Coated article including titanium oxycarbide and method of making same

The present invention relates to a method of making a coated article including a layer including titanium oxycarbide. In certain example embodiments, a titanium oxide layer (e.g. TiOx, where x is from 1 to 3, preferably about 2) is deposited on the substrate by sputtering; and then using a high voltage ion source (s) to implant the high energy carbon ions (C) into the titanium oxide layer so as to form a layer including titanium oxycarbide.

It is known in the art to coat a glass substrate with a layer of titanium oxide (e.g. TiOx, or other stoichiometry). The titanium oxide layer, if provided as the outermost layer on a glass substrate, may exhibit a fairly low contact angle θ as determined by the lying water drop method after prolonged exposure to ultraviolet (UV) light and water.

The contact angle θ is generally discussed in US Patent Nos. 6,303,225 and 6,631,731, which are hereby incorporated by reference. In some cases, high contact angles are desired, and in others, low contact angles are desired. The desired contact angle depends on the situation in which the intended product is to be used.

JP6158273 (A) discloses very hard thin, crystalline coatings of B, Ti, Si, etc. carbides.

The described coatings are formed by chemical vapor deposition of carbide-forming elements and / or oxides of carbide-forming elements under conditions that do not have a thermal effect on the substrate, followed by implantation with C and O ions.

US Patent No. 5,135,808 discloses a product that is a coated, substantially optically transparent substrate, such as, for example, glass, glass ceramics, sapphire etc. having improved abrasion resistance, comprised of a parent substrate, at least one interlayer, and an outer substantially optically transparent layer of diamond-like carbon. A method of making this product is also disclosed comprising etching the substrate by sputtering and applying layers by chemical vapor deposition.

The titanium oxide layers have some problems in terms of durability. For example, the scratch resistance of a titanium oxide layer is not much greater than that of glass. As a result, coated articles having an exposed layer of titanium oxide are highly susceptible to damage (e.g., scratching) during shipping and the like and are problematic in this regard.

Accordingly, it is apparent that there is a need for a coated article that is more durable (e.g., scratch-resistant) than pure titanium oxide. In certain example instances, a small contact angle θ may also be desirable.

The coated article made by the exemplary method of this invention includes a layer including titanium oxycarbide and / or titanium carbide. To form a coated article, a layer including titanium oxide (e.g., TiOx, where x is from 1 to 3, preferably about 2) is deposited on the substrate by sputtering (e.g., magnetron sputtering) or any other deposition technique. Different layer (s) may or may not be provided between the substrate and the layer comprising titanium oxide in various embodiments of this invention. After sputtering the layer containing TiOx, ion beam source (s) are used to implant at least carbon ions into TiOx. When implanting into a layer containing TiOx, the carbon ions have sufficient ion energy to penetrate the surface of the layer and knock out the oxygen (O) atoms from the TiOx particles, so as to allow the formation of a substantially continuous layer including titanium oxycarbide near the surface of the previously sputtered layer . In embodiments where the sputtered TiO x layer is sufficiently thick, a layer including titanium oxycarbide may be formed over the TiO x layer which was originally the underside of the previously sputtered TiO x layer.

A relatively high voltage is required at the ion source (s) in order to provide the carbon ions from the ion source with sufficient energy to: (a) penetrate the surface and implant into the sputtered TiOx layer, (b) knock out oxygen from TiOx particles, and (c) perform ( a) and (b) to a degree sufficient to form a substantially continuous layer of titanium oxycarbide. In order to achieve energy sufficient in this regard, according to certain example embodiments of this invention, an anode-cathode voltage of at least about 800 V, more preferably at least about 1500 V, more preferably at least about 2000 V, is used in the ion source (s). V, and most preferably at least about 2500 V. By way of example only, in the case of

When C ions are produced using acetylene (C2H2) as feed gas in the ion source, the above-mentioned ion source voltages translate to corresponding ion energies of at least 200 eV per ion C, more preferably at least about 375 eV per ion. C, even more preferably at least about 500 eV per ion C, and even more preferably at least about 625 eV per ion C.

In certain embodiments, C ions are implanted deep enough into the sputtered TiO x layer to allow formation of a substantially continuous layer including titanium oxycarbide at least in the upper portion thereof. This titanium oxycarbide layer may include TiO, TiC, OC, CC, CH, and / or combinations thereof. In certain example embodiments, at least some C ions (or C atoms) are implanted into the sputtered layer to a depth d of at least 2.5 nm (25 A) below the top surface of the sputtered layer (more preferably at least 5.0 nm (50 A). A), even more preferably at least 10 nm (100 A).

A coated article prepared, as explained above, to include a layer comprising titanium oxycarbide has a higher scratch resistance than that of a pure titanium oxide layer. Moreover, in certain example embodiments, the use of C ion implantation allows for the improvement of certain contact angle θ characteristics. For example, the resultant coated article may be capable of achieving lower contact angles θ (initial or after UV / water exposure) than a Diamond-Like Carhon (DLC) layer and / or a pure titanium oxide layer. The resulting coated article may also be capable of maintaining a low contact angle (s) θ for a period longer than that of a titanium oxide layer. Thus, it can be seen that the implantation of C ions / atoms into the layer comprising titanium oxide is advantageous in several respects.

Alternatively, in certain embodiments, in addition to the C ions that are implanted into the layer comprising titanium oxide to form titanium oxycarbide, the titanium oxycarbide may be further deposited by a high energy ion beam on the oxycarbide such that a thin layer may form on the oxycarbide. containing amorphous diamond-like carbon (DLC) with a large number of carbon-carbon sp bonds³ (e.g., at least 40% of such bonds, more preferably at least 50% of such bonds). In certain example embodiments of this invention, this additional DLC layer may be 0.1 to 10 nm (1-100 A) thick, more preferably 0.1 to 4 nm (1-40 A) thick, and most preferably about 0.1 to 4 nm (1-40 A) thick. 1 to 3 nm (10-30 A) thick. This optional DLC layer may or may not be hydrogenated (e.g. containing from about 1 to about 25% H, more preferably from about 3 to about 18% H) or may contain other dopants in various embodiments of this invention, and may have a density of at least 2.4 g / cm 2³. This DLC inclusive layer may be used to increase durability in certain embodiments of this invention.

In certain embodiments, the present invention provides a method of making a coated article, the method comprising: providing a substrate; sputtering a layer comprising titanium oxide TiOx (where x is from 1 to 3) on the substrate to thereby form a sputtering layer and, using at least one ion source, using an anode-cathode voltage of at least about 1500 V to cause directing at least carbon ions towards the sputtering layer containing titanium oxide yes, that at least some of the carbon ions are implanted into the sputtered layer to a depth of at least 2.5 nm (25 A) below the surface of the sputtered layer.

In other embodiments of this invention, there is provided a method of making a coated article, the method comprising: providing a substrate; forming a layer comprising a metal oxide on the substrate; and directing at least carbon ions towards the layer comprising the metal oxide, at least some of the carbon ions having an ion energy of at least 200 eV per carbon ion such that at least some of the carbon ions are implanted in the layer, thereby forming an oxy-carbide-containing layer.

In other embodiments of this invention, a coated article is provided comprising a coating on a substrate, the coating comprising: a sputtered layer comprising metal oxide and at least carbon ions that are ion beam implanted into the sputtered metal oxide layer, at least some of which carbon ions are implanted to a depth of at least 2.5 nm (25 A) below the surface of the sputtered layer, thereby forming an oxy-carbide containing layer.

PL 209 665 B1

Figure 1 is a schematic partial cross sectional view illustrating a technique for making a coated article according to an example embodiment of this invention.

Fig. 2 is a sequence of operations illustrating certain steps involved in making the article of Fig. 1 in accordance with an exemplary embodiment of this invention.

Figure 3 is a cross-sectional view of an exemplary ion source that may be used to implant carbon ions into the originally sputtered layer comprising the titanium oxide of Figs. 1-2, in accordance with an exemplary embodiment of this invention.

Figure 4 is a perspective view of the ion source of Figure 3.

Figure 5 is an XPS (X-ray Photoelectron Spectroscopy) graph showing the elements / components present in atomic amounts throughout the thickness of the layer system of Example 1 in the first position on the substrate u.

Figure 6 is an XPS plot showing the elements / components present in atomic amounts throughout the thickness of the layer system of Example 1 at a second location on the substrate (different from the first location measured in Figure 5).

Figure 7 is a plot of contact angle θ versus time comparing a sputtering layer of TiO2 alone with a sputtering layer of TiO2 implanted and / or coated with different amounts of C.

Examples of implementation:

Certain examples of the method of the present invention provide a coated article that includes a layer including titanium oxycarbide. To produce a coated article in certain example embodiments, a layer of titanium oxide (e.g., TiOx, where x is from 1 to 3, more preferably from 1.5 to 2.5, and most preferably about 2) is deposited on the substrate by a sputtering method. ion (e.g. sputtering using a magnetron) or any other suitable deposition technique. In various embodiments of this invention, other layer (s) may or may not be provided between the substrate and the titanium oxide. After sputtering the layer containing TiOx, at least one ion beam source is used to implant carbon (C) ions into TiOx. Upon implantation into the TiO x layer, the carbon ions have enough ion energy to penetrate the surface of the sputtered layer and knock out oxygen (O) from the TiO x particles so as to allow the formation of a substantially continuous layer comprising titanium oxycarbide near the surface of the previously sputtered layer. In embodiments where the sputtered TiO x layer is sufficiently thick, a layer including titanium oxycarbide may be formed over the TiO x layer which was originally the underside of the previously sputtered TiO x layer.

A coated article comprising at least one substantially continuous layer including titanium oxycarbide has improved scratch resistance compared to that of the pure titanium oxide layer. Moreover, in certain example embodiments, the use of C implantation enables certain contact angle θ characteristics to be improved. For example, it has been found that the resultant coated article may be capable of achieving lower contact angles θ (initial or after UV / water exposure) than would be the case with a pure amorphous diamond-like carbon (DLC) layer and / or a pure TiOx layer.

Surprisingly, the resultant coated article may also be able to maintain a low contact angle (s) θ for a longer period than would be the case with a layer of titanium oxide alone. Thus, it can be observed that the implantation of C ions / atoms into the layer containing titanium oxide is advantageous in several important respects.

The oxy-carbide-containing coated articles described herein can be used in a variety of commercial applications including, but not limited to, insulating glass window units, vehicle windows, architectural windows, furniture applications, and / or the like.

Fig. 1 is a cross-sectional view of a manufactured coated article according to an exemplary embodiment of this invention, and Fig. 2 shows the steps that are carried out in making the coated article of Fig. 1. Referring to Figs. 1-2, a substrate (e.g. a glass substrate, with or without other layers (see step A in Fig. 2). The amorphous or titanium oxide (TiOx) layer 3 is then deposited by sputtering onto a substrate (see step B in Fig. 2). The sputtered titanium oxide of layer 3, in various embodiments of this invention, may or may not be doped with other elements. Layer 3 may be from about 5 to about 100 nm (50-1000 Å) thick in certain example embodiments of this invention, more preferably from about 5 to about 50 nm (50-500 Å) thick. After spraying onto a TiO-containing substrate_x of layer 3, the coated article moves towards 5, as indicated in Fig. 1, with respect to at least one source

25. At least one carbon containing gas (e.g. a hydrocarbon gas such as C.₂H.₂ or the like) is introduced through the ion source (s) or is used in the ion source (s) such that the ion source (s) causes the emission of an ion beam containing carbon (C) ions towards the side containing TiO_x layer 3 (see step C in Fig. 2). The C ions in the ion beam have sufficient energy to be implanted into the TiO-containing beam_x layer 3 as indicated in Fig. 1. The dots in Fig. 1 in layer 3 represent C ions / atoms that have been implanted into the sputtering layer 3; and the portion of layer 3 on the right in Fig. 1 has no dots implanted because it has not yet passed under the ion source. It should be noted that the ion beam from source 25 may be focused, diffused, or collimated in various embodiments of this invention.

Implantation of C ions / atoms into sputter containing TiO_x layer 3 causes the formation of the titanium oxycarbide layer 3b at least in proximity to the surface of the layer as indicated in Fig. 1 (see also step D in Fig. 2).

This implantation of C ions / atoms into layer 3 results in a significant improvement in the durability of the obtained layer over that of layer 3 before implantation of the C ions / atoms. For example, the scratch resistance is significantly improved.

Moreover, it has surprisingly been found that in some cases the presence of the implanted carbon in layer 3 makes it possible to obtain a rather low contact angle θ of the resulting amorphous layer with respect to pure titanium oxide. For example, Fig. 7 illustrates that the implanted layer 3 can achieve an initial contact angle θ smaller than the amorphous titanium oxide layer alone. Thus, microcrystalline TiO2 (anatase or rutile) is not necessarily needed to induce low contact angles in a layer comprising titanium oxide. Moreover, it was surprisingly found that when C ions / atoms were implanted in layer 3 and a low contact angle θ was achieved, the ability of the layer to maintain a small contact angle (s) θ over time was significantly improved compared to when the ions / atoms were C were not implanted (see Fig. 7).

Yet another surprising aspect of certain example embodiments of this invention is that implantation of C ions / atoms into layer 3 allows the implanted layer to accomplish hydrophilic behavior (low contact angle (s) θ in the presence of green visible light, without the need for UV radiation to necessarily need to be used. inducing low contact angles). In other words, visible green light can cause, for example, a reduction in the contact angle of the implanted layer, which is advantageous in many industrial situations.

In certain example embodiments of this invention, the layer including titanium oxycarbide has a contact angle θ of no greater than about 20 degrees, more preferably no greater than about 15 degrees. This contact angle can be either the initial contact angle, or after exposure to UV light and water (QUV) for at least 50 hours. QUV exposure is known in the art.

The carbon ions, when implanted into the TiO x layer, have sufficient energy to knock out the oxygen (O) from the TiO x particles so as to allow the formation of an essentially continuous titanium oxycarbide layer 3b near the surface of the previously sputtered layer as indicated in Fig. 1.

Fig. 1 also shows an embodiment where sputtering containing TiO_xlayer 3 was sufficiently thick that layer 3b including titanium oxycarbide (dotted area indicated in Fig. 1) could be molded over TiO-containing_x a layer 3a which was initially the bottom of a previously sputtered layer of TiOx. In certain example embodiments, the titanium oxycarbide layer 3b may be characterized at least in part by TiO_xC._ywhere x / y is from 0.5 to 1.5.

It is also believed that the implantation of C ions / atoms into layer 3, as indicated in Fig. 1, may result in a heterojunction between the resulting layers 3a and 3b. This heterojunction is formed at the interface between layers 3a and 3b (or alternatively at the interface between the semiconducting layer 3b and the underlying semiconducting layer containing DLC), these layers having differing gaps (TiOx has a band gap of around 3.2 eV +/- about 0.1, and the DLC may have a band gap of about 1.9 to 2.2 eV). Under chemical equilibrium conditions, the Fermi levels are equalized in both materials so that bending of the band can occur. This bending of the band creates an internal field in the heterojunction. Charge builds up on the surface. It is believed that when incident light (e.g. visible green light) hits this charge on the heterojunction, electron-hole pairs are formed and cause the contact angle to decrease.

PL 209 665 B1

Relatively high voltage is required at the ion source (s) 25 to provide the carbon ions in the ion beam with sufficient energy for: (a) implantation into sputtered TiOx layer 3, (b) oxygen breakout from TiO particles_x, and (c) performing (a) and (b) sufficiently that a substantially continuous titanium oxycarbide layer 3b can be formed. In order to achieve sufficient energy in this regard, according to certain example embodiments of this invention, an anode-cathode voltage of at least about 800 V, more preferably at least about 1500 V, even more preferably at least about 800 V, is used in the ion source (s). at least about 2000 V, and even more preferably at least about 2500 V. In some instances, even a source voltage of at least about 3500 V may be used.

The above-mentioned "voltage" (or accelerating voltage) that is used in the ion source (s) 25 to cause C ions / atoms to implant in layer 3 is the voltage between the anode and cathode of the ion source 25.

As is known in the art, "ion energy" is related to, but distinct from, this anode / cathode "voltage". For example, for molecular acetylene (C2H2), the energy of a fragment ion is half (1/2) of the accelerating voltage. Thus, the ion energy of a fragment of the molecule, for a given voltage of 2000 V, would be 2000/2 = 1000 V. Moreover, in the case of C ions prepared from acetylene (C2H2) used in the ion source as the feed gas, there are two carbon atoms in the fragment of the molecule. Thus, in this case, the energy per carbon ion is the energy of the fragment ion divided by 2. In other words, for example, when C ions are produced in ion source 25, using C₂H.₂ as a feed gas, ion source voltages (i.e., at least about 800 V, 1500 V, 2000 V, and / or 2500 V as explained above) translate to ion energies of at least about 200 eV per ion C, more preferably at least about 375 eV per ion C, even more preferably at least about 500 eV per ion C, and even more preferably at least about 625 eV per ion C.

In certain example embodiments of this invention, it is important to use one or more of the aforementioned ion source voltages and / or ion energy. This is because if too low ion energy (or voltage at ion source 25) is used (e.g. 75 eV per C ion is too low), implantation of C ions and / or formation of a continuous layer including titanium oxycarbide cannot be achieved.

It should be noted that when a gaseous hydrocarbon such as C2H2 is used as the feed gas in the source 25, the ions in the resulting beam will include both C ions and H ions. Thus, the titanium oxycarbide layer 3b may be doped with H. in certain embodiments of this invention. In certain example embodiments, layer 3b may contain from 0 to 20% H, more preferably from about 1 to 18% H, and even more preferably from about 5 to 15% H. In some cases, other materials may also be present in layers 3a, 3b, as indicated in the XPS plots discussed herein.

In certain example embodiments of this invention, C ions are implanted into sputtered TiO_x layer 3 deep enough to allow the formation of a substantially continuous oxy-carbide titanium layer 3b at least near the top thereof. In certain example embodiments, at least some C ions (and / or C atoms) are implanted into the sputtered layer 3 to a depth d of at least 2.5 nm (25 Å) below the top surface of the sputtered layer (more preferably at least 5.0 nm (50 A), even more preferably at least 10.0 nm (100 A).

Insufficient implantation may lead to a lack of improvement in durability or similar drawbacks, or to its very rapid wear.

In certain example embodiments of this invention, ion source (s) 25 may be operated to emit only enough C ions towards layer 3 so as to cause C ions / atoms to implant in layer 3 as indicated in Fig. 1, but not to cause the formation of an amorphous DLC layer (e.g., ta-C or ta-C: H) over the titanium oxycarbide layer 3b. Alternatively, in other embodiments of the present invention, the source (s) 25 is operated to cause a thin layer (not shown) containing amorphous DLC (e.g., ta-C or ta-C: H) to form over the titanium oxycarbide layer 3b. Exemplary characteristics of such DLC layers are discussed in US Patent No. 6,261,693, the entirety of which is hereby incorporated by reference. This thin DLC layer may be from about 0.1 to about 3 nm (1-30 Å) thick in certain example embodiments, more preferably from about 0.1 to about 2.0 nm (1-20 Å) thick. It should be noted that in some cases they can also be delivered

Other layers over the oxycarbide. Moreover, this very thin DLC inclusive layer, in certain embodiments, may be made to be wasted in the sense that it may be designed to wear (e.g., disappear) over time. Thus, for example, such a thin DLC inclusive layer may be used to protect a coated article from scratching or similar damage during shipping, processing, etc., and then worn over time to expose the titanium oxycarbide inclusive layer 3b, which may have a more desirable low profile. contact angle and / or good durability. It should also be noted that, in certain example embodiments, the titanium oxycarbide may be loss-making, in the sense that it wears over time after it has served its purpose of protecting the coating from scratching or the like during shipping, processing, etc.

Alternatively, in certain example instances, this overlying DLC ​​inclusive layer may be even thicker than 3 nm (30 Å). Such an overlying DLC ​​inclusive layer (s) may contain a large number of sp bonds³ carbon-carbon (e.g., such bonds may be at least 40%, more preferably at least 50% of CC bonds in this layer), may or may not be hydrogenated (e.g., from about 1 to about 25% H, more preferably from about 3 up to about 18% H) or may contain other impurities in various embodiments of this invention, and / or may have a density of at least 2.4 g / cm 2³ in some cases.

Figures 3-4 illustrate an exemplary ion source 25 that may be used to implant C ions in layer 3, in accordance with certain example embodiments of this invention. The ion source 25 includes a gas / power inlet 26, an anode 27, a grounded cathode 28 as part of the magnet, a cathode as part of the magnet 29, and insulators 30. In some embodiments, a 3 kV (or other voltage) power supply may be used for source 25. ) direct current and / or alternating current. The voltage described above is provided between the anode 27 and cathode 29 of the ion source close to the electrical break near the racetrack-shaped cathode gap. Ion beam source 25 is based on the principle of a known gridless ion source design. The line source includes a linear sheath (which is the cathode and which can be grounded) within which lies a concentric anode (which is positive voltage). This cathode-anode and magnetic field geometry 33 provides a CD (closed drift) configuration. The source can also work in a reactive mode. The source may include a metal housing with a racetrack shaped slot, as shown in Figures 3-4, wherein, in exemplary cases, the hollow housing has a ground potential. The electrode - anode 27 is located in the cathode body 28 (electrically insulated) and is located just below the aperture. The anode 27 may be connected to a positive voltage of 3,000 volts (V) or more (or whatever the need to vary the energy of the ions used herein). Both electrodes may be water cooled in certain embodiments. One or more feed or precursor gases (e.g., acetylene, other gaseous hydrocarbon, or any other suitable gas) are fed through the cavity between the anode and cathode (or alternatively may be otherwise supplied to the source).

Still referring to Figures 3-4, the electricity ionizes the gas (s) to form plasma inside the source 25. The ion beam exiting the slit is approximately uniform in the longitudinal direction and has a Gaussian profile in the transverse direction. Exemplary ions 34 in the ion beam are illustrated in Figure 3. Sources as long as four meters can be made, although sources of different lengths are contemplated in various embodiments of this invention. The electron layer 25 completes the circuit, thereby allowing the ion beam source to function properly. The ion beam source shown in Figures 3-4 is exemplary only. Thus, in alternative embodiments of the present invention, an ion beam source device or apparatus as described and shown in the first three figures of US Patent No. 6,002,208 (which is hereby incorporated by reference in its entirety) may be used. Other suitable types of ion sources can also be used.

In some embodiments, the oxycarbide may be heated during and / or after ion beam exposure, from, for example, about 100 to 650 degrees Celsius. This heating can make the surface more hydrophilic and / or promote the formation of oxycarbides.

For illustrative purposes only, several examples have been made and analyzed in accordance with various embodiments of the present invention. In each of the examples mentioned in the list below, a layer 3 of amorphous TiO was sputtered onto a 3 mm thick glass substrate 1 using a magnetron.₂ approximately 22-23 nm (220-230 A) thick.

PL 209 665 B1

Each sample was then passed under the ion source at a rate of 4.2 x 10^-2 m / s (100 inches per minute) when the source 25 was using acetylene gas to emit at least C ions towards layer 3. The beam was incident on layer 3 at an angle of about 90 degrees.

In Example 1, the layers were deposited on the tin side of the float substrate 1, while in Examples 2-4 the layers were deposited on the air side of the substrate 1 (opposite to the tin). The implantation process for each of the examples is shown below. The gas flows given below are the total flows of acetylene gas in the source in normal cubic centimeter units and the voltage is the anode / cathode voltage at source 25.

Table 1

Implantation process for examples

<td></td><td>Gas and flow</td><td>Tension</td><td>Electricity</td><td>Pressure</td>

<td>Example 1</td><td>C2H2 100 Ncm³</td><td>4500 V.</td><td>0.87A</td><td>2.26 x 10⁶ Pa (0.30 mTorr)</td>

<td>Example 2</td><td>C2H2 100 Ncm³</td><td>3000 V.</td><td>0.79 A.</td><td>2.41 x 10 '⁶ Pa (0.32 mTorr)</td>

<td>Example 3</td><td>C2H2 120 Ncm³</td><td>3000 V.</td><td>1.01 A.</td><td>2.63 x 10 '⁶ Pa (0.35 mTorr)</td>

<td>Example 4</td><td>C2H2 310 Ncm³</td><td>3000 V.</td><td>1.17 A.</td><td>7.44 x 10⁶ Pa (0.99 mTorr)</td>

Example 1 was analyzed by XPS at two different sites indicated in Figures 5 and 6. The 1.5 nm steps (15 A) were used in the XPS analysis.

Fig. 5 is an XPS plot showing the elements / components present in atomic amounts throughout the thickness of the layer system of Example 1 in the first position on the substrate, where in the plot the vertical axis is atomic percentages and the horizontal axis is depth in the coating from its outer surface in angstroms. (A, 10^-1 nm) with respect to a sputtering silicon dioxide layer as known in the art.

Fig. 6 is similar to Fig. 5, except that the data was measured elsewhere in the sample of Example 1. The instrument used for the measurements was a Physical Electronics Quantum 2000 Scanning XPS and the X-ray source was a monochrome A1 Ka source.

The analysis field was 0.2 by 0.2 mm and the take-off angle was 45 degrees. The sputtering conditions used for the reference thickness were as follows: 1 keV Ar⁺, raster 2 mm x 2 mm, ~ 0.5x10^-10 m / s (~ 30 x A / min) relative to SiO2.

As indicated in Figures 5-6, on the surface, the proportion of CO versus CC / CH appears to be similar in both fields. The C1s spectra reflect a mixture of metal oxides and hydroxide / organic components. Moreover, it should be noted that the thickness of the coating appears to be less at the location of Fig. 5 than at the location of Fig. 6 (an increase in the Si content in Figures 5-6 indicates the presence of a glass substrate under the coating). The deep profile C1s spectra in Fig. 5 do not reveal the presence of TiC as such, suggesting rather intermediate forms of C in the TiO matrix_x (ie titanium oxycarbide) possibly related to both Ti and O (again, titanium oxycarbide). Thus, the term "titanium oxycarbide" as used herein includes the bonding of TiOC as well as situations where C is in the TiO x matrix but does not necessarily have to be bonded thereto.

Unfortunately, the strong interference of the peaks in the Ti2p spectra made it impossible to distinguish between TiC and TiO, which have almost the same binding energy; and also made it impossible to distinguish different oxidation states due to the interference of the Ti2p3 and Ti2p1 spectra. This led the inventors to use two determinations for Ti, elemental Ti and TiOxCy / TiC.

In Fig. 5, a significant portion of Ti appears to be in the elemental state near the interface of the glass substrate 1, and little TiC was observed, judging by the absence of the C-Ti peak in the C1s spectra. In contrast, the C-Ti bond was indeed present in the C1s spectra in Fig. 5 and peaked at about 5 nm (50 Å). Intermediate C forms in the TiOx matrix, as mentioned above, were also present in the C1s spectra in Fig. 6.

Fig. 6 also shows a higher concentration of TiOxCy / TiC at about 5 nm (50 A), and a significant amount of titanium oxycarbide is present in this context throughout the thickness of layer 3, suggesting a homogeneous distribution of the titanium oxycarbide component. In Fig. 6, elemental Ti was present in the film, except in the top 5 nm (50 Å). It was also found that the film of Example 1 had a very low contact angle, which angle decreased upon exposure to visible light, and a greater scratch resistance compared to titanium oxide.

PL 209 665 B1

Fig. 7 is a graph comparing Example 2 (TiO2 + C implantation) against both a layer of TiO2 alone on the substrate and an implanted C layer of TiO2 coated with a DLC layer approximately 0.4 nm (40 Å) thick above it. It can be seen that the coated article of Example 2 had a smaller initial contact angle than either of the other two articles, which is advantageous in some cases. Moreover, Fig. 7 indicates that in Example 2 it was possible to keep the contact angle low for a longer period than in the other two samples.

While the invention has been described with reference to the embodiment currently considered to be the most practical and preferred, it should be understood that the invention is not intended to be limited to the disclosed embodiment, but rather to cover various modifications and equivalent arrangements within the scope of the appended claims.