valve body 910 having an inlet 901 for reactive chemical, such as a
precursor chemical, and an outlet 904 towards a reaction chamber
(reaction chamber not shown in FIG. 9). A closure 191 comprised by
the pulsing valve 900 has an open and closed configuration to open
and close, respectively, a route from the reactive chemical inlet
901 to the reaction chamber outlet 904. FIG. 9 shows the closure
191 in its closed configuration.
[0218] The pulsing valve 900 further comprises an additional flow
channel inlet or outlet to purge the closure. In FIG. 9 is shown an
additional flow channel outlet 903. The outlet 903 is at the same
side of the closure 191 as the reactive chemical inlet 901. In this
embodiment, the outlet (or pipe end) 903 forms a starting point of
a waste line bypassing the reaction chamber. The waste line may
extend, for example, to a particle trap or vacuum pump (not
shown).
[0219] The flow channel or outlet 903 is positioned to reside
within a flow channel providing the reactive chemical inlet 901.
Accordingly, the outlet pipe 903 has a cross-sectional flow area
that is smaller than the corresponding cross-sectional flow area of
the flow channel (inlet pipe) providing the reactive chemical inlet
901. In an embodiment, the flow channel or outlet 903 has a
cross-sectional flow area that is less than 25% of the
cross-sectional flow area of the surrounding flow channel providing
the reactive chemical inlet 901.
[0220] In the closed configuration of the closure 191, reactive
chemical from the reactive chemical inlet 901 flows to purge the
closure 191 on its way from the reactive chemical inlet 901 to the
waste channel outlet 903 of the valve. The flow direction of the
purge is along the surface of the closure.
[0221] The pulsing valve 900 may further comprise a carrier gas
inlet 911 in fluid communication (via the closure 191) with the
reaction chamber outlet 904. When the closure 191 is in its closed
configuration, the closure 191 rests on the reactive chemical inlet
901, or on a closure sealing ring (not shown), closing the route
from the reactive chemical inlet 901 to the reaction chamber outlet
904. At the same time this arrangement provides for a curved route
(see FIG. 11) from inlet 911 to outlet 904 in between the closure
191 and the valve body 910. Carrier gas/inactive gas flowing along
this route purges the closure 191 at an area around the area of the
reactive chemical inlet 901.
[0222] FIG. 10 shows the pulsing valve 900 with its closure 191 in
an open configuration. The reactive chemical flows from the
reactive chemical inlet 901 to the reaction chamber outlet 904.
Depending on the embodiment, the reactive chemical is mixed with a
carrier gas arriving from inlet 911. A suction into the additional
flow channel outlet 903 is maintained to prevent reactive chemical
from stagnating therein.
[0223] FIG. 11 shows the fluid communication path of carrier (or
inactive) gas from the inlet 911 to outlet 904. The route is open
during an entire deposition cycle or sequence with the difference
that when the closure 191 is in its closed configuration the route
bypasses the reactive chemical inlet area and when the closure 191
is in its open configuration the carrier gas flow purges the entire
area of the closure 191. The route may be implemented by a toroidal
shaped flow path ("a donut ring structure") around the closure
191.
[0224] FIG. 12 shows a further example embodiment in which a
closure of a pulsing valve is purged. The pulsing valve 900'
otherwise corresponds to the structure and operation of the pulsing
valve 900 except that it is the reactive chemical inlet pipe 901'
that resides within the flow channel (waste line) 903', and not
vice versa. Accordingly, in this embodiment, the valve body 910
provides the waste line outlet 903' and the reactive chemical inlet
pipe 901' is the smaller pipe positioned within the outlet pipe
903'.
[0225] FIG. 12 shows the valve closure 191 in its closed
configuration. In the closed configuration of the closure 191,
reactive chemical from the reactive chemical inlet 901' flows to
purge the closure 191 on its way from the reactive chemical inlet
901' to the flow channel 903' (waste line outlet of the valve
900').
[0226] FIG. 13 shows the pulsing valve 900' with its closure 191 in
an open configuration. The reactive chemical flows from the
reactive chemical inlet 901' to the reaction chamber outlet 904.
Depending on the embodiment, the reactive chemical is mixed with a
carrier gas arriving from inlet 911. A suction into the waste line
903' is maintained to prevent reactive chemical from stagnating in
the line.
[0227] FIG. 14 shows a further substrate processing apparatus in
accordance with certain example embodiments. The substrate
processing apparatus 1400 comprises a reaction chamber 1430
configured to house a substrate 600 within a reaction space 1421
defined by the reaction chamber 1430. In certain example
embodiments, the apparatus comprises an outer chamber 1440
surrounding the reaction chamber 1430 thereby closing an
intermediate space 1422 in between the reaction chamber 1430 and
the outer chamber 1440. In certain example embodiments, the
intermediate space 1422 is heated by a heater 1445 positioned in
the space 1422.
[0228] The pulsing valve 900, acting as a hot valve, is positioned
within the heated intermediate space 1422. A reactive chemical
in-feed line 1401 extends from a reactive chemical source (not
shown) to the reactive chemical inlet 901 of the pulsing valve 900.
A waste line 1402 begins at the waste line outlet 903 of the
pulsing valve 900, and it extends via the intermediate space 1422
to exhaust. The waste line 1402 in certain example embodiments
joins to an exhaust line 1455 that extends from the reaction
chamber 1430 to a vacuum pump (not shown). In other embodiments,
the waste line 1402 instead extends to a chemical extraction with
the aid of separate means creating vacuum for the line (not
shown).
[0229] The pulsing valve 900 has similar structure and operation as
described in connection of FIGS. 9-11. Accordingly, the pulsing
valve 900 comprises a valve body having an inlet 911 for carrier
gas arriving from a carrier gas line 1403. The pulsing valve
further has an outlet 904 through which inactive gas or a mixture
of carrier gas and pulsed reactive chemical (depending on the
processing cycle phase) flow along a reaction chamber in-feed line
1404 towards the reaction chamber 1430. A closure comprised by the
pulsing valve has an open and closed configuration to open and
close, respectively, a route from the reactive chemical inlet 901
to the reaction chamber outlet 904. The reaction chamber in-feed
line 1404 may end up to the upper wall or lid 1420 of the reaction
chamber 1430 wherefrom the fluid that flows therein is delivered
into the interior of the reaction chamber 1430. In certain example
embodiments, as shown in FIG. 14, the in-feed line 1404 is routed
to travel along the side wall of the reaction chamber 1430 into an
attachment point. A metal-metal contact may be provided at the
attachment point allowing a discontinuation of the in-feed line
1404 when the reaction chamber lid 1420 is lifted at line 1460 for
top-loading a substrate into the reaction chamber 1430.
[0230] FIG. 14 further shows an actuating element 1480 of the
pulsing valve 900. The actuating element 1480 causes movement of
the closure 191 to provide the open and closed configurations of
the closure 191. The actuating element 1480 can be located inside
or outside of the heated and/or vacuum intermediate space 1422. In
the event the actuating element is located outside, actuation may
be guided to the valve 900 by such methods as a mechanical bar,
pneumatic means, hydraulic means, or magnet. In certain example
embodiments, the actuating element 1480 receives instructions in
the form of signals from a control system 1450 that controls the
operation of the apparatus 1400. The control system 1450 (see FIG.
15) comprises at least one processor 1451 to control the operation
of the apparatus 1400 and at least one memory 1452 comprising a
computer program or software 1453. The software 1453 includes
instructions or a program code to be executed by the at least one
processor 1451 to control the apparatus 1400. The software 1453 may
typically comprise an operating system and different
applications.
[0231] The at least one memory 1451 may form part of the apparatus
1400 or it may comprise an attachable module. The control system
1450 further comprises at least one communication unit 1454. The
communication unit 1454 provides for an interface for internal
communication of the apparatus 1400. In certain example
embodiments, the control unit 1450 uses the communication unit 1454
to send instructions or commands to and to receive data from
different parts of the apparatus 1400, for example, measuring and
control devices, valves, pumps, and heaters.
[0232] The control system 1450 may further comprise a user
interface 1456 to co-operate with a user, for example, to receive
input such as process parameters from the user.
[0233] As to the operation of the apparatus 1400, the control
system 1450 controls e.g. the process timings of the apparatus. In
certain example embodiments, the apparatus 1400 is configured, by
means of being programmed, for example, to purge, during the entire
substrate processing cycle or sequence, all surface areas of the
closure exposed to processing gases. In particular, this may be
interpreted to contain all open (i.e., non-covered) areas of the
closure that are exposed to a precursor gas flow at least during
certain periods of the deposition cycle or sequence. These open
areas include exposed areas that are not contacted by any fixed
part of the valve 900.
[0234] In certain example embodiments, the apparatus 1400 is
programmed to purge the closure at the area of the reactive
chemical inlet 901 continuously by said reactive chemical during
the entire substrate processing cycle or sequence, and purge the
closure around that area continuously by carrier gas.
[0235] In certain example embodiments, the apparatus 1400 is
programmed to provide the channel 1402, which can also be denoted
as a suction channel, with suction during the entire substrate
processing cycle or sequence. Furthermore, the apparatus in certain
example embodiments is programmed to provide a gas flow within the
reactive chemical in-feed line 1401 during the entire substrate
processing cycle or sequence. The apparatus 1400 is thus programmed
to purge the closure at the area of the reactive chemical inlet 901
during the entire substrate processing cycle or sequence, this
purge being by reactive gas in certain embodiments.
[0236] In certain example embodiments, the apparatus is programmed
to pulse reactive chemical into a carrier gas flow that is
configured to flow from the inlet 911 to the outlet 904.
[0237] In certain example embodiments, said continuous purge of the
closure does not occur through the additional flow channel (waste
line) 1402 or does not occur through the additional flow channel
1402 during the entire substrate processing cycle or sequence. For
example, when the closure is in the open configuration, the purge
in certain example embodiments is implemented from the inlet(s)
901, 911 to the reaction chamber outlet. In certain example
embodiments, the additional flow channel 1402 is closed or at least
partially closed when the closure is in the open configuration.
[0238] In certain example embodiments, the flow into the waste line
1402 is reduced but not stopped during the periods in which the
closure is in its open configuration.
[0239] Each flow channel may contain its own pulsing control,
pressure control, mass flow control, and/or valve control to change
and/or limit the flow within the flow channel concerned. Depending
on static or dynamic flows or pressure, those flow control means
may be used to ensure the desired flow direction of one or any
channel in the apparatus or valve.
[0240] Although there is only one pulsing valve shown in FIG. 14 it
is clear that there may be a plurality of pulsing valves with
similar structural and operational features, and/or one or more
other pulsing valves with different known structures.
[0241] FIG. 16 shows a substrate processing apparatus 1600
containing certain modifications to the substrate processing
apparatus 1400. Instead of the pulsing valve 900, the pulsing
valve(s) 900' described in connection with FIGS. 12 and 13 may be
used. Instead of or in addition to attaching the pulsing valves in
free portions of the in-feed lines the pulsing valve(s) may
alternatively be positioned at the side wall of the reaction
chamber 1430, as illustrated by reference numeral 900*, or they may
be positioned at the lid structure or upper wall 1420, or both at
the side wall and at the lid structure/upper wall 1420. Further, in
certain example embodiments, at least one pulsing valve can be
positioned inside of the reaction chamber 1430. In certain example
embodiments, all of the one or more pulsing valves are positioned
at the side wall and/or in the free portions in between of the
chambers 1430 and 1440, and the reaction chamber 1430 is open from
the top to receive energy needed in surface reactions at the
substrate surface from the top, wherein the energy may be in the
form of plasma or photons, for example.
[0242] In certain example embodiments, the reaction chamber 1430
comprises a hatch 1431 at its side wall for loading and unloading
substrates. The structure 1420 may be a fixed chamber upper wall or
a removable lid. In certain example embodiments, the structure 1420
is a removable lid. The substrate or substrates 600 are loaded from
the top side of the reaction chamber by lifting the lid 1420. A
preferred position of the pulsing valve(s) is then at the side wall
or in the free portions of the in-feed lines. In the event the
removable lid has pulsing valve(s) at the lid, the pipings 1401,
1402 etc. can be designed to connect and disconnect if needed, for
example at line 1460 in FIG. 16. In certain example embodiments,
the reaction chamber 1430 is lowered, for example, by a bellows
structure 1470 to form a substrate loading route in between the
chamber 1430 and lid 1420. A similar arrangement has been described
in a co-pending international application PCT/FI12017/050071 filed
by the same application. This enables loading from the side of the
reaction chamber.
[0243] In the presented embodiments there can be means to adjust or
limit flow with flow control devices (or arrangements) in any of
the presented lines or flow channels. Examples of such devices are
valves, mass flow controllers, ALD valves, non-completely closing
valves, multi-stage digital valves and valves with parallel of
routes with a restricted gas flow, for example. These devices
operate under the control of the control system 1450. The presented
lines or flow channels may also comprise pressure indicators if
needed, for example, in the reactive chemical in-feed line
1401.
[0244] In some embodiments, the closure 991 has a steady (constant)
configuration, whereupon fluid flow via the pulse valve is adjusted
with the aid of flow controlling elements positioned in flow
channels in fluid communication with the pulsing valve. The term
"steady" is utilized hereby to indicate the closure whose
configuration remains constant during operation, thereby the open
and closed configurations are not provided.
[0245] FIG. 17 shows the substrate processing apparatus equipped
with certain flow control devices in accordance with certain
example embodiments. The substrate processing apparatus 1700 shown
in FIG. 17 is generally of the type described in connection with
FIG. 14 or 16. It comprises the hot valve type of pulsing valve 900
positioned within the heated intermediate space.
[0246] The reactive chemical in-feed line 1401 comprises at least
one flow control device 1 to control the flow from a reactive
chemical source (not shown) to the valve 900. The at least one flow
control device comprises a valve controlled by the control system
1450. In certain example embodiments, the valve is located in
connection with the source. The at least one flow control device 1
may additionally comprise a mass flow controller controlled by the
control system 1450.
[0247] Similarly, the carrier gas line 1403 comprises at least one
flow control device 3 to control the flow from a carrier gas (or
inactive gas) source (not shown) to the valve 900. The at least one
flow control device comprises a valve controlled by the control
system 1450. In certain example embodiments, the valve is located
in connection with the carrier gas source. The at least one flow
control device 3 may additionally comprise a mass flow controller
controlled by the control system 1450.
[0248] In certain example embodiments, the waste line 1402
comprises at least one flow control device 2 to control outgoing
flow from the valve 900. The at least one flow control device 2 is
controlled by the control system 1450. In certain example
embodiments, the control system 1450 is programmed to allow a
precursor chemical to flow along the waste line 1402 via the at
least one flow control device 2 during an entire substrate
processing cycle or sequence, such as a vacuum deposition cycle or
a vacuum deposition sequence. In certain example embodiments, the
control system 1450 is programmed to restrict the flow in the waste
line 1402 during a period in which the reactive chemical is desired
to be present in the reaction chamber 1430 (for example, during the
precursor vapor pulse period of the precursor in question). During
this time the flow of the precursor chemical or vapor in question
into the waste line 1402 is reduced but not completely stopped to
avoid stagnation.
[0249] The exhaust line 1455 may also have at least one flow
controlling device 5 controlled by the control system 1450. The
reaction chamber in-feed line 1404 may also have at least one flow
controlling device (although not shown in FIG. 17) controlled by
the control system 1450.
[0250] Further embodiments include use of the valve 900, etc.
outside or at least partially outside of the reaction and/or vacuum
chambers 1430 and 1440 as shown in FIG. 18. There can be heated
inlet line(s) extending all the way from a source (not shown) to
the reaction chamber 1430. The line(s) can be heated from the
outside or from the inside, as presented for example in U.S. Pat.
No. 8,741,062 B2. The heated area on the outside of the heated
chambers 1430 and 1440 is denoted by reference numeral 180. Further
the valve 900, etc. located outside of the vacuum chamber 1440 can
have a separate heating in a manner presented in the said prior art
patent publication.
[0251] FIG. 19 shows yet another example embodiment in which a
closure of a pulsing valve is purged. The pulsing valve 900''
comprises a valve body 910 having an inlet 901'' for reactive
chemical, such as a precursor chemical, and an outlet 904'' towards
a reaction chamber (reaction chamber not shown in FIG. 19). A
closure 191 comprised by the pulsing valve 900'' has an open and
closed configuration to open and close, respectively, a route from
the reactive chemical inlet 901'' to the reaction chamber outlet
904''. FIG. 19 shows the closure 191 in its closed
configuration.
[0252] The pulsing valve 900'' further comprises an additional flow
channel outlet to purge the closure. In FIG. 19 is shown a waste
channel outlet 903''. The outlet 903'' is at the same side of the
closure 191 as the reactive chemical inlet 901''. This means that
when the closure is in its closed configuration the inlet 901'' and
outlet 903'' are in fluid communication, but the flow from inlet
901'' and outlet 903'' to the outlet 904'' is prevented (by the
closure 191 that covers an opening separating the two sides of the
valve 900''). The inlet 901'' is in fluid communication with the
outlet 903'' in a similar manner as the inlet 911 was in fluid
communication with the outlet 904 through the curved route
(toroidal shaped flow path) in the embodiment shown in FIGS. 11 and
12.
[0253] In the closed configuration of the closure 191, gas from the
reactive chemical inlet 901'' thus flows to purge the closure 191
(on the reactive chemical side of the opening) on its way from the
reactive chemical inlet 901'' to the waste channel outlet 903'' of
the valve. The flow direction of the purge is along the surface of
the closure.
[0254] The pulsing valve 900'' in certain example embodiments
further comprises a carrier gas inlet 911'' in fluid communication
(via the closure 191) with the reaction chamber outlet 904''. A
flow channel providing the carrier gas inlet 911'' approaches the
closure at an oblique angle taking a turn at the closure and
continuing towards the reaction chamber (and providing the reaction
chamber outlet 904'' of the valve). The channel may therefore be an
L-shaped channel. In a preferred embodiment, the flow from the
pulsing valve to the reaction chamber is unrestricted. The flow
path from the pulsing valve to the reaction chamber is realized
without any intermediate flow restricting elements such as a valve
or a filter.
[0255] When the closure 191 is in its closed configuration, the
closure 191 rests on a closure sealing ring 1905 and closes the
route from the reactive chemical inlet 901'' to the reaction
chamber outlet 904''. The surface of the closure on the carrier gas
inlet and reaction chamber outlet side (of the opening or sealing
ring 1905) is purged by carrier gas (or inactive gas) arriving from
the carrier gas inlet 911''. The closure on the other side of the
opening or sealing ring 1905 (i.e., on the reactive chemical inlet
and waste line outlet side) is purged by reactive and/or carrier
gas as described in the preceding).
[0256] FIG. 20 shows the pulsing valve 900'' with its closure 191
in an open configuration. The reactive chemical flows from the
reactive chemical inlet 901'' to the reaction chamber outlet 904''.
Depending on the embodiment, the reactive chemical is mixed with a
carrier gas (inactive gas) arriving from inlet 911''. In addition,
the reactive chemical itself may be a mixture of reactive chemical
and carrier gas when arriving at the reactive chemical inlet 901''
(which applies to other embodiments as well). A suction into the
waste channel outlet 903'' is maintained to prevent reactive
chemical from stagnating therein. The flow geometry of the reactive
chemical is such that the turn along the route from the reactive
chemical inlet 901'' to the reaction chamber outlet 904'' is less
sharp than the turn along the route from the carrier gas inlet
911'' to the reactive chemical outlet 904'' to provide a minimum
flow barrier for the reactive chemical.
[0257] The waste line beginning at the waste channel outlet 903''
in the embodiments shown in FIGS. 19 and 20 optionally comprises at
least one flow control device 2 to control outgoing flow from the
valve 900''. The at least one flow control device 2 is controlled
by the control system 1450. In certain example embodiments, the
control system 1450 is programmed to allow a precursor chemical to
flow along the waste line via the at least one flow control device
2 during an entire substrate processing cycle or sequence, such as
a vacuum deposition cycle or a vacuum deposition sequence. In
certain example embodiments, the control system 1450 is programmed
to restrict the flow in the waste line during a period in which the
reactive chemical is desired to be present in the reaction chamber
1430 (for example, during the precursor vapor pulse period of the
precursor in question). During this time the flow of the precursor
chemical or vapor in question into the waste line is reduced but
not completely stopped to avoid stagnation.
[0258] In certain implementations, the flow channel providing the
carrier gas inlet 911'' and reaction chamber outlet 904'' is a
larger capacity channel than the flow channels providing the
reactive chemical inlet 901'' and waste line outlet 903''.
[0259] FIG. 21 shows the three-dimensional structure allowing a
toroidal shaped flow path in more detail. The curved route 21a
along the structure from inlet A to outlet B is formed when the
closure (not shown) rests on the sealing ring 1905 (closed
configuration). The route from inlet A via the sealing ring 1905 to
the other side of the ring to outlet C is formed when the closure
moves away from the ring 1905 (open configuration). In certain
example embodiments, the purging route 21a at least partially
extends to a backside of the closure.
[0260] FIG. 22 shows a further design of the pulsing valve of FIGS.
19 and 20, taking advantage of the toroidal shaped flow path shown
in FIG. 21. The flow control device 2 and the control system 1450
has not been drawn in FIG. 22. The presented design differs from
that shown in FIGS. 19 and 20 only in that the sharp angle in the
channel providing the carrier gas inlet 911'' and reaction chamber
outlet 904'' has been replaced by a non-sharp, curved channel. What
has been described concerning FIGS. 19-21 apply to the embodiment
shown in FIG. 22.
[0261] FIG. 22 thus shows a two-dimensional projection of the
pulsing valve of FIG. 21, in which the reactive chemical inlet
901'' corresponds to the inlet A in FIG. 21 and the waste line
outlet 903'' corresponds to the outlet B in FIG. 21,
accordingly.
[0262] The actuating element 1480 moves the closure 191 so that the
closure either seals or opens (broken line) the opening between the
reactive chemical inlet & waste channel outlet side and the
inactive (carrier) gas inlet & reaction chamber outlet side of
the valve. In an embodiment, the valve body 910 is made of metal
and is shown by the striped area in FIG. 22. In the closed
configuration of the closure 191, the gas incoming from the
inactive (carrier) gas inlet 911'' continuously purges the inactive
(carrier) gas inlet & reaction chamber outlet side of the
closure 191 and the gas incoming from the reactive chemical inlet
901'' and having the curved or toroidal flow path on the other side
of the opening purges the closure 191 on the other side of the
opening (i.e., purges the area of the closure 191 around the center
area of the closure 191). The valve body 910 separates the curved
or toroidal flow path from the channel providing the carrier gas
inlet 911'' and reaction chamber outlet 904''. In the open
configuration of the closure 191, in certain example embodiments,
the gas incoming from the reactive chemical inlet 901'' purges the
entire surface of the closure 191 and flows mainly via the reaction
chamber outlet 904'' but also via the waste line outlet 903''. The
purging effect is supplemented by the gas incoming from the
inactive (carrier) gas inlet 911''. Accordingly, presented design
avoids gaps that are not continuously purged.
[0263] In some embodiments, such as depicted in FIGS. 21 and/or 22,
for example, the pulsing valve 100, 300, 900, 900', 900'', 900* is
implemented without non-continuously purged gaps (or "pockets") in
a meaning of the purging being independent of the state of pulsing
valve. Thus, independent of said pulsing valve being open or
closed, all the surfaces in the valve are subjected to the gas
flow.
[0264] In certain example embodiments, instead of the open and
closed configuration of the closure, there are provided an open and
partially closed configuration of the closure to allow open and
partially closed operation as regards the flows flowing via the
valve. In certain example embodiments, there are provided an open,
a partially closed and a closed configuration of the closure.
[0265] FIG. 23 shows yet another embodiment. In this embodiment,
the pulsing valve is not a "pulsing valve" in its conventional
meaning but another flow guiding device. The flow guiding device
2300 is fluidly connected to the reaction chamber accommodating the
substrate to be processed (not shown in FIG. 23). The flow guiding
device comprises a reactive chemical inlet 901'', an outlet towards
the reaction chamber (i.e., a reaction chamber outlet 904''), and a
flow guiding element 991 for routing incoming gas from the reactive
chemical inlet 901'' to the reaction chamber outlet 904'' or to
another outlet 903'' of the device 2300. The flow guiding element
991 in this embodiment is a stationary closure. The flow guiding
element 991 may be a flow divider, such as an edge, positioned at a
position in which the incoming flow from the reactive chemical
inlet 901'' branches into a flow towards different outlets (herein:
outlets 903'' and 904'' at opposite (different) directions). Said
another outlet 903'' may be a waste line outlet. The different flow
directions (and entry of fluid flow into said directions) may be
caused by the shape of the element 991 or by a change in the shape
of the element 991. In some embodiments, the different flow
directions (and entry of fluid flow into said directions) are
caused by pressure differences in a flow channel junction area
within the device 2300. In some embodiments, the different flow
directions (and entry of fluid flow into said directions) are
caused by pressure differences in a junction area where a flow
channel connects the flow channel leading from the carrier gas
inlet 911'' to reaction chamber outlet 904'' and said another
outlet (waste channel outlet) 903''.
[0266] The device 2300 further comprises an inactive or carrier gas
inlet 911''. The flow of inactive or carrier gas from the inlet
911'' towards the reaction chamber outlet 904'' is maintained
during an entire substrate processing cycle or sequence.
[0267] The substrate processing apparatus that comprises the device
2300 also comprises a control system (for example, the control
system 1450). In certain example embodiments, the control system
provides pressure-based control of flow rate from the reactive
chemical inlet 901'' to the reaction chamber outlet 904'' and to
said another outlet 903''. In certain example embodiments, the
control system comprises a pressure changing device (such as a
pump, mass flow controller, etc., not shown) positioned in the
pipeline providing said another outlet 903'' to cause a change in
pressure within the pipeline. Depending on pressure conditions
within the device 2300, gas flowing from the reactive chemical
inlet 901'' flows to the outlet 903'' or 904'' (mixing up with
inactive carrier gas flowing from inlet 911'') or to both outlets
903'' and 904''. In certain example embodiments, if the gas flowing
from the reactive chemical inlet 901'' flows only to the outlet
903'' the gas flowing from the inlet 911'' flows also to the outlet
903'' in addition to flowing to outlet 904''. In that way the
surfaces of the device 2300 are continuously purged (during the
entire substrate processing cycle or sequence). The pressure
conditions within the device are altered by said pressure changing
device and possible other pressure changing devices positioned in
suitable parts of the apparatus.
[0268] FIG. 24 shows a method according to certain example
embodiments of the present disclosure. In step 2401, reactive
chemical is supplied to a reaction chamber via a pulsing valve/flow
guiding device for substrate processing. The supply of reactive
chemical to the reaction chamber is interrupted in step 2402. The
purging of the closure/flow guiding element is continued in step
2403.
[0269] Without limiting the scope and interpretation of the patent
claims, certain further technical effects of one or more of the
example embodiments disclosed herein are listed in the following. A
technical effect is providing valve surfaces having reactive gas
with a continuous purge. This concerns especially those surfaces
which could conduct reactive gas into the direction of the reaction
chamber. A further technical effect is providing a geometry within
a pulsing valve eliminating the formation of non-purged pipeline
portions. A further technical effect is providing a valve
connection or joint between a chemical in-feed line and a main
inactive gas line with no dead space on either side of the
joint/connection. A further technical effect is improving
operational reliability.
[0270] The foregoing description has provided by way of
non-limiting examples of particular implementations and embodiments
of the disclosed embodiments a full and informative description of
the best mode presently contemplated by the inventors for carrying
out the aspects of the disclosed embodiments. It is however clear
to a person skilled in the art that the aspects of the disclosed
embodiments are 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 present disclosure.
[0271] Furthermore, some of the features of the above-disclosed
embodiments of this present disclosure 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 disclosure, and not in limitation
thereof. Hence, the scope of the present disclosure is only
restricted by the appended patent claims.
* * * * *