A method for manufacturing coated articles

Abstract

The present invention relates to a method for depositing a coating material onto a substrate by physical vapor deposition, thereby producing a coated substrate, wherein said method comprises the steps of (a) vaporizing at least part of a target material to generate a flow having an energy flux towards a substrate, wherein in said flow a coating material is produced; (b) reducing the energy flux of said flow by removing a portion of said coating material from said flow by means of at least one net placed in front of the substrate.

Description

[0001] A METHOD FOR MANUFACTURING COATED ARTICLES

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to a method for depositing a coating material onto a substrate by physical vapor deposition, thereby producing a coated substrate. The present invention further relates to a coated article obtained by the method of the present invention.

[0004] BACKGROUND OF THE INVENTION

[0005] Physical vapour deposition (hereafter PVD) methods have been widely used for producing thin films and depositing coatings on a variety of substrates.

[0006] PVD is based on the transfer of a material from a target material onto a substrate. PVD methods allow to vaporize the target material, which is then condensed on the substrate to produce a coated substrate.

[0007] Among PVD techniques, magnetron sputtering is based on the sputtering of a target material, in a vacuum chamber. Due to the application of a negative electrical potential to the target, in the presence of a low pressure environment, ions are formed (plasma), and are attracted to the target, leading to the sputtering of said target. The sputtered material is then condensed on the surface of a substrate arranged in front of the sputtering target.

[0008] Coatings were found to have a significant importance in numerous applications, such as in optical applications, or in photocatalysis. In particular, the morphology, and notably the crystal structure of the coating obtained by PVD methods was found to be of particular importance to tune the properties of the coating to the desired use.

[0009] Various methods have been proposed to tune the crystal structure of the coating obtained by PVD methods, and in particular by magnetron sputtering.

[0010] It is for example known to apply an additional external voltage on part on the magnetron sputtering device apparatus, such as notably described in CN101307430A. This reference notably discloses the use of a conductive filter. The conductive filter which is for example a grid which is electronically connected to a substrate holder, and forms a high potential anode for the system, with the aim to suppress high energy particles reaching the substrate.

[0011] It is also known from CN 1 10284103 A to place a filter electrode, consisting of parallel metal wires in front of a substrate, in a magnetron sputtering coating device. Said filter electrode, aims at filtering, and absorbing secondary electrons, thereby reducing the damages caused by the bombardments on a substrate.

[0012] However, since it is necessary to apply bias-voltage to the substrate holder and / or the filters, thereby requiring the use of an additional power supply, the coating manufacturing is expensive. Further, the electrical field created by the use of bias-voltage may create disturbance on the plasma during magnetron sputtering, thereby affecting the deposition of the coating on the substrate.

[0013] Another solution to tune the crystal structure of the coating involves changing the plasma parameters, such as notably described by W. Schbnberger et. Al (Surface and Coating Technology, Volume 293, p. 16-20). This article discloses the deposition of rutile TiC films by pulsed and high power pulsed magnetron sputtering. A stronger bombardment enables a higher mobility of the deposited particles to promote the generation of a crystalline structure.

[0014] Kongsri et Al. (Material science and Applications, 2019, 10, 216-226) further discloses the influence of the substrate-target distance on the structural and optical properties of a TiC film deposited on substrates by dualcathode de unbalanced magnetron sputtering. It was notably shown that the decrease of the substrate-target distance in said method influences the crystallinity of rutile TiO2 as a result of the increase of the concentration of Ti+and the increase of the deposition energy. However, such methods may lead to poor coating quality. Indeed, higher energy bombardment may lead to the delamination of the coating by increasing the coating stress, as a result of the increase in energy of the sputtered species.

[0015] In view of all the above, there remains a continuous need for an improved method for depositing a coating material onto a substrate by PVD, said method allowing the tuning of the morphological and crystallographic properties of the coating material deposited onto the substrate, while said method does not require additional power sources and / or which does not disturb the plasma.

[0016] SUMMARY OF THE INVENTION

[0017] The Inventors have now surprisingly found that it is possible to provide an improved method for depositing a coating on a substrate by means of physical vapor deposition methods, overcoming the above-mentioned disadvantages.

[0018] It is thus an object of the present invention to provide a method for depositing a coating material onto a substrate by physical vapor deposition, thereby producing a coated substrate, wherein the method comprises the steps of :

[0019] (a) vaporizing at least part of a target material to generate a flow having an energy flux towards a substrate, wherein in said flow a coating material is produced;

[0020] (b) reducing the energy flux of said flow by removing a portion of said coating material from said flow by means of at least one net placed in front of the substrate; and characterized in that the at least one net is a three-dimensional foam [3D foam, herein-after] ; and between 40.0 and 98.0 atomic percent [hereinafter at.%] of said coating material is removed from said flow by capturing it by means of the at least one net before it is deposited onto the substrate; and characterized in that the 3D foam has a random pattern, in that the 3D foam is made from at least one metal or a compound thereof, or at least one metalloid or a compound thereof, or at least one non-metal or a compound thereof; and in that the 3D foam has a porosity of between 60.0% and 99.0%, preferably of between 70.0% and 98.5%, more preferably of between 75.0% and 98.0%, even more preferably of between 80.0% and 98.0%.

[0021] DETAILED DESCRIPTION OF THE INVENTION

[0022] Within the context of the present invention, the term “comprising” should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps. It needs to be interpreted as specifying the presence of the stated features, integers, steps, or components as referred to, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof. Thus, the scope of the expression “a composition comprising components A and B” should not be limited to compositions consisting only of components A and B. It means that with respect to the present invention, the only relevant components of the composition are A and B. Accordingly, the terms “comprising” and “including” encompass the more restrictive terms “consisting essentially of” and “consisting of”.

[0023] As used herein, the terms "optional" or "optionally" means that a subsequently described event or circumstance can or cannot occur, and that the description includes instances where said event or circumstance occurs and instances where it does not.

[0024] As mentioned above, according to step (a) of the method according to the present invention, at least part of a target material is vaporized. Within the context of the present invention, the target material may be any target material known to the skilled person, which is suitable for a method of depositing a coating material onto a substrate by physical vapor deposition. It is understood that the choice of the target material may be dependent on the end-use of the coated substrate, and more in particular on the desired properties of the coated substrate.

[0025] Non-limiting examples of suitable target materials mention may be made of any element from the group 3 to 14, compounds thereof or alloy thereof.

[0026] The expression “compounds of elements from the group 3 to 14”, as used herein, may have the broadest meaning generally understood in the art in which form such compounds may exist, and may notably include an oxide, a nitride, a carbide, a complex thereof or a mixture thereof.

[0027] Preferably, the target material is selected from the group consisting of aluminum (Al), chromium (Cr), copper (Cu), Indium Tin oxide (ITO), tungsten (W), molybdenum (Mo), tantalum (Ta), silicon (Si), silicon dioxide (SiO2), gold (Au), silver (Ag), titanium (Ti), titanium oxide (TiOx), zinc (Zn), vanadium (V), zirconium (Zr), tin (Sn), aluminum oxide (AI2O3), cobalt (Co), carbon (C), boron (B), lanthanum (La) and alloy thereof. More preferably, the target material is selected from the group consisting of aluminum (Al), chromium (Cr), copper (Cu), tungsten (W), molybdenum (Mo), tantalum (Ta), gold (Au), silver (Ag), titanium (Ti), zinc (Zn), vanadium (V), zirconium (Zr), tin (Sn), cobalt (Co), and alloy thereof. Titanium (Ti) is especially preferred.

[0028] The target material, as defined above, may be commercially available or may be prepared by using any conventional methods known to the skilled in the art.

[0029] According to the present invention, the vaporization of at least part of the target material, as detailed above, may be carried out by any known vaporization techniques, including notably sputtering or evaporation techniques. According to one embodiment of the method of the present invention, the vaporization of the at least part of the target material, as detailed above, is carried out by sputtering techniques.

[0030] It is further understood that the skilled person in the art will carry out said sputtering techniques according to general practice. Non limiting examples of sputtering techniques mention may be made of magnetron sputtering techniques, ion beam sputtering techniques, high power impulse magnetron sputtering, diode sputtering techniques, triode sputtering techniques or reactive sputter deposition sputtering techniques.

[0031] According to a preferred embodiment of the method of the present invention, the vaporization of the at least part of the target material, as detailed above, is carried out by magnetron sputtering techniques.

[0032] It is understood that the skilled person in the art will carry out said magnetron sputtering techniques according to general practice, that is to say notably, under optimal pressure and temperature conditions, optimal electrical field, and optimal magnetic field.

[0033] As mentioned above, the vaporization of at least part of the target material results in the generation of a flow having an energy flux towards the substrate, wherein in said flow a coating material is produced.

[0034] Within the context of the present invention, the term “flow” as used herein, may have the broadest meaning generally known to the art. In particular, the flow refers to the motion of solid, liquid or gases.

[0035] Within the context of the present invention, the term “energy flux” is intended to denote the flow rate of the energy of all species comprised in the flow, as detailed above, and produced during the vaporization of the target material, e.g. by sputtering, in particular by magnetron sputtering techniques (such as for example the coating material, and any other ions, electrons and neutral species, and / or photons thereby produced), per unit area. In other words, within the context of the present invention, the term “energy flux” is intended to denote the sum of the energy flux of the coating material (EFcoating material) comprised in the flow, as detailed above, and of the energy flux of any other species comprised in the flow and produced during the vaporization.

[0036] Within the context of the present invention, the energy flux, as detailed above, will be expressed in mW.cnr2, which is equivalent to mJ.s’1.cnr2([quantity of energy]], [time]-1[area]-1).

[0037] In general, known systems in the art can be used for the vaporization of at least part of the target material, thereby generating a flow towards a substrate. A non-limiting example of such system notably include a vacuum chamber, which may be optionally equipped with one or more than one gas valve, allowing to control the environment of said vacuum chamber.

[0038] In particular, the vaporization of the at least part of the target material in a vacuum chamber, as detailed above, may be initiated upon the application of an external power source on the target material, said external power source may be notably initiated upon heating, or bombarding said target material by incident particles, or a combination thereof. The coating material thereby undergoes a phase transition from a condensed phase ( / .e. a liquid phase or a solid phase) to a vapor phase. Said vapor phase thus travels through the vacuum chamber. In other words, the vapor phase flows through the vacuum chamber, and a flow is thus generated.

[0039] As said, the flow generated according to step (a) of the method of the present invention contains a coating material.

[0040] Within the context of the present invention, the “coating material” is intended to denote the material which is effectively deposited on the substrate. It is understood that, depending on the vaporization method, the chemical nature of the coating material may differ from the chemical nature of the target material. For example, the chemical nature of the coating material may be the same as for the target material (which is typically the case in the evaporation of at least part of the target material) or, upon vaporization, the material contained in the vapor phase may undergo oxidation, ionization, degradation and the like, thereby producing the coating material. As said above, the vaporization is advantageously carried out by sputtering techniques, in particular by magnetron sputtering techniques. In these sputtering techniques, part of the target material is generally bombarded by incident particles, such as, ionized argon, oxygen, nitrogen or carbonaceous gas particles, the latter being in the form of a plasma. As a result of the bombardment of the incident particles on the surface of the target material, part of the target material is ejected and reacts with the incident particles, thereby producing the coating material. It is understood to the skilled person in the art that during a vaporization by sputtering techniques, in particular magnetron sputtering techniques, side-reactions may occur, and other side-products, such as any other ions, electrons, neutral species, and / or photons can be produced, thereby generating a flow having an energy flux.

[0041] In general, the substrate is placed at an appropriate distance from the target material, according to standard practice in the art, in order to assure the deposition of the coating material.

[0042] As used herein, “an appropriate distance” refers to a distance in which the substrate is far enough from the target material in order to avoid damages of the substrate and / or the coating but close enough to ensure an adequate deposition of the coating material by PVD.

[0043] According to one embodiment of the method of the present invention, the substrate is placed at a distance of at least 4.0 cm, preferably at a distance of at least 8.0 cm, more preferably at a distance of at least 12.0 cm from the target material.

[0044] It is further understood that the upper limit of the distance of the substrate from the target material, as detailed above, is advantageously of at most 30.0 cm, preferably of at most 25.0 cm, more preferably of at most 20.0 cm.

[0045] According to a preferred embodiment of the method of the present invention, the substrate is placed at a distance of between 4.0 cm and 30.0 cm, or of between 8.0 cm and 25.0 cm, or from between 12.0 cm and 20.0 cm from the target material.

[0046] As said, according to step (b) of the method according to the present invention, at least one net is placed in front of the substrate, thereby reducing the energy flux, as detailed above, by removing a portion of said coating material, as detailed above, from the flow, as detailed above, before it is deposited onto the substrate.

[0047] As said, it is required that the at least one net is at least one three- dimensional foam [3D foam, herein-after], and that between 40.0 and 98.0 at.% of the coating material, as detailed above, is removed from the flow (said percentage being abbreviated Pr herein-after), as detailed above, by capturing it by means of the 3D foam before it is deposited onto the substrate.

[0048] Within the context of the present invention, the expressions “at least one net” and “at least one 3D foam” are intended to denote one or more than one net and one or more than one 3D foam, respectively.

[0049] In the rest of the text, the term “3D foam” is understood, for the purposes of the present invention, both in the plural and the singular form.

[0050] Within the context of the present invention, the term “3D foam” is intended to refer to a framework, having a predetermined thickness, said framework being composed of walls and cells, the cells being defined as volumes which are not occupied by said walls.

[0051] Preferably, the 3D foam has a thickness of at least 1 .0 mm, or at least 1 .1 mm, or at least 1 .2 mm, or at least 1 .5 mm.

[0052] Preferably, the 3D foam, as detailed above has a thickness of at most 10.0 mm, or at most 7.5 mm, or at most 5.0 pm, or at most 3.5 mm.

[0053] In a preferred embodiment of the method of the present invention, the 3D foam has a thickness from 1.0 and 10.0 mm, or from 1.1 to 7.5 mm, or from 1 .2 to 5.0 mm, or from 1 .5 to 3.5 mm.

[0054] The inventors have surprisingly found that by placing a 3D foam in front of the substrate, as detailed above, and by removing from the flow, as detailed above, between 40.0 and 98.0 at.% of the coating material (said percentage being abbreviated Pr herein-after) by means of the 3D foam, as detailed above, the morphology, and more in particular the crystal structure of the coating can be easily and cost-effectively tuned, as demonstrated in the working examples. In other words, the morphology, and more in particular the crystal structure of the coating, may be easily adjusted to the desired end-use of the coated substrate.

[0055] Without being bound to this theory, it seems that the energy of the coating material is not affected by the 3D foam. In other words, the energy flux can be simply reduced by removing a portion of the coating, that is to say by removing between 40.0 and 98.0 at.% of the coating material, as detailed above, and not by modifying the energy of the coating material or filtering the coating material by its energy. Thus, it is inferred that the coating formation process, such as the diffusion, island growth or crystallization can be tuned without modifying the energy of the coating material before it is deposited on the substrate.

[0056] It will be clear to the skilled person that, further to the removal of the coating material, as detailed above, other species, such as for example other ions, neutral species, electrons and photons may further be removed.

[0057] Thus, another advantage of the method according to the present invention is that there is no need to use bias-voltage or to change the energy of the coating material, as detailed above, to tune the morphology, and more in particular the crystal structure of the coating.

[0058] Therefore, there is no need to connect the 3D foam, as detailed above, electronically to a power source. Preferably, the 3D foam, as detailed above, is electrically grounded or is at floating potential.

[0059] As said, the 3D foam has a random pattern, meaning that the 3D foam is a framework, having a predetermined thickness, said framework being composed of walls and cells, the cells being defined as volumes which are not occupied by said walls, wherein said walls and cells do not define a definite pattern.

[0060] As said, the 3D foam is made from at least one metal or a compound thereof, or at least one metalloid or a compound thereof, or at least one non- metal or a compound thereof.

[0061] Within the context of the invention, the expression “at least one metal or a compound thereof, or at least one metalloid or a compound thereof, or at least one non-metal, or a compound thereof” is intended to denote “one metal or more than one metal”; or “one metal compound or more than one metal compound”; or “one metalloid or more than one metalloid”, or “one metalloid compound or more than one metalloid compound”; or “one non-metal or more than one non-metal”; or “one non-metal compound or more than one non- metal compound”. Mixtures of metals, of non-metals or mixtures of compounds thereof may be used.

[0062] In the rest of the text, the terms “metal”, “metal compound”, “metalloid “, “metalloid compound”, “non-metal” and “non-metal compound” are understood, for the purposes of the present invention, both in the plural and in the singular form.

[0063] Non-limiting examples of metal mention may be made of copper, nickel, tungsten, iron, platinum, and cobalt or combination thereof.

[0064] The “compound of metal”, as used herein, may have the broadest meaning generally understood in the art in which form such compounds may exist, and may notably include an oxide, a nitride, a carbide or an alloy.

[0065] Non-limiting examples of said metal oxide compound mention may be made of chromium oxide, copper oxide, aluminum oxide, lanthanum iron oxide or tin oxide.

[0066] Non-limiting examples of said metal nitride compound mention may be made of titanium nitride.

[0067] Non-limiting examples of said metal carbide compound mention may be made of chromium carbide or titanium carbide. Non-limiting examples of said alloy metal compound mention may be made of nickel chrome, cupronickel, or iron-chromium-aluminum alloys.

[0068] Non-limiting examples of metalloid mention may be made of silicon or boron.

[0069] The “compounds of metalloid” as used herein, may have the broadest meaning generally understood in the art in which form such compounds may exist, and may notably include an oxide, a nitride, or a carbide.

[0070] Non-limiting examples of oxide metalloid compounds mention may be made of silicon dioxide (SiC ).

[0071] Non-limiting examples of carbide metalloid compounds mention may be made of silicon carbide (SiC).

[0072] Non-limiting examples of nitride metalloid compounds mention may be made of silicon nitride (Si3N4) and boron nitride (BN).

[0073] Non-limiting examples of non-metal mention may be made of carbon.

[0074] The “compounds of non-metal”, as used herein, may have the broadest meaning generally understood in the art in which form such compounds may exist, and may notably include an oxide, or an organic compound.

[0075] Non-limiting examples of said organic compound mention may be made of polyether ether ketone (PEEK) and polyurethane (PUR).

[0076] Preferably, the 3D foam, as detailed above, is made from carbon or nickel.

[0077] As said, the 3D foam, as detailed above, has a porosity of at least 60.0%, preferably of at least 70.0%, more preferably of at least 75.0%, even more preferably of at least 80.0%.

[0078] It is further understood that in the method of the present invention, the porosity of the 3D foam, as detailed above, is advantageously at most 99.0%, more preferably at most 98.5%, even more preferably at most 98.0%.

[0079] According to the method of the present invention, the 3D foam, as detailed above, has a porosity of between 60.0% and 99.0%, preferably of between 70.0% and 98.5%, more preferably of between 75.0% and 98.0%, even more preferably of between 80.0% and 98.0%.

[0080] Within the context of the present invention, the term “porosity” is intended to denote the ratio of the volume of the cells of the foam over the total volume of the 3D foam, and is thus determined as a percentage.

[0081] Preferably, the 3D foam, as detailed above, has a linear pore density of at least 5 pores per centimeter, preferably of at least 10 pores per centimeter, more preferably of at least 12 pores per centimeter, even more preferably of at least 15 pores per centimeter.

[0082] It is further understood that in the method of the present invention, the 3D foam, as detailed above has advantageously a linear pore density of at most 250 pores per centimeter, preferably of at most 150 pores per centimeter, more preferably of at most 100 pores per centimeter, even or preferably of at most 75 pores per centimeter.

[0083] In a preferred embodiment of the method of the present invention, the 3D foam, as detailed above, has a linear pore density of from 5 to 250 pores per centimeter, preferably from 10 to 150 pores per centimeter, more preferably from 12 to 100 pores per centimeter, even more preferably from 15 to 75 pores per centimeter.

[0084] Within the context of the present invention, the term “linear pore density” is intended to denote the number of pores that are counted along a line of one centimeter in length.

[0085] According to a preferred embodiment of the method of the present invention, the 3D foam, as detailed above, has a pore size of at least 10.0 pm, preferably of at least 20.0 pm, more preferably of at least 30.0 pm.

[0086] It is further understood that in the method of the present invention, the 3D foam, as detailed above, has advantageously a pore size of at most 1500.0 pm, preferably of at most 1200.0 pm, more preferably of at most 1000.0 pm.

[0087] In a preferred embodiment of the method of the present invention, the 3D foam, as detailed above, has pore size in the range from 10.0 to 1500.0 pm, preferably from 20.0 to 1200.0 pm, even more preferably from 30.0 to 1000.0 pm.

[0088] The 3D foam, as detailed above, may be synthetically prepared by a variety of methods known to the art, or may be commercially available.

[0089] Non-limiting examples of commercially available 3D foam suitable for use in the method of the present invention include carbon foam VC00-FA- 000138 from Goodfellow or open cell Nickel foam from Novamet Specialty Products Corporation.

[0090] Methods of preparation of 3D foams, as detailed above, are for example disclosed in Progress in Materials Science 46 (2001 ) 559-632, US 10,590,529 B2 or EP 1 477578 A1 , and may be for example carried out by the introduction of gas bubbles during said methods, by melt metallurgical methods, by solid matter processing or by electrolytic techniques, the whole content of said references being herein incorporated by reference.

[0091] It is understood that the 3D foam, as detailed above, is placed in such a way that the energy flux, is able to be reduced, as detailed in step (b) of the method of the present invention.

[0092] Furthermore, it goes without saying that the 3D foam, as detailed above, is placed in such a way that the portion of the coating material, as detailed above, which is not removed from the flow by means of the 3D net, in particular the 3D foam is deposited onto the substrate.

[0093] According to certain embodiments of the method of the present invention, the 3D foam, as detailed above, and the substrate are in contact with each other. In other words, the 3D foam may be inserted directly in front of the substrate, without leaving any space between the 3D foam, and the substrate.

[0094] According to certain embodiments of the method of the present invention, the 3D foam, as detailed above, is placed at a distance of at least 0.5 cm, or at a distance of at least 1 .0 cm, or at a distance of at least 2.0 cm from the front of the substrate, with the proviso that the substrate is placed at a distance from the target material larger than the distance of the 3D foam, from the substrate.

[0095] It is further understood that the upper limit of the distance of the 3D foam, as detailed above, from the front of the substrate, as detailed above, may be of at most 20.0 cm, or of at most 15.0 cm, or of at most 10.0 cm from the front of the substrate, with the proviso that the substrate is placed at a distance from the target material larger than the distance of the 3D foam, from the substrate.

[0096] According to certain embodiments of the method of the present invention, the 3D foam, as detailed above, is placed at a distance of between 0.5 cm and 20.0 cm, or of between 1 .0 cm and 15.0 cm, or from between 2.0 cm and 10.0 cm from the front of the substrate, with the proviso that the substrate is placed at a distance from the target material larger than the distance of the 3D foam, from the substrate.

[0097] The inventors have also surprisingly found that by placing the 3D foam, as detailed above, in front of the substrate, said substrate is less prone to thermal degradation. It was also found that the coating being deposited on the substrate, according to the method of the present invention, is less prone to degradation, such as delamination from the substrate. Thus, the method according to the present invention enables the use of a larger choice of substrates.

[0098] It is inferred that by placing the 3D foam, as detailed above, according to the method of the present invention, enables the thermal radiation to be reduced before reaching the substrate.

[0099] It is understood that the choice of the substrate may be dependent on the end-use of the coated substrate, preferably the substrate is a shaped article.

[0100] It is understood that the shaped article may be of any size, such as for example a nanometric size, a micrometric size, a millimetric size or a centimetric size. Thus, it is understood that the shaped article may take the form of particles, powders, blocks, sheets, films, foils, tubes, strands, fibres, pieces, or a combination thereof. It is understood that the shaped article may be of any shape, such as for example, round shapes, flat-shapes, wireshapes, or complex 3D shapes with or without cavities or a combination thereof. Preferably, the shaped article has a flat shape, such as a wafer.

[0101] Within the context of the present invention, the substrate, as detailed above, may be composed of any material suitable for a method of depositing a coating material onto a substrate by physical vapor deposition. It is understood that the choice of the substrate material may be dependent on the end-use of the coated substrate.

[0102] Non-limiting examples of suitable substrate materials mention may be made of polymers, such as polyether ether ketone (PEEK) or polyurethane (PUR), metals, such as stainless steel, titanium, aluminum, or copper, or non- metals such as silicon or glass (SiC ).

[0103] Preferably, the substrate is selected from the group consisting of silicon wafers, stainless steel, titanium, aluminum, copper, more preferably, the substrate is a silicon wafer.

[0104] Optionally, if desired, the substrate, as detailed above, may be subjected to at least one pre-treatment step prior to depositing the coating material, as detailed above, such as including a cleaning step, an etching step and the like.

[0105] As said, by means of the 3D foam, as detailed above, the energy flux of the flow, as detailed above, is reduced by removing between 40.0 and 98.0 at.% of said coating material from said flow, as detailed above, by capturing it by means of the 3D foam, before it is deposited onto the substrate.

[0106] Within the context of the present invention, it is understood that “between 40.0 and 98 at.% of the coating material is removed from the flow”, as detailed above, is expressed as the total number of atoms comprised in the coating material, which is removed by means of the 3D foam, relative to the total number of atoms comprised in the coating material before the capture of the coating material by means of the 3D foam.

[0107] According to the present invention, the removal of the coating material from the flow, as detailed above, is determined by Rutherford Backscattering Spectroscopy (RBS).

[0108] RBS is a known analysis to the skilled in the art to determine a total number of atoms of coating deposited on a substrate, per square centimeter of said substrate, by measuring the backscattering of a beam of high energy ions (typically protons or alpha-particles), said beam bombarding the coated substrate. Said backscattering is preferably detected by two detectors set at 135 and 165 degrees relative to the incident beam direction. Said RBS analysis has notably been described by Shao Lin et al. in Rutherford Backscattering Spectrometry, ASM handbook, Vol. 10, materials characterization, as it will be discussed herein-after.

[0109] In particular, the percentage of coating material removed from the flow (herein-after Pr), as detailed above, expressed in atomic percent (at.%), can be calculated according to the following formula : wherein:

[0110] - Db is the total number of atoms per square centimeter of coating deposited on the substrate, according to the method of the present invention, Db being determined for instance by RBS using for instance an alpha-particle beam at 2.4 MeV, the backscattering being preferably detected by two detectors set at 135 and 165 degrees relative to the incident beam direction; and

[0111] - Dn is the total number of atoms per square centimeter of coating deposited onto a reference substrate, Dnbeing determined for instance by RBS using for instance an alpha-particle beam at 2.4 MeV, wherein said backscattering is preferably detected by two detectors set at 135 and 165 degrees relative to the incident beam direction, and wherein said reference substrate is placed at the same distance from the target material as the substrate used to determine Db, as detailed hereinabove. The reference substrate is thus used for determining the total number of atoms per square centimeter of coating material that would reach a substrate, when no 3D net, in particular no 3D foam, is placed in front of said substrate.

[0112] It will be clear to the skilled person that the removal of the coating material from the flow, as detailed above (in other words, the percentage of coating material removed from the flow Pr), is directly linked to the values of the total number of atoms per square centimeter of coating deposited on the substrate Db, as compared to the values of the total number of atoms per square centimeter of coating deposited on a reference substrate Dn, as detailed above.

[0113] Db and Dnare in general expressed in Thin Film Unit (TFU), said unit denoting 1015atoms of the coating per square centimeter of the coated substrate.

[0114] It will also be clear to the skilled person that, in order to determine the total number of atoms per square centimeter of coating deposited on the substrate Db, the coating material has to be first deposited onto the substrate by physical vapor deposition, as detailed above, and according to the method of the present invention, thereby producing a coated substrate.

[0115] In the same manner, in order to determine the total number of atoms per square centimeter of coating deposited onto a reference substrate Dn, the coating material has to be first deposited onto the reference substrate by physical vapor deposition, thereby obtaining a coated reference substrate, under exactly the same conditions as when determining Db, except that the 3D foam, as detailed above, is absent and that the reference substrate is placed at the same distance from the target material as the substrate according to the present invention when determining Dt>.

[0116] Preferably, when determining Db and Dn, the deposition of the coating material onto the substrate and onto the reference substrate, as detailed above, is carried out concomitantly, meaning that the substrate, and the reference substrate are placed in the same chamber during the physical vapor deposition, as detailed above, a schematic representation of a set-up being illustrated in Figure 7. Said set-up allows a direct comparison between the coated substrate and the coated reference substrate.

[0117] Subsequently, it will be understood that said coated substrate and coated reference substrate, as detailed above, are typically placed in a Rutherford Backscattering instrument, of which a schematic representation is illustrated in Figure 8, for the determination of, respectively, Db and Dn.

[0118] It will be also clear to the skilled person that the determination of Db and Dn, determined by RBS, as detailed above, is known, and as notably been described by Shao Lin et al. in Rutherford Backscattering Spectrometry, ASM handbook, Vol. 10, materials characterization, as detailed herein-after.

[0119] In general, the coated substrate and the coated reference substrate, as detailed above, are placed in the Rutherford Backscattering instrument. In general, an incident beam of high energy ions is generated and collides with the coating of the coated substrate (or the coated reference substrate), as detailed above. The resulting backscattered beam is, in general, detected by means of at least one detector, preferably by means of two detectors, more preferably by means of two detectors set at 135 and 165 degrees relative to the incident beam direction. The number of backscattered particles A is thus detected. The total number of atoms per square centimeter of coating deposited on a substrate D is thus derived from the well-known equation (1 ) as detailed above :

[0120] A = ofiQD Equation (1 ) wherein A is the number of detected backscattered particles; Q is the total number of incident particles; 1 is the solid detection angle; and a is the scattering cross section, a may be extracted from well-known tabulated values, such as, for example tabulated value extracted from the Ion Beam Analysis Nuclear Data Library (IBANDL - https: / / www- nds.iaea.org / exfor / ibandl.htm); or a may be calculated according to well- known equation defined in equation (3) of Rutherford Backscattering Spectrometry, ASM handbook, Vol. 10, materials characterization, and detailed herein-below : wherein Zi is the atomic number of a projectile of mass m; Z2 is the atomic number of the target atom of mass M2, e is the electron charge, E is the kinetic energy of an incident projectile, 0 is the scattering angle; the projectile corresponding to the species originating from the incident beam of high energy ions, wherein, in particular, the projectile is an alpha particle, and wherein the target atom is corresponding to the species which is bombarded by the projectile.

[0121] According to a preferred embodiment of the method of the present invention, at least 50.0 at.%, more preferably at least 60.0 at.%, even more preferably at least 70.0 at.%, even more preferably at least 80.0 at.% of the coating material is removed from the flow, by capturing it by means of the 3D foam, as detailed above, before it is deposited onto the substrate.

[0122] It is understood that the upper limit of the amount of the coating material removed from said flow should not be detrimental to the deposition of the coating material onto the substrate. Thus, in a preferred embodiment of the method of the present invention, at most 98.0 at.%, more preferably at most 97.0 at.%, even more preferably at most 96.0 at.%, even more preferably at most 95.0 at.% of the coating material is advantageously removed from the flow, as detailed above, by capturing it by means of the 3D foam, as detailed above, before it is deposited onto the substrate.

[0123] According to a preferred embodiment of the method of the present invention, between 50.0 at.% and 98.0 at.%, more preferably between 60.0 at.% and 97.0 at.%, even more preferably between 70.0 at.% and 96.0 at.%, even more preferably between 80.0 at.% and 95.0 at.% of the coating material, as detailed above, is advantageously removed from the flow, as detailed above, by capturing it by means of the 3D foam, as detailed above, before it is deposited onto the substrate.

[0124] As said, according to step (b) of the present invention, the energy flux of the flow, as detailed above, is reduced by means of the 3D foam, as detailed above, placed in front of the substrate, as detailed above.

[0125] According to the present invention, the reduction of the flux and / or said energy flux, as detailed above, can be recorded and / or determined by any method / means known by the skilled person in the art. In particular, said reduction of the flux and / or said energy flux, as detailed above can be recorded and / or determined by using an Active Thermal Probe (Active Thermal Probe, Ampower Science and Engineering GmbH), according to standard practice known to the skilled person in the art, such as the method described in DE102007033947A1 , said reference being herein incorporated by reference. A schematic representation of said Active Thermal Probe and the set-up for recording the reduction of the flux is presented in Figure 6. In particular, said Active Thermal Probe can be recording the energy flux of the flow, as detailed above, by measuring the difference of heating power required by said probe, placed in the chamber of the vaporization device, to keep a predetermined temperature when the flow is generated (Wpg) compared to when the flow is not generated (Wpn). The difference of heating power (expressed in mW) is then divided by the probe surface to obtain the energy flux (the energy flux is therefore expressed in mW.crrr2). As the probe surface is constant, the reduction of the flux (herein-after Rc), as detailed above, can thus be determined by measuring the difference of heating power required by the probe to keep a predetermined temperature, when said probe is used during the method of depositing a coating according to the present invention (Wpn 3D) - (WPg 3D) (that is to say, by placing a 3D foam, as detailed above) as compared to a reference measurement when the probe is used during a method of depositing a coating when no 3D foam is placed (Wpnref - Wpgref).

[0126] It will be understood that the Active Thermal Probe can comprise, notably, a temperature-sensing substrate fixed on a rod, the latter being connected to a power supply for providing said heating power and thus for controlling the temperature. Thus, the Active Thermal Probe, by being equipped with a substrate, can act as a substrate according to the method of the present invention, to determine Wpg3D and Wpn3D.

[0127] Similarly, it will be understood that the Active Thermal Probe, can act as a reference substrate, to determine Wpgref and Wpnref, said Active Thermal Probe being placed at the same distance from the target material as the Active Thermal probe used to act as a substrate according to the method of the present invention to determine Wpg3D and Wpn3D.

[0128] Thus, according to the present invention, the reduction of the flux, expressed in %, and as detailed above, can be determined according to the following formula: 100 wherein: - WPg 3D is the heating power required by said probe to keep a predetermined temperature when the flow, as detailed above is generated, and wherein the 3D foam, is placed according to the method of the present invention;

[0129] - WPn 3D is the heating power required by said probe to keep a predetermined temperature when the flow, as detailed above is not generated, and wherein the 3D foam, is placed according to the method of the present invention;

[0130] WPg ref is the heating power required by said probe to keep a predetermined temperature when the flow is generated during a reference experiment, and wherein no 3D foam is placed; and

[0131] - WPn ref is the heating power required by said probe to keep a predetermined temperature when the flow is not generated during a reference experiment, and wherein no 3D foam is placed.

[0132] According to a preferred embodiment of the method of the present invention, the energy flux of the flow is reduced by at least 5.0 %, or by at least 7.0%, or by at least 10.0% or by at least 12.0% or by at least 15.0%, or by at least 17.0%, or by at least 20.0 %, by means of at least one 3D net, in particular by means of the 3D foam, as detailed above, placed in front of the substrate, as detailed above.

[0133] It is understood that the upper limit of the reduction of the energy flux of the flow should not be detrimental to the deposition of the coating material onto the substrate.

[0134] Thus, in a preferred embodiment of the method of the present invention, the energy flux of the flow is reduced by at most 50.0 %, or by at most 45.0%, or by at most 40.0%, or by at most 37.0%, or by at most 35.0%, or by at most 32.0%, or by at most 30.0%, by means of at least one 3D net, in particular the 3D foam, as detailed above, placed in front of the substrate, as detailed above. According to a preferred embodiment of the method of the present invention, the energy flux of the flow is reduced by between 5.0 % and 50.0 %, or by between 7.0 % and 45.0 %, or by between 10.0 % and 40.0 %, or by between 12.0% and 37.0%, or by between 15.0% and 35.0 %, or by between 17.0% and 32.0% or by between 20.0 % and 30.0 %, by means of at least one 3D foam, as detailed above, placed in front of the substrate, as detailed above.

[0135] According to one embodiment of the method of present invention, in step (b), one 3D foam, as detailed above, is placed in front of the surface, as detailed above.

[0136] It is understood that the distance, between the 3D foam, from the substrate, as detailed above, equally apply to this embodiment.

[0137] According to another embodiment of the method of the present invention, in step (b), more than one 3D foam, as detailed above, are placed in front of the surface, as detailed above. This enables that multiple coatings deposition onto the substrate can take place, in which each of said coatings may have a different morphology, and in particular a different crystal structure by simply selecting the more than one 3D foam, as detailed above.

[0138] It is understood that the distance, between the 3D foam, from the substrate, as detailed above, equally apply to this embodiment.

[0139] When more than one 3D foam, as detailed above, are placed in front of the substrate, as detailed above, said more than one 3D foam are advantageously placed on a rotatable holder.

[0140] Using a rotatable holder permits to change in a simple manner the 3D foam, as detailed above, for another 3D foam, without the need to stop the deposition method of the coating material onto said substrate.

[0141] Another aspect of the present invention is a coated article comprising the coated substrate obtained by the method of the present invention.

[0142] It is understood that all definitions and preferences, as described above, equally apply for all further embodiments, as described below. EXAMPLES

[0143] The invention will be now described in more details, whose purpose is merely illustrative and are not intended to limit the scope of invention.

[0144] Figure 1 a) is a Scanning Electron Microscopy (SEM) image of a carbon foam according to example 1 of the present invention.

[0145] Figure 1 b) is a Scanning Electron Microscopy (SEM) image of a Nickel foam according to example 2 of the present invention.

[0146] Figure 2 is an X-ray diffraction pattern of the coating obtained according to example 1 of the present invention.

[0147] Figure 3 is an X-ray diffraction pattern of the coating obtained according to example 2 of the present invention.

[0148] Figure 4 is an X-ray diffraction pattern of the coating obtained according to comparative example 1 of the present invention.

[0149] Figure 5 is an X-ray diffraction pattern of the coating obtained according to comparative example 2 of the present invention.

[0150] Figure 6 is a schematic representation of a set-up for the determination of the reduction of the flux, by means of an Active Thermal Probe.

[0151] Figure 7 is a schematic representation of a set-up for determining the removal of the coating material from the flow.

[0152] Figure 8 is a schematic representation of a set-up for the determination of the total number of atoms per square centimeter of coating deposited onto (a) a substrate according to the present invention (Db) and (b) a reference substrate (Dn).

[0153] Raw materials:

[0154] The following materials were bought commercially and used for the experiments without purification :

[0155] - Carbon 3D foam (purchased from Goodfellow) - Ni 3D foam (purchased from Novamet Specialty Products Corporation)

[0156] - Silicon wafers with <100> orientation (purchased from Siegert Wafer)

[0157] The specifications of said Carbon 3D foam and Ni 3D foam are summarized in Table 1 below:

[0158] Table 1

[0159] General procedure:

[0160] Deposition of a UO2 coating

[0161] A deposition of a TiC coating on Si wafers with <100> orientation was carried out in a magnetron sputtering device. The chamber of the magnetron sputtering device was equipped with a 2” circular Ti target (99.995% purity, Kurt J. Lesker) mounted on a single magnetron.

[0162] Said Si wafers, which were previously ultrasonically cleaned in acetone and isopropanol, were mounted on a grounded substrate holder located in front of the Ti target.

[0163] The distance between the target and the sample holder was 134 mm. Prior to deposition, the chamber was pumped down below 6.7x10-3Pa (5.0x10-6Torr), and the target was cleaned during 5min at a constant power of 100W in an Ar atmosphere at a pressure of 0.48 Pa (3.6 mTorr). The sputtering of the target occurs in an Ar / C mixture at a constant pressure of 0.48 Pa (3.6 mTorr). The oxygen supply (expressed in seem) in the chamber was either constant, or regulated using an OES regulation device (RS100, Innovative Coating Solutions) in order to sputter the target in the transition regime. Regardless of the operation of the magnetron, the mean power is kept at 300W. No external heating is used during deposition.

[0164] Determination of the crystal structure of the deposited coatings

[0165] The crystal structures of the deposited coatings were determined using an X-ray diffractometer (X’Pert PRO Panalytical, Netherlands in 9 / 29 configuration), at a given wavelength of 1.5406A (Cu Ka line), and a X-ray diffractometer in glancing incidence configuration (STADI MP, STOE), operating at the same wavelength.

[0166] Determination of the energy flux

[0167] The energy flux of the species present in the plasma was recorded using an Active Thermal Probe (Active Thermal Probe, Ampower Science and Engineering GmbH). Said Active thermal probe was recording the energy flux of the flow, by measuring the difference of heating power required by said probe, placed in the chamber of the magnetron sputtering device, to keep a predetermined temperature when the flow is generated (Wpg) compared to when the flow is not generated (Wpn). The difference of heating power (expressed in mW) was then divided by the probe surface to obtain the energy flux (the energy flux is therefore expressed in mW.cnr2). As the probe surface is constant, the reduction of the flux Rc, was thus determined by measuring the difference of heating power Wpn- Wpgrequired by the probe to keep a predetermined temperature, when said probe was used during the method of depositing a coating according to the working examples (Wpn3D) - (Wpg3D) (that is to say, by placing the 3D foam, as detailed above), as compared to a reference measurement when the probe is used during a method of depositing a coating when no 3D foam is placed (Wpnref - Wpgref). Thus, the reduction of the flux, as expressed in %, was determined according to the following formula: 100 wherein

[0168] - WPg 3D is the heating power required by said probe to keep a predetermined temperature when the flow was generated, and wherein the 3D foam, according to the working examples, was placed;

[0169] - WPn 3D is the heating power required by said probe to keep a predetermined temperature when the flow was not generated, and wherein the 3D foam according to the working examples, was placed; WPg ref is the heating power required by said probe to keep a predetermined temperature when the flow was generated during a reference experiment, and wherein no 3D foam was placed; and

[0170] - WPn ref is the heating power required by said probe to keep a predetermined temperature when the flow was not generated during a reference experiment, and wherein no 3D foam was placed.

[0171] The set-up used for the determination of the energy flux is schematized in Figure 6.

[0172] The Active Thermal probe 1 comprising, notably, a temperaturesensing substrate 2, a rod 3, and a power source 4 to provide heating power to the temperature-sensing substrate 2, was placed in the chamber 5 of the magnetron sputtering device, said chamber 5 containing the target material 6 placed on the magnetron 7.

[0173] For determining Wpg3D and Wpn3D, the chamber 5 of the magnetron sputtering device was equipped with the foam 8. It is understood that the foam 8 was placed in the path between the magnetron 7 and the temperaturesensing substrate 2 of the Active Thermal Probe. The target material 6 was subsequently vaporized and a flow 9 was generated. The energy flux of the flow 9 was reduced by removing a portion of the coating material from the flow by means of the foam 8, thereby producing a flow having a reduced energy flux 10.

[0174] The temperature-sensing substrate 2 of the Active Thermal probe, acting as the substrate according to the present invention, is thus coated, and the heating power required by said probe 1 to keep a predetermined temperature was measured, when the flow was generated (Wpg3D), and when the flow was not generated (Wpn3D).

[0175] For determining Wpgref and Wpnref, the chamber 5 of the magnetron sputtering device was not equipped with the foam 8. It is understood that the temperature-sensing substrate 2 of the Active Thermal probe is located at the same distance from the target material 6 as the temperature-sensing substrate 2 of the Active thermal probe when determining Wpg3D and Wpn3D.

[0176] The target material 6 was subsequently vaporized and a flow 9 was generated.

[0177] The temperature-sensing substrate 2 of the Active Thermal Probe, acting as the reference substrate is thus coated, and the heating power required by said probe 1 to keep a predetermined temperature was measured, when the flow was generated (Wpgref), and when the flow was not generated (WPn ref).

[0178] Determination of the at. % removal of the coating material

[0179] The determination of the atomic percentage of the coating material removed by the 3D foams was carried out by Rutherford Backscattering Spectroscopy (RBS), and is illustrated in Figure 7 and 8.

[0180] A substrate 11 placed on a sample holder 12 and the foam 8 placed in front of the substrate 11 were placed in a chamber 5 of the magnetron sputtering device. The chamber 5 was equipped with the target material 6 placed on the magnetron 7, according to the general procedure for the Deposition of a TiC coating detailed above. A reference substrate 13 was also placed on a sample holder 12’ in the chamber 5, at the same distance from the target material 6 as the substrate 11. It is understood that the foam 8 was placed in the path between the target material 6 and the substrate 11 and not in the path between the target material 6 and the reference substrate 13. The target material 6 was subsequently vaporized and a flow 9 is generated. The energy flux of the flow 9 is reduced by removing a portion of the coating material from the flow by means of the foam 8, thereby producing a flow having a reduced energy flux 10. A coated substrate according to the method of the present invention and a coated reference substrate were thereby produced.

[0181] The coated substrate was removed from the chamber 5 and placed in a Rutherford backscattering apparatus, of which a schematic representation is found in Figure 8. The Rutherford backscattering apparatus notably comprises a collimator 14, a source 15 of a beam of alpha-particles 16, and two detectors 17 and 17’ respectively set at angles Oi and Q2, of respectively 135 and 165 degrees relative to the incident beam direction. The coated substrate 18 and the coated reference substrate 18’ were independently placed in the path of a beam of alpha-particles 16. The beam of alpha-particles 16 thereby collides with the coating of the coated substrate 18 or the coated reference substrate 18’, and backscattered particles 19 are emitted. The detectors 17 and 17’ detect the backscattered particles which travel, respectively, at the angles O1 and Q2, of respectively 135 and 165 degrees relative to the incident beam direction.

[0182] In particular, the total number of atoms of coating deposited on a substrate, per square centimeter of said substrate, was determined by measuring the backscattering of a beam of alpha-particles at 2.4 MeV (generated by a Tandetron particle accelerator), said beam is bombarding the coated substrate. The backscattering was detected by two detectors set at 135 and 165 degrees relative to the incident beam direction.

[0183] The percentage of coating material removed from the flow (herein-after Pr), as detailed above, is expressed in atomic percent (at.%), and is calculated according to the following formula : wherein:

[0184] - Db is the total number of atoms per square centimeter of coating deposited on the substrate, according to the method of the present invention; and

[0185] - Dn is the total number of atoms per square centimeter of coating deposited onto a reference substrate, wherein said reference substrate is placed at the same distance from the target material as the substrate used to determine Db, as detailed herein-above.

[0186] It should be noted that the removal of the coating material from the flow, as detailed above, (in other words, the percentage of coating material removed from the flow, Pr), is directly linked to the values of the total number of atoms per square centimeter of coating deposited on the substrate Db, as compared to the values of the total number of atoms per square centimeter of coating deposited on a reference substrate Dn.

[0187] It will be also clear to the skilled person that the determination of Db and Dn, determined by RBS, as detailed above, is known, and has notably been described by Shao Lin et al. in Rutherford Backscattering Spectrometry, ASM handbook, Vol. 10, materials characterization.

[0188] The total number of atoms per square centimeter of coating deposited on a substrate D was thus derived from the well-known equation (1 ) as detailed above : A = afiQD Equation (1 ) wherein A is the number of backscattered particles being detected by the Rutherford Backscattering equipment; Q is the total number of incident particles; 1 is the solid detection angle and a is the scattering cross section. In the case of oxygen, a was extracted from well-known tabulated values, said tabulated values were extracted from the Ion Beam Analysis Nuclear Data Library (IBANDL - https: / / www-nds.iaea.org / exfor / ibandl.htm). In the case of titanium, a was calculated according to well-known equation defined in equation (3) of Rutherford Backscattering Spectrometry, ASM handbook, Vol. 10, materials characterization, and detailed herein-below : wherein Zi is the atomic number of a projectile of mass m; Z2 is the atomic number of the target atom of mass M2, e is the electron charge , E is the kinetic energy of an incident projectile, 0 is the scattering angle; the projectile corresponding to the species originating from the incident beam of high energy ions, wherein, that is to say, alpha particles, and wherein the target atom is titanium, and corresponds to the species which was bombarded by the projectile.

[0189] Example 1

[0190] A deposition of a TiC coating on an Si substrate was carried out according to the general procedure, using the magnetron in DC mode (MDX- 1 k-Advanced Energy), and by inserting directly in front of the substrate a carbon 3D foam without leaving any space between the carbon 3D foam and the substrate. The coating material was removed by the carbon foam by 88.1 at.% (in other words the percentage of removal of the coating material Pr= 88.1 at.%), as determined by the method of determination of the at.% removal of the coating material as disclosed in the general procedure.

[0191] The measured energy flux behind the carbon 3D foam was 76.0 mW / cm2and the energy flux was reduced by 24.3% (in other words the percentage of reduction of the energy flux Rc=24.3 %) when the flow passes through the 3D carbon foam, as measured by the method of determination of the energy flux according to the general procedure.

[0192] The resulting X-ray diffraction pattern of the coating obtained according to example 1 of the present invention, as shown in Figure 2, shows both characteristic patterns of anatase TiC and rutile TiO2, as determined in the method of determination of the crystal structure of the deposited coatings according to the general procedure.

[0193] Results are summarized in Table 2.

[0194] Example 2

[0195] A deposition of a TiC coating on an Si substrate was carried out according to the general procedure, using the magnetron in DC mode (MDX- 1 k-Advanced Energy), and by inserting directly in front of the substrate a nickel 3D foam without leaving any space between the nickel 3D foam and the substrate.

[0196] The coating material was removed by the nickel foam by 94.6 at.% (in other words the percentage of removal of the coating material Pr= 94.6 at.%), as determined by the method of determination of the at.% removal of the coating material as disclosed in the general procedure. The measured energy flux behind the nickel 3D foam was 72.6 mW / cm2and the energy flux was reduced by 27.7% (in other words the percentage of reduction of the energy flux Rc=27.7%) when the flow passes through the 3D nickel foam, as measured by the method of determination of the energy flux according to the general procedure.

[0197] The resulting X-ray diffraction pattern of the coating obtained according to example 2 of the present invention, as shown in Figure 3, shows both characteristic patterns of anatase TiC and rutile TiO2, as determined in the method of determination of the crystal structure of the deposited coatings according to the general procedure

[0198] Results are summarized in Table 2.

[0199] Comparative Example 1

[0200] A deposition of a TiO2 coating on Si substrates was carried out according to the general procedure, using the magnetron in DC mode (MDX- 1 k-Advanced Energy), without inserting any 3D foam between the target and the sample holder.

[0201] No coating material was removed.

[0202] The measured energy flux was 100.4 mW / cm2, as measured by the method of determination of the energy flux according to the general procedure. No reduction of the energy flux was observed.

[0203] The resulting X-ray diffraction pattern of the coating obtained according to comparative example 1 of the present invention, as shown in Figure 4, shows characteristic patterns of anatase TiC , without the presence of rutile TiO2, as determined in the method of determination of the crystal structure of the deposited coatings according to the general procedure.

[0204] Results are summarized in Table 2. Comparative Example 2

[0205] A deposition of a TiO2 coating on Si substrates was carried out according to the general procedure, using the magnetron in High-power impulse magnetron sputtering (HiPIMS) mode (HiPSTER 10, lonautics), without inserting any 3D foam between the target and the sample holder.

[0206] No coating material was removed.

[0207] The resulting X-ray diffraction pattern of the coating obtained according to comparative example 2 of the present invention, as shown in Figure 5, shows both characteristic patterns of anatase TiO2 and rutile TiC , as determined in the method of determination of the crystal structure of the deposited coatings according to the general procedure.

[0208] Results are summarized in Table 2.

[0209] Table 2

[0210] Using the method according to the present invention, as demonstrated in the working examples 1 and 2, and as summarized in Table 2, enabled the production of a coating comprising a mixture of rutile and anatase TiC .

[0211] It is known to the person skilled in the art that rutile TiO2 is a crystal structure of higher energy than anatase TiO2.

[0212] Using standard magnetron sputtering in DC mode according to standard method known to the person skilled in the art, and notably according to the to the method of deposition of a TiO2 coating according to the general procedure, as detailed above does not generally lead to the production of rutile TiO2, (as demonstrated using a method according to standard practice, and as exemplified in comparative example 1 ).

[0213] Using magnetron sputtering in DC mode according to the method of deposition of a TiO2 coating according to the general procedure, as detailed above, does not lead to the production of rutile TiC , (as demonstrated using a method according to standard practice, and as exemplified in comparative example 1 ).

[0214] Furthermore, using magnetron in DC mode using harsher conditions (such as for example, using low pressure, a short distance between the target material and the substrate, using a high power density on the target, or a combination thereof), which would be required to obtain rutile TiO2 using DC mode usually leads to high mechanical stress on the coating, and may cause its delamination, which may reduce the choice of substrates.

[0215] Thus, the crystal structure of the coating was simply tuned to higher energetic crystal structure rutile TiO2, by placing a 3D foam, without requiring the need of bias-voltage or harsh conditions.

[0216] Furthermore, the crystal structure of the coating was simply tuned to higher energetic crystal structure rutile TiO2 without the need to use HiPIMS mode.

[0217] It is known to the person skilled in the art that said HiPIMS mode is a standard method according to general practice to enable the generation of higher energetic coating material, which consequently enables to obtain higher energetic crystal structure, as exemplified in comparative example 2 but the disadvantage is that the use of such HiPIMS mode may cause the delamination of the coating, which may reduce the choice of substrates.

Claims

CLAIMS1 . A method for depositing a coating material onto a substrate by physical vapor deposition, thereby producing a coated substrate, wherein the method comprises the steps of :(a) vaporizing at least part of a target material to generate a flow having an energy flux towards a substrate, wherein in said flow a coating material is produced;(b) reducing the energy flux of said flow by removing a portion of said coating material from said flow by means of at least one net placed in front of the substrate; and wherein the energy flux denotes the flow rate of the energy of all species comprised in the flow, and produced during the vaporization of the at least part of the target material, per unit area, and is expressed in mW.cnr2; the method being characterized in that the at least one net is a three-dimensional foam [3D foam, herein-after]; and between 40.0 and 98.0 atomic percent [hereinafter at.%] of said coating material is removed from said flow by capturing it by means of the at least one net before it is deposited onto the substrate; and characterized in that the 3D foam has a random pattern, in that the 3D foam is made from at least one metal or a compound thereof, or at least one metalloid or a compound thereof, or at least one non-metal or a compound thereof; and in that the 3D foam has a porosity of between 60.0% and 99.0%, preferably of between 70.0% and 98.5%, more preferably of between 75.0% and 98.0%, even more preferably of between 80.0% and 98.0%.

2. The method according to claim 1 , wherein the step of vaporizing at least part of the target material of step (a) is carried out by sputtering techniques, preferably by magnetron sputtering techniques.

3. The method according to claim 1 or claim 2, wherein the substrate is placed at a distance of between 4.0 cm and 30.0 cm, preferably of between 8.0 to 25.0 cm, more preferably of between 12.0 and 20.0 cm from the target material.

4. The method according to any one of claims 1 to 3, wherein the 3D foam has a thickness from 1 .0 to 10.0 mm, preferably from 1 .1 to 7.5 mm, more preferably from 1 .2 to 5.0 mm, even more preferably from 1 .5 to 3.5 mm.

5. The method according to any one of claims 1 to 4, wherein the 3D foam is electrically grounded or is at floating potential.

6. The method according to any one of claims 1 to 5, wherein the 3D foam is made from carbon or nickel.

7. The method according to any one of claims 1 to 6, wherein the 3D foam and the substrate are in contact with each other.

8. The method according to any one of claims 1 to 6, wherein the 3D foam is placed at a distance of between 0.5 cm and 20.0 cm, or of between 1.0 cm and 15.0 cm, or from between 2.0 cm and 10.0 cm from the front of the substrate, with the proviso that the substrate is placed at a distance from the target material larger than the distance of the 3D foam from the substrate.

9. The method according to any one of claims 1 to 8, wherein between 50.0 at.% and 98.0 at.%, more preferably between 60.0 at.% and 97.0 at.%, even more preferably between 70.0 at.% and 96.0 at.%, even more preferably between 80.0 at.% and 95.0 at.% of the coating material, is removed from the flow.

10. The method according to any one of claims 1 to 9, wherein more than one 3D foam are placed in front of the substrate, said more than one 3D foam are placed on a rotatable holder.

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