A method and apparatus for atomic layer deposition on a substrate

Abstract

A method and apparatus for atomic layer deposition on a substrate. The method comprises providing the substrate. The method comprises a layer forming step. The layer forming step comprises supplying a precursor to a surface of the substrate. The layer forming step comprises supplying a co-reactant to the surface of the substrate. The co-reactant is a combination of ozone and water vapour. The water vapour and ozone of the co-reactant are supplied to the substrate surface simultaneously. Depositing an atomic layer on the surface of the substrate upon interaction between the substrate surface, the precursor and the co-reactant.

Description

[0001] Title: A method and apparatus for atomic layer deposition on a substrate

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to the field of atomic layer deposition. In particular, the invention relates to the field of atomic layer deposition on a substrate. More in particular, the invention relates to a method for atomic layer deposition on a substrate and an apparatus for atomic layer deposition on a substrate.

[0004] BACKGROUND

[0005] Atomic Layer Deposition, ALD, is a key process in e.g. fabricating semiconductor devices and / or surface layers such as dielectric layers, semi- conductive, conductive and various types of metal layers, and part of the set of tools for synthesizing nanomaterials. ALD is a thin-film deposition technique based on the sequential use of a gas-phase chemical process. It is common in ALD reactions to use two chemicals referred to as “precursors”, that are sometimes referred to as “reactants” instead. These precursors in gas form are admitted separately into the reactor in alternate pulses. The precursors react with the surface of a substrate material one at a time in a sequential manner. Each precursor chemisorbs individually onto the substrate, rather than reacting in the gas phase. Gas-phase reactions are avoided by purging with inert gas between each precursor pulse. In addition, the mixing of the two precursors is avoided, as each of the precursors is supplied to the substrate sequentially in a separate pulse.

[0006] An ALD process can be combined with a subsequent further chemical process. An example of the application of ALD in combination with subsequent treatment by another chemical is disclosed in Johnson et al. (December 2023), Improving the barrier properties of tin oxide in metal halide perovskite solar cells using ozone to enhance nucleation, Joule 7, 2873-2893, 2023 Elsevier Inc. In said article, a plurality of layers of tin oxide is deposited using ALD, followed by a step of treating the resulting plurality of tin oxide layers with ozone, and a subsequent depositing of a second plurality of tin oxide layers. A thin film layer of material such as aluminum oxide, silicon oxide and / or other material is formed on the substrate. This process can be alternatingly repeated in order to deposit a thin film layer uniformly across the substrate material through repeated exposure to separate precursors.

[0007] Under ideal saturated reaction conditions, substrate-precursor reactions are self-limiting and the surface is saturated with precursor fragments at the end of each pulse. Ligands in the fragments are eliminated by reaction with the other precursor during the next pulse, which is sometimes referred to as “ligand exchange”. As the growth reactions occur only at the surface, deposition is relatively slow, however it allows for atomic-level control of film thickness and a relatively high degree of uniformity of the layer characteristics across the substrate.

[0008] Each single deposited atomic layer of deposited material on the substrate requires the supply of a certain amount of precursor material. In saturated reaction conditions, at the end of a pulse some precursor molecules are left over once the surface is saturated with precursor fragments. The excess precursor molecules are removed from the substrate surface by purging with an inert gas. Due to the removal of excess precursor molecules, such ALD reactions under saturated reaction conditions are costly, unsustainable and inefficient.

[0009] SUMMARY

[0010] It is an object to provide a method for atomic layer deposition on a substrate and an apparatus for atomic layer deposition on a substrate. More in general, it is an object to provide an improved method and / or apparatus for atomic layer deposition on a substrate.

[0011] Thereto, according to a first aspect is provided a method for atomic layer deposition on a substrate. The substrate can comprise a planar or curved surface. The method comprises providing the substrate. The substrate can be held on a receptacle. The receptacle can be positioned in a reaction chamber during processing thereof. The method comprises a layer forming step. The layer forming step comprises supplying a precursor to a surface of the substrate. The precursor can be supplied to the surface of the substrate by a precursor supply unit. The layer forming step comprises supplying a co-reactant to the surface of the substrate. The co-reactant can be supplied to the substrate by a co-reactant supply unit. The coreactant is a combination of ozone and water vapour. The ozone can be supplied to the substrate by a ozone supply unit, and / or the water vapour can be supplied to the substrate by a water vapour supply unit. The water vapour and ozone of the co-reactant are supplied to the substrate surface simultaneously. The water vapour and the ozone can be directed at the same portion of the substrate surface upon supply of the co-reactant to the substrate. The water vapour and the ozone can be supplied to the substrate simultaneously during a predetermined period in time. The water vapour and the ozone can therefore be mixed so as to exist at or near the substrate surface at the same moment in time. The layer forming step results in depositing an atomic layer on the surface of the substrate upon interaction between the substrate surface, the precursor and the co-reactant.

[0012] The atomic layer can be deposited on the surface of the substrate using Atomic Layer Deposition, ALD. The precursor and / or co-reactant supply units can be configured for, in use, enabling reaction between the substrate surface, the precursor and the co-reactant. The reaction can comprise a chemical reaction and / or the reaction can comprise establishing an atomic and / or covalent bond. The method can further comprise additional layer forming steps for depositing multiple atomic layers on top of each other on the substrate, wherein at least one atomic layer can comprise a different material composition than the material of the other ones of the deposited atomic layers. In order to obtain this different material composition, a further precursor and / or further co-reactant can be supplied to the substrate surface from one or more further material supply units.

[0013] Without wishing to be bound by any theory, experiments with trimethylaluminum, TMA, as a, i.a. metalorganic, precursor have suggested that the surface reaction between ozone and the ligands of TMA can be seen as a complex multi-step surface reaction scheme involving the formation of formate, e.g. HCO-2, and carbonate groups, e.g. CCL2-. From Density-functional theory, DFT, calculations two different types of reaction mechanisms are proposed. A first type of reaction mechanism involves Oxygen atom, O, insertion of the ozone, O3, in the Carbon-Hydrogen atom, C-H, bond of the TMA after reaction with the substrate. The second type of mechanism involves O insertion in the Aluminum- Carbon atom, Al-C, bond of the TMA after reaction with the substrate, thereby forming a methoxy group, CH3O. In any of the types of reaction mechanisms the formation of an -Oxygen-Hydrogen atom, -OH, terminated surface by ozone, O3, oxidation would require the reaction of two neighboring methyl groups, CH3, forming a pair of methoxy groups, CH3O, which can then lead to the formation of formate, e.g. HCO-2, and / or carbonate groups, e.g. COs2-.

[0014] In addition, said experiments suggest that, despite the observed higher reactivity of O3 compared to H2O, in reaction with TMA on the substrate, the formation of an -OH terminated surface takes relatively more time than experiments using H2O as a co-reactant reaction only, due to the probability of O insertion at two neighboring methyl groups and the subsequent methoxy, formate, carbonate to hydroxyl formation. This overall process is believed to be more time consuming than the relatively simple (and single) ligand exchange reaction of the -CH3 with H2O forming the OH group and gaseous CH4. It is apparent from the experiments that in all types of O3 oxidation schemes the formation of an intermediate hydroxyl group, e.g. -OH, is part of the neighbor “pair” interaction.

[0015] On the other hand, in reactions not according to the invention of TMA with only H2O as a co-reactant, and without ozone as a co-reactant, the reaction rates at low temperatures were found to be significantly decreased. Hence, by supplying both H2O and O3 simultaneously as co-reactants to the TMA chemisorbed on the substrate, the formation of OH groups can be significantly enhanced. This is believed to be because the H2O can form an -OH site forming a reaction pair with a methoxy group in any of the intermediate O3 reaction steps. The observed result is that simultaneous co-dosing of water vapour and ozone to TMA chemisorbed on the substrate causes the Growth Per Cycle, GPC, to be higher than in a similar experiment with only one of water vapour and ozone as a coreactant. In addition, it was experimentally derived that simultaneously co-dosing of water vapour and ozone to TMA chemisorbed on the substrate yields a higher deposition rate of a single co-reactant dosing step compared to a similar experiment with only one of water vapour and ozone as a co-reactant. It has furthermore been derived that a process of dosing only water vapour to TMA chemisorbed on the substrate, i.e. a reaction not according to the invention, yields a lower quality atomic layer on the substrate surface than the process of simultaneously co-dosing water vapour and ozone to TMA chemisorbed on the substrate in a single co-reactant dosing step. It has been derived that the atomic layer formed by dosing water vapour only has a lower degree of crystallinity, a higher number of hydroxyl groups, a higher defect state density, and a lower smoothness compared to the atomic layer formed by simultaneously co-dosing water vapour and ozone to the substrate. In such atomic layer deposited on the substrate surface dosing only water vapour to TMA, hydroxyl groups act as chemical impurities that degrade the dielectric quality and introduce losses in Near Infrared, NIR, wavelengths in an aluminum oxide, A12O3, deposited atomic layer.

[0016] Experiments with other precursor types, such as nickel and indium types of precursors, where H2O as a co-reactant is not reactive, also show enhanced film growth per cycle when simultaneously co-dosing O3 and H2O vapour with respect to using only O3 as a co-reactant. Precursor types having an amide complex, such as a precursor with an azanide anion, NH2“, upon being used in a similar experiment with simultaneous co-reactant dosing of O3 and H2O, allow for adjusting material characteristics that are inherent with the resultant product of interaction between said precursor, the substrate surface and the co-reactant. Determining the desired precursor type for use in the method of atomic layer deposition therefore has the advantage that certain material characteristics can be controlled.

[0017] Optionally, the water vapour and ozone of the co-reactant are supplied to the substrate surface through a same co-reactant supply nozzle. The co-reactant supply nozzle can be in fluid communication with the water vapour supply unit and the ozone supply unit. The co-reactant supply nozzle can be configured to direct the water vapour and the ozone at the same portion of the substrate surface upon supply of the co-reactant to the substrate. The ozone and water vapour may be pre-mixed prior to supply of the co-reactant to the supply nozzle. The pre-mixing can e.g. occur at the entrance of a supply line supplying the co-reactant to the supply nozzle. Optionally, the ratio between the amount of water vapour and ozone of the co-reactant is between 1:1000 and 1:1. Preferably, the ratio between the amount of water vapour and ozone of the co-reactant is between 1:500 and 1:4, more preferably, the ratio is between 1:200 and 1:4, such as between 1:125 and 1:5. The amount of supplied water vapour can be lower than, equal to, or higher than the amount of supplied ozone. Alternatively, or additionally, the partial pressure of water vapour is e.g. between 5-200 Pa, such as between 10-50 Pa, and the partial pressure of ozone is e.g. between 1000-5000 Pa, such as between 1500 and 4000 Pa.

[0018] It has been found that a too high partial pressure of the water vapour may lead to undesired condensation. As such, to prevent condensation or at least reduce a risk of condensation, it is preferred that the partial pressure of the water vapour is below 1200 Pa, preferably below 1000 Pa, below 800 Pa, below 600 Pa or even below 400 Pa.

[0019] The ratio between the amount of water vapour and ozone of the coreactant supplied to the substrate can be constant over time or can vary over time. When the ratio between the amount of water vapour and ozone varies over time, the relative amount of ozone can increase or decrease. It is also possible that the absolute amount of ozone and / or water vapour varies over time. When the ratio between the amount of water vapour and ozone is varied over time, material can be deposited providing a gradient in material properties of the deposited material.

[0020] Optionally, the precursor is arranged to, upon being supplied to the surface of the substrate, interact with the surface of the substrate such that a first surface product on the substrate is formed. The co-reactant can be arranged to, upon being supplied to the surface of the substrate, interact with the first surface product on the substrate such that the atomic layer on the surface of the substrate is formed. The interaction of the precursor and the surface of the substrate can comprise a first reaction therebetween, causing the first surface product to be formed on the substrate surface. The interaction of the co-reactant and the first surface product can comprise a second reaction therebetween, causing the atomic layer to be formed on the substrate surface. Each one of the first and second reactions can comprise at least one of a chemical reaction and establishing an atomic bond.

[0021] Optionally, the ozone interacts with the first surface product in a first way upon being supplied to the surface of the substrate such that a second surface product on the substrate is formed. The water vapour can interact with the first surface product and / or the second surface product on the substrate in a second way upon being supplied to the surface of the substrate. The interaction of the ozone and the first surface product can comprise a third reaction therebetween, causing the second surface product to be formed on the substrate surface. The interaction of the water vapour and the first and / or second surface product can comprise one or more fourth reactions therebetween, causing the atomic layer and / or a third surface product to be formed on the substrate surface. Each one of the third and fourth reactions can comprise a chemical reaction, establishing an atomic bond and / or a ligand exchange.

[0022] Alternatively or additionally, the water vapour can interact with the first surface product in a third way upon being supplied to the surface of the substrate such that a second surface product on the substrate is formed. The ozone can interact with the first surface product and / or the second surface product on the substrate in a fourth way upon being supplied to the surface of the substrate. The interaction of the water vapour and the first surface product can comprise a fifth reaction therebetween, causing the second surface product to be formed on the substrate surface. The interaction of the ozone and the first and / or second surface product can comprise one or more sixth reactions therebetween, causing the atomic layer and / or a fourth surface product to be formed on the substrate surface. Each one of the fifth and sixth reactions can comprise a chemical reaction, establishing an atomic bond and / or a ligand exchange.

[0023] Optionally, the precursor is supplied to the substrate surface prior to supplying the co-reactant to the substrate surface. Alternatively, the co-reactant is supplied to the substrate surface prior to supplying the precursor to the substrate surface. The precursor and the co-reactant can be supplied to the substrate one at a time. The precursor and the co-reactant can be supplied to the substrate one at a time during a predetermined period in time. Optionally, the layer forming step comprises supplying the precursor and the co-reactant to the substrate surface consecutively with an intervening first purge step comprising supplying a portion of a purging gas to the surface of the substrate. The purging gas can be arranged to, upon being supplied to the surface of the substrate, purge non-adsorbed particles from the surface of the substrate.

[0024] Optionally, the method further comprises a second purge step comprising supplying a further portion of the purging gas to the surface of the substrate after the step of depositing the atomic layer, such as after supplying both the ozone and the water vapour. The purging gas can be arranged to, upon being supplied to the surface of the substrate, purge non-adsorbed particles from the surface of the substrate.

[0025] Optionally, the method comprises alternatingly repeating the layer forming step and the second purge step. The method can be repeated multiple times to deposit multiple atomic layers on top of each on the substrate, such that a desired local and / or overall layer thickness can be reached.

[0026] Optionally, the method is performed at a temperature lower than or equal to 150 degrees Celsius. The methodis preferably performed at a temperature lower than or equal to 100 degrees Celsius , e.g. for deposition of AI2O3 such as at about 75 degrees Celsius.

[0027] Optionally, the amount of precursor supplied to the substrate surface during a single layer forming step is less than the amount required to saturate the surface of the substrate with the precursor. This allows for reaction conditions at the substrate surface wherein the amount of precursor is unsaturated.

[0028] Optionally, the amount of ozone supplied to the substrate surface during a single layer forming step is less than the amount required for saturated surface reaction. The amount of water vapour supplied to the substrate surface during the single layer forming step can be sufficient to complete saturated surface reaction. This allows for saturated reaction conditions at the substrate surface while the amount of ozone by itself is insufficient for saturated reaction conditions.

[0029] Optionally, the amount of water vapour supplied to the substrate surface during a single layer forming step is less than the amount required for saturated surface reaction. The amount of ozone supplied to the substrate surface during the single layer forming step can be sufficient to complete saturated surface reaction. This allows for saturated reaction conditions at the substrate surface while the amount of water vapour by itself is insufficient for saturated reaction conditions.

[0030] Optionally, the precursor is a metal-organic precursor. Alternatively or additionally, the precursor can comprise a halide, alkoxide, R-diketonate, organometallic, organometallic cyclopentadienyl-type compound or amido complex. An example of a metal-organic precursor is trimethylaluminum.

[0031] Any method for atomic layer deposition on a substrate of the present disclosure may be performed at atmospheric pressure. At atmospheric pressure may be understood as at a pressure which is not actively altered, in particular actively reduced, for example by a vacuum pump. Depending on weather and altitude, atmospheric pressure may generally be approximately 1 atm. It will thus be appreciated that the substrate is preferably held at atmospheric pressure. Preferably, the method is performed at a temperature lower than 100 degrees Celsius, or at least lower than 150 degrees Celsius.

[0032] In a preferred embodiment of the method, the method is performed at atmospheric pressure, at a temperature lower than 150 degrees Celsius and with the ratio between the amount of water vapour and ozone of the co-reactant between 1:1000 and 1:1. Furthermore, preferably, the precursor used is trimethylaluminum.

[0033] In general, the present disclosure contemplates using spatial atomic layer deposition, in which the precursor and the co-reactant may be supplied continuously and / or simultaneously. In particular, the precursor supply unit and co-reactant supply unit can thus be configured for supplying the precursor and the co-reactant separated in space. When the substrate is held on a receptacle, and the receptacle is moved with respect to the precursor supply unit and co-reactant supply unit in a conveyance direction, different sections of the receptacle can be exposed to either the precursor or the co-reactant. Purging gas can be used to separate the precursor from the co-reactant. When the precursor is supplied by a precursor supply unit and the co-reactant is supplied by a co-reactant supply unit, the substrate may be moved relative to the precursor supply unit and the core act ant supply unit. Any method for atomic layer deposition on a substrate of the present disclosure may the be a method for spatial atomic layer deposition. Any apparatus for atomic layer deposition on a substrate may be an apparatus for spatial atomic layer deposition on a substrate. In such apparatus, the substrate and / or receptacle may be movable with respect to the precursor supply unit and co-reactant supply unit in a conveyance direction. To move the substrate and / or receptacle, the apparatus may comprise an actuator for moving the receptacle, such as an electric actuator.

[0034] According to a second aspect is provided an apparatus for atomic layer deposition on a substrate. The apparatus comprises a receptacle for holding the substrate thereon. The apparatus comprises a precursor supply unit for supplying a precursor to a surface of the substrate. The apparatus comprises a co-reactant supply unit configured for supplying a co-reactant to the surface of the substrate. The co-reactant supply unit comprises an ozone supply unit and a water vapour supply unit. The co-reactant supply unit is configured for supplying the water vapour and ozone of the co-reactant to the substrate surface simultaneously. The water vapour and the ozone can therefore be mixed so as to exist at or near the substrate surface at the same moment in time. The precursor supply unit and coreactant supply unit are configured for depositing an atomic layer on the surface of the substrate upon interaction between the substrate surface, the precursor and the co-reactant. The apparatus can comprise a controller for controlling the supply units. The controller can be configured for controlling the co-reactant supply unit for supplying the water vapour and ozone of the co-reactant to the substrate surface simultaneously.

[0035] Optionally, the co-reactant supply unit is configured for supplying the water vapour and ozone of the co-reactant to the substrate surface through a same co-reactant supply nozzle. The co-reactant supply nozzle can be in fluid communication with the water vapour supply unit and the ozone supply unit. The controller can control the water vapour supply unit and the ozone supply unit to supply the water vapour and ozone to the substrate simultaneously.

[0036] Optionally, the ratio between the amount of water vapour and ozone of the co-reactant is between 1:1000 and 1:1. Preferably, the ratio between the amount of water vapour and ozone of the co-reactant is between 1:500 and 1:4, more preferably, the ratio is between 1:200 and 1:4, such as between 1:125 and 1:5. It has been found a ratio lower than 1:10 may already provide beneficial results. The amount of supplied water vapour can be lower than, equal to, or higher than the amount of supplied ozone. Alternatively, or additionally, the partial pressure of water vapour is e.g. between 5-200 Pa, such as between 10-50 Pa, and the partial pressure of ozone is e.g. between 1000-5000 Pa, such as between 1500 and 4000 Pa.

[0037] Optionally, the precursor supply unit and the co-reactant supply unit are configured for supplying the precursor to the substrate surface prior to supplying the co-reactant to the substrate surface. The controller can be configured for controlling the precursor supply unit and the co-reactant supply unit for supplying the precursor to the substrate surface prior to supplying the co-reactant to the substrate surface Alternatively, the precursor supply unit and the co-reactant supply unit are configured for supplying the co-reactant to the substrate surface prior to supplying the precursor to the substrate surface. The controller can be configured for controlling the precursor supply unit and the co-reactant supply unit for supplying the co-reactant to the substrate surface prior to supplying the precursor to the substrate surface

[0038] Optionally, the apparatus further comprises a purging gas supply unit configured for in a first purge step supplying a portion of a purging gas to the surface of the substrate after the step of supplying the precursor to the substrate surface, and wherein the purging gas supply unit is configured for in a second purge step supplying a further portion of the purging gas to the surface of the substrate after the atomic layer is deposited on the surface of the substrate.

[0039] Optionally, the apparatus is configured for alternatingly repeating the supplying of the precursor to the substrate surface, the supplying of the purging gas to the surface of the substrate, the supplying of the co-reactant to the substrate surface, and the supplying the purging gas to the surface of the substrate. Hence, repeatedly atomic layers can be deposited on top of each other on the substrate.

[0040] Optionally, the apparatus is configured for depositing the atomic layer on the surface of the substrate at a temperature lower than or equal to 150 degrees Celsius. In particular, the apparatus may be configured for depositing the atomic layer on the surface of the substrate at a temperature lower than or equal to 100 degrees Celsius, or even lower than 75 degrees Celsius.

[0041] Optionally, the amount of precursor supplied to the substrate surface during a single step of supplying precursor and co-reactant and depositing the atomic layer on the surface of the substrate is less than the amount required to saturate the surface of the substrate.

[0042] Optionally, the amount of ozone supplied to the substrate surface during a single step of supplying precursor and co-reactant and depositing the atomic layer on the surface of the substrate is less than the amount required for saturated surface reaction. Herein the amount of water vapour supplied to the substrate surface during the single step of supplying precursor and co-reactant and depositing the atomic layer on the surface of the substrate can be sufficient to complete saturated surface reaction.

[0043] Optionally, the amount of water vapour supplied to the substrate surface during a single step of supplying precursor and co-reactant and depositing the atomic layer on the surface of the substrate is less than the amount required for saturated surface reaction. Herein the amount of ozone supplied to the substrate surface during the single step of supplying precursor and co-reactant and depositing the atomic layer on the surface of the substrate can be sufficient to complete saturated surface reaction.

[0044] Optionally, the precursor supply unit and co-reactant supply unit are configured for supplying the precursor and the co-reactant separated in space with respect to each other as seen from the substrate.

[0045] Optionally, the ozone supply unit and water vapour supply unit are configured for supplying the ozone and the water vapour separated in space with respect to each other as seen from the substrate.

[0046] For any apparatus for atomic layer deposition on a substrate, the apparatus is preferably configured for atomic layer deposition at atmospheric pressure. In particular, the substrate may be positioned at a location or in a chamber which is at atmospheric pressure. Additionally, or alternatively, the precursor supply unit is configured for supplying the precursor to the surface of the substrate at atmospheric pressure. Additionally, or alternatively, the coreactant supply unit is configured for supplying the co-reactant to the surface of the substrate at atmospheric pressure. Any optional purging gas supply unit may be configured to purge gas to the surface of the substrate at atmospheric pressure. It will be understood that it is contemplated that the apparatus does not comprise a vacuum pump or other system for actively reducing pressure around the substrate. The substrate may thus be present in a chamber, wherein a pressure inside the chamber is at approximately atmospheric pressure, for example within a maximum deviation of 10% of atmospheric pressure.

[0047] It will be appreciated that any of the aspects, features and options described in view of the method for atomic layer deposition on a substrate apply equally to the apparatus for atomic layer deposition on a substrate, and vice versa. It will also be clear that any one or more of the above aspects, features and options can be combined.

[0048] BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Embodiments of the present invention will now be described in detail with reference to the accompanying drawings in which:

[0050] Figures 1A and IB show illustrations of a schematic representation of an example of a side view of an apparatus for atomic layer deposition on a substrate;

[0051] Figures 2A and 2B show illustrations of a schematic representation of an example of a side view of an apparatus for atomic layer deposition on a substrate;

[0052] Figures 3A and 3B show illustrations of a schematic representation of an example of a side view of an apparatus for atomic layer deposition on a substrate;

[0053] Figures 4A and 4B show illustrations of a schematic representation of an example of a side view of an apparatus for atomic layer deposition on a substrate;

[0054] Figure 5 shows an exemplary flow chart of a method for atomic layer deposition on a substrate; and Figures 6A-13B show examples of results from experiments.

[0055] DETAILED DESCRIPTION

[0056] Figures 1A and IB show illustrations of a schematic representation of an example of a side view of an apparatus 1 for atomic layer deposition on a substrate 2. The apparatus 1 comprises a receptacle 4, a precursor supply unit 6 and a co-reactant supply unit 8. The receptacle 4 is configured for holding the substrate 2 thereon. The precursor supply unit 6 is configured for supplying a precursor 10 to a surface 12 of the substrate 2. The co-reactant supply unit 8 is configured for supplying a co-reactant 14 to the surface 12 of the substrate 2. The co-reactant supply unit 8 comprises an ozone supply unit 16 and a water vapour supply unit 18. The co-reactant supply unit 8 is configured for supplying the ozone 20 and water vapour 22 of the co-reactant 14 to the substrate surface 12 simultaneously. The precursor supply unit 6 and co-reactant supply unit 8 are configured for depositing an atomic layer 24 on the surface 12 of the substrate 2 upon interaction between the substrate surface 12, the precursor 10 and the coreactant 14. In this example, the ratio between the amount of ozone 20 and water vapour 22 of the co-reactant 14 is between 1:50 and 20:1. Here, the amount of precursor 10 supplied to the substrate surface 12 during a single step of supplying precursor 10 and co-reactant 14 and depositing the atomic layer 24 on the surface 12 of the substrate 2 is less than the amount required to saturate the surface 12 of the substrate 2. The amount of precursor 10 required to saturate the substrate surface 12 is to be interpreted herein as the amount of precursor 10 required to cover the substrate surface 12 with one monolayer of material of the atomic layer 24 deposited during a single step of supplying precursor 10 and co-reactant 14 and depositing the atomic layer 24.

[0057] In Figure 1A, the co-reactant supply unit 8 is configured for supplying the ozone 20 to the substrate surface 12 through an ozone supply nozzle 26, and for supplying the water vapour 22 to the substrate surface 12 through a water vapour supply nozzle 28. In Figure IB, the co-reactant supply unit 8 is configured for supplying both the ozone 20 and water vapour 22 of the co-reactant 14 to the substrate surface 12 through a co-reactant supply nozzle 30. Figures 2A and 2B show illustrations of a schematic representation of an example of a side view of the apparatus 1 for atomic layer deposition on the substrate 2. The apparatus 1 can comprise the apparatus 1 according to Figures 1A or IB. In the examples of Figures 2A and 2B, the precursor supply unit 6 and the co-reactant supply unit 8 are configured for supplying the precursor 10 to the substrate surface 12 prior to supplying the co-reactant 14 to the substrate surface. First, in Figure 2A, the precursor 10 is supplied to the surface 12 of the substrate 2. Here, the precursor 10 is arranged to, upon being supplied to the surface 12 of the substrate 2, interact with the surface 12 such that a first surface product 32 on the substrate 2 is formed. After supplying the precursor 10, the co-reactant 14 is supplied to the surface 12 of the substrate 2 in Figure 2B. In this example, the coreactant 14 is arranged to, upon being supplied to the surface 12 of the substrate 2, interact with the first surface product 32 on the substrate 2 such that the atomic layer 24 on the surface 12 of the substrate 2 is formed.

[0058] Figures 3A and 3B show illustrations of a schematic representation of an example of a side view of the apparatus 1 for atomic layer deposition on the substrate 2. The apparatus 1 can comprise the apparatus 1 of Figures 1A or IB, and / or of Figures 2A and 2B. In the example of Figures 3A and 3B, the apparatus 1 further comprises a purging gas supply unit 34. The purging gas supply unit 34 is configured for in a first purge step supplying a portion of a purging gas 36A to the surface 12 of the substrate 2 after the step of supplying the precursor 10 to the substrate surface 12. The portion of the purging gas 36A purges leftover precursor 10 particles away from the substrate surface 12 in the first purge step. The first purge step is shown in Figure 3A, and is in this example performed after the first surface product 32 is formed on the substrate 2. The purging gas supply unit 34 is configured for in a second purge step supplying a further portion of the purging gas 36B to the surface 12 of the substrate 2 after the atomic layer 24 is deposited on the surface 12 of the substrate 2. The further portion of the purging gas 36B purges redundant co-reactant 14 particles away from the substrate surface 12 in the second purge step. The second purge step is shown in Figure 3B, and is in this example performed after the atomic layer 24 is deposited on the substrate 2. It will be appreciated that the purging gas supply unit 34 may include a first purging gas nozzle 35A for supplying the first portion of the purging gas 36A and a second purging gas nozzle 35B for supplying the second portion of the purging gas 36B.

[0059] The apparatus 1 is in this example configured for alternatingly repeating the supplying of the precursor 10 to the substrate surface 12, the supplying of the purging gas 36A to the surface 12 of the substrate 2, the supplying of the co-reactant 14 to the substrate surface 12, the depositing the atomic layer 24 on the surface 12 of the substrate 2 and the supplying the purging gas 36B to the surface 12 of the substrate 2. Here, the apparatus 1 is configured for depositing the atomic layer 24 on the surface 12 of the substrate 2 at a temperature lower than or equal to 150 degrees Celsius.

[0060] Figures 4A and 4B show illustrations of a schematic representation of an example of a side view of the apparatus 1 for atomic layer deposition on the substrate 2. In Figures 4A and 4B, the precursor supply unit 6 and co-reactant supply unit 8 are configured for supplying the precursor 10 and the co-reactant 14 separated in space with respect to each other as seen from the substrate 2. In this example, the receptacle 4 is movable with respect to the precursor supply unit 6 and co-reactant supply unit 8 in a conveyance direction D, indicated by the dashed arrow, e.g. from a first position to a third position. In Figure 4A, the receptacle 4 is in the first position and the precursor 10 is supplied to a portion 38 of the surface 12 of the substrate 2. Here, the precursor supply unit 6 is arranged for directing the supplied precursor 10 at the substrate surface 12 in Figure 4A, thereby forming a first surface product 32 on the substrate 2. After supplying the precursor 10, the receptacle 4 is conveyed to a second position in which the purging gas 36A is supplied to the same portion 38 of the surface of the substrate 2. Figure 4B shows the situation with the substrate 2 moved to the third position, in which the coreactant 14 is supplied to the portion 38 of the surface 12 of the substrate 2. In this example, the co-reactant 14 supplied to the substrate surface 12 is arranged to interact with the first surface product 32 on the substrate 2 such that the atomic layer 24 on the surface 12 of the substrate 2 is formed. In this example, after supplying the co-reactant 14, the receptacle 4 is conveyed to a fourth position in which the purging gas 36B is supplied to the same portion 38 of the surface of the substrate 2. It will be appreciated that a continuous process is also possible in which a substrate 2 is fed in the conveyance direction D past a head 9 comprising the supply units 6 and 8, and optionally 34. The substrate can e.g. be a roll of substrate material that is wound and / or unwound past the head 9 while atomic layers are deposited onto the substrate. The receptacle can support the substrate e.g. in a sliding way, or in a non-sliding way. The receptacle can e.g. be formed by a roller supporting the substrate.

[0061] Figure 5 shows an exemplary flow chart of a method 100 for atomic layer deposition on the substrate 2. The method 100 can be performed using for example the apparatus 1 described in view of any of Figures 1A-4B. Optional steps are shown in dashed boxes. In a first step 102, the method 100 comprises providing the substrate 2. The precursor 10 is supplied to the surface 12 of the substrate 2 in step 104. Step 104 is performed after step 102. Optionally, in step 106 a portion of a purging gas 36A is supplied to the surface 12 of the substrate 2. Step 106 can be performed after step 104. The co-reactant 14 is supplied to the surface 12 of the substrate 2 in step 108. The co-reactant 14 is a combination of ozone 20 and water vapour 22. The water vapour 22 and ozone 20 of the co-reactant 14 are supplied to the substrate surface 12 simultaneously. In this example, the step 104 of supplying the precursor 10 to the substrate surface 12 is performed prior to the step 108 of supplying the co-reactant 14 to the substrate surface 12. Here, the steps 104 and 108 are performed consecutively with optionally an intervening first purge step 106.

[0062] In step 110, the method 100 comprises depositing the atomic layer 24 on the surface 12 of the substrate 2 upon interaction between the substrate surface 12, the precursor 10 and the co-reactant 14. The step 110 is performed after and / or in simultaneous with step 108. Steps 104, optionally 106,_108 and 110 together comprise a layer forming step. In step 112, the method 100 optionally further comprises a second purge step. A further portion of the (or a different) purging gas 36B is supplied to the surface 12 of the substrate 2 in optional step 112. Step 112 is performed after the step 110 of depositing the atomic layer 24. The method 100 in this example comprises alternatingly repeating the layer forming step, i.e. steps 104, 106, 108 and 110, and the second purge step, i.e. step 112. The water vapour 22 and ozone 20 of the co-reactant 14 can be supplied to the substrate surface 12 through the same co-reactant supply nozzle 30. The ratio between the amount of ozone 20 and water vapour 22 of the co-reactant can e.g. be between 1:1000 and 1:1. Preferably, the ratio between the amount of water vapour and ozone of the co-reactant is between 1:500 and 1:4, more preferably, the ratio is between 1:200 and 1:4, such as between 1:125 and 1:5. The amount of supplied water vapour can be lower than, equal to, or higher than the amount of supplied ozone. Alternatively, or additionally, the partial pressure of water vapour is e.g. between 5-200 Pa, such as between 10 -50 Pa, and the partial pressure of ozone is e.g. between 1000-5000 Pa, such as between 1500-4000 Pa.. In this example, the precursor 10 is arranged to, upon being supplied to the surface 12 of the substrate 2 in step 104, interact with the surface 12 of the substrate 2 such that a first surface product 32 on the substrate 2 is formed. Here, the co-reactant 14 is arranged to, upon being supplied to the surface 12 of the substrate 2 in step 108, interact with the first surface product 32 on the substrate 2 such that the atomic layer 24 on the surface 12 of the substrate 2 is formed. The method 100 is in this example performed at a temperature lower than or equal to 150 degrees Celsius. The precursor 10 is in this example a metalorganic precursor, e.g. trimethylaluminum, TMA.

[0063] The ozone 20 can in this example be arranged to interact with the first surface product 32 in a first way upon being supplied to the surface 12 of the substrate 2 such that a second surface product on the substrate is formed. Here, the water vapour 22 can be arranged to interact with the first surface product 32 and / or the second surface product on the substrate 2 in a second way upon being supplied to the surface 12 of the substrate 2. The amount of precursor 10 supplied to the substrate surface 12 during a single layer forming step is in this example less than the amount required to saturate the surface 12 of the substrate 2.

[0064] Further, the amount of ozone 20 supplied to the substrate surface 12 during a single layer forming step can be less than the amount required for saturated surface reaction, and the amount of water vapour 22 supplied to the substrate surface 12 during the single layer forming step can be sufficient to complete saturated surface reaction. Alternatively, the amount of water vapour 22 supplied to the substrate surface 12 during a single layer forming step can be less than the amount required for saturated surface reaction, and the amount of ozone 20 supplied to the substrate surface 12 during the single layer forming step can be sufficient to complete saturated surface reaction.

[0065] Example 1

[0066] Deposition of AI2O3 using TMA as precursor and a combination of O3 and H2O vapour (in various concentrations) as co-reactant, simultaneously supplied, using a setup as described in view of figures 4A and 4B. Ozone was generated using an AbsoluteOzone type Atlas 300 ozone generator. The substrate was moved relative to the head at a speed of 800 mm / s. The process temperature was 75 °C. The substrate was processed in 800 passes by the head. All the films were deposited on polished silicon wafers to enable accurate determination of the film properties, such as thickness and refractive index, of the aluminum oxide layer. The films were characterized by a Woollam M2000 spectroscopic ellipsometer. To determine the optical properties of the aluminum oxide layer the CompleteEASE software and a Cauchy dispersion relation is used.

[0067] Figure 6A shows a photograph of AI2O3 deposited in 800 passes with only H2O vapour as coreactant at a flow of 0.03 slm (vapour pressure of 13 Pa). The result is an extremely non-homogeneous deposition.

[0068] Figure 6B shows a photograph of AI2O3 deposited in 800 passes with only O3 as coreactant produced at 500 W (partial pressure of 3800 Pa). A very uniform film growth is observed. The ozone exposure is clearly under-saturated as the GPC=0.08 nm.

[0069] Figure 6C shows a photograph of AI2O3 deposited in 800 passes with H2O vapour as coreactant at a flow of 0.03 slm (vapour pressure of 13 Pa), and O3 as coreactant produced at 500 W (partial pressure of 3800 Pa) simultaneously. Hence the ratio of [H2O] / [O3] was about 0.003. A very uniform film growth is observed. Film growth is saturated as the GPC=0.10 nm.

[0070] Using H2O as co-reactant, at low temperatures, requires very long purge times to remove the water, typically more than 0.5 s. The amount of ozone that can be generated is also limited, typically 10 wt%, thus limiting the GPC or throughput of the spatial ALD process. By adding a small amount of H2O to the ozone gas flow the throughput can be significantly increased.

[0071] Figures 7 A and 7B show the effect of the coreactant containing an increasing amount of water vapour in combination with ozone. Ozone was produced at 500 W (3800 Pa). Figure 7 A shows the GPC as a function of H2O flow rate (in slm). Figure 7B shows the GPC as a function of water vapour partial pressure in Pa.

[0072] Figures 8 A and 8B show the effect of the coreactant containing an increasing amount of ozone in combination with water vapour. Water vapour was provided at 0.5 slm (200 Pa). Figure 8A shows the GPC as a function of ozone generator power (in W). Figure 8B shows the GPC as a function of ozone partial pressure in Pa.

[0073] Figure 9 shows an example of the GPC as a function of H2O / O3 ratio. It can be seen from figure 9 that already a very small ratio of [H2O] / [O3] = 0.003 shows a marked increase in GPC. A ratio of [H20] /

[0003] >0.001 is preferred to increase the GPC and / or throughput.

[0074] Figures 10A and 10B show an example of water vapour transmission rate, WVTR, of a PET foil sample having an AI2O3 layer deposited thereon, as a function of water vapour content of the coreactant in combination with ozone. Ozone was produced at 500 W (3800 Pa). Figure 10A shows the WVTR as a function of H2O flow rate (in slm). Figure 10B shows the WVTR as a function of water vapour partial pressure in Pa. It can be seen that the WVTR markedly diminishes at small additions of water vapour to ozone in the coreactant.

[0075] Figures 11A and 11B show an example of water vapour transmission rate, WVTR, of a PET foil sample having an AI2O3 layer deposited thereon, as a function of ozone content of the coreactant in combination with water vapour. Water vapour was supplied at 0.5 slm (200 Pa). Figure 11A shows the WVTR as a function of ozone generator power (in W). Figure 11B shows the WVTR as a function of ozone partial pressure in Pa. So, besides a higher GPC, using co-dosing, the overall water vapour transmission rate, WVTR, is also significantly improved. The overall WVTR was measured using a Technolox Deltaperm system characterizing the permeability over a total area of 50 cm2. The overall WVTR encompasses the permeation through pinholes as well as the intrinsic permeation through the aluminum oxide layer. The overall WVTR was characterized at 38 °C and 90% RH. As a substrate for characterizing the WVTR of the aluminum oxide layers a 100 pm thick PET Melinex 401 was used. For all the experiments 200 ALD passes at a process temperature of 75 °C were used.

[0076] Example 2

[0077] Deposition of NiO using a setup as described in view of figures 4A and 4B. The process temperature was 120 °C. Ozone was generated using an AbsoluteOzone type Atlas 300 ozone generator. The Ni precursor “Alanis” produced by Air Liquide was vaporized in a bubbler. The substrate was moved relative to the head at a speed of 100 mm / s. As co-reactant a combination of O3 and H2O, simultaneously supplied in various concentrations, was used. The substrate was processed in 800 passes by the head. The ozone generator was producing ozone at 500 W (3800 Pa) power without addition of water the GPC = 0.073 nm.

[0078] Figures 12A and 12B show the effect of the coreactant containing an increasing amount of water vapour in combination with ozone. Ozone was produced at 500 W (3800 Pa). Figure 12A shows the GPC as a function of H2O flow rate (in slm). Figure 12B shows the GPC as a function of water vapour partial pressure in Pa. Adding a small amount of water from 200 to 1700 Pa increases the GPC from 0.105 to 0.125 nm. Hence the ratio of [H2O] / [O3] was about 0.05 to 0.45. Thus by adding a small amount of H2O to the ozone flow yielded almost a 50% increase in the GPC.

[0079] Example 3

[0080] Deposition of In2O3 using a setup as described in view of figures 4A and 4B. Ozone was generated using an AbsoluteOzone type Atlas 300 ozone generator. The In precursor “Infinite” produced by Air Liquide was vaporized in a bubbler. The process temperature was 110 °C, when using ozone or a combination of ozone and water vapour as coreactant, or 100 °C, when using water vapour as coreactant. The substrate was moved relative to the head at a speed of 100 mm / s. As co- reactant a combination of O3 and H2O in various concentrations was used. The substrate was processed in 800 passes by the head.

[0081] Figure 13A shows the GPC as a function of the precursor exposure (exposure time x partial pressure), for the co-reactant being only water, only ozone, or ozone and water vapour simultaneously. This experiment showed that the GPC is increased by addition of some H2O vapour to the ozone coreactant.

[0082] Additionally, it was found that the refractive index of In2O3 increased markedly with the addition of a small amount of H2O vapour to the ozone coreactant. Figure 13B shows a graph showing measured refractive index values for In2O3 samples deposited using for the co-reactant only water, only ozone, or ozone and water vapour simultaneously, respectively.

[0083] Herein, the invention is described with reference to specific examples of embodiments of the invention. It will, however, be evident that various modifications and changes may be made therein, without departing from the essence of the invention. For the purpose of clarity and a concise description features are described herein as part of the same or separate embodiments, however, alternative embodiments having combinations of all or some of the features described in these separate embodiments are also envisaged.

[0084] However, other modifications, variations, and alternatives are also possible. The specifications, drawings and examples are, accordingly, to be regarded in an illustrative sense rather than in a restrictive sense.

[0085] For the purpose of clarity and a concise description features are described herein as part of the same or separate embodiments, however, it will be appreciated that the scope of the invention may include embodiments having combinations of all or some of the features described.

[0086] In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word ‘comprising’ does not exclude the presence of other features or steps than those listed in a claim. Furthermore, the words ‘a’ and ‘an’ shall not be construed as limited to ‘only one’, but instead are used to mean ‘at least one’, and do not exclude a plurality. The mere fact that certain measures are recited in mutually different claims does not indicate that a combination of these measures cannot be used to an advantage.

Claims

Claims1. A method for atomic layer deposition on a substrate, comprising: providing the substrate; and a layer forming step, comprising:- supplying a precursor to a surface of the substrate;- supplying a co-reactant to the surface of the substrate, wherein the co-reactant is a combination of ozone and water vapour, wherein the water vapour and ozone of the co-reactant are supplied to the substrate surface simultaneously; and- depositing an atomic layer on the surface of the substrate upon interaction between the substrate surface, the precursor and the co-reactant.

2. The method according to claim 1, wherein the water vapour and ozone of the co-reactant are supplied to the substrate surface through a same coreactant supply nozzle.

3. The method according to claim 1 or 2, wherein the ratio between the amount of water vapour and ozone of the co-reactant is between 1:1000 and 1:1.

4. The method according to claim 1, 2 or 3, wherein the precursor is arranged to, upon being supplied to the surface of the substrate, interact with the surface of the substrate such that a first surface product on the substrate is formed, and wherein the co-reactant is arranged to, upon being supplied to the surface of the substrate, interact with the first surface product on the substrate such that the atomic layer on the surface of the substrate is formed.

5. The method according to claim 4, wherein the ozone is arranged to interact with the first surface product in a first way upon being supplied to the surface of the substrate such that a second surface product on the substrate is formed, and wherein the water vapour is arranged to interact with the firstsurface product and / or the second surface product on the substrate in a second way upon being supplied to the surface of the substrate.

6. The method according to any of the preceding claims, wherein the precursor is supplied to the substrate surface prior to supplying the co-reactant to the substrate surface.

7. The method according to claim 6, wherein the layer forming step comprises supplying the precursor and the co-reactant to the substrate surface consecutively with an intervening first purge step comprising supplying a portion of a purging gas to the surface of the substrate.

8. The method according to claim 7, wherein the method further comprises a second purge step comprising supplying a further portion of the purging gas to the surface of the substrate after the step of depositing the atomic layer.

9. The method according to claim 8, wherein the method comprises alternatingly repeating the layer forming step and the second purge step.

10. The method according to any of the preceding claims, wherein the method is performed at a temperature lower than or equal to 150 degrees Celsius.

11. The method according to any of the preceding claims, wherein the amount of precursor supplied to the substrate surface during a single layer forming step is less than the amount required to saturate the surface of the substrate.

12. The method according to any of the preceding claims, wherein the amount of ozone supplied to the substrate surface during a single layer forming step is less than the amount required for saturated surface reaction, and whereinthe amount of water vapour supplied to the substrate surface during the single layer forming step is sufficient to complete saturated surface reaction.

13. The method according to any of claims 1-11, wherein the amount of water vapour supplied to the substrate surface during a single layer forming step is less than the amount required for saturated surface reaction, and wherein the amount of ozone supplied to the substrate surface during the single layer forming step is sufficient to complete saturated surface reaction.

14. The method according to any of the preceding claims, wherein the precursor is a metal-organic precursor.

15. An apparatus for atomic layer deposition on a substrate, comprising: a receptacle for holding the substrate thereon, a precursor supply unit for supplying a precursor to a surface of the substrate; and a co-reactant supply unit configured for supplying a co-reactant to the surface of the substrate, wherein the co-reactant supply unit comprises an ozone supply unit and a water vapour supply unit, wherein the co-reactant supply unit is configured for supplying the water vapour and ozone of the co-reactant to the substrate surface simultaneously, wherein the precursor supply unit and co-reactant supply unit are configured for depositing an atomic layer on the surface of the substrate upon interaction between the substrate surface, the precursor and the co-reactant.

16. The apparatus according to claim 15, wherein the co-reactant supply unit is configured for supplying the water vapour and ozone of the co-reactant to the substrate surface through a same co-reactant supply nozzle.

17. The apparatus according to claim 15 or 16, wherein the ratio between the amount of water vapour and ozone of the co-reactant is between 1:1000 and 1:1.

18. The apparatus according to any of claims 15, 16 or 17, wherein the precursor supply unit and the co-reactant supply unit are configured for supplying the precursor to the substrate surface prior to supplying the coreactant to the substrate surface.

19. The apparatus according to claim 18, further comprising a purging gas supply unit configured for in a first purge step supplying a portion of a purging gas to the surface of the substrate after the step of supplying the precursor to the substrate surface, and wherein the purging gas supply unit is configured for in a second purge step supplying a further portion of the purging gas to the surface of the substrate after the atomic layer is deposited on the surface of the substrate.

20. The apparatus according to claim 19, wherein the apparatus is configured for alternatingly repeating the supplying of the precursor to the substrate surface, the supplying of the purging gas to the surface of the substrate, the supplying of the co-reactant to the substrate surface, the depositing the atomic layer on the surface of the substrate and the supplying the purging gas to the surface of the substrate.

21. The apparatus according to any of claims 15-20, wherein the apparatus is configured for depositing the atomic layer on the surface of the substrate at a temperature lower than or equal to 150 degrees Celsius.

22. The apparatus according to any of claims 15-21, wherein the amount of precursor supplied to the substrate surface during a single step of supplying precursor and co-reactant and depositing the atomic layer on the surface of the substrate is less than the amount required to saturate the surface of the substrate.

23. The apparatus according to claim any of claims 15-22, wherein the precursor supply unit and co-reactant supply unit are configured for supplyingthe precursor and the co-reactant separated in space with respect to each other as seen from the substrate.

24. The method according to any of the claims 1-14, wherein the method is performed at a temperature lower than 150 degrees Celsius and wherein the ratio between the amount of water vapour and ozone of the co-reactant is between 1:1000 and 1:1.

25. The method according to claim 24, wherein the method is performed at a temperature lower than 100 degrees Celsius.

26. The method according to any of the claims 1-14 or 24, wherein the method is performed at atmospheric pressure.

27. The method according to any of the claims 1-14 or 24-26, wherein the precursor is trimethylaluminum.

28. The method according to any of the claims 1-14 or 24-27, wherein the substrate is held on a receptacle, and the receptacle is moved with respect to the precursor supply unit and co-reactant supply unit in a conveyance direction.

29. The method according to any of the claims 1-14 or 24-28, wherein the precursor is supplied by a precursor supply unit, the co-reactant is supplied by a co-reactant supply unit, and the substrate is moved relative to the precursor supply unit and the co-reactant supply unit.

30. The method according to any of the claims 1-14 or 24-29, wherein the partial pressure of the water vapour is below 1200 Pa, preferably below 600 Pa.

31. The method according to any of the claims 1-14 or 24-30, wherein the ratio between the amount of water vapour and ozone of the co-reactant is lower than 1:10.

32. The apparatus according to any of claims 15-23, wherein the receptacle is movable with respect to the precursor supply unit and co-reactant supply unit in a conveyance direction.

33. The apparatus according to any of claims 15-23 or 32, configured for atomic layer deposition at atmospheric pressure.

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