Plasma source and apparatus for atomic layer deposition

Abstract

A plasma source comprising a plasma deposition head, an electrode plate, and a gas supply system. The plasma deposition head comprises an opening for delivering atmospheric plasma to a substrate and a slot cavity extending from the opening. The electrode plate is mounted in the slot cavity and extends from inside the deposition head towards the opening. The gas supply system comprises a gas inlet, a gas supply chamber, and a gas outlet. The gas supply chamber receives a mass flow of gas from the gas inlet and is arranged to divide the mass flow of gas between the gas outlets. The gas outlets are provided on the opposite side of the electrode plate. In use, the mass flow of gas is divided to provide a flow of atmospheric plasma on the opposite side of the electrode plate.

Description

Technical Field

[0001] The present invention relates to plasma sources and to apparatuses for atomic layer deposition comprising such plasma sources.

Background Art

[0002] Spatial atomic layer deposition (S-ALD) is a thin film growth technique based on the sequential exposure of a substrate to half-reactions. In plasma-enhanced ALD, one of the half-reactions is formed by plasma species.

[0003] To improve plasma source efficiency, it is beneficial to have a uniform mass flow of gas towards the substrate. In a plasma source, gas is supplied through a narrow gap along a high-voltage electrode. The gap is typically defined by the distance between one side of the high-voltage electrode and the opposing wall of a second electrode, and the gap width is set in the range of, for example, 0.05 to 0.25 mm. Typically a ceramic plate, having buried conductors substantially over its entire plate surface, for manufacturing and / or alignment tolerances of the electrodes, the gap width can vary along the length of the gap in the direction of the mass flow of gas which can adversely affect the deposition quality, due to out-of-flatness of the electrode plate. These variations then give rise to regions of higher and lower flow resistance along the gap length, causing variations in the mass flow of gas towards the substrate.

[0004] The uniformity of the mass flow of gas towards the substrate strongly depends on gap width variations. By accurately defining the geometric properties of the gap and the high-voltage electrode during the manufacturing and assembly process, gap width variations can be reduced. However, variations inherent in the manufacturing process, such as flatness and straightness tolerances, can still leave some geometric errors and thus can still be a limiting factor for the efficiency of the plasma source.

[0005] Furthermore, during the operation of the plasma source, the plasma generated within the gap creates a high-temperature environment. Thermal gradients and non-uniform thermal expansion in the components or structure of the plasma source can lead to relative displacement and misalignment of the components. Therefore, during the use of the plasma source, the thermal effects can additionally vary the geometric properties of the gap and thus its resistance to the gas flow, thereby potentially further limiting its efficiency. Summary of the Invention Problems to be Solved by the Invention

[0006] An object of the present invention is to provide a plasma source for, for example, atomic layer deposition, in which the uniformity of the mass flow of gas towards the substrate is improved. Means for Solving the Problems

[0007] In summary, the present invention relates to a plasma source. The plasma source includes a plasma deposition head, an electrode plate, and a gas supply system. The plasma deposition head includes an opening for delivering atmospheric plasma from the deposition head to the substrate, and a slot cavity having parallel walls extending from opposite edges of the opening. The electrode plate is mounted in the slot cavity and extends from the inside of the deposition head towards the opening. The gas supply system includes a gas inlet, a gas supply chamber, and a gas outlet. The gas supply chamber receives the mass flow of gas from the gas inlet and is arranged to divide the mass flow of gas between the gas outlets.

[0008] The gas outlets are provided on the opposite side of the electrode plate, and during use, the mass flow of gas is evenly divided to provide a flow of atmospheric plasma on the opposite side of the electrode plate.

[0009] By dividing the mass flow of gas in the slot cavity between opposite sides of the electrode plate, in addition to the nominal gap width, geometric variations in the gap width along the length of the gap, caused for example by flatness errors of the electrode plate, are reduced. As a result, the uniformity of the mass flow of gas through the gaps on each opposite side of the electrode plate is significantly improved compared to conventional techniques where a single mass flow is passed through a single gap.

[0010] For example, a flatness error of the electrode plate can cause an increase in flow resistance on one side of the electrode plate, but at the same time can cause a decrease in flow resistance on the opposite side of the electrode plate. Therefore, the difference in flow resistance along the slot cavity on one side of the electrode plate can be compensated by counteracting the difference in flow resistance along the slot cavity on the other side of the electrode plate. Having a split flow of atmospheric plasma provided from opposite sides of the electrode plate, as opposed to a single conventional plasma source for the mass flow of gas, provides a net combined flow of atmospheric plasma with a more uniform mass flow that effectively compensates for each other.

[0011] To deliver atmospheric plasma along a certain width of the substrate, the mass flow of gas may be uniformly divided along the width of the plasma source. In such a case, the gas supply chamber preferably extends across opposite sides of the electrode plate along the width of the electrode plate. Accordingly, the mass flow of gas is sent to a large volume provided in front of the slot cavity along the width of the electrode plate, and the slot cavity can function as a flow restrictor, so that the mass flow of gas is uniformly distributed along the width of the electrode plate.

[0012] In some embodiments, the gas supply chamber and the gas outlet are integrated into the plasma deposition head. In this way, the volume and channels that define the flow characteristics of the gas can be controlled during the manufacture of the plasma deposition head, thereby reducing the manufacturing and assembly tolerances of the plasma source.

[0013] To separate functions, the gas supply chamber can comprise a divided volume and a supply volume. The divided volume may be connected to the gas inlet and may extend across the opposite side of the electrode plate. The divided volume is arranged to receive the mass flow of gas from the gas inlet and divide the mass flow of gas between the opposite sides of the electrode plate. The supply volume may be connected to the divided volume and may extend along the width of the electrode plate. The supply volume is arranged to receive the divided mass flow of gas from the divided volume and supply the mass flow of gas uniformly along the width of the electrode plate towards the gas outlet.

[0014] The gas supply system may further comprise a channel portion having a plurality of channels arranged along the width of the electrode plate and connecting the gas supply chambers to respective gas outlets. Each channel of the plurality of channels can be arranged to direct a portion of the mass flow of gas from the gas supply chamber towards the respective gas outlet. Thus, the mass flow of gas along the width of the electrode plate can be controlled, for example, to uniformly divide the mass flow of gas along the width of the electrode. For example, non-uniform mass flow of gas along the width of the electrode plate can be corrected by individually adjusting one or more specific portions of the mass flow of gas through the plurality of channels.

[0015] In some embodiments, the channel portion is provided by a stack of shim plates mounted between the slot cavity wall and the electrode plate. The stack of shim plates may cover the gas supply chamber and the gas outlet, and the plurality of channels can be provided by notches in each shim plate of the stack of shim plates. By using shim plates, the channel portion is highly configurable, for example, by varying the size and shape of the notches, the number of shim plates in the stack, or the thickness of the shim plates. Thus, different configurations of the channel portion can be produced by using different combinations of shim plates that can be manufactured and assembled with high precision, thereby enabling the flow characteristics of the plasma source to be reliably determined.

[0016] To determine the mass flow of gas from the gas supply chamber towards the gas outlet along the width of the electrode plate, the channel portion can be provided with a throttle. The throttle can be provided, for example, in a plurality of channels to cause an increase in the flow resistance acting on a portion of the mass flow of gas guided through one or more of the plurality of channels.

[0017] The throttle can be formed, for example, by reducing the size of one or more notches in the shim plate.

[0018] Alternatively or additionally, the throttle can be formed by reducing the thickness of one or more shim plates.

[0019] In some further embodiments, the gas supply system includes a flow homogenizer disposed between the channel portion and the gas outlet and arranged to evenly distribute the mass flow of gas along the width of the electrode plate. The flow homogenizer may include holes that extend at an acute angle from a plurality of channels into the wall and connect to recesses in the wall that communicate with the slot cavity. The recess may have a homogenizer plane that is substantially perpendicular to the mass flow of gas guided through the holes. When the mass flow of gas hits the homogenizer plane, it is diffused across the homogenizer plane and guided into the slot cavity. Thus, the mass flow of gas is more evenly divided by passing through the flow homogenizer.

[0020] In some preferred embodiments, the plasma deposition head includes a first component that defines a first wall of the slot cavity and a second component that defines a second wall of the slot cavity. The electrode plate may include a mountable portion mounted to the first and / or second component of the plasma deposition head, and a suspendable portion that extends from the mountable portion and is free on all other sides. In this way, the above architecture substantially separates the geometries of the slot cavity and the electrode plate into planar surfaces that are easily accessible by manufacturing tools, so that the mass flow of gas passing along the slot cavity walls and the electrode plate can be determined with relatively high precision.

[0021] The mountable part of the electrode plate can be fixed, for example, between the first and second parts of the plasma deposition head.

[0022] In some variations of these embodiments, a stack of shim plates may be fixed between the first or second part and the electrode plate on each opposite side of the electrode plate. The stack of shim plates may cover the gas supply chamber and the gas outlet. Each shim plate of the stack of shim plates can be provided with a notch, thereby creating a channel structure for guiding the mass flow of gas from the gas supply chamber through the stack of shim plates towards the gas outlet.

[0023] Preferably, each stack of shim plates has a total thickness that defines the respective nominal gap width between the first and second walls of the slot cavity and the opposite side of the electrode plate. Thus, the nominal gap width, and hence the gap width variation, is determined by the thickness of the shim plates that can be managed, for example, by measurement and selection.

[0024] In some embodiments, the plasma deposition head comprises an exhaust system for discharging gas from the substrate, the exhaust system comprising an exhaust port and an exhaust channel integrated with the plasma deposition head, and the exhaust channel extends between the substrate and the exhaust port parallel to the slot cavity on each opposite side of the electrode plate. Thus, after the atmospheric plasma interacts with the substrate, the gas can be discharged through the exhaust channel on either side of the electrode plate, limiting the restraint of the mass flow of gas along the opposite sides of the electrode plate.

[0025] Preferably, the electrode plate comprises a distal edge that is aligned within 3 millimeters of the opposing edge of the opening. In this way, the flow of atmospheric plasma provided on opposite sides of the electrode plate remains substantially on each opposite side of the electrode plate until they are delivered through the opening of the plasma deposition head and interact with the substrate. Therefore, the influence of geometric variations at the end of the slot cavity between the distal edge of the electrode plate and the opposing edge of the opening on the mass flow of gas is limited.

[0026] Preferably, the electrode plate comprises a laminated alumina layer, and a metal electrode is printed on one of the alumina layers. In this manufacturing technique, the flatness of the electrode plate can be limited, whereas the present invention compensates the difference in flow resistance along the slot cavity on one side of the electrode plate with the difference in flow resistance along the slot cavity on the other side of the electrode plate, thereby enabling the use of these types of electrode plates in a plasma source regardless of geometric variations along the electrode plate.

[0027] The plasma deposition head can be made of a conductive material such as, for example, metal. Thus, the plasma deposition head, specifically the wall of the slot cavity, can form a counter electrode with respect to the flat plate electrode for generating atmospheric plasma in the slot cavity.

[0028] Another aspect of the present invention relates to an apparatus for atomic layer deposition comprising a plasma source as described herein.

[0029] The apparatus may further comprise a transfer mechanism arranged to transfer the substrate and the plasma source relative to each other parallel to the plane of the substrate. Thus, the atmospheric plasma delivered from the plasma source can interact with the substrate region as it is transferred parallel to the plane of the substrate.

[0030] The present invention will be further described in the figures.

Brief Description of the Drawings

[0031]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Best Mode for Carrying Out the Invention

[0032] The present invention will be described more fully hereinafter with reference to the accompanying drawings in which embodiments of the invention are shown. In the drawings, the absolute and relative dimensions of systems, components, layers and regions may be exaggerated for clarity. Embodiments may be described with reference to schematic and / or cross-sectional views of ideal and / or intermediate structures as possible embodiments of the invention. In the description and the drawings, like numerals refer to like elements throughout. In addition to relative terms, their derivatives should be construed to refer to the orientation as described at that point in the description or as illustrated in the drawings. These relative terms are for convenience of description and do not require that the system be constructed or operate in a particular orientation unless otherwise specified.

[0033] FIG. 1 illustrates a plasma source 100 and includes a plasma deposition head 110 having an opening 111 for delivering atmospheric plasma from the deposition head 110 to a substrate 50. The plasma deposition head can be made of, for example, a conductive material, such as a metal like steel or an aluminum alloy. The plasma deposition head 110 includes a slot cavity 112 having parallel walls 113-1, 113-2 extending from opposing edges of the opening 111. The plasma deposition head 110 can be manufactured, for example, as a single piece in which the slot cavity 112 is formed by, for example, milling, EDM or other suitable material removal processes. Alternatively, the plasma deposition head 110 can be composed of a plurality of sub-components that form the slot cavity 112 in an assembled state.

[0034] An electrode plate 120 is mounted in the slot cavity 112 and extends from the interior of the deposition head 110 toward the opening 111. The electrode plate 120 can include, for example, a metal electrode whose sides are coated with a dielectric layer. For example, the electrode plate 120 may be a ceramic plate with a metal conductor embedded therein and extending beneath the surface of the ceramic plate. Alternatively, it may include a laminated alumina layer and the metal electrode may be printed on one of the alumina layers.

[0035] The plasma source 100 further includes a gas supply system 130 having a gas inlet 131, a gas supply chamber 132, and a gas outlet 133. The gas supply chamber 132 is arranged to receive the gas mass flow M from the gas inlet 131 and divide the gas mass flow between the gas outlets 133, for example, into mass flows M1 and M2. As illustrated in FIG. 1, the electrode plate 120 is mounted in the slot cavity such that the gas outlet 133 is provided on the opposite side of the electrode plate 120, extends from the inside of the deposition head towards the opening, and effectively creates two slots 112-1 and 112-2 that output plasma flows M1* and M2* respectively after the corresponding gas flows M1 and M2 are guided along the opposite side of the plate 120. By freely suspending both electrode surfaces in the slot cavity to mount the electrodes, the deviation from flatness of one side of the electrode plate in one direction towards one slot wall 113 leads to a constriction increase along the electrode surface and a corresponding decrease in the plasma flow, but can be compensated on the opposite surface thereof towards the opposing slot wall 113, which has a corresponding constriction decrease, effectively compensating each other. As a result, at the opening 111, the decrease in plasma output in one slot 112-1 is compensated by the corresponding slot 112-2 facing the electrode plate.

[0036] As illustrated in FIG. 1, the electrode plate 120 includes a distal edge 121 that may be aligned with the opposing edge of the opening 111, so that the gas mass flows M1 and M2 through the slot cavity remain substantially separated by the electrode plate 120 until they exit the opening 111. Preferably, the alignment between the opposing edge of the opening 111 and the distal edge 121 of the electrode plate 120 is within 3 millimeters, for example, between 0 and 2 millimeters, more preferably between 0 and 1 millimeter.

[0037] Figure 2 illustrates an embodiment of the plasma source 100, and a gas supply system 130, such as a gas inlet 131, a gas supply chamber 132 and / or a gas outlet 133, is integrated into the plasma deposition head 110. These structures can be provided, for example, by manufacturing holes, pockets, recesses or channels in the wall structure of the plasma deposition head 110. For example, the gas outlet 133 can be formed by an array of holes or by grooves or slits extending into the wall of the slot cavity 112. The array, grooves or slits may be arranged along the width W of the electrode plate 120 to uniformly divide the mass flow of the exhaust gas along the width of the electrode plate.

[0038] For the same reason, as illustrated in Figure 2, the gas supply chamber 132 may extend across the opposite side of the electrode plate 120 along the width W of the electrode plate 120. The electrode plate 120 may penetrate the gas supply chamber 132, and one or more holes or notches may be provided in the electrode plate 120 inside the gas supply chamber 132 to allow the gas to pass from one side of the electrode plate 120 to the other side.

[0039] The plasma deposition head 110 may further include an exhaust system 140 for discharging gas from the substrate. The exhaust system 140 includes, for example, an exhaust port 141 integrated into the plasma deposition head 110 and one or more exhaust channels 142. As illustrated in Figure 2, the exhaust channel 142 extends between the substrate and the exhaust port parallel to the slot cavity 112.

[0040] Figures 3 and 4 illustrate an exemplary embodiment of the plasma source 100, where the plasma deposition head 110 includes a first component 114 that defines a first wall 113-1 of the slot cavity and a second component 115 that defines a second wall 113-2 of the slot cavity. The electrode plate 120 includes a mountable portion 122 that is mounted to the first and / or second components 114, 115 of the plasma deposition head. For example, the mountable portion can be fixed between the first and second components 114, 115 of the plasma deposition head 110. The electrode plate 120 further includes a suspendable portion 123 that extends from the mountable portion 122 and is free on all other sides.

[0041] On each opposite side of the electrode plate 120, a stack of shim plates 150 is fixed between the first or second component 114, 115 and the electrode plate 120. The stack of shim plates 150 can include, for example, two or more shim plates, and the shim plates can have equal or different thicknesses. As shown in FIGS. 3 and 4, the stack of shim plates 150 covers the gas supply chamber 132 and the gas outlet 133, and each shim plate of the stack of shim plates is provided with a notch 134, thereby creating a channel structure for guiding the mass flow of gas from the gas supply chamber 132 through the stack of shim plates 150 towards the gas outlet 133.

[0042] The total thickness of each stack of shim plates 150 can be used to define the respective nominal gap widths between the first and second walls 113-1, 113-2 of the slot cavity and the opposite sides of the electrode plate 120. Therefore, by varying the number of shim plates and / or by varying the thicknesses of the individual shim plates, the mass flow of gas along each opposite side of the electrode plate 120 can be determined.

[0043] As illustrated in FIGS. 3 and 4, the function of the gas supply system can be further separated by providing the gas supply chamber 132 with a divided volume 135 and a supply volume 136. The divided volume 135 can be connected to the gas inlet 131 and may extend across the opposite side of the electrode plate 120. Thus, the divided volume 135 is arranged to receive the gas mass flow M from the gas inlet 131 and to divide the gas mass flow M into divided gas mass flows M1, M2 between the opposite sides of the electrode plate 120.

[0044] The supply volume 136 can be connected to the divided volume 135 and may extend along the width W of the electrode plate 120. Thus, the supply volume 136 is arranged to receive the divided gas mass flows M1, M2 from the divided volume 135 and to uniformly supply the divided gas mass flow along the width W of the electrode plate 120 towards the gas outlet 133.

[0045] The divided volume 135 and the supply volume 136 may be formed by, for example, one or more recesses in the plasma deposition head 110. For example, as illustrated in FIG. 3, the divided volume 135 may comprise a first part and a second part, and the gas mass flow passes, for example, through the stack of shims 150 and the passages in the electrode plate 120 from the first part in the first component 114 to the first part in the second component 115, then from the first part in the second component 115 to the second part in the second component 115, and then, for example, through another or the same passages in the stack of shims 150 and the electrode plate 120, from the second part in the second component 115 to the second part in the first component 114. Thus, the gas mass flow can be divided across the opposite sides of the electrode plate 120.

[0046] The supply volume 136 may, for example, as illustrated in FIG. 3, comprise first and second branches respectively connected to the first and second parts of the divided volume 135. In this way, the gas mass flow can be evenly distributed along the width W of the electrode plate 120.

[0047] The gas supply system 130 may further include a channel portion 137 having a plurality of channels 138 arranged, for example, along the width W of the electrode plate 120. The plurality of channels 138 can be arranged, for example, to connect the gas supply chamber 132 to respective gas outlets 133, and each channel of the plurality of channels 138 is arranged to direct a portion of the split mass flows M1, M2 of the gas from the gas supply chamber 132 towards the respective gas outlets 133.

[0048] As illustrated in FIGS. 3 and 4, the channel portion 137 can be provided by a stack of shim plates 150 described herein that are mounted between the slot cavity walls 113-1, 113-2 and the electrode plate 120.

[0049] The channel portion 137 may include a throttle 151 arranged to increase the flow resistance in order to determine the split mass flows M1, M2 of the gas from the gas supply chamber 132 towards the gas outlets 133 along the width W of the electrode plate 120. The throttle 151 can be formed, for example, by reducing the size of one or more notches in the shim plate and / or by reducing the thickness of one or more shim plates.

[0050] As illustrated in FIGS. 3 and 4, the gas supply system 130 may further include a flow homogenizer 139 installed between the channel portion 137 and the gas outlets 133 and arranged to evenly distribute the split mass flows M1, M2 of the gas along the width W of the electrode plate 120. The flow homogenizer 139 can include, for example, holes 139-1 that extend at an acute angle from the plurality of channels 138 into the walls 113-1, 113-2 and connect to recesses 139-2 in the walls 113-1, 113-2 that communicate with the slot cavity. The recess 139-2 may include a homogenizer plane 139-3 that is directed substantially perpendicular to the split mass flows M1, M2 of the gas conducted through the holes 139-1.

[0051] FIG. 5 shows an embodiment of an apparatus 500 for atomic layer deposition comprising a plasma source 100 described herein. In addition to the plasma source, the apparatus 500 may further comprise, for example, a system for delivering a medium and / or catalyst to a substrate, such as nitrogen or a metal organic precursor, and a system for exhausting gases and materials from the substrate 50.

[0052] The apparatus 500 may further comprise a transfer mechanism 550 arranged to transfer the substrate 50 and the plasma source 100 relative to each other parallel to the plane P of the substrate 50. For example, the transfer mechanism 550 can be arranged to transfer the substrate 50, for example along the plane P, while the plasma source 100 is stationary. Alternatively, the substrate 50 may be kept stationary while the transfer mechanism 550 is arranged to transfer the plasma source 100 parallel to the plane P.

[0053] It is believed that the operation and structure of the present invention will be apparent from the above description and the accompanying drawings. For the purposes of clarity and concise description, features are described herein as part of the same or separate embodiments, however, it will be recognized that the scope of the present invention may include embodiments having combinations of all or some of the described features.

[0054] The present invention applies not only to manufacturing applications where a plasma source is used for atomic layer deposition, but also to other technical, industrial or diagnostic applications where a plasma source is used. It will be apparent to those skilled in the art that the present invention is not limited to any of the embodiments described herein and that modifications considered to be within the scope of the appended claims are possible. Kinematic inversion is also considered to be essentially disclosed and can be within the scope of the present invention. In the claims, any reference signs shall not be construed as limiting the claims.

[0055] As used in the specification and claims of this application, the term "lamination" refers to the result of any technique or process for manufacturing a multi-layer material, such that the composite material achieves improved strength, stability, sound insulation, appearance, or other properties from the use of different materials. A laminated component or laminate is defined herein as a permanently assembled object created, for example, using heat, pressure, electricity, welding, or adhesives. Various materials, techniques, and equipment may be used to provide the laminate. The present invention is not limited to electrode plates having a lamination of alumina, but may comprise any other dielectric material suitable for use in a plasma source, such as glass, quartz, ceramics (e.g., alumina or zirconium dioxide), polymers, or combinations thereof. For example, a simultaneous firing ceramic laminate may be manufactured by applying electrodes to a stack of layers, for example comprising a layer containing a dielectric material such as alumina or zirconium dioxide and one or more layers containing an organic binder material, and then heating the stack to form a composite material.

[0056] The terms "comprising" and "including", as used in this description or the appended claims, should be construed in an inclusive sense rather than an exclusive or exhaustive sense. Thus, expressions such as "including" or "comprising" as used herein do not preclude the presence of other elements, additional structures, or additional acts or steps in addition to those listed. Further, the words "a" and "an" are not to be construed as limited to "only one", but rather are used to mean "at least one" and do not exclude a plurality. Features that are not specifically or explicitly described or claimed may additionally be included in the structure of the present invention without departing from its scope.

[0057] Expressions such as "means for..." should be read as "components configured for..." or "members constructed as...", and should be interpreted to include equivalents to the disclosed structures. The use of expressions such as "important", "suitable", "particularly suitable", etc. is not intended to limit the present invention. As long as structures, materials, or acts are considered essential, they are shown as such without expression. Additions, deletions, and modifications within the scope of those skilled in the art can generally be made without departing from the scope of the present invention defined by the claims.

Explanation of Reference Numerals

[0058] 50 Substrate 100 Plasma source 110 Plasma deposition head 111 Opening 112 Slot cavity 112-1, 112-2 Slots 113-1, 113-2 Parallel walls 114 First component 115 Second component 120 Electrode plate 121 Distal edge 122 Mountable part 123 Hangable part 130 Gas supply system 131 Gas inlet 132 Gas supply chamber 133 Gas outlet 134 Notch 135 Divided volume 136 Supply volume 137 Channel part 138 Channel 139 Flow homogenizer 139-1 Hole part 139-2 Concave part 139-3 Homogenizer plane 140 Exhaust system 141 Exhaust port 142 Exhaust channel 150 Shim plate 151 Throttle Apparatus for Atomic Layer Deposition Transfer Mechanism Mass Flow of Gases M, M1, M2 Plasma Flows M1*, M2*

Claims

1. - A plasma deposition head, comprising a slot cavity having an opening for delivering atmospheric plasma from the plasma deposition head to a substrate and parallel walls extending from opposing edges of the opening; - An electrode plate mounted in the slot cavity and extending from inside the plasma deposition head toward the opening; - A gas supply system comprising a gas inlet, a gas supply chamber, and a gas outlet, the gas supply chamber being arranged to receive a mass flow of gas from the gas inlet and divide the mass flow of gas between the gas outlets; comprising wherein the gas outlet is provided on the opposite side of the electrode plate, and during use, the mass flow of gas is divided to provide a flow of atmospheric plasma on the opposite side of the electrode plate. A plasma source.

2. The plasma source according to claim 1, wherein the gas supply chamber extends along the width of the electrode plate across the opposite side of the electrode plate.

3. The plasma source according to claim 1 or 2, wherein the gas supply chamber and the gas outlet are integrated with the plasma deposition head.

4. The gas supply chamber is - A divided volume connected to the gas inlet and extending across the opposite side of the electrode plate, the divided volume being arranged to receive a mass flow of gas from the gas inlet and divide the mass flow of gas between the opposite sides of the electrode plate; - A supply volume connected to the divided volume and extending along the width of the electrode plate, the supply volume being arranged to receive a divided mass flow of gas from the divided volume and supply the mass flow of gas uniformly along the width of the electrode plate toward the gas outlet; The plasma source according to any one of claims 1 to 3, comprising.

5. The plasma source according to claim 4, wherein the supply volume comprises a channel portion arranged along the width of the electrode plate and having a plurality of channels connecting the gas supply chamber to respective gas outlets, each channel of the plurality of channels being arranged to direct a portion of the mass flow of gas from the gas supply chamber toward a respective gas outlet.

6. The channel part is provided by a stack of shim plates mounted between the wall of the slot cavity and the electrode plate, the stack of shim plates covering the gas supply chamber and the gas outlet, and the plurality of channels being provided by notches in each shim plate of the stack of shim plates. The plasma source according to claim 5.

7. The plasma source according to claim 5 or 6, wherein the channel part comprises a throttle to determine the mass flow of the gas from the gas supply chamber towards the gas outlet along the width of the electrode plate.

8. The plasma source according to claim 7, wherein the throttle is formed by reducing the size of one or more notches in the shim plate.

9. The plasma source according to claim 7 or 8, wherein the throttle is formed by reducing the thickness of one or more shim plates.

10. The gas supply system comprises a flow homogenizer arranged to evenly distribute the mass flow of the gas along the width of the electrode plate, the flow homogenizer extending at an acute angle from the plurality of channels into the wall and having a hole connecting to a recess in the wall communicating with the slot cavity, the recess having a homogenizer plane oriented substantially perpendicular to the mass flow of the gas conducted through the hole. The plasma source according to any one of claims 5 to 9.

11. The plasma deposition head comprises a first component defining a first wall of the slot cavity and a second component defining a second wall of the slot cavity, the electrode plate having a mountable part mounted on the first and / or second component of the plasma deposition head and a suspendable part extending from the mountable part and being free on all other sides. The plasma source according to any one of claims 1 to 10.

12. The plasma source according to claim 11, wherein the mountable part is fixed between the first and second components of the plasma deposition head.

13. On each opposite side of the electrode plate, a stack of shim plates is fixed between the first or second component and the electrode plate, the stack of shim plates covers the gas supply chamber and the gas outlet, and each shim plate of the stack of shim plates is provided with a notch, thereby creating a channel structure for guiding the mass flow of the gas from the gas supply chamber through the stack of shim plates towards the gas outlet. The plasma source according to claim 11 or 12.

14. The plasma source according to claim 13, wherein the stack of shim plates has a total thickness that defines a respective nominal gap width between the first and second walls of the slot cavity and the opposite side of the electrode plate.

15. The plasma source according to any one of claims 1 to 14, wherein the plasma deposition head comprises an exhaust port integrated with the plasma deposition head and one or more exhaust channels, and an exhaust system for discharging gas from the substrate, and the exhaust channels extend between the substrate and the exhaust port parallel to the slot cavity.

16. The plasma source according to any one of claims 1 to 15, wherein the electrode plate comprises a distal edge that is aligned within 3 millimeters of the opposing edge of the opening.

17. The plasma source according to any one of claims 1 to 16, wherein the electrode plate comprises a laminated alumina layer, and a metal electrode is printed on one of the laminated alumina layers.

18. The plasma source according to any one of claims 1 to 17, wherein the plasma deposition head is made of a conductive material.

19. An apparatus for atomic layer deposition, comprising the plasma source according to any one of claims 1 to 18.

20. The apparatus according to claim 19, further comprising a transfer mechanism arranged to transfer the substrate and the plasma source relative to each other parallel to the plane of the substrate.

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