DE102017216139B3 - Process for producing a layer - Google Patents

Abstract

The invention relates to an attachment (1) for a plasma source (2) for metering precursors, comprising at least one nozzle (5) attached to the plasma source (2) or otherwise locatable in a fixed position to the plasma source (2) in that a precursor flowing out of the nozzle (5) is exposed to a plasma jet emerging from the plasma source (2) at a predetermined angle (ω) and with a predetermined distance (b) which can be set within a range of 0.5 mm to 10 mm between an outlet opening the nozzle (5) and a substrate to be coated (4) can be fed. The invention further relates to a method for producing a layer on a substrate (4), wherein in the vicinity of the substrate (4) at least one precursor via the attachment (1) in or in the vicinity of a plasma stream emerging from a plasma source (2) metered becomes.

Description

The invention relates to a method for depositing a layer or a mixed layer.

The production and use of mixed layers is known.

In particular, physical vapor deposition (PVD) processes such as thermal evaporation [Gaffney, A.M., et al. "Journalization of Catalysis 229.1 (2005): 12-23.] Or sputtering [Hovsepian, P. Eh, A.P. Ehiasarian, and U. Ratayski. "CrAlYCN / CrCN nanoscale multilayer PVD coatings deposited by the combined high power impulse magnetron sputtering / unbalanced magnetron sputtering (HIPIMS / UBM) technology." Surface and coatings technology 203.9 (2009): 1237-1243.] Are described for the preparation of mixed oxide films. As a rule, however, a corresponding vacuum and system technology is required for such methods, which is associated with additional costs.

Mixed layers can also be produced under normal pressure conditions. Above all, thermal CVD (chemical vapor deposition) such as the APCVD (Atmospheric Pressure Chemical Vapor Deposition) should be mentioned in this context. The energy required for the chemical reaction of the precursors is often provided in this method by heating the substrate material. Thus, substrate temperatures of 200 ° C to 700 ° C [ Wang, HB, et al. "Deposition and characterization of YSZ thin films by aerosol-assisted CVD." Materials Letters 44.1 (2000): 23-28 . Gesheva, KA, et al. "Crystallization of chemically vapor deposited molybdenum and mixed tungsten / molybdenum oxide films for electrochromic application." Thin Solid Films 515.11 (2007): 4609-4613 . Bodurov, Georgi, et al. "Thin film optical coatings of vanadium oxides and mixed tungsten / vanadium oxides deposited by APCVD employing precursors of vanadyl acetylacetonate and a mixture of tungsten hexacarbonyl." Physics Procedia 46 (2013): 127-136.]. This fact thus excludes the coating of temperature-sensitive substrates such as plastics.

Another method for producing thin mixed oxide layers is the sol-gel technique [ Galatsis, Kosmas, et al. "MoO ₃ , TiO ₂ and WO ₃ sol-gel gas sensors." Sensors and Actuators B: Chemical 83.1 (2002): 276-280 . Rampaul, Ashti, et al. "Titania and tungsten doped titania thin films on glass; active photocatalysts. "Polyhedron 22.1 (2003): 35-44 .]. The sol-gel process is a wet-chemical coating process, whereby a subsequent post-treatment step (drying, heat treatment, UV curing) of the layers is generally necessary. The wet-chemical deposition and / or the aftertreatment can also be limiting factors in the choice of the substrate material.

Mixed oxides or mixed oxide thin layers or mixed layers in general can be used in a variety of fields. Catalyst layers (Mo / V / Nb / Te oxides [ Gaffney, AM, et al. "Characterization and catalytic studies of PVD synthesized Mo / V / Nb / Te oxide catalysts." Journal of Catalysis 229.1 (2005): 12-23 .]), Wear protection layers [ Hovsepian, P. Eh, AP Ehiasarian, and U. Ratayski. "CrAlYCN / CrCN nanoscale multilayer PVD coatings deposited by the combined high power impulse magnetron sputtering / unbalanced magnetron sputtering (HIPIMS / UBM) technology." Surface and coatings technology 203.9 (2009): 1237-1243 .], ion-conducting layers (YSZ [Wang, HB, et al., "Deposition and characterization of YSZ thin films by aerosol-assisted CVD." Materials Letters 44.1 (2000): 23-28.]), electrochromic layers, among others, for switchable glasses (MoO _{x, x} Mowo [Gesheva, KA, et al "Crystallization of Chemically vapor deposited molybdenum and tungsten mixed / molybdenum oxide films for electrochromic application." Thin Solid films 515.11 (2007):.. 4609-4613]), layers for Spintronic Applications (eg, Y ₃ FesO ₁₂ - Yttrium Iron Garnet YIG [Dubs, Carsten, et al., Sub-micrometer yttrium iron garnet LPE films with low ferromagnetic moments losses.] J. Phys. D: Appl. Phys (2017), https://doi.org/10.1088/1361-6463/aa6b1c]) or photocatalytically active coatings (TiO _x , TiWO _x [Rampaul, Ashti, et al., Titania and tungsten doped titanium thin films on glass; active photocatalysts. "Polyhedron 22.1 (2003): 35-44.]). In addition, the growth rate of layers can be increased [ Bodurov, Georgi, et al. "Thin film optical coatings of vanadium oxides and mixed tungsten / vanadium oxides deposited by APCVD employing precursors of vanadyl acetylacetonate and a mixture of tungsten hexacarbonyl." Physics Procedia 46 (2013): 127-136 .]. In the production of WO ₃ to the precursor W (CO) ₆ additionally V (CO) ₆ or vanadium acetylacetonate were introduced with the aim to increase layer growth rates and thus to make the coating process more economical. In this example, an APCVD coating process was used to deposit the layers (heating the substrates to 400-500 ° C and heating the gas streams to precursor transport to ~ 170 ° C necessary). Further fields of application of mixed oxide layers would be the battery technology [Davari, Elaheh, et al. "Manganese cobalt mixed oxide film as a bifunctional catalyst for rechargeable zinc-air batteries." Electrochimica Acta 211 (2016): 735-743.], Using methods such as electrodeposition (electroplating), which is an electrochemical coating method.

Titanium dioxide is used in a variety of applications. Worth mentioning are applications in the field of UV protection, photocatalytically active layers (eg self-cleaning surfaces) or catalysts and in some cases antimicrobial applications. Titanium dioxide in the form of nanoparticles is especially interesting due to the high specific surface area [ Wei, Xiaojin, et al. "Photocatalytic TiO ₂ nanoparticles enhanced polymer antimicrobial coating." Applied Surface Science 290 (2014): 274-279 .]. For many applications, however, TiO ₂ immobilized in the form of layers is more advantageous. Conventional methods for producing TiO ₂ thin films are physical vapor deposition (PVD) such as sputtering [ Tang, H., et al. "Electrical and optical properties of TiO ₂ anatase thin films." Journal of Applied Physics 75.4 (1994): 2042-2047 . Tölke, Tina, et al. TiO ₂ layers. "Thin Solid Films 518 (2010), 4242-4246 ], Sol-gel [Yu, Jiaguo, et al. "Preparation, microstructure and photocatalytic activity of the porous TiO ₂ anatase coating by sol-gel processing." Journal ofsol-gel Science and Technology 17.2 (2000): 163-171], or chemical vapor deposition (CVD) [Richards, BS, NTP Huong , and A. Crosky. "Highly porous nanocluster TiO ₂ films deposited using APCVD in excess of water vapor." Journal of The Electrochemical Society 152.7 (2005): F71-F74.]. However, CVD processes have the disadvantage that the substrates are frequently heated during the coating (~ 250 ° C. [Jung, Sang-Chul, and Nobuyuki Imaishi. "Preparation, crystal structure, and photocatalytic activity of TiO ₂ films by chemical vapor deposition." Korean Journal of Chemical Engineering 18.6 (2001): 867-872.]) To produce photocatalytically active layers. A thermal aftertreatment (~ 450 ° C [Mills, Andrew, et al., "Photocatalytic oxidation of deposited sulfur and gaseous sulfur dioxide by TiO ₂ films." The Journal of Physical Chemistry C 111.14 (2007): 5520-5525.]) however, often necessary for sol-gel processes. Such methods are correspondingly unsuitable for the coating of temperature-sensitive substrates. In the literature, however, sol-gel methods are also known, which at significantly lower substrate or post-treatment temperatures (~ 100 ° C [Langlet, M., et al., Sol-gel preparation of photocatalytic TiO ₂ films on polymer substrates. "Journal of sol-gel science and technology 25.3 (2002): 223-234.], 120 ° C [Yun, Young Jin, et al., "Low-temperature coating of sol-gel anatase thin films." Materials Letters 58.29 (2004): 3703- 3706.]) produce photocatalytically active layers. However, these approaches involve several and often time-consuming operations (eg, eight hours of sol temperature treatment).

Against this background, plasma-based processes that allow layers with similar property spectra in just one step could be of interest. Plasma-enhanced CVD (PECVD) processes were investigated in this context in the literature. In addition to processes that work in a vacuum, there are also methods that allow layer production under atmospheric pressure conditions. One possibility would be the use of DBD sources. Thus, the production of TiO _x layers with the use of TiCl ₄ was described in the literature, the nanocrystalline constituents [ Xu S., J. Xu, X. Peng, J. Zhang, Plasma Sci. Technol. 8 (1999) 292 . Zhu, A-M., et al. "Crystalline, Uniform - Sized TiO ₂ Nanosphere Films by a Novel Plasma CVD Process at Atmospheric Pressure and Room Temperature." Chemical Vapor Deposition 13.4 (2007): 141-144 .].

From the AT 517 694 A4 a device for applying a coating on a surface of a substrate with a plasma generator comprising an anode and a cathode for generating an atmospheric plasma jet by electrical discharge in a working gas, said plasma generator having a discharge channel for the plasma jet, which extends via an outflow to the and a supply means having an inlet side for charging the supply means with a coating material and an outlet side for introducing the coating material into the plasma jet is provided. It is proposed that the supply device is connected on the inlet side to an evaporator for the coating material and on the outlet side has an outlet opening for the gaseous coating material which is directed into the outflow region. With the aid of the local adjustability of the material introduction into the plasma jet, it is possible in particular to make the functional properties of the coating more homogeneous and better controllable.

From the DE 10 2004 029 911 A1 For example, the preparation of inorganic layers on a substrate using a hot gas stream and a precursor-containing carrier gas stream is known. With relatively low and easily controllable heat input and a high diversity of materials, it enables both the coatable substrates and the layers themselves to produce homogeneous, adherent layers with significantly higher deposition rates. The hot gas stream and the carrier stream, which is much cooler than the Hot gas stream, are brought together only in the vicinity of the substrate to be coated to form a mixture whose temperature does not chemically and / or physically affects the entire substrate.

The invention is based on the object to provide an improved method for depositing a layer.

The object is achieved by a method for depositing a layer.

Advantageous embodiments of the invention are the subject of the dependent claims.

An attachment according to the invention for a plasma source for metering precursors comprises at least one nozzle which can be attached to the plasma source or otherwise arranged in a fixed position relative to the plasma source, such that a precursor flowing out of the nozzle projects a plasma jet emerging from the plasma source at a predetermined angle and can be supplied with an adjustable in a range of 0.5 mm to 10 mm predetermined distance between an outlet opening of the nozzle and a substrate to be coated.

In one embodiment, a distance between an exit opening of the plasma source and the substrate and / or the angle is adjustable.

In one embodiment, at least two nozzles are provided.

In one embodiment, the at least two nozzles are independently adjustable in pitch and / or angle.

In a method according to the invention for producing a layer on a substrate, at least one precursor is metered into the vicinity of the substrate via an attachment as described above in or in the vicinity of a plasma stream emerging from a plasma source. Proximity means here that the precursor does not have to interact directly with the plasma stream. This is the case, for example, if the distance between the exit opening of the plasma source and the substrate is chosen to be particularly large and the distance between the exit opening of the nozzle and the substrate is very small. It would also be conceivable to dose the precursor off-center to the plasma stream.

According to the invention, by metering in a plurality of precursors in or in the vicinity of the plasma stream, a metal oxide mixed layer or a metal oxide / semiconductor oxide mixed layer is deposited.

In one embodiment not according to the invention, an oxide layer, a nitride layer, a carbide layer, a phosphate layer, a polymer layer, or by metering in a plurality of precursors in or in the vicinity of the plasma stream is mixed with a metal oxide / nonmetal oxide mixed layer, a semiconductor oxide / nonmetal oxide mixed layer, a polymer Mixed layer, a metal oxide / polymer mixed layer, a semiconductor oxide / polymer mixed layer or a composite layer consisting of a matrix layer, which is loaded with particles, deposited.

In one embodiment, the precursors are supplied to the attachment in the form of a gas or gas mixture, as an aerosol or in solid form, for example as a powder.

According to the invention, a distance between an outlet opening of the nozzle and a substrate to be coated in a range of 0.5 mm to 10 mm is set by means of the attachment.

In one embodiment, air or nitrogen is used as the working gas for the plasma source.

In one embodiment, a temperature control of the substrate takes place during the coating process and / or a subsequent heat treatment.

In an alternative embodiment, a tempering of the substrate during the coating process and / or a subsequent heat treatment are omitted.

The invention further relates to a component comprising a surface which is coated by means of the method described above with a photocatalytically active TiO _x layer or SiO _x / TiO _x mixed layer.

Furthermore, the invention relates to a component comprising a surface which is coated by means of the method described above with an yttrium-iron-garnet or yttrium-aluminum-garnet or SiO _x / SnO _x - mixed layer.

Furthermore, the invention relates to a component comprising a surface which is coated by means of the method described above with an optically transparent SiO _x / TiO _x or SiO _x / SnO _x mixed layer, wherein a refractive index or a refractive index gradient over the layer thickness by varying the mixing ratio of two Metered precursors is specifically adjustable.

The plasma jets used according to the invention have the advantage, in comparison with conventional coating processes, that surface areas can also be treated selectively. The heating and / or evaporation of the precursors is not absolutely necessary. Instead, the precursors are supplied in aerosol form. Thus, no heating of hoses is necessary to prevent condensation of the precursor.

A new attachment for plasma nozzles was developed with which the entry points of the precursor into the plasma can be adjusted. It has surprisingly been found that specifically mixed layers (layers consisting of several metal oxides, for example silicon oxide and titanium oxide) can be produced by simultaneous introduction of different precursors. Such layers show, inter alia, the possibility of selectively adjusting various coating properties (refractive index, photocatalytic activity, transmission, antimicrobial activity) by varying the mixing ratio, without temperature control of the substrate during the coating process or subsequent heat treatment (often 400 ° C. to 500 ° C.) C) is necessary.

Because of this, the coating of temperature-sensitive substrates (for example plastics, wood, WPC, composites, fibers, textiles, paints or painted surfaces) is also possible for the first time, above all for the deposition of photocatalytically active layers. Furthermore, the article has the advantage that contamination of the plasma nozzles does not take place, in contrast to the feed of the precursor directly through the plasma nozzle (so-called direct mode). Thus, a long-term stable plasma and coating process is possible, and cleaning steps of the plasma nozzles can be dispensed with.

In particular, the deposition takes place at atmospheric pressure.

Embodiments of the invention are explained in more detail below with reference to drawings.

• 1 eine schematische Ansicht eines Aufsatzes für eine Plasmaquelle zur Dosierung von Precursoren,
• 2 eine schematische Ansicht der Plasmaquelle und des Aufsatzes, wobei die Düse verstellbar an der Plasmaquelle angeordnet ist,
• 3 eine schematische Ansicht der Plasmaquelle und des Aufsatzes mit zwei Düsen,
• 4 eine schematische Ansicht einer weiteren Ausführungsform einer Plasmaquelle mit linienförmigem Plasma und eines Aufsatzes zur Dosierung von Precursoren,
• 5 ein Diagramm mit einer Elementkonzentration in Abhängigkeit von einer Dosiermenge eines titanhaltigen Precursors,
• 6 FTIR-Spektren von SiO_x / TiO_x Mischschichten und reinen SiO_x und TiO_x Plasmaschichten,
• 7 ellipsometrisch ermittelte Brechzahlen von Schichten in Abhängigkeit von einer Dosierrate für SiO_x / TiO_x Mischschichten und reine SiO_x und TiO_x Plasmaschichten,
• 8 relative Bandenflächen aus FTIR-Messungen in Abhängigkeit von einer Bestrahlungszeit für SiO_x / TiO_x Mischschichten und reine SiO_x und TiO_x Plasmaschichten,
• 9 eine Schichtzusammensetzung in Abhängigkeit vom Precursorfluss für SiO_x / SnO Mischschichten und reine SiO_x und SnO Plasmaschichten,
• 10 UV/VIS-Spektren von Schichten in Transmission für SiO_x / SnO Mischschichten und reine SiO_x und SnO Plasmaschichten,
• 11 UV/VIS-Spektren von Schichten in Transmission für TiO_x Plasma schichten,
• 12 eine Bandlückenbestimmung für TiO_x Plasmaschichten,
• 13 relative Bandenflächen aus FTIR-Messungen in Abhängigkeit von einer Bestrahlungszeit für TiO_x Plasmaschichten und Referenzproben,
• 14 die Schichtdicke in Abhängigkeit von der Anzahl der Durchläufe der Beschichtung für SiO_x Plasmaschichten, und
• 15 der Schichtdickenverlust nach abrasiver Beanspruchung in Abhängigkeit von der Anzahl der Durchläufe der SiO_x Beschichtung.

Show:

• 1 a schematic view of an essay for a plasma source for the dosage of precursors,
• 2 a schematic view of the plasma source and the attachment, wherein the nozzle is adjustably arranged on the plasma source,
• 3 a schematic view of the plasma source and the attachment with two nozzles,
• 4 a schematic view of another embodiment of a plasma source with linear plasma and an attachment for the dosage of precursors,
• 5 a diagram with an element concentration as a function of a metered quantity of a titanium-containing precursor,
• 6 FTIR spectra of SiO _x / TiO _x mixed layers and pure SiO _x and TiO _x plasma layers,
• 7 ellipsometrically determined refractive indices of layers as a function of a metering rate for SiO _x / TiO _x mixed layers and pure SiO _x and TiO _x plasma layers,
• 8th relative band areas from FTIR measurements as a function of an irradiation time for SiO _x / TiO _x mixed layers and pure SiO _x and TiO _x plasma layers,
• 9 a layer composition as a function of the precursor flow for SiO _x / SnO mixed layers and pure SiO _x and SnO plasma layers,
• 10 UV / VIS spectra of layers in transmission for SiO _x / SnO mixed layers and pure SiO _x and SnO plasma layers,
• 11 UV / VIS spectra of layers in transmission for TiO _x plasma layers,
• 12 a band gap determination for TiO _x plasma layers,
• 13 relative band areas from FTIR measurements as a function of an irradiation time for TiO _x plasma layers and reference samples,
• 14 the layer thickness as a function of the number of passes of the coating for SiO _x plasma layers, and
• 15 the layer thickness loss after abrasive stress as a function of the number of passes of the SiO _x coating.

Corresponding parts are provided in all figures with the same reference numerals.

1 shows a schematic view of an essay 1 for a plasma source 2 for the dosage of precursors.

Preliminary experiments have shown that it is advantageous for many precursors to reduce their interaction time in the plasma to a necessary minimum. Long residence times of the precursors in the plasma, for example, lead to excessive particle formation and agglomeration, which can cause the formation of lower-quality layers, for example with regard to abrasion stability. To reduce the interaction time to a necessary level, became an essay 1 developed and manufactured. The essay 1 includes at least one nozzle 5 at the plasma source 2 attached or otherwise in a fixed position to the plasma source 2 is arrangeable, such that one out of the nozzle 5 effluent precursor one from the plasma source 2 leaked plasma jet at an angle ω can be fed. This angle ω as well as a distance b between an outlet opening of the nozzle 5 and a substrate 4 and a distance a between an exit opening of the plasma source 2 and the substrate 4 can be adjustable.

2 is a schematic view of the plasma source 2 and the essay 1 , where the nozzle 5 adjustable at the plasma source 2 is arranged.

With the help of this essay 1 For example, precursors can be in the form of aerosol droplets and / or gaseous, for example at a distance b from about 0.5 mm to 10 mm and at an adjustable angle ω , from 0 ° to 90 °, more preferably between 0 ° and 60 ° (for example, of 45 °), to the plasma jet through the nozzle 5 , (For example, with an inner diameter of 2 mm, stainless steel) are introduced into the plasma jet.

In one embodiment, the essay 1 several nozzles 5 include. 3 is a schematic view of the plasma source 2 and the essay 1 with two nozzles 5 , each of which is adjustable at the plasma source 2 is arranged, for example by means of a clamp 3 and swivel arms 6 , Thus, over a variable number of nozzles 5 the number of precursors can be selected according to the requirements of the coating.

In embodiments of methods for creating binary mixed layers, two nozzles were used 5 used. Furthermore, this system constructively offers the possibility of a variable number n of nozzles 5 and thus to introduce a variable number of precursors, which allows the possibility of forming even more complex layer systems.

Another advantage of this design is the possibility of spacing b regardless of the distance a between an exit opening of the plasma source 2 and the substrate 4 to change. Thus, on the one hand, the distance a be changed to the thermal influence of the plasma on the substrate 4 to adjust and minimize if necessary. And second, the distance b be adjusted so that the necessary time for the implementation of the precursor and layer formation interaction time is given in the plasma, but excessive energy input into the precursor can be avoided. Also, for the deposition of mixed layers 1 + n nozzles can be used and their respective distance b regardless of the distances b adapted to the other nozzles. Thus, the distances b1 (for nozzle 1 ), b2 (for nozzle 2 ), etc. are optimally adapted to the respective precursor substance (plasma precursor interaction time), for the layer conversion.

4 shows a schematic view of another embodiment of a plasma source 2 with line-shaped plasma and an adapted attachment 1 ,

In 4 is the plasma source 2 shown, wherein the line-shaped plasma emerges from the slot below the source. In this embodiment, the essay contains 1 a pipe with one on the width of the Plasma adapted arrangement of outlet openings (nozzle 5 ), through which the precursor is introduced into the plasma. Here are analogous to 1 the distances a . b and the angle ω variably adjustable.

Table 1 shows possible variable coating parameters. Table 1: Process parameters of mixed layers process parameters unit Adjustment plasma power [W] 50 to 600 working gas [-] Nitrogen, (air) traversing [Mm / s] 1 to 300 Number of passes [-] 1 to 100 Distance a [Mm] 5 to 40 Distance b [Mm] 0.5 to 10 Parameter precursor dosing Precursor concentration (liquid precursor → aerosol dosing system) [Wt .-%] 0 to 100 Precursor flow microdosing pump (liquid precursor → aerosol dosing system) [Ul / min] 5 to 200 Two-substance nozzle pressure (aerosol dosing system) [bar] 1 to 6 Precursor flow of organosilicon precursor (hexamethyldisiloxane → evaporator unit) [Ml / min] 1 to 25

For layer deposition, a plasma source was used 2 CAT (curved arc technology) 600 (W) from Tigres GmbH (Marschacht, Germany). This plasma source operates at powers between 50 and 600 W, with powers of 600 W being used for most of the studies listed above. This plasma source 2 can be operated, inter alia, with the working gases air, nitrogen and argon, wherein the layer quality was best in terms of abrasion resistance and optical quality when using nitrogen. As a result, most of the experiments carried out were carried out with nitrogen. Alternatively, however, other plasma systems, preferably jet plasma sources and / or other working gases may also be used. Precursors can on the one hand as aerosol via an aerosol dosing (as in the EP 2 743 373 B1 described) in combination with a two-fluid nozzle and a micro-metering pump are provided to the plasma. The liquid precursors are delivered by the microdosing pump with flow rates typically from 5 to 200 μl / min in hoses to the two-fluid nozzle. The two-fluid nozzle is operated with gas pressures of 1 to 6 bar and so the liquid precursor atomized to form an aerosol, wherein the type of gas as the working gas of the plasma source can be selected or may be different. By the aerosol dosing system, a separation and limitation of the maximum droplet sizes can be realized and the aerosol then passes through the nozzles 5 of the essay 1 in the plasma zone and / or to the substrate. Due to the aerosol dosing system, a very homogeneous coating image is obtained.

On the other hand, precursors (eg hexamethyldisiloxane) can be introduced in gaseous form. In the illustrated examples (I, II and IV), precursors were introduced via the evaporator unit STS 10.0 from Sura Instruments GmbH directly through the metering nozzles. Gas flows from 1 to 25 ml / min can be achieved with this system. However, the metered addition is not limited to gaseous precursors or liquid precursors. Alternatively, for example, nanoparticle dispersions or powders may be used and delivered to the plasma via the attachment 1 ,

Example I (SiO _x / TiO _x mixed layers)

In one embodiment, for depositing the titanium-containing layer constituent, the precursors TTIP (titanium (IV) isopropoxide, 97%, Sigma Aldrich), TBO (titanium (IV) butoxide, 97%, Sigma Aldrich) and TIPO (titanium (IV) diisopropoxide bis (acetylacetonate), 75 wt .-% in isopropanol) directly into the working gas flow of the plasma source 2 metered. The introduction took place in the form of aerosol droplets with the aid of an aerosol dosing system, as in EP 2 743 373 B1 described. The EP 2 743 373 B1 is hereby incorporated by reference. Here, the liquid precursor is atomized by means of a two-fluid nozzle and a transported secondary gas stream (also nitrogen). The first two precursors (TTIP, TBO) are extremely sensitive to water (eg humidity), which requires an additional modification of the dosing system (additional heating of the hoses). Furthermore, this property, when introduced directly into the working gas stream, leads to layers of lower quality with regard to abrasion resistance and photocatalytic activity. An advantage in this context is the use of TIPO. This precursor is significantly less sensitive to humidity, which simplifies metering and reduces clogging of nozzles and other components with smaller inside diameters. Additional heating of the hoses is not necessary with the use of this precursor. Furthermore, this precursor appears to react less rapidly in the plasma, which reduced the excessive formation of coarse particles and thus could produce denser and more stable layers. Despite this improvement, the layers were comparatively dusty. The direct introduction of the precursors into the working gas stream leads to a relatively long residence time of the precursors in the reactive plasma space (conversion of the precursors and agglomeration of the particles formed).

Thus, it was expedient to increase the interaction time of the precursors by using the in at least one of the 1 to 4 shown and described above 1 to reduce to a necessary minimum.

In addition to the titanium-containing component, silicon-containing precursors can be introduced. In the experiments carried out hexamethyldisiloxane (HMDSO) was gaseous via the evaporator unit STS 10.0 Fa. Sura Instruments GmbH introduced. To produce SiO _x / TiO _x mixed layers, the amount of introduced HMDSO was kept constant, the amount of the titanium-containing precursor increased stepwise from 0 to 7.5 μl / min, 15 μl / min and 30 μl / min. Also in connection with the combination of precursors the reduction of the interaction time was expedient and led to higher quality layers.

For reasons of comparability, layer thicknesses of about 100 nm were realized for all investigations. For this, the influence of the distance was in preliminary experiments b , the plasma power, the precursor concentration and the number of runs to the deposition rate [nm / run] examined. The traversing speed with which the substrate 4 under the plasma source 2 was moved, was left constant at 250 mm / s and a grid spacing of 1 mm.

Coating thickness determinations were made using an Alpha-Step D-600 profilometer (KLA Tencor, Milpitas, USA). The tests produced layers on glass slides (+30 nm Pyrosil coating to avoid possible alkali diffusion into the layers) and Si wafers. All substrates were first ultrasonically cleaned in isopropanol / acetone (1: 1, V: V) and dried with compressed air. X-ray photoelectron spectroscopy (XPS) was performed with an AXIS ULTRA DLD (Kratos Analytical Ltd., Manchester, UK) to determine the chemical composition of the layers. Ellipsometric investigations were used to determine the layer thickness and the refractive index of the layers.

The following section presents selected results from studies on these mixed-layer systems.

5 shows a diagram with the element concentration e , that is, the chemical surface composition of the SiO _x / TiO _x mixed layers in atomic%, determined by means of XPS, as a function of the metered amount of the titanium-containing precursor, that is, the precursor flow P in μl / min.

The representation of the oxygen concentration is omitted here, since the focus should be on the Si / Ti ratio. The Si content at which no titanium-containing precursor was introduced (precursor flow P = 0) is about 28 atomic%; Ti is not detectable at this point. With the increase of the titanium-containing precursor flow P If the Ti concentration of the layers increases, the Si content decreases. Contents of about 8 atomic% Ti could be achieved by using 30 μl / min Ti precursor flow P be achieved. It is also striking that with increasing Ti content, the carbon content of the layers increases, which is due to unreacted constituents of the organo-organic precursor. The assumption that additionally precursor residues of the titanium-containing precursor are embedded in the layers is determined by FTIR measurements ( 6 ) underpinned.

6 shows the thus determined FTIR spectra of the mixed layers and pure SiO _x (0 μl / min) and TiO _x plasma layers. Shown is the absorbency A depending on the wave number k in cm ^-1 . Shown are a curve K0 for a precursor flow P of 0 μl / min, curve K1 for a precursor flow P of 7.5 μl / min, curve K2 for a precursor flow P of 15 μl / min, curve K3 for a precursor flow P of 30 μl / min and curve K4 for a pure TiO _x plasma without SiO _x .

These investigations showed that as the TIPO flux increases, the band area increases, which are mainly due to CH ₂ and CH ₃ vibrations of this precursor [Sigma Aldrich, FTIR spectrum]. In addition, it can be stated that the proportion of Si-O-Si vibrations with increasing TIPO precursor flow P decreases, but the Si-OH content increases.

Ellipsometrically determined refractive indices of the layers are shown in 7 depending on the TIPO dosing rate. Shown is the refractive index n depending on the Ti precursor flow P , The titanium-free SiO _x layer has a refractive index of about 1.46. The refractive index n of the layers decreases with increasing Ti precursor flow P to. The refractive index n for pure TiO _x layers, which were produced with this coating method, is around 1.84. These experiments showed that it is due to the adaptation of the Ti precursor flow P possible, the chemical compositions and refractive indices n to selectively influence and / or adjust the layers.

Furthermore, the photocatalytic activity of the coatings was investigated by stearic acid degradation. The FT-IR transmission spectra were investigated with a MB3000 FT-IR spectrometer (ABB, Zurich, Switzerland) in a wavenumber range of 2000 cm ^-1 to 4000 cm ^-1 and a spectral resolution of 2 cm ^-1 . Stearic acid is a commonly used model substance and comes close to compounds that naturally attach to surfaces. The deposition of stearic acid on the TiO _x surfaces was carried out in a vacuum chamber. 7 mg stearic acid were positioned on a hot plate and evaporated after reaching the desired vacuum. This preparation step resulted in a stearic acid layer thickness of about 100 nm on the sample surface. Subsequently, the samples were irradiated at a distance of 20 cm under a daylight lamp (Ultra-VITALUX® sun lamp, OSRAM) for 3 hours. After 0, 30, 60, 120 and 180 minutes of irradiation, FT-IR spectra were recorded in the above measurement range. Specifically, the bands at about 2800 cm ^-1 to 3000 cm ^-1 , which are due to CH ₃ and CH ₂ stretching shrinkages of stearic acid, were examined here. If the photocatalytic activity is present, the band area is reduced as the irradiation time increases. The photocatalytic activity of the films was then compared with the activity of a commercially available product, the Pilkington Activ ^® (Nippon Sheet Glass Co. Ltd.). Pilkington Activ ^® consists of an about 15 nm thick anatase layer on a 4 mm float glass. The float glass is additionally provided with an about 30 nm thick SiO ₂ layer to prevent alkali diffusion [Mills, Andrew, et al. "Photocatalytic oxidation of deposited sulfur and gaseous sulfur dioxide by TiO ₂ films." The Journal of Physical Chemistry C 111.14 (2007): 5520-5525.].

The result of this experiment will be in 8th shown. The diagram shows the relative band areas F from FTIR measurements as a function of the irradiation time t shown. Here, the output bands are normalized to 100% and the band areas after 30, 60, 120 and 180 min irradiation are correspondingly based on the initial value. A reduction of the relative value thus shows the photocatalytic property of the layers. The titanium-free SiO _x layer S0 (0 μl / min) showed no reduction of the band area of the stearic acid, whereby this layer is not to be assigned any photocatalytic activity. With increasing Ti content of the layers S1 (7.5 μl / min), S2 (15 μl / min), S3 (30 μl / min) and S4 (pure TiO _x -Plasmaschichten) increases the photocatalytic activity. The mixed layer S3 which was produced with the highest TIPO flux (30 μl / min) showed the highest activity and caused a reduction of the band area by about 20% after 180 min irradiation. In comparison, silicon-free TiO _x plasma layers were used S4 Stearic acid is no longer detected after 120 minutes. Thus, a significant reduction in the photocatalytic activity was observed by mixing with SiO _x . The curve SA illustrates the photocatalytic activity of the layer of the commercially available product ^® Pilkington Activ.

Example II (SiO _x / SnO _x mixed layers)

As another embodiment, silica / tin oxide / mixed layers were prepared. Here, analogously to the preparation of the silica / titanium oxide mixed layers, instead of the titanium-containing precursor (TIPO), the organotin precursor tetrabutyltin (TBT) was prepared using the above-described article 1 brought in.

XPS studies also showed the potential to produce such mixed layer systems. In 9 the layer composition is represented as a function of the TBT precursor flow. Shown is the element concentration e depending on the TBT precursor flow P ,

Comparable with the composition of the silica / titanium oxide / mixed layers, an increasing tin content can be achieved for this layer system with the increase in the TBT precursor flow P determine. The increase in the carbon content of the layers, which is due to unreacted precursor constituents (especially of the TBT), is also clear. This proportion is relatively high, especially for the SnO _x layer. This indicates that the plasma energy in the coating process is too low to fully implement the precursor. Optionally in this case would be an increase in the distance b for the organotin precursor TBT, the heating of the substrate material or a subsequent heat treatment step possible to reduce or remove any remaining Precursorreste. Also the use of plasma sources 2 Higher performance could be effective for better implementation of the precursor.

In addition, UV / VIS spectra of the layers were recorded on glass substrates in transmission, which in 10 are shown. Shown is the transmission T depending on the wavelength λ , As the Sn content of the layers increases, the absorption edge shifts to higher wavelengths. Furthermore, here for the mixed layers, a transmission increase from about 390 nm wavelength for the mixed layers. The dotted curve in this diagram represents the transmission spectrum of an uncoated glass slide.

Example III: TiO _x plasma layers

In the experiments described in Example I above all the silicon-free TiO _x -BeSchichtungen showed excellent photocatalytic properties. Surprisingly, it was found that this very good photocatalytic activity without heating the substrate (substrate temperature 18-25 ° C) and without a thermal aftertreatment can be achieved, in conjunction with a good transparency of the layers. There is only a small input of temperature via the plasma energy into the substrate material, so that it is also possible to coat temperature-sensitive materials (eg plastics, fibers or textiles).

In the following section, we will therefore examine in more detail the photocatalytic properties of such layers as a function of various system parameters.

For depositing high-quality layers, it was advantageous to meter in the precursors as close to the substrate as possible (using the attachment described above) 1 ). In experiments in which this precursor was introduced further away from the substrate, only a dust-like covering of the substrate surface could be achieved, which was neither abrasion resistant nor photocatalytically active.

TiO _x layers were produced with the process parameters given in Table 2. Table 2: Process parameters titanium oxide: comparison of plasma power Process parameters unit value plasma power [W] 300 W, 600 W working gas [-] nitrogen traversing [Mm / s] 25 mm / s Number of passes (layer thickness about 100 nm) [-] 3 Distance a [Mm] 20 Distance b [Mm] 5 Parameter precursor dosing precursor concentration [Wt .-%] 50 Precursor flow microdosing pump [Ul / min] 25 Two fabric nozzle pressure [bar] 4.5

By means of scanning electron microscopic investigations on fracture edges of the deposited layers, the influence of the plasma power on the layer properties was investigated. It was found that low power generally leads to smooth and homogeneous layers. The use of high power leads in comparison to rougher layers and coarser particles on the surface, but nevertheless to a homogeneous coating image. However, the use of lower power led to the formation less stable coatings, which after 1000 wash cycles (Washability Test, according to ASTM D2486) no coating on the substrate surface was more detectable. In addition, a photocatalytic activity of the layer produced at 300 W power was undetectable or absent. By contrast, the layers deposited at 600 W only showed a relative layer thickness loss of ~ 25% after 1000 cycles, which may be due to the removal of loose particles on the surface. Furthermore, very good photocatalytic properties could be detected, which are comparable and in some cases better with the photocatalytic effect of the Pilkington Activ ^® (results shown in the following sections). As a result, subsequent tests were performed on plasma powers of 600W.

In further investigations was the influence of the distance b and the precursor concentration on the thickness, morphology, optical properties, photocatalytic activity, and abrasion resistance of the layers. It was the distance b varies between 2 mm and 9 mm. With decreasing precursor concentration, the number of coating passes was increased accordingly to realize a final layer thickness of about 100 nm (layer deposition rate determined in previous layer thickness measurements).

Scanning electron microscopic investigations were carried out at break edges of the deposited TiO _x coatings, which had concentrations of 50, 25 and 12.5% and distances b of 2 mm and 5 mm were made. With increasing distance b the number of coarse particles on the surface increases. A similar trend can be observed with decreasing precursor concentration. Especially at concentrations of 25% and 12.5% and distance b of 5 mm, it was possible to produce layers with a very dense particle concentration at the surface, ie layers with a high specific surface area. This observation coincides with scanning electron micrographs of top views of the layers. By increasing the distance b increases the interaction time of the precursor with the plasma. On the one hand, this can lead to a more complete conversion of the precursor to TiO _x , but on the other hand also to the formation of larger particles and their agglomeration. If the distance is further increased to 7 or 9 mm, only dustier layers are formed, which are neither resistant to ultrasound nor washability. Thus, distances should be used to produce adherent layers b smaller than 7 mm can be selected.

The UV-Vis transmission spectra are exemplary for layers in 11 compared using 25% precursor and different distances b were manufactured. Shown is the transmittance T depending on the wavelength λ , Furthermore, these spectra became the band gaps E _g definitely, in 12 where α is the optical absorption coefficient. It could be observed that with increasing distance b and thus increasing the interaction time between plasma and precursor, the band gap is reduced from 3.73 eV to 3.65 eV. This could furthermore be attributed to the increased number of passes, that is to say to an increased energy input through the plasma (in order to realize a layer thickness of about 100 nm) or else by changes in the layer structure.

From [Hong, Yong Cheol, et al. "Band gap narrowing of _TiO2 by doping nitrogen in atmospheric microwave plasma." Chemical Physics Letters 413.4 (2005). 454-457] is known that it is possible through the use of nitrogen-containing plasmas, TiO _x layers with nitrogen to dope. In this publication, layers produced by means of a sol-gel process could be doped using a plasma discharge in low pressure. Such dopants can have the advantage that photocatalytic effects are also or additionally initiated by the irradiation with visible light, which can increase the effectiveness of the coating

At this point, selected investigations of the photocatalytic activity of the coatings will be shown. In one example, the influence of nitrogen plasma post-activation compared to non-post-activated coatings shall be shown ( 13 ). As can be seen from the diagram, an uncoated glass sample Ref caused no degradation of the stearic acid or reduction of the CH ₂ and CH ₃ band surface. Significant effects were shown by the Pilkington Activ ^® surface (Active. 7) and the plasma jet samples P1 . P2 . P3 , The effects of the TiO _x layers were comparable in this test and it was possible after 3 hours of irradiation, about 85% of stearic acid were degraded. P4 represents the effect of the nachaktivierten samples. These were significantly better in the test and no stearic acid could be detected after 3 hours of irradiation more.

Example IV: SiO _x Coatings

In addition to titanium-containing precursors, the organosilicon precursors HMDSO (metered in via an evaporator unit, for example the STS 10.0 - Sura Instruments GmbH) and TEOS (metered in via the aerosol dosing system off EP 2 743 373 B1 ) for layer deposition with the attachment 1 used. Even with the deposition of quartz-like layers, as the layer thickness increases, coarser particles form on the surface, which is the maximum achievable layer thickness d and thus limits possible uses. Thus, the formation of coarser particles by substrate-closer metering of the precursor (via the described attachment) could be avoided and thicker layers could be produced. In the case of thicker layers, consequently, higher concentrations of new functionalities (antimicrobial agents, dyes, hydrophobic substances, polymers, flameproofing media, UV protection media, photocatalytic or magnetic particles, carbon nanotubes, nanoparticles such as quantum dots, carbon dots, graphene) can also be incorporated into the SiO _x Matrix layers are introduced, which need not necessarily be of oxidic origin, as in the case of Examples I (SiO _x / TiO _x ) and II (SiO _x / SnO). First, pure SiO _x layers were considered in first experiments ( 14 ) prepared with HMDSO as precursor. Shown is the layer thickness d in nm depending on the number DL the runs of the coating. For the results shown below, the coating parameters are shown in Table 3. However, the coating process is not limited to this parameter range (see Table 1). Table 3: Process parameters silicon oxide process parameters unit Adjustment plasma power [W] 600 working gas [-] nitrogen traversing [Mm / s] 25 Number of passes [-] 1 to 4 Distance a [Mm] 20 Distance b [Mm] 2 to 5 Precursor flow of organosilicon precursor (hexamethyldisiloxane → evaporator unit) [Ml / min] 1 to 2

Depending on the dosing rate and number of passes, layers of different thicknesses can be realized. Generally, with the dosing rate, the number increases DL at runs and the distance b the layer thickness. In these experiments, layers in the range of up to 1 μm could surprisingly be produced, which are mechanically stable despite these very large layer thicknesses (4% layer thickness loss .DELTA.d after 1,000 washability cycles, see 15 ). In comparison, it is not possible with conventional Precursordosierungen to realize such thick layers mechanically stable.

• - Einsatz temperatursensibler Precursoren, die durch die Variation der Interaktionszeit im Plasma besser verarbeitet werden können (z. B. für Polymerschichten, Polymer-Mischschichten, DLC-Schichten, hydrophobe Schichten und weitere kohlenstoffbasierte Schichtsysteme)
• - Erzeugung weiterer Metall- und/oder Halbleiter- und/oder Nichtmetallbasierter Oxidschichten auf Basis von z. B. Si, Ti, Sn, Zn, Al, Zr, W, Li, Na, Mg, Co, Mn, In, Sb, Ce, Y, Fe, Ni, V, Mo, Nb, Te, Cu, Ba, Ca, P, S, C, N, F;
• - Erzeugung von Metalloxid-Mischschichten und/oder Metalloxid/Halbleiteroxid-Mischschichten und/oder Metalloxid/Nichtmetalloxid-Mischschichten und/oder Halbleiteroxid/Nichtmetalloxid-Mischschichten, bspw. SiO_x / TiO_x, SiO_x / SnO_x, YIG (yttrium iron garnet), YAG (yttrium aluminium garnet), LiCoO₂, LiFePO₄ oder weitere Mischungen der obengenannten Elemente
• - Realisierung von Metalloxid/Polymer-Mischschichten, Halbleiteroxid/Polymer-Mischschichten und Kompositschichten, bestehend aus einer Matrixschicht, die mit Partikeln (z. B. antimikrobielle Wirkstoffe, Farbstoffe, hydrophobe Substanzen, Polymere, Flammschutzmedien, UV-Schutzmedien, photokatalytische oder magnetische Partikel, Kohlenstoffnanoröhren, Nanopartikel wie Quantum Dots, Carbon Dots, Graphen) beladen ist
• - Erzeugung von Hartstoffschichten wie Nitride oder Carbide
• - Phosphatschichten (wie z. B. Magnesiumphosphat, Zinkphosphat, Eisenphosphat) als Korrosionsschutzschichten oder direkte Konversionsschichten an metallischen Bauteiloberflächen bei Verwendung von Phosphorsäure oder Triethylphosphat.

It is expected that a variety of additional layers, layer stoichiometries and / or functionalities can be achieved with this developed article:

• Use of temperature-sensitive precursors, which can be better processed by varying the interaction time in the plasma (for example for polymer layers, polymer mixed layers, DLC layers, hydrophobic layers and other carbon-based layer systems)
• - Production of other metal and / or semiconductor and / or non-metal-based oxide layers based on z. B. Si, Ti, Sn, Zn, Al, Zr, W, Li, Na, Mg, Co, Mn, In, Sb, Ce, Y, Fe, Ni, V, Mo, Nb, Te, Cu, Ba, Ca, P, S, C, N, F;
• Production of metal oxide mixed layers and / or metal oxide / semiconductor oxide mixed layers and / or metal oxide / non-metal oxide mixed layers and / or semiconductor oxide / non-metal oxide mixed layers, for example SiO _x / TiO _x , SiO _x / SnO _x , YIG (yttrium iron garnet ), YAG (yttrium aluminum garnet), LiCoO ₂ , LiFePO ₄ or other mixtures of the above elements
• Realization of metal oxide / polymer mixed layers, semiconductor oxide / polymer mixed layers and composite layers, consisting of a matrix layer with particles (eg antimicrobial agents, dyes, hydrophobic substances, polymers, flame retardants, UV protection media, photocatalytic or magnetic particles , Carbon nanotubes, nanoparticles such as quantum dots, carbon dots, graphene)
• - Production of hard coatings such as nitrides or carbides
• - Phosphate layers (such as magnesium phosphate, zinc phosphate, iron phosphate) as corrosion protection layers or direct conversion layers on metallic component surfaces using phosphoric acid or triethyl phosphate.

• o Durch Variation der Precursorkonzentration, Flussraten, Verhältnisse lassen sich die Metalloxid-Konzentrationen in den Schichten (z. B. Si-O_x, TiO_x, SnO_x) von 0% bis 100% einstellen.
• o Der Aufsatz 1 für Plasmasysteme erlaubt die gleichzeitige Eindosierung von mehreren Precursoren (gasförmig, flüssig -> Aerosole, Feststoffe - in Flüssigkeiten dispergiert und Pulver -> ebenso Aerosole), auch an unterschiedlichen Punkten im Plasma oder in der Nähe, durch Variation des Abstandes b für jede Düse 5. Weiterhin ist es denkbar, die Presursoren auch außermittig zum Plasmastrahl einzudosieren als zusätzliche Einstellgröße.
• o Dadurch ist eine gezielte Einstellung der Plasma-Precursor Interaktionszeit für jede Precursorsubstanz gegeben für eine optimale Umsetzung und daraus resultierenden Schichteigenschaften.

With the essay 1 and the method described, the realization of mixed layers is possible by simultaneous dosing of several (1 + n) chemical precursor substances (precursors) via an arrangement of several nozzles ( 5 ) (Number = 1 + n)

• By varying the precursor concentration, flow rates, ratios, the metal oxide concentrations in the layers (eg Si-O _x , TiO _x , SnO _x ) can be adjusted from 0% to 100%.
• o The essay 1 for plasma systems allows the simultaneous metering of several precursors (gaseous, liquid -> aerosols, solids - dispersed in liquids and powder -> aerosols also), even at different points in the plasma or in the vicinity, by varying the distance b for each nozzle 5 , Furthermore, it is conceivable to dose the presursors off-center to the plasma jet as an additional adjustment variable.
• This provides a targeted adjustment of the plasma precursor interaction time for each precursor substance for optimum conversion and resulting layer properties.

• o kein zusätzliches Temperieren der Substrate notwendig → Substrattemperaturen 18 °C bis 25 °C)
• o Es erfolgt lediglich ein geringer Temperatureintrag über die Plasmaenergie in das Substratmaterial, so dass auch eine Beschichtung temperatursensibler Materialien (z. B. Kunststoffe, Fasern oder Textilien) möglich wird.
• o Das Einbringen des titanhaltigen Precursors TIPO als Aerosol in das Plasma ist ohne Heizen der Aerosoldosiereinheit und Schläuchen möglich. Daraus ergibt sich ein hohes Anwendungspotential und gute Wirtschaftlichkeit für den gesamten Beschichtungsprozess.
• o Eine Dotierung der Schichten durch Plasmanachaktivierung ist möglich (z. B. Stickstoffdotierung bei Verwendung folgender Arbeitsgase oder - gasgemische: N₂, Ar/N₂, He/N₂, N₂/H₂, N₂/NH₃) oder Kohlenstoffdotierung bei Verwendung von CO₂, Ar/CO₂, Ar/C₃H₈, Ar/C₂H₂).

In the case of TiO _x silicon-free plasma layers (100% TiO _x and 0% SiO _x ) deposited with the attachment 1 , surprisingly shows a very good photocatalytic activity without heating the substrate and without thermal aftertreatment.

• o no additional tempering of the substrates necessary → substrate temperatures 18 ° C to 25 ° C)
• o Only a small input of temperature via the plasma energy into the substrate material takes place, so that it is also possible to coat temperature-sensitive materials (eg plastics, fibers or textiles).
• o The introduction of the titanium-containing precursor TIPO as an aerosol into the plasma is possible without heating the aerosol dosing unit and hoses. This results in a high application potential and good economy for the entire coating process.
• A doping of the layers by plasma post-activation is possible (eg nitrogen doping using the following working gases or gas mixtures: N ₂ , Ar / N ₂ , He / N ₂ , N ₂ / H ₂ , N ₂ / NH ₃ ) or carbon doping when using CO ₂ , Ar / CO ₂ , Ar / C ₃ H ₈ , Ar / C ₂ H ₂ ).

In the case of titanium-free SiO _x plasma layers (100% SiO _x and 0% TiO _x ) deposited with the attachment 1 , transparent layers are possible up to the micron layer thickness range at surprisingly simultaneously very good abrasion resistance.

The plasma jet system preferably uses air or nitrogen as the working gas, but can also be operated with noble gases (eg argon, helium), hydrogen-containing gases or other gas mixtures.

LIST OF REFERENCE NUMBERS

1

essay

2

plasma source

3

clamp

4

substratum

5

jet

6

poor

a

distance

A

absorbance

b

distance

d

layer thickness

DL

Number of passes

.DELTA.d

Layer thickness loss

e

element concentration

E _g

bandgap

F

band surface

k

wavenumber

K0

Curve

K1

Curve

K2

Curve

K3

Curve

K4

Curve

λ

wavelength

n

refractive index

P

precursor flow

P1

sample

P2

sample

P3

sample

P4

sample

Ref

uncoated glass sample

SA

Curve

S0

layer

S1

layer

S2

layer

S3

layer

S4

layer

t

exposure time

T

transmission

ω

angle

Claims (7)

A method for producing a layer on a substrate (4) by means of an attachment, comprising at least two nozzles (5) attached to a plasma source (2) or otherwise arranged in a fixed position to the plasma source (2), such that one precursor flowing out of the respective nozzle (5) from a plasma jet emerging from the plasma source (2) at a predetermined angle (ω) and with a predetermined distance (b) set between 0.5 mm and 10 mm between an outlet opening of the nozzle ( 5) and a substrate (4) to be coated, wherein in the vicinity of the substrate (4) a plurality of precursors via the attachment (1) through the at least two nozzles (5) in or in the vicinity of the from the plasma source (2) metered plasma streams are metered so that a metal oxide mixed layer or a metal oxide / semiconductor oxide mixed layer is deposited, wherein the distance (b) of one of the nozzles (5) between the outlet opening the nozzle (5) and the substrate to be coated (4) regardless of the distance (b) at least one other of the nozzles (5) between the outlet opening of the nozzle (5) and the substrate to be coated (4) to obtain a predetermined plasma precursor Interaction time is adjusted for the respective precursor. Method according to Claim 1 , wherein the precursors are supplied to the attachment (1) in the form of a gas or gas mixture, as an aerosol or in solid form. Method according to one of Claims 1 or 2 where air or nitrogen is used as working gas for the plasma source. Method according to one of Claims 1 to 3 wherein a temperature control of the substrate during the coating process and / or a subsequent heat treatment takes place or is omitted. A component comprising a surface obtained by the method of any of Claims 1 to 4 coated with a photocatalytically active SiO _x / TiO _x mixed layer. A component comprising a surface obtained by the method of any of Claims 1 to 4 coated with an yttrium-iron-garnet or yttrium-aluminum garnet or SiO _x / SnO _x mixed layer. A component comprising a surface obtained by the method of any of Claims 1 to 4 is coated with an optically transparent SiO _x / TiO _x or Si-O _x / SnO _x mixed layer, wherein a refractive index or a refractive index gradient over the layer thickness by varying the mixing ratio of two metered precursors is selectively adjustable.

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