Multifunctional coatings, methods of making multifunctional coatings, related coated articles and uses

Abstract

A method of forming a coating on a substrate is provided, the method including using a molecular layer deposition (MLD) process to deposit at least one layer directly or indirectly on the surface, and depositing an inorganic film on / over the at least one layer using an atomic layer deposition (ALD) process. Conditions are established within the formed coating that allow unbound, unreacted, and / or partially reacted precursors to enter into a chemical interaction with harmful environmental species that have infiltrated into defect sites within the coating and seal the defect sites by forming a sealing compound. Further provided are laminate coatings, uses of laminate coatings, and coated articles.

Description

[Technical field]

[0001] The present invention relates generally to producing coated articles by chemical deposition processes. Specifically, the present invention relates to depositing multi-layer laminate coatings onto sensitive and potentially flexible substrates. These multi-layer laminate coatings provide a protective layer that provides a number of functions including a corrosion or moisture barrier for a variety of sensitive and flexible substrates, and further, the protective barrier layer provides the ability to withstand a significant amount of damage. [Background technology]

[0002] The production of protective coatings on a wide variety of substrates via chemical deposition techniques in the vapor phase, such as atomic layer deposition (ALD) and molecular layer deposition (MLD), has been widely described in the art.

[0003] Atomic layer deposition techniques are based on alternating self-saturating surface reactions. Different reactants (precursors), provided as molecular compounds or elements in non-reactive (inert) gaseous carriers, are pulsed sequentially into a reaction space containing a substrate. Following precursor deposition, the substrate is purged with an inert gas. A conventional ALD cycle (deposition cycle) proceeds in two half-reactions (pulse-purge of the first precursor; pulse-purge of the second precursor), which results in the self-limiting (self-saturating) formation of a monolayer of material, typically with a thickness of 0.05-0.2 nm. The cycle is repeated as many times as necessary to obtain a film with a given thickness. Typical substrate exposure times for each precursor are 0.01-1 seconds. ALD techniques have been developed for the atomic-level growth of inorganic materials. The most common precursors include metal oxides, elemental metals, metal nitrides, and metal sulfides. ALD-deposited films are fully conformal and pinhole-free.

[0004] Molecular layer deposition is also a continuous, self-limiting vapor phase deposition that allows the production of (ultra)thin organic and hybrid organic-inorganic films. Similar to ALD, the layer-by-layer nature of molecular layer deposition allows the production of highly conformal thin films with sub-nanometer thickness control. Whereas two or more organic precursors are employed in the production of purely organic (polymeric) structures, hybrid organic-inorganic films are typically synthesized using a combination of inorganic compounds and organic polymers. Common organic precursors are polymer molecules that contain, for example, -OH, -COOH, CONH2, -CHO, -NH2, -SH, -CN functional groups.

[0005] A variety of packaging applications, particularly those used in medical packaging (containers, pharmaceutical packaging, etc.), require sterile packaging solutions. In many cases, the coating solution needs to be transparent, thin and scalable, resistant to corrosive liquids and ambient moisture, non-cytotoxic, and it is crucial that it can conformally and controllably coat surfaces of different shapes.

[0006] US 2010 / 178481 (George et al.) describes ALD-MLD coatings deposited on flexible substrates. The coatings include multiple layers of inorganic materials other than silica, such as metal oxides, metals, or semi-metal nitrides. At least some of the adjacent layers are separated from each other by at least one silica layer and at least one organic polymer layer. The inorganic and silica layers are deposited by ALD, and the organic polymer or hybrid inorganic-organic polymer layer is deposited by MLD.

[0007] US 2013 / 296988 (Weber et al.) describes a medical implant that includes a nanolaminate having at least one ceramic layer deposited by ALD and at least one polymer layer deposited by MLD, sol-gel processing, liquid source mist generated chemical vapor deposition (LSMCD), or plasma enhanced chemical vapor deposition (PECVD). Nanoclays and / or nanodiamonds are incorporated into the polymeric material in addition to or instead of the ceramic material to improve strength and wear resistance.

[0008] US Patent Application Publication No. 2013 / 333835 (Carcia et al.) describes a process for producing rigid or flexible protective barrier coatings, including hybrid inorganic-organic, polymer alloys, by combining ALD and MLD techniques. The transparent alloys may be formed directly on the object to be protected or on a carrier substrate that may subsequently be employed to protect the object. The actual barrier structure resembles a barrier-capping structure.

[0009] However, while the previously recognized multilayer coatings deposited using the atomic and molecular layer deposition techniques have been found to act as efficient corrosion-resistant barriers, in many cases these coatings become deprived of their protective capabilities when the coatings suffer mechanical damage.

[0010] In this regard, updates in the field of fabrication of protective encapsulations are still desirable, particularly in light of addressing the challenges associated with the deposition of said coatings during the manufacture of biomedical devices, such as implantable bioelectronic solutions. Summary of the Invention [Problem to be solved by the invention]

[0011] The object of the present invention is to solve or at least alleviate each of the problems resulting from the limitations and shortcomings of the related art, which is achieved by a method for forming a coating on a substrate, a self-healing laminate coating, related articles and uses according to the respective independent claims attached hereto. [Means for solving the problem]

[0012] According to an aspect of the present invention, there is provided a method for forming a coating on a substrate using molecular layer deposition processes and atomic layer deposition according to what is claimed in independent claim 1. Effect of the Invention

[0013] In one embodiment, a method of forming a coating on a substrate comprises the steps of: (i) depositing, directly or indirectly, on a surface of said substrate, at least one layer of an essentially porous bulk material using a molecular layer deposition (MLD) process; and (ii) depositing an inorganic film on / over the at least one layer formed in step (i) using an atomic layer deposition (ALD) process; Including, This results in the formation of a coating in which unbound, unreacted, and / or partially reacted precursors within the at least one layer of essentially porous bulk material enter into chemical interaction with harmful environmental species that have penetrated into defect sites within the coating and seal the defect sites by forming a sealing compound.

[0014] The harmful environmental species may include any one of water molecules, hydroxyl radicals, nitrous oxide species, biological molecules such as proteins, and the like, which originate from the environment surrounding the substrate coated with the film stack and which penetrate into defect sites within the film.

[0015] In some cases, conditions are established within the coating that allow unbound, unreacted, and / or partially reacted precursors to infiltrate into the bulk of the essentially porous material during step (i).

[0016] In an embodiment, the inorganic film formed in step (ii) comprises at least one deposited layer.

[0017] In an embodiment, the inorganic film formed in step (ii) comprises a plurality of deposited layers arranged in a stack, each deposited layer in the stack having the same or a different composition.

[0018] In an embodiment, the deposition layer forming the inorganic film in step (ii) comprises any compound selected from the group consisting of aluminum (III) oxide (Al2O3), titanium (IV) oxide (TiO2), hafnium (IV) oxide (HfO2), tantalum (V) oxide (Ta2O5), zirconium (IV) oxide (ZrO2), and silicon dioxide (SiO2).

[0019] In an embodiment, the plurality of deposited layers forming the inorganic film in step (ii) comprises deposited layers of aluminum(III) oxide (Al2O3) alternating with deposited layers of a metal oxide compound different from aluminum(III) oxide.

[0020] In an embodiment, the plurality of deposition layers forming the inorganic film in step (ii) comprises deposition layers of aluminum (III) oxide (Al2O3) alternating with deposition layers of any one of titanium (IV) oxide (TiO2), hafnium (IV) oxide (HfO2), tantalum (V) oxide (Ta2O5), and zirconium (IV) oxide (ZrO2).

[0021] In an embodiment, the plurality of deposited layers forming the inorganic film in step (ii) comprises deposited layers of aluminum oxide (III) (Al2O3) alternating with deposited layers of hafnium oxide (IV) (HfO2).

[0022] In an embodiment, the method includes repeating steps (i) and (ii) until a film having a desired total thickness is formed. In an embodiment, said step (ii) is performed before step (i). In an embodiment, an MLD layer deposited in step (i) alternates with every second or third ALD deposited layer deposited in step (ii).

[0023] In an embodiment, the method further comprises pre-treating the substrate, hi an embodiment, pre-treating the substrate comprises treating the substrate with one of ozone (O3), oxygen (O2), and / or by depositing a primer layer onto the surface of the substrate using the atomic layer deposition process, the primer layer enhancing adhesion of the essentially porous material layer formed in step (i) to the surface of the substrate.

[0024] In an embodiment, the method further comprises depositing a polymer film on / over the coating as a top layer, hi an embodiment, the polymer film constituting the top layer is made of polydimethylsiloxane (PDMS) or polyurethane (PU).

[0025] In another aspect, a self-healing coating stack is provided according to what is claimed in independent claim 14.

[0026] In an embodiment, the self-healing coating stack is formed on a substrate, and (a) at least one layer of an essentially porous bulk material deposited using a molecular layer deposition (MLD) process; (b) an inorganic film deposited using an atomic layer deposition (ALD) process; Including, Within the at least one layer of essentially porous bulk material, unbound, unreacted, and / or partially reacted precursors enter into chemical interaction with harmful environmental species that have penetrated into defect sites within the coating and seal the defect sites by forming a sealing compound.

[0027] In an embodiment, the inorganic membrane (b) comprises at least one deposited layer.

[0028] In an embodiment, within the laminate coating, the inorganic film (b) comprises a plurality of deposited layers arranged in a stack, each deposited layer within the stack having the same or a different composition.

[0029] In an embodiment, in the laminate coating, the deposition layer forming the inorganic film (b) is made of any compound selected from the group consisting of aluminum oxide (III) (Al2O3), titanium oxide (IV) (TiO2), hafnium oxide (IV) (HfO2), tantalum oxide (V) (Ta2O5), zirconium oxide (IV) (ZrO2), and silicon dioxide (SiO2).

[0030] In an embodiment, within the laminate coating, the inorganic film (b) comprises stacked layers of aluminum oxide (III) (Al2O3) alternating with stacked layers of a metal oxide compound different from aluminum oxide (III).

[0031] In an embodiment, within the laminate coating, the inorganic film (b) includes a deposition layer of aluminum oxide (III) (Al2O3) alternating with a deposition layer of any one of titanium oxide (IV) (TiO2), hafnium oxide (IV) (HfO2), tantalum oxide (V) (Ta2O5), and zirconium oxide (IV) (ZrO2).

[0032] In an embodiment, within the coating stack, the inorganic film (b) comprises deposited layers of aluminum oxide (III) (Al2O3) alternating with deposited layers of hafnium oxide (IV) (HfO2).

[0033] In an embodiment, within the laminate coating, the inorganic film (b) comprises stacked layers of aluminum oxide (III) (Al2O3) alternating with stacked layers of tantalum oxide (V) (Ta2O5).

[0034] In an embodiment, the laminate coating comprises the inorganic film (b) deposited on / over the substrate and / or on / over the at least one layer of essentially porous material (a).

[0035] In an embodiment, the laminate coating comprises the inorganic film (b) deposited on / over the substrate using an atomic layer deposition (ALD) process. In an embodiment, the inorganic film (b) is formed with a plurality of deposition layers arranged into at least one stack having any one of the following compositions: Al2O3-SiO2-Al2O3-TiO2; Al2O3-HfO2-Al2O3-ZrO2; Al2O3-HfO2-ZrO2; or TiO2+[(Al2O3-TiO2)]. In an embodiment, the above-mentioned series of deposition layers in the inorganic film (b) are arranged into a repeating stack.

[0036] In an embodiment, the laminate coating comprising the inorganic film (b) deposited on / over the substrate using an ALD process further comprises at least one layer (a) consisting of an essentially porous bulk material deposited using a molecular layer deposition (MLD) process.

[0037] In an embodiment, the laminate coating comprises at least one layer (a) consisting of an essentially porous bulk material, the at least one layer being deposited directly on the substrate or on top of the inorganic film (b), optionally on top of a first stack of the plurality of deposited layers provided within the inorganic film (b).

[0038] In an embodiment, the laminate coating further comprises a primer layer formed on the substrate surface to enhance adhesion of the essentially porous material layer (a) to the substrate surface, the primer layer being optionally deposited using an atomic layer deposition process.

[0039] In an embodiment, the laminate coating further comprises a polymer film deposited on / over the coating as a top layer. The polymer film constituting the top layer may be made of polydimethylsiloxane (PDMS).

[0040] In an embodiment, within the laminate coating, the substrate is selected from the group consisting of a medical device, a medical packaging, an organic light emitting diode (OLED), and a sensor.

[0041] In an embodiment, the sealing compound formed within the essentially porous bulk material (layer (a)) is a product of unbound, unreacted, and incompletely reacted (partially reacted) precursors and harmful environmental species, including any one of water molecules, hydroxyl radicals, nitrous oxide species, and the like, that originate from the environment surrounding the substrate coated with the laminate coating and penetrate into defect sites within the coating.

[0042] In a further aspect, there is provided a use of a laminate coating according to some of the above aspects and embodiments as a desiccant. In a further aspect, there is provided a use of a laminate coating according to some of the above aspects and embodiments in packaging, in particular in medical packaging. In a further aspect, there is provided a use of a laminate coating according to some of the above aspects and embodiments in any one of the following applications: catalyst supports, solid electrolytes for microbatteries, lithium ion battery separators, free standing membranes, water repellent layers on sensors, fluorescent thin films, barrier films for flexible electronic devices, barrier films for optical elements, in particular LEDs, quantum dots, and / or nanorod LEDs, barriers for nanoparticles, e.g. phosphorescent nanoparticles, flexible smart windows, smart contact lenses, smart sensors, and space related applications.

[0043] In some other aspects, a packaging article has a surface coated with a laminate coating according to some of the above aspects and embodiments and / or formed by a method according to some of the above aspects and embodiments. In an embodiment, the packaging article is selected from the group consisting of a container, optionally with a pump, a tray, optionally with a multi-compartment tray, an ampoule, a vial, a syringe, a blister pack, an individually wrapped pack, and a pouch. In an embodiment, the packaging article has a substrate comprising or consisting of glass or a polymer, such as polyurethane (PU), liquid crystal polymer (LCP), and / or polyethylene terephthalate (PET).

[0044] In some other aspects, a medical device, such as an implantable medical device, is provided, the medical device having a surface coated with a laminate coating according to some of the previous aspects and embodiments and / or formed by a method according to some of the previous aspects and embodiments. In some other aspects, the medical device is formed as an ultrasonic medical device, optionally a piezoelectric micromachined ultrasonic transducer (PMUT) or a capacitive micromachined ultrasonic transducer (CMUT).

[0045] The usefulness of the present invention arises for a variety of reasons, depending on each particular embodiment of the invention.

[0046] The main advantage of ALD is that it all derives from the continuous, self-saturating gas-surface reaction control of the deposition process. Such a film growth mode allows extremely conformal and uniform films to be coated on three-dimensional objects with arbitrary shapes. Therefore, ALD technology has high potential in the production of high-quality coatings required for various applications, in particular medical applications. Due to the relatively low temperatures (85-150°C) utilized during ALD deposition, the coatings can be conformally deposited even on sensitive substrate materials. In addition, since ALD coatings are largely amorphous (not crystalline), these coatings do not provide an easy path for harmful, e.g. corrosive, species through the coating.

[0047] Overall, the present invention provides a method for producing (nano)laminated coatings that have improved (micro)defect resistance and also act as a reliable low-temperature barrier against harmful environmental species such as moisture and / or ions, UV light, heat, oxygen, and the like. The present invention further provides a deposition method for producing self-repairing / self-healing coatings that are compatible with low-temperature thermal processing methods.

[0048] The method presented hereby relates to the fabrication of thin film encapsulating coatings, particularly on sensitive and optionally flexible substrates, which are self-sustaining and capable of self-repairing from a significant amount of damage.

[0049] Through careful selection of coating materials, multiple, extremely thin inorganic layers can be ALD deposited. This allows the coating structure to remain flexible, while the periodic structure ensures good barrier properties by increasing the volume of impermeable material (e.g., metal oxide material). On the other hand, the MLD layer acts as a "decoupling" layer between ALD-deposited inorganic barrier films, thereby blocking defect propagation through the coating and increasing the water vapor transmission rate (WVTR) lag time or moisture permeation by forming tortuous paths.

[0050] The (nano)laminate coatings are particularly suitable for use in the medical sector, e.g. for implantable electronic devices in cardiology and neurology, as they serve as a protective, non-toxic and long-lasting medical coating solution.

[0051] Improving operational reliability and extending life span are particularly important for implantable medical devices, since replacement of the implant often involves a surgical procedure, and therefore improving the reliability of such devices along with their performance characteristics is of great benefit to both patients and healthcare systems.

[0052] The present invention further enables extended life and improved performance of moisture sensitive components used in industrial and consumer electronic devices.

[0053] In this disclosure, materials having layer thicknesses of less than 1 micrometer (μm) are referred to as "thin films."

[0054] The expressions "reactive fluid" and "precursor fluid" refer in this disclosure to a fluid stream that contains at least one compound (precursor compound) (hereinafter precursor) in an inert carrier.

[0055] In this disclosure, the term "biocompatibility" is used in its general sense, i.e., defined as the ability of a device or system of technical nature exposed to a biological environment to perform its function without exhibiting major clinically untoward symptoms both in the short and long term. The assessment of biocompatibility primarily involves analyzing the ability of the materials that make up the device / system to interact with the biological environment without causing unwanted inflammation or complications in the body.

[0056] In this disclosure, unless otherwise indicated, the term "environment" refers to the environment surrounding a substrate coated with a coating according to an embodiment.

[0057] In this disclosure, the term "body" (in the context of expressions such as "body implantable", "body environment", etc.) is used primarily with respect to humans. However, the concepts of the present invention may be fully applied to articles, such as medical devices, constructed and / or used with non-human mammals or other animals.

[0058] The term "a number of" as used herein means any positive integer starting from 1, e.g., 1, 2, or 3, whereas the term "a plurality of" as used herein means any positive integer starting from 2, e.g., 2, 3, or 4.

[0059] The terms "first" and "second" are not intended to denote any order, quantity, or importance, but are only used to distinguish one element from another, unless otherwise expressly stated. [Brief description of the drawings]

[0060] [Figure 1] 1A-1C are schematic diagrams illustrating a conceptual self-healing coating stack 10 according to an embodiment, generally designated 10, positioned on a substrate 20. As shown in FIG. [Diagram 2] FIG. 2 is a schematic diagram showing an ALD-nanolaminate coating at 10 ′ located on a substrate 20 . [Diagram 3] 3A and 3B show water vapor transmission rate (WVTR) and defect area test results obtained for a stacked coating according to an embodiment compared to a monolithic ALD structure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0061] 1A, 1B, and 1C show the underlying concept of a protective coating stack (hereinafter coating), generally designated 10, formed on a substrate 20, according to an embodiment. In some cases, the protective coating is self-healing.

[0062] The coating 10 is advantageously configured for an optionally flexible component (substrate) susceptible to erosion or corrosion induced by various adverse environmental species originating from the environment surrounding the substrate 20 coated with the coating 10. The environment may be, for example, the atmosphere, any gaseous medium, such as ambient air, and / or any moisture-containing environment, such as an essentially liquid medium (essentially aqueous medium, e.g., water, ion-containing medium, saline medium, etc.), or a solid medium (e.g., powder or particles). For clarity, it is mentioned that the atmosphere / ambience surrounding the coated substrate may also represent a moisture-containing medium. In some cases, the environment includes various in vitro cultures (e.g., cell cultures) and in vivo media. The latter may represent body fluids and tissues.

[0063] The term "moisture" is used herein to indicate the presence of liquid, specifically water, in the environment surrounding the coated substrate. In some cases, the term relates to the amount of water vapor present in the atmosphere.

[0064] The coating 10 is formed on the substrate 20 using molecular layer deposition (MLD) and atomic layer deposition (ALD) techniques. Through careful selection of precursors (reactants) for these deposition processes, the coating 10 can be made to have self-healing properties. The coating 10 can be formed to cover a portion of the substrate or the entire substrate.

[0065] Coating 10 includes at least one layer or film 11 consisting of an essentially porous bulk material. Layer 11 is also referred to as an "essentially porous layer" or "MLD" layer. Layer 11 is deposited directly or indirectly onto the surface of substrate 20 using an MLD process. Direct deposition refers to depositing essentially porous layer 11 on / over the surface of substrate 20, whereas indirect deposition refers to depositing the essentially porous layer on / over a primer layer formed (directly) on substrate 20, as described further below.

[0066] In some embodiments, the MLD layer 11 is formed as a purely organic polymer film. In some other embodiments, the MLD layer 11 is formed as a hybrid organic-inorganic film layer.

[0067] The deposition setup used for the MLD and ALD reactions may be based on, for example, the ALD equipment described in U.S. Pat. No. 8,211,235 (Lindfors) or the equipment trademarked as Picosun R-200 Advanced ALD system available from Picosun Oy, Finland. Such a setup allows for depositing materials at the atomic and molecular level.

[0068] An exemplary ALD reactor includes a reaction chamber that establishes a reaction space (deposition space) in which the production of the coating 10 described herein takes place. The reactor further includes several instruments configured to mediate fluid flows (inert and reactive fluids containing precursor compounds P1, P2) into the reaction chamber. These instruments are provided, for example, as several intake / supply lines and associated switching and / or regulating devices, for example valves. Unreacted / unbound precursors and generated by-products are typically drawn out of the reaction chamber by a vacuum pump.

[0069] In a typical MLD cycle, a molecule of a first precursor reacts with reactive (binding) sites on the surface of a substrate. This creates a molecular layer of the first precursor on the substrate surface. After purging, a molecule of a second precursor reacts with new reactive sites created through deposition of the first precursor, thus forming a molecular layer of the second precursor. At the same time, the surface chemistry is converted back to the initial reactive groups. The cycle is completed with a second purge. By repeating the four steps (MLD precursor 1-purge-MLD precursor 2-purge), a polymer film can be grown at the molecular level.

[0070] To enable the fabrication of hybrid organic-inorganic films, the MLD process utilizes polymeric precursors (e.g., metal alkoxide materials) in combination with some of the common precursors typically used in ALD (e.g., tetramethylammonium, TMA).

[0071] An exemplary MLD process for depositing the inherently porous film 11 as a hybrid organic-inorganic film layer is described below.

[0072] An exemplary MLD process utilizes 7-octenyltrichlorosilane (7-OTS) as a polymer precursor. During the deposition cycle, first 7-OTS and water used as a catalyst are introduced into the reaction space of the deposition reactor, followed by ozone (O3) treatment. 7-OTS has terminal vinyl (-CH=CH2) groups that can be converted to carboxylic acid groups (-COOH) using ozone. The deposition cycle continues by introducing the metal precursor into the reaction space, followed by water. In the described process, trimethylaluminum (TMA) is used as the metal precursor because it reacts with the carboxylic acid groups to form linkers that can bond the polymer layers together. By repeating the TMA-H2O sequence one to four times, a monolayer of, for example, aluminum(III) oxide (Al2O3) is formed with a large number of reactive Al-OH sites. Subsequent deposition of 7-OTS and water into the reaction space results in the structure of a hybrid organic-inorganic MLD film (11). Here, the Al2O3 layer is embedded between organic polymer layers. The MLD deposition temperature is in the range of about 50°C to about 200°C, and is mainly about 90°C.

[0073] Similarly, hybrid poly(aluminum ethylene glycol) polymers can be grown by sequentially exposing the substrate to TMA and ethylene glycol (EG). MLD deposition temperatures for hybrid poly(aluminum ethylene glycol) polymers range from about 85° C. to 175° C.

[0074] Examples of non-TMA metal precursors that may be used to deposit the inherently porous film 11 include, for example, titanium tetraisopropoxide (TTIP, Ti(OCH(CH)), zirconium butoxide (Zr(CHO), and diethylzinc (DEZ, ZnEt).

[0075] The coating 10 further includes an inorganic film 12 deposited using atomic layer deposition on / overlying the at least one layer of essentially porous material 11. The inorganic film 12 is also referred to in general terms as an "ALD film / layer."

[0076] As mentioned above, ALD is a special chemical deposition method based on the sequential introduction of at least two reactive precursor species to at least one substrate. In some specific methods, such as photon-enhanced ALD or plasma-enhanced ALD, one of these reactive precursors can be replaced by energy, which leads to a single precursor ALD process. For example, the deposition of a pure element, such as a metal, requires only one precursor. Binary compounds, such as oxides, can be formed with one precursor chemical when the precursor chemical contains both elements of the binary material to be deposited. Thin films grown by ALD are dense, pinhole-free, and have a uniform thickness.

[0077] In ALD, at least one substrate is typically exposed to temporally separated precursor pulses in a reaction vessel to deposit material on the substrate surface by successive self-saturating surface reactions. In the context of this disclosure, the term ALD includes all applicable techniques based on atomic layer deposition, as well as any equivalent or closely related techniques, such as the following ALD subtypes: plasma-assisted ALD, PEALD (plasma-enhanced atomic layer deposition), and photon-enhanced atomic layer deposition (also known as photo-ALD or flash-enhanced ALD).

[0078] A basic ALD deposition cycle consists of four consecutive steps, namely, steps involving the introduction of a first precursor and a second precursor into a reaction chamber in tandem. The precursors entering the reaction chamber are preferably gaseous substances containing the given precursor chemical carried by an inert carrier (gas). The chamber is purged with an inert gas between pulses of precursor. The delivery of the precursor chemicals into the reaction space and the film growth on the substrate are regulated by regulating instruments, such as a three-way ALD valve, a mass flow controller, or any other device suitable for this purpose. One deposition cycle (ALD precursor 1-purge-ALD precursor 2-purge) typically results in an inorganic material (mono)atomic layer formed by a half-reaction between the first and second precursors.

[0079] The above deposition cycles can be repeated until the deposition sequence produces an inorganic thin film, e.g., film 12, of the desired thickness. The deposition cycles can be as simple as those described above, or they can be more complex. For example, the cycles can include three or more reactant vapor pulses separated by purge steps, or certain purge steps can be omitted. Photo-enhanced ALD, on the other hand, has different options for purging, e.g., with only one active precursor. All these deposition cycles form a timed deposition sequence controlled by a logic unit or microprocessor.

[0080] The ALD processes utilized to produce the coatings employ deposition temperatures ranging from about 80 to 250° C. Depositions in the range of about 85 to 125° C. enable or facilitate coating of thermally sensitive substrates, such as substrates containing polymers and / or electrical circuitry.

[0081] 1A-1C show an exemplary coating 10 including two MLD layers 11 (11A, 11B) alternating with a corresponding number (here two) of ALD layers 12 (12A, 12B). A stack structure for coating 10 can include one to five MLD layers alternating with a corresponding number of ALD layers. Existing deposition techniques make it possible to construct stack coating structures including more than five MLD layers 11 (that interface with ALD film 12). However, a coating including one to five MLD layers 11 alternating with the same amount of ALD film 12 provides sufficient protection against corrosion induced by common environmental agents, such as moisture.

[0082] In some embodiments, the coating 10 may be formed as a periodic layered structure in which essentially porous layers 11, 11A, 11B (MLD) are interfaced with essentially impermeable conformal layers 12, 12A, 12B (ALD) that are essentially impermeable (unless damaged and / or defective).

[0083] In some embodiments, the inorganic film 12 deposited using atomic layer deposition techniques includes at least one deposition layer.

[0084] Thus, the coating 10 can be realized by an (ALD) film including one deposition layer (not shown). In such a case, the inorganic film 12 is formed with a single ALD deposited layer of a given material, e.g., a metal oxide. The inorganic film 12 can also be formed in several successive deposition cycles. In this case, the film 12 is composed of several monolayers of the same material.

[0085] In some embodiments, inorganic film 12 includes multiple deposited layers arranged into at least one stack. In the case of film 10 shown in Figures 1A-1C, each of ALD films 12 (12-A, 12-B) consists of three deposited layers 12A-1, 12A-2, and 12A-3 (corresponding to film 12A) and 12B-1, 12B-2, and 12B-3 (corresponding to film 12B) arranged one on top of the other to form a stack. The deposited layers 12-1, 12-2, and 12-3 that form inorganic film 12 ("ALD layers") can have the same or different compositions.

[0086] It should be noted that, to avoid repetition, the reference numbers 12-1, 12-2, 12-3 refer to designating individual deposited layers within film 12A (to be understood as 12A-1, 12A-2, and 12A-3) and within film 12B (to be understood as 12B-1, 12B-2, and 12B-3).

[0087] The individual deposition layers, e.g., 12-1, 12-2, 12-3 (FIGS. 1A-1C), can be formed as monolayers within one (ALD) deposition cycle (having the sequence ALD precursor-purge-ALD precursor 2-purge). In some embodiments, each deposition layer can be formed in several successive deposition cycles (whereby the deposition layer is composed of several monolayers) that produce a deposition layer (e.g., 12-1) having a desired thickness.

[0088] 1A-1C, the inorganic film 12 itself represents a layered (laminate) structure. Deposits of a material having a first composition (M1 for "Material 1") alternate with deposits of a material having a second composition (M2 for "Material 2"). In this configuration, deposits 12-1 and 12-3 are formed from a first material (e.g. aluminum oxide (III) or alumina Al2O3), whereas deposit 12-2 is formed from a second material (e.g. silicon dioxide (IV) or silica SiO2).

[0089] In some embodiments, the deposited layers forming film 12 have different compositions, or alternatively, a coating configuration is contemplated in which all deposited layers (e.g., 12-1, 12-2, 12-3) are made of the same material.

[0090] For clarity, the total number (n1, n2) of the multiple ALD deposited layers, e.g., 12-1, 12-2, 12-3, may vary depending on the layer composition, the substrate to be coated, and the substrate application. As an example, the total number (n1, n2) of deposited layers may vary from 1 to 100. In most cases, n1, n2 vary from 1 to 20. The thickness of each deposited layer 12-1, 12-2, 12-3 may vary from 1 to 20 nm, and typically these layers are 1 to 5 nm thick.

[0091] In some exemplary embodiments, the coating 10 includes several MLD-deposited organic or hybrid (organic-inorganic) 1-20 nm films 11 (11A, 11B) alternating with inorganic ALD films 12 (12A, 12B) having the thicknesses described above. Within the coating 10, the inorganic films 12 may have a uniform composition (e.g., each formed from a single metal oxide). Additionally or alternatively, the films 12 may be formed with a (nano)layer stack consisting of 1-4 deposition layers (1-20 nm for each deposition layer).

[0092] As will be apparent to one skilled in the art, depending on the reaction conditions, for example, multiple 1-3 nm deposition layers may be deposited to adjust the thickness of the resulting stack and thus the resulting inorganic film 12.

[0093] The molecular layer deposition process and the atomic layer deposition process are repeated until a layered coating structure having a desired total thickness (n) is formed to form the coating 10. The total thickness of the coating 10 can be in the range of about 10 nm to about 1000 nm.

[0094] To form the ALD film 12, the deposition layer can be made from a selection of (metal) oxide species including, by way of example, aluminum (III) oxide (Al2O3), titanium (IV) oxide (TiO2), hafnium (IV) oxide (HfO2), tantalum (V) oxide (Ta2O5), zirconium (IV) oxide (ZrO2), niobium (V) oxide (Nb2O5), and silicon dioxide (SiO2). Metal nitride compounds can also be used, such as titanium nitride and aluminum nitride. The use of any other suitable compounds is not excluded.

[0095] In an embodiment, a coating 10 can be provided in which the multiple stacked layers (e.g., 12-1, 12-2, 12-3) forming the inorganic film 12 include stacked layers of aluminum(III) oxide (Al2O3) alternating with stacked layers of at least one metal oxide compound different from aluminum(III) oxide. The at least one metal oxide compound different from aluminum(III) oxide can be replaced in the stack by a semiconductor oxide (e.g., silica) or by an elemental metal, a nitride compound, a carbide compound, a sulfide compound, or any other suitable compound.

[0096] In an embodiment, the multiple deposition layers forming inorganic film 12 include deposition layers of aluminum (III) oxide (Al2O3) alternating with deposition layers of any one of titanium (IV) oxide (TiO2), hafnium (IV) oxide (HfO2), tantalum (V) oxide (Ta2O5), and zirconium (IV) oxide (ZrO2).

[0097] As an example, the coating 10 may be in the following form: Al2O3+ X It may comprise several essentially porous MLD-deposited polymer layers 11 alternating with inorganic ALD film stacks 12 having the morphology [(HfO2-Al2O3-ZrO2-Al2O3)]. The MLD layers 11 can be deposited between each ALD-deposited layer, i.e. more frequently, or between every 2-3 ALD-deposited layers (not shown).

[0098] A further exemplary stack morphology for the membrane 12 is, for example, the following (nano)laminate: Al2O3-SiO2-Al2O3-TiO2; Al2O3-HfO2-Al2O3-ZrO2; Al2O3-HfO2-ZrO2; TiO2+[(Al2O3-TiO2)]; Al2O3-SiO2; Al2O3-HfO2; Al2O3-Ta2O5; and Al2O3-Ta2O5-Al2O3-HfO2 Examples include:

[0099] In some cases, the (nano)laminates mentioned above may be arranged in a repeating stack and have an exemplary composition of x[(12-1)-(12-2)-(12-3)-(12-n)].

[0100] To obtain the alumina (Al2O3) layer, precursors TMA and water were used. To obtain the zirconia (ZrO2) layer, precursors tetrakis(ethylmethylamino)zirconium (TEMAZr) and water were used. Other ALD precursors that react with water include diethylzinc (DEZ,ZnEt2), titanium tetrachloride (TiCl4), tetrakis(dimethylamido)titanium (TDMATi), tetrakis(ethylmethylamido)-hafnium(IV) (TEMAHf), and tetrakis(ethylmethylamido)-hafnium(IV) (TEMAHf) of the general formula Me(RCp). x and tert-butylimido)tris(ethylmethylamido)tantalum (TBTEMTA).

[0101] The inorganic film 12 formed using ALD techniques is fully conformal to the surface it is coated on.

[0102] It is assumed here that a person skilled in the art can reproduce layered structures 12 made of other inorganic compounds based on the given examples.

[0103] FIG. 2 shows a profiled substrate 20 coated with a layered coating embodied at 10' (S1 refers to the plateau region and S2 refers to the three-dimensional profile pattern). The layered coating is realized as a layered structure including multiple deposited layers forming an inorganic film 12, fabricated using atomic layer deposition techniques. The morphology shown in FIG. 2 is realized without the presence of an MLD interface layer. The exemplary stack morphology for the inorganic film 12 described above can be utilized in the coating 10'.

[0104] In some embodiments, the coating 10' formed on the substrate 20 includes an inorganic film 12 deposited on / over the substrate forming a plurality of deposited layers arranged into at least one stack having any one of the following compositions: Al2O3-HfO2, Al2O3-Ta2O5, Al2O3-SiO2-Al2O3-TiO2, Al2O3-HfO2-Al2O3-ZrO2, Al2O3-HfO2-ZrO2, TiO2+[(Al2O3-TiO2)], and Al2O3-Ta2O5-Al2O3-HfO2. In the described embodiments, each deposited layer M1-M4 is comprised of an oxide compound, although other compounds (e.g., elemental metals, nitrides, carbides, sulfides, and the like) may be utilized. Stacks of 2, 3, 4 or even 5 or more deposited layers are contemplated, and these stacks may be repeated one above the other (not shown). Any other (nano)laminate morphology may also be employed, including, for example, those mentioned above.

[0105] The laminate coating shown in Figure 2 may further include at least one layer 11 of essentially porous bulk material deposited by an MLD process (not shown). The at least one layer of essentially porous bulk material may be deposited directly on the substrate 20 or on top of the inorganic film 12. In the case of a configuration involving a repeating stack of inorganic deposited layers (ALD layers), an MLD layer may be deposited on top of the first stack (shown as M1-M4 in Figure 2). Alternatively, an MLD layer 11 may be deposited after every 2-3 ALD deposited layers (not shown).

[0106] In an embodiment, the coating 10, 10' is fabricated on a substrate 20 formed as a medical device including functional electronic components. In an embodiment, the coating 10, 10' is fabricated on a substrate formed as an implantable medical device, optionally a miniature implant device. In a further embodiment, the coating 10 is fabricated on a substrate formed as an implantable ultrasonic medical device, such as a piezoelectric micromachined ultrasonic transducer (PMUT) or a capacitive micromachined ultrasonic transducer (CMUT).

[0107] Diagnostic sonography is an ultrasound-based diagnostic imaging technique used to visualize subcutaneous body structures, including tendons, muscles, joints, blood vessels, and internal organs, for possible pathologies or lesions. The method is also suitable for imaging soft tissues. Along with non-invasive ultrasound imaging solutions and / or epicutaneous applications, ultrasonically powered implantable devices are being developed. The latter devices utilize wireless power transmission via acoustic waves to remotely sense the physiological environment within soft biological tissues, instead of inductive (near-field) and radio frequency (RF) links.

[0108] For the above mentioned methods, it is important that the packaging of the transducer or sensor device is ultrasound compatible, i.e., the packaging has minimal effect on the acoustic signal. In addition, especially implantable medical devices must be protected with a coating that is biocompatible and prevents leakage of metal ions into the body. As an example, PMUT devices contain electrodes made of aluminum or molybdenum, thus requiring a biocompatible encapsulation.

[0109] Biocompatibility and ion-proof barrier properties are achieved by a coating 10, 10' comprising a multi-layer inorganic (ALD) film stack (12, 12A, 12B). The coating 10, 10' realised for ultrasound imaging devices can be realised as a laminate structure comprising multiple deposition layers produced by atomic layer deposition. Such a structure can also be realised without the presence of an MLD interface layer (Figure 2, reference 10'). Providing a polymer cover film 22 on the ALD-deposited (nano)laminate 10' shown in Figure 2 can be beneficial in applications where there is a strong need for conformal encapsulation of biocompatible devices, e.g. soft tissue-compatible devices.

[0110] Examples of ALD-deposited film stack (12) morphologies that are particularly suitable for coating ultrasonic medical devices include Al2O3-HfO2, Al2O3-Ta2O5, and Al2O3-HfO2-Al2O3-Ta2O5. Encapsulating an ultrasonic diagnostic device (e.g., the transducer described above) with a coating 10, 10' that includes a stack 12 based on these morphologies does not result in any change in the function, e.g., frequency, of the device. In addition, it has been observed that these coatings remain intact when the ultrasonic device, e.g., the transducer, is acoustically excited by pulses having an amplitude set at 0.1-10 V (the vibration during excitation was about 0.5 nm / V).

[0111] Within coating 10, the combination of the MLD and ALD layers forms a barrier that prevents harmful environmental agents originating from the local environment surrounding a substrate 20 coated with coating 10 from penetrating defective and / or damaged sites 30 (FIG. 1B) in the coating structure and from contacting the substrate.

[0112] Environmental substances act here as species that are detrimental to the integrity and / or functionality of the substrate, the nature of these detrimental species depending on the environment surrounding the coated substrate.

[0113] In some embodiments, the coating 10 is configured to protect the substrate from damage caused by water from moisture infiltration into defect and / or damaged areas 30 of the coating. In this case, environmental water acts as the harmful / corrosive species. In some other cases, the harmful environmental species may be various environmental factors including, for example, ions and / or low molecular weight compounds, as well as UV light, heat, oxygen and / or other gases, and the like, by way of example only.

[0114] By combining deposited layers with different physical (porosity, texture) as well as chemical properties, the coating 10 acts as a moisture barrier.

[0115] By selecting the (chemical) composition of the layers and the deposition method, the coating 10 can further be made to have self-repairing / self-healing capabilities.

[0116] 1B, which shows the coating 10, several defect sites and / or localized degradation sites 30 have formed during deposition and / or use. The defects include mechanical damage, such as cracks, scratches, etc., as well as localized delamination and / or other damage induced by various factors, such as exposure to moisture and / or ions, UV light, heat, oxygen, and the like.

[0117] The defects 30 may begin at a macro level, thereby depriving the coating of its protective and / or aesthetic properties. Additionally or alternatively, the defects 30 may begin at a micro- and nano-level, and therefore may not always be visible to the human eye. The defects 30 are observed to form primarily in the inorganic (ALD) film 12, since the inorganic ALD film 12 forms a physical barrier. This may be due to the non-porous nature of the inorganic (ALD) film. When the film 12 is broken, it loses its conformal properties, which in turn allows various environmental species to penetrate into the coating through the damaged site 30. When multiple breaks occur in different layers of the stack (see FIG. 1B and the damaged sites in films 12A, 12B), the harmful species tend to propagate deeper into the coating until they reach the substrate 20. Localized exposure of the substrate to harmful environmental species, such as moisture, causes corrosion of the substrate inside the protective coating.

[0118] The coating 10 includes essentially porous (MLD) layers 11 (11A, 11B) that separate the conformal inorganic films 12 (12A, 12B) from each other and block defect propagation through the laminate barrier coating (10) by acting as so-called decoupling layers.

[0119] Thus, in an embodiment, the coating 10 is configured to prevent environmental moisture 31, e.g. water molecules, from adversely affecting the underlying substrate when they penetrate into the laminate through micro-defects 30. This is achieved by constructing a (nano)laminate in which conditions are established that allow essentially free precursor compounds 121, e.g. unbound, unreacted and / or not fully reacted precursor compounds, to penetrate into the essentially porous bulk material during the deposition stage (i.e. during deposition of the MLD layer 11 consisting of said essentially porous bulk material). In the bulk of said porous film 11, unbound, unreacted and / or partially reacted precursors 121 enter into a state of chemical interaction with harmful environmental species 31 that have penetrated into the defect sites 30 in the coating and seal said defect sites by forming a sealing compound 32 (FIG. 1C).

[0120] In an exemplary embodiment, a coating 10 having the structure revealed by Table 1 was obtained. [Table 1]

[0121] In the configurations shown in Table 1, the Al2O3 layers (12A-1, 12A-3, 12B-1, 12B-3) act as a (moisture) barrier, while the SiO2 layers (12A-2, 12B-2) function as capping layers to prevent hydrolysis of aluminum oxide. The nano (porous) layers 11A, 11B serve as ductile "decoupling" layers that can retain unbound / unreacted precursors that have permeated out of the (ALD) film 12.

[0122] In the coating structure of the given example, unbound or not fully reacted precursors 121 (e.g. TMA dimer molecules) penetrate into the essentially porous layers 11A, 11B during the deposition stage of said essentially porous layers 11A, 11B. Here, said unbound precursors 121 react with "external" water molecules 31 that were retained in said layers 11A, 11B before the deposition of the inorganic oxide layers 12A, 12B ("external" water molecules mean water molecules that entered the coating 10 from outside the coated substrate, e.g. with environmental moisture). The reaction of said unbound precursors 121 with water molecules, here representing harmful environmental species 31, leads to the formation of a new sealing compound 32. In the presented example, the reaction of TMA (121) with water (31) produces Al2O3 and / or Al(OH)x, which act as sealing compound 32.

[0123] The spots 32 formed by the sealing compound at the defect sites 30 throughout the stack depth can be seen as sealing "patches". The sealing patches block harmful environmental species (e.g. water originating from humidity) from penetrating through the layered coating structure 10 (see enlarged box in Fig. 1C). These "patches" self-assemble within the bulk of the essentially porous MLD layer 11 (11A, 11B) when a substrate coated with the coating 10 is exposed to an environment containing potentially harmful substances. As mentioned above, the environment can be any environment / ambience surrounding the coated compound (substrate coated with the coating 10) intended for storage, transportation, and / or operation. This environment contains environmental species (e.g. diffused water droplets) that are potentially destructive to the integrity / functionality of the coated compound.

[0124] The unbound, unreacted, or incompletely reacted (partially reacted) precursor compound 121, such as a TMA (dimer) molecule, acts herein as a "self-healing material."

[0125] In addition to being capable of self-repair (self-healing), the coating 10 is also adapted to have a desiccant function. The desiccant function is obtained by chemical interaction of a precursor that is not fully reacted with a liquid / vapor, e.g., water. Thus, the present invention further relates to the use of the coating stack 10 as a desiccant.

[0126] In an embodiment, the coating stack 10 further comprises a primer layer 21 produced by pretreating the substrate 20 prior to depositing the essentially porous layer 11. The pretreatment may be carried out by (low-temperature) ALD deposition of at least one monolayer of alumina (Al2O3) using precursors of TMA and water, optionally in conjunction with a plasma-assisted process. The pretreatment may further be carried out by treating the substrate with ozone (O3) or oxygen (O2). Any other suitable pretreatment method aimed at enhancing the adhesion of the polymer molecules to the substrate may be employed.

[0127] In an embodiment, the laminate coating 10, 10' further comprises a cover film 22 deposited on / over the laminate (10, 10') as a top layer. The top cover layer 22 is preferably a polymer film, such as a polydimethylsiloxane (PDMS) film (see reference P1 in FIG. 2). Other examples include polyurethane, silicone, and the like.

[0128] PDMS is one of the most commonly used polymers for coating medical devices, particularly implantable medical devices, due to its high biocompatibility and biostability. One of the major concerns associated with this polymer is its high water vapor permeability, which causes water condensation and void formation, which leads to corrosion of (metal) substrates. Utilizing PDMS in combination with the laminate coating 10 according to the present disclosure overcomes such drawbacks.

[0129] The polymer cover film 22 can be deposited using, for example, a dip-coating or (over)molding process.

[0130] For practical reasons, cover film 22 is typically deposited on / over ALD film 12. Since ALD films are not porous, they act as a physical barrier layer, and thus ALD deposited layer 12 is used as an upper layer in stack 10 (before depositing cover film 22 or when realizing coating 10 without cover film 22).

[0131] The coatings 10, 10', which include a polymer cover film 22, e.g. made of PDMS, as a capping layer, have outstanding electrical insulating properties, which makes them particularly suitable for the encapsulation of electrically powered medical devices, e.g. biomedical implants.

[0132] Tests performed by immersing electronic substrates 20 deposited with laminate coatings 10, 10' including PDMS cover film 22 in PBS (phosphate buffered saline) medium at 87° C. showed that the substrates remained functional for about 9.5 months. Coatings 10, 10' including ALD films 12 were deposited at 150° C. on Si / SiO2 chips (substrate size approximately 3 cm x 1 cm) with TiN or Al conductive lines. Other substrates included printed circuit boards (PCBs) made of composite materials, such as FR4 grade glass reinforced epoxy laminate materials.

[0133] For example, in accelerated tests (85°C, PBS) with online resistance measurements, the (nano)laminate coatings 10, 10' (deposited at about 200°C) remained functional until the end of the test (100 days), which correlates with the lifetime of the coated substrate in a body fluid environment (37°C) for 8 years.

[0134] The ALD deposited films described above included several deposited layers of Al2O3 alternating with deposited layers of any one or more of HfO2, ZrO2, TiO2, SiO2, Nb2O5, Ta2O5, and any combination thereof.

[0135] Tensile tests showed that there is excellent interfacial strength between the ALD-deposited film 12 and PDMS. In contrast, the adhesion between two polymers (e.g., the MLD-deposited polymer layer 11 and the PDMS layer 22) is significantly weaker.

[0136] 3A shows water vapor transmission rate (WVTR) results as a function of temperature (°C) obtained for a coating 10 deposited with alternating MLD and ALD layers. FIG. 3A shows that the ALD / MLD films (B-E) have two orders of magnitude better WVTR compared to the monolithic ALD film (A), with WVTR values ​​<1E-5 g / m at ambient. 2It shows that ALD / MLD coatings 10 consisting of five or six dyads (C, D, E) show better results than coatings consisting of three dyads (B). A dyad is defined in this context by the combination of an essentially porous MLD layer 11 and an inorganic ALD layer 12.

[0137] FIG. 3B shows defect area measurements obtained for a layered coating 10 according to an embodiment compared to a monolithic ALD structure. The measurements in FIG. 3B were obtained for defect area (%) at 1.96% tensile strain after immersion in acetone at 90° C. of a polycarbonate substrate 20 (PC, 250 μm) coated with coating 10 (total thickness 50 nm). The substrate 20 may include a primer layer 21 (interfacial layer). Coating 10 including two or three stacks (dyads) of MLD-ALD layers (labeled 11 and 12) shows significantly reduced defect area coverage compared to the non-layered (monolithic) ALD layer (right-most column). The results shown in Figure 3B were obtained using an inorganic ALD film consisting of Al2O3, however, other oxide compounds, such as metal oxides (e.g., HfO2, ZrO2, TiO2, Nb2O5, Ta2O5, or any combination thereof), or silica (also in combination with Al2O3) show similar behavior. The essentially porous MLD layers were either purely organic polymer layers or hybrid polymer layers.

[0138] The results shown in FIGS. 3A and 3B indicate that the MLD layer acts as a “decoupling” layer between the ALD-deposited inorganic barrier films, thereby blocking defect propagation through the coating and increasing the water vapor transmission rate (WVTR) lag time or moisture permeation by creating a tortuous path.

[0139] Furthermore, when a laminate coating 10 combining MLD and ALD layers was used instead of a monolithic ALD coating, a lag was observed between detection of cracks in the coating and detection of damage to the substrate 20 (results not shown), illustrating the fact that the substrate remains protected even though the individual ALD layers become damaged and cracked.

[0140] Substrate samples coated with the combined MLD and ALD coating stack 10 are approximately five times more likely to survive post-deposition cooling and analysis without developing macroscopic defects. Macroscopic defects are detected based on anomalously low activation energies for moisture permeation compared to the baseline. Analysis of such samples with an optical microscope confirms the presence of macroscopic defects. Thus, the coating stack 10 is more crack resistant than (monolithic) ALD films.

[0141] The present invention further relates to the use of the laminate coating 10 according to the embodiment in packaging, in particular in medical packaging.

[0142] In one aspect, a packaging article is thus provided having a surface coated with the coating 10 according to an embodiment. The packaging article may be formed as any one of a container for solids or liquids, optionally a pump-equipped container, a tray, optionally a multi-compartment tray, an ampoule, a vial, a syringe, a blister pack, an individually wrapped pack, and a pouch.

[0143] The laminate coatings described herein may be used on the interior and exterior surfaces of medical packaging articles. When used on the interior surfaces of ampoules, syringes, etc., the laminate coatings may protect the packaged product from contamination by the packaging material (substrate). When used on the exterior surfaces of packaging articles, the laminate coatings provide protection from water molecules, protein molecules or clusters, hydroxyl radicals, nitrous oxide species, etc., which may originate from the environment surrounding the coated article.

[0144] The coating 10, 10' can be realized to partially or completely cover the substrate 20. Complete encapsulation is advantageous for protecting medical devices, in particular implantable medical devices, by efficiently preventing failure of the device caused, for example, by moisture and / or corrosive environment in body fluids.

[0145] Substrates used in the manufacture of packing articles, particularly medical packing articles, and / or medical devices described herein may comprise or consist of either plastic or glass. Plastics may include polymeric materials including, by way of example, polyurethane (PU), liquid crystal polymer (LCP), and / or polyethylene terephthalate (PET).

[0146] In an embodiment, a laminate coating is formed on a substrate, and the laminate coating comprises an inorganic film deposited on / over the substrate using an atomic layer deposition (ALD) process, the inorganic film forming a plurality of stacked layers arranged in a stack, the stacked layers consisting of aluminum (III) oxide (Al2O3) alternating with stacked layers consisting of hafnium (IV) oxide (HfO2). In an embodiment, the laminate coating formed on a substrate comprises an inorganic film deposited on / over the substrate using an atomic layer deposition (ALD) process, the inorganic film forming a plurality of stacked layers arranged in a stack, the stacked layers consisting of a repeating Al2O3-SiO2-Al2O3-TiO2 stack. In an embodiment, the multilayer coating formed on the substrate comprises an inorganic film deposited on / over the substrate using an atomic layer deposition (ALD) process, the inorganic film forming a plurality of deposition layers arranged in a stack, the deposition layers being composed of a repeating Al2O3-HfO2-Al2O3-ZrO2 stack. In an embodiment, the multilayer coating formed on the substrate comprises an inorganic film deposited on / over the substrate using an atomic layer deposition (ALD) process, the inorganic film forming a plurality of deposition layers arranged in a stack, the deposition layers being composed of a repeating Al2O3-HfO2-ZrO2 stack. In an embodiment, the multilayer coating formed on the substrate comprises an inorganic film deposited on / over the substrate using an atomic layer deposition (ALD) process, the inorganic film forming a plurality of deposition layers arranged in a stack, the deposition layers being composed of a repeating TiO2+[(Al2O3-TiO2)] stack. In an embodiment, a layered coating formed on a substrate includes an inorganic film deposited on / over the substrate using an atomic layer deposition (ALD) process, the inorganic film forming a plurality of deposition layers arranged in a stack, the deposition layers consisting of a repeating Al2O3-Ta2O5-Al2O3-HfO2 stack.In an embodiment, a layered coating formed on a substrate includes an inorganic film deposited on / over the substrate using an atomic layer deposition (ALD) process, the inorganic film forming a plurality of deposition layers arranged in a stack, the deposition layers being comprised of a repeating Al2O3-Ta2O5 stack.

[0147] In an embodiment, the laminate coating optionally includes at least one layer of essentially porous bulk material by the MLD process. In an embodiment, the at least one layer of essentially porous bulk material deposited by the MLD process can be located directly on the substrate or on top of the first repeat stack.

[0148] The present invention further relates to a coated article having a surface coated with the coating 10 according to the embodiment.

[0149] The coated article can be formed as a medical device, for example a body implantable medical device, optionally including functional electronic components for developing so-called (bio)electronic solutions. The medical device can thus be formed as an implant without electronic components (one-part or multi-part implant) or as a body implantable medical device containing an electric / electronic system, optionally a self-powered system. The implantable medical device can be configured to be entirely inside the body or can be provided outside the body and connected to an internal organ or another body part. Examples of such devices include implantable cardiac pacemakers, monitors and defibrillators (e.g. implantable cardioverter defibrillators ICD), cochlear implants, various neurological implants and stimulators, infusion pumps, hemodynamic systems, microelectromechanical systems (MEMS), and various (miniaturized) sensors, including biosensors for measuring pressure, flow, strain, etc., as well as (bio)chemical sensors, for example sensors for use in the treatment of diabetes (e.g. sensors for continuous glucose monitoring (CGM)) and sensors for use in other chemically regulated conditions.

[0150] In terms of functionality, implantable devices include various monitoring and / or measuring devices, such as devices that measure the levels of chemicals in biological fluids that serve as markers for certain diseases, and devices applicable to the treatment of certain conditions or syndromes via neuromodulation, or via regulating the levels of said chemicals in biological fluids (e.g., stimulators used to treat migraines).

[0151] The coated article may optionally be provided as a part or component for use in the fabrication of miniature sensors and / or semiconductor devices. The article may further be provided as a printed circuit board (PCB) or PCB assembly (PCBA). The article may further be provided as a non-invasive (medical) device, or part thereof, such as a wearable sensor (sensor system) or semiconductor component / PCB(A).

[0152] Additionally, the present invention relates to medical devices, such as body implantable medical devices. The above and similar medical devices, as well as any related articles configured to be implantable within the body, are contemplated.

[0153] Moreover, as will be apparent to those skilled in the art, surface modification is an added benefit of this method, where one or more ALD layers are deposited followed by an MLD layer resulting in surface functional groups that promote adhesion for various subsequent processes. As such, this method provides applications for catalyst supports, solid electrolytes for microbatteries, acts as a template for freestanding membranes, acts as a water repellent layer on sensors, provides a base for forming fluorescent thin films, allows gap filling by deposition on trench structures followed by mineralization, acts as a protective barrier film for flexible electronic devices, acts as a barrier in applications for optical elements, particularly LEDs, quantum dots, and / or nanorod LEDs, acts as a barrier for nanoparticles, e.g., phosphorescent nanoparticles, and acts as a protective barrier film for high aspect ratio structures and trenches, including smart contact lenses, and smart sensors. Additionally or alternatively, the methods disclosed herein can also be adapted for the manufacture of flexible smart windows, lithium ion battery separators (including ceramic membranes), and for various space-related applications.

[0154] As is clear to those skilled in the art, with the advancement of technology, the basic ideas of the invention may be implemented and combined in various ways. The invention and its embodiments are thus not limited to the above examples, but may vary generally within the scope of the claims.

Claims

1. 1. A method of forming a coating on a substrate, comprising: (i) depositing, directly or indirectly, on the surface of said substrate, at least one layer consisting essentially of a porous bulk material using a molecular layer deposition (MLD) process; and (ii) depositing an inorganic film on / overlying the at least one layer formed in step (i) using an atomic layer deposition (ALD) process; Including, This forms the coating, wherein conditions are established that allow unbound, unreacted, and / or partially reacted precursors to penetrate the essentially porous bulk material during the deposition phase of step (i), the precursors permeating the essentially porous bulk material enter into chemical interaction with harmful environmental species that have penetrated the coating at defect sites in the coating and seal the defect sites by forming a sealing compound; and the inorganic film formed in step (ii) has a plurality of stacked deposition layers, and the plurality of deposition layers include deposition layers of aluminum oxide (III) (Al 2 O 3 ) alternating with deposition layers of hafnium oxide (IV) (HfO 2 ) and / or tantalum oxide (V) (Ta 2 O 5 ); A method for forming a coating on a substrate.

2. 10. The method of claim 1, comprising repeating steps (i) and (ii) until a coating having a desired total thickness is formed.

3. 2. The method of claim 1, wherein step (ii) is performed before step (i).

4. The method of claim 1 further comprising pre-treating the substrate.

5. The pretreatment of the substrate is performed using ozone (O ３ ), oxygen (O ２ 5. The method of claim 4, comprising treating the substrate with any one of the following:

6. The method of claim 1 further comprising depositing a polymer film on / over said coating as a top layer.

7. The method of claim 6 , wherein the polymer film constituting the top layer is made of polydimethylsiloxane (PDMS) or polyurethane (PU).

8. 10. The method of claim 1, wherein the harmful environmental species include any one of water molecules, hydroxyl radicals, nitrous oxide species, biomolecules, and the like that originate from the environment surrounding the substrate coated with the film stack and penetrate into defect sites in the coating.

9. A self-healing laminate coating formed on a substrate; and (a) at least one layer of an essentially porous bulk material deposited directly or indirectly on the surface of said substrate using a molecular layer deposition (MLD) process; (b) an inorganic film deposited on / overlying at least one layer of the essentially porous bulk material using an atomic layer deposition (ALD) process; Including, wherein conditions are established in the coating that allow unbound, unreacted, and / or partially reacted precursors to penetrate the essentially porous material bulk of layer (a) during deposition; the precursors permeating the essentially porous bulk material enter into chemical interaction with harmful environmental species that have penetrated the coating at defect sites in the coating and seal the defect sites by forming a sealing compound; and The inorganic film (b) has a plurality of stacked deposition layers, and the plurality of deposition layers include deposition layers of aluminum oxide (III) (Al 2 O 3 ) alternated with deposition layers of hafnium oxide (IV) (HfO 2 ) and / or tantalum oxide (V) (Ta 2 O 5 ). Self-healing laminated coating.

10. 10. The laminate coating of claim 9, further comprising a primer layer formed on the substrate surface to enhance adhesion of the essentially porous material layer (a) to the substrate surface, the primer layer optionally being deposited using an atomic layer deposition process.

11. The laminate coating of claim 10 further comprising a polymer film deposited on / over said coating as a top layer.

12. The laminate coating of claim 11 , wherein the polymer film constituting the top layer is made of polydimethylsiloxane (PDMS).

13. 10. The laminate coating of claim 9, wherein the sealing compound formed within the essentially porous bulk material is a product of unbound, unreacted, and / or partially reacted precursors and adverse environmental species, including any one of water molecules, hydroxyl radicals, nitrous oxide species, and the like, that originate from the environment surrounding the substrate coated with the laminate coating and penetrate into defect sites within the coating.

14. Use of the laminate coating according to any one of claims 9 to 13 as a drying agent.

15. Use of the laminate coating according to any one of claims 9 to 13 in packaging, in particular in medical packaging.

16. 14. Use of the laminate coating according to any one of claims 9 to 13 in applications for any one of catalyst supports, solid electrolytes for microbatteries, lithium ion battery separators, free standing membranes, water repellent layers on sensors, fluorescent thin films, barrier films for flexible electronic devices, barrier films for optical elements, in particular LEDs, quantum dots and / or nanorod LEDs, barrier films for nanoparticles / phosphors, flexible smart windows, smart contact lenses, smart sensors, and space related applications.

17. A packaging article having a surface coated with a laminate coating described in any one of claims 9 to 13 and / or a coating formed by the method described in any one of claims 1 to 8.

18. 18. The packaging article of claim 17, selected from the group consisting of a container, optionally with a pump, a tray, optionally with a multi-compartment tray, an ampoule, a vial, a syringe, a blister pack, an individually wrapped pack, and a pouch.

19. 18. The packaging article of claim 17, comprising glass or a polymer, such as polyurethane (PU), liquid crystal polymer (LCP), and / or polyethylene terephthalate (PET).

20. A medical device, such as an implantable medical device, having a surface coated with a laminate coating described in any one of claims 9 to 13 and / or a coating formed by a method described in any one of claims 1 to 8.

21. 21. The medical device of claim 20, formed as an ultrasonic medical device, optionally a piezoelectric micromachined ultrasonic transducer (PMUT) or a capacitive micromachined ultrasonic transducer (CMUT).

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