EP2507183A1

EP2507183A1 - Method for structuring a surface by means of ion-beam etching, structured surface and uses

Info

Publication number: EP2507183A1
Application number: EP10799099A
Authority: EP
Inventors: Elin Sondergard; Sébastien LE ROY; Alban Letailleur; Etienne Barthel; Constance Magne
Original assignee: Saint Gobain Glass France SAS; Compagnie de Saint Gobain SA
Current assignee: Saint Gobain Glass France SAS; Compagnie de Saint Gobain SA
Priority date: 2009-12-01
Filing date: 2010-11-24
Publication date: 2012-10-10
Also published as: WO2011067511A1; KR101874127B1; US9371250B2; CN102712527B; KR20120117997A; EA201290412A1; FR2953213A1; FR2953213B1; JP2013512178A; US20120288676A1; BR112012013341A2; CN102712527A; JP6050118B2

Abstract

The invention relates to a method for structuring a surface, in other words, for forming at least one set of irregularities or patterns (2) having a submicronic height H and at least one characteristic lateral dimension W referred to as the micronic or submicronic width, on a surface of a material (1), in particular a glass, by means of ion-beam etching using an optionally neutralised ion beam, characterised in that said method comprises the following steps: providing said material with a thickness of at least 100 nm, the material being hybrid and solid and including a single or mixed oxide of element(s), the molar percentage of oxide in the material being at least 40%, in particular 40% to 94%, and at least one species, separate from the oxide element(s), in particular a metal, the molar percentage of species in the material ranging from 6% to 50% and being lower than the percentage of said oxide, with at least the majority of the species having a largest characteristic dimension smaller than 50 nm, said hybrid material in particular being metastable prior to said etching; optionally heating said hybrid material prior to said etching; and structuring the surface of said hybrid material with an etching time of less than one hour on an etching surface of more than 1 cm² until said set of patterns is formed, the structuring step optionally including heating the hybrid material.

Description

METHOD FOR ION ABRASION SURFACE STRUCTURING, STRUCTURED SURFACE AND USES

The present invention relates to the field of surface structuring and aims in particular at an ionic abrasion surface structuring method, a structured surface product and its uses.

The structuring of materials is of considerable interest because it finds applications in many technological fields.

The creation of a network of geometric patterns makes it possible to give a material a new and original function without changing its composition and its volume properties.

Characteristic techniques of small dimensions, in particular width or submicron period, the techniques of structuring are for the most part techniques using transfer masks for liquid or dry etching including lithographic techniques (optical lithography, electronic lithography ...) , used in microelectronics, or for (small) integrated optical components.

However, they are unsuitable for mass production processes for glass products, for one or more of the following reasons:

their high cost (manufacture of the mask, setting up, alignment ...);

- their slowness (scanning) and their complexity (several stages);

the limitation of the size of the patterns (by the wavelength);

the small size of the structural surfaces.

The ionic abrasion, generally under a wide, non-focused source, of typically low energy Ar ⁺ ions (typically between 200 and 2000 eV), is another large-area structuring technique which has the advantage of do not use masking.

In the publication entitled "Ion beam erosion of amorphous materials: evolution of surface morphology", Nucl. Instr. and Meth. in Phys. Res. B 230 (2005) pages 551 -554, A. Toma et al. Of the glass is abraded at 35 ° under Ar ⁺ at 800 eV at a flux of 0.4 mA / cm ² , giving a periodic network of wrinkles, of type sinusoid of micrometric length, of low height, ie of the order of 5 nm in one hour and 20 nm for three hours thirty, period and width of 175 nm in one hour and 350 nm in three hours thirty. These morphologies and sizes at one and three thirty hours characterized by atomic force microscopy ("AFM" in English) are illustrated in Figures 1c and d.

The ionic abrasion is therefore slow and also generates wrinkles with a low aspect ratio defined by the height over the width of less than 0.1. Thus, the present invention firstly relates to a high-performance method of manufacturing a structured product, especially glass, on a submicron scale and in line with industrial constraints: speed and simplicity of design (without the need for masking, in particular a step preferably), and / or adaptation to any size of surface, even the largest, and with flexibility and control over the type and / or size of patterns and their density.

This process also aims to expand the range of structured products available including glass, in particular aims to obtain new geometries of new features and / or applications.

For this purpose, the invention firstly proposes a surface structuring method that is to say forming at least one set of irregularities called patterns (generally of the same shape on average) with a submicron height and at least one sub-micron or sub-millimetric lateral dimension (called width) by ionic abrasion (involving elastic collisions of ions and atoms) with an ion beam (typically cations) possibly neutralized (typically by electrons ripped off) by the beam before impact with the material to be structured) which comprises the following steps:

the supply of said material having a thickness of at least 100 nm, a hybrid solid material and comprising:

a single or mixed oxide of element (s), the molar percentage of oxide in the material being at least 40%, especially between 40 and 94%,

and at least one species of nature distinct from the element or elements of the oxide, in particular more mobile than the oxide under ionic abrasion (and in the case of mixed oxide, more mobile than at least one oxide, especially the majority oxide), which is preferably a metal, the molar percentage of species (s) in the material ranging from 6% up to 50%, in particular ranging from 20% to 30% or even 40% and being lower than the percentage said oxide, species, with at least the majority of the species (or species), or even at least 80% or even 90%, having a greater characteristic dimension (called size) less than 50 nm, preferably less than or equal to at 25 nm, or even less than or equal to 15 nm,

in particular said hybrid material being metastable before abrasion, that is to say kinetically stable under normal conditions of temperature and pressure and thermodynamically unstable under normal conditions of temperature and pressure, being in a local minimum potential energy, separated from the global minimum by a given activation energy Ea,

- the (pre) heating possible before abrasion the material, in particular so as to reduce (without canceling) the activation energy up to a value E1 which is then brought by the abrasion (by an ad hoc selection of the energy of the ions of the beam and the flux), (possible heating because if Ea is too high, the kinetics of the aggregation of the mobile species of metal type is too slow compared to the abrasion speed of the hybrid material ), the (pre) heating and abrasion being spaced over time, the preheating possibly being replaced by a radiative treatment type IR,

the structuring of the surface of said hybrid material under said ionic abrasion, thus rendering said hybrid material (metastable) kinetically unstable by the energy input of the beam ions, thus structuring obtained by the formation of a self-contained mask composed of a set of zones (in the form of droplets) essentially of said species, of metal type, and / or a set of zones enriched in said species, of metal type of the material, mask formed by the aggregation of said species of metal type on the surface of said hybrid material,

with an abrasion time of less than one hour, preferably less than or equal to 30 min or even less than or equal to 15 min, of said hybrid solid material (metastable),

by the ion beam, typically rare gas (s), preferably Ar, or also Ne, Xe, Kr, and / or oxygen O ₂ , nitrogen N ₂ or carbon dioxide C0 ₂ ,

with an abrasion surface greater than 1 cm ² , or even greater than or equal to 10 cm ² , this with a source often called wide, especially linear (long and narrow), to facilitate a sweeping of the surface

the beam preferably having an energy of less than 5 keV, even less than or equal to 2 keV,

this especially under normal incidence or at a given angle of preference of less than 70 ° relative to the normal to the abraded surface, until forming said set of patterns.

the possible heating during the abrasion of the hybrid material, in particular so as to reduce (without canceling) the activation energy.

Until now, structuring under ionic abrasion of glass and more widely of fast oxides and / or point patterns or "2D" (as opposed to long periodic wrinkles) has never been observed. Now, the Applicant has identified the intrinsic properties of an oxide-based material that make ionic abrasion possible and that control the morphology of the surfaces created during etching.

The oxide and mobile element will segregate if provided with the necessary energy by ionic abrasion

The abrasion and the creation of the mask are simultaneous. The intrinsic properties of the material control the surface morphology created during etching.

It is thus possible to make a structured material, directly functional, in one step.

In the oxide, it is thus necessary to add at least one adhoc species, in particular having the following properties that the skilled person will select:

a mobility greater than that of the oxide under ionic abrasion, so that the segregation and the masking dominate the relaxation of the surface which smooths the surface, to thus select the species one can help for example studies on the diffusion ions in silicates or in other oxides),

an abrasion speed which is sufficiently different from that of the oxide to increase the structuring speed, the difference (in absolute value) preferably being greater than 10%, preferably greater than 20%, even more preferably greater than 50%; (To thus select the species, it is possible to use, for example, known deposition rates, for example for magnetron sputtering).

a cohesive energy high enough to allow segregation. The species is in sufficient quantity on the large surface of abrasion to feed the masking and to obtain a sufficient density of grounds.

The species is on a sufficient depth related to the desired depth of etching, to feed the masking during etching.

The species is closely related to the oxide but is not miscible.

The size of the species is limited for a homogeneous distribution of the species in the material and therefore a more homogeneous structure.

The rate of the species in the oxide is measurable by microprobe or XPS

Naturally after structuring, in the structured thickness, the rate of the species can vary, for example with a concentration profile depending on the height of the structuring profile, and even the state of the metal.

To try to fabricate new patterns, especially punctual (pins, hollow), we could try to generate during ionic abrasion contamination in situ on the surface of the oxide (glass) by depositing a metal such as Fe, Au, Ag, Pt. From a target placed near or from the ion gun. This method would not allow a constant degree of pollution over a large area. The degree of pollution is imposed and limited. This structuring process would therefore be less well controlled, less homogeneous, and therefore more difficult to industrialize. And the range of morphologies is further restricted. The oxidized material thus contaminated would not be metastable.

The class of oxide-metal hybrid materials judiciously selected according to the invention spontaneously creates a mask that is sufficiently dense, homogeneous and self-sustaining during ionic abrasion, giving access to one or more of the following characteristics:

and to homogeneity of structuring, that is to say an average height H, a mean shape, a similar average density over the abraded surface,

- on unpublished grounds,

- Unpublished patterns in 2D, recessed, generally rounded (circular) of lateral dimension or submicron W average width, possibly substantially symmetrical, so with a maximum average lateral dimension L, or length, submicron and close or substantially equal to the width (width W = length L approximately or at least W greater than or equal to 0,3L under oblique incidence and 0,8L under normal incidence), hollow oriented according to the angle of incidence,

- Unusual patterns in 2D, in relief, relief generally rounded edges (circular), for example in the form of cones or bumps, lateral dimension or submicron W average width, possibly substantially symmetrical, so with a mean maximum lateral dimension "Or length L submicron and close or substantially equal to the width

(width W = length L approximately or at least W greater than or equal to 0,3L under oblique incidence and 0,8L under normal incidence), relief oriented according to the angle of incidence,

to optionally isotropic units, that is to say without preferred direction (s) of orientation, typically the case at normal incidence or close to normal,

to optionally anisotropic motifs, typically the case in oblique incidence,

to a dense pattern network, that is to say, with an average spacing ratio D on width W less than 10) less than or equal to 5, or even less than or equal to

2, this on a scale of 1 cm ² or even 100 cm ² or even 1 m ² , at a height of pattern H which may be greater than in the prior art, and rapidly.

For each pattern, the height taken into account is the maximum height, the width is measured at the base. The spacing D is the average distance between the centers of 2 adjacent patterns.

The distances H, W, D can be measured by AFM, and / or SEM scanning electron microscopy. The averages are for example obtained on at least 50 patterns.

The structured material has a set of patterns generally:

- average height H greater than 5 nm, see greater than or equal to 30 or

50 nm,

of average width W, which may be less than 300 nm for optical applications in particular, even more preferentially less than 200 nm,

average spacing D, less than 300 nm, and even more preferably less than 200 nm.

The aspect ratio (H / W) may be greater than 3.

The density, that is D / W, can depend on the height.

Preferably the width W is less than or equal to 5D, in particular less than

D.

The average standard deviation of height H, width W, may be less than 30%

(For example at high temperature, high flux, or even less than or equal to 10%, even less than or equal to 5%.

The average standard deviation of the spacing D may be less than 50% (for example at high temperature) or even less than 30%, even less than or equal to 10%.

Structuring is not created by the physics of the ion / surface interaction

(regardless of composition) as described by the classical Bradiey Harper theory.

The hybrid material may be termed metastable. The known definition of metastability is the ability for a material to be kinetically stable but not thermodynamically stable. The transformation leading to the stable state is slow or even zero. If a physico-chemical system is represented by its potential energy, a metastable state will be characterized by a state that corresponds to a local minimum of potential energy. In order for the system to reach the state of the global energy minimum corresponding to the state of thermodynamic equilibrium, it must be supplied with a quantity of energy called activation energy Ea.

For a given hybrid, the activation energy may depend on the manufacturing process. Structuring is not a consequence of the enrichment of the surface into one of the components, but is induced by the intrinsic metastability of the material. This metastability is controlled by the selection of the oxide, the mobile species.

The hybrid material may consist essentially of mineral material. The hybrid material may comprise at least 70 mol% of the sum of the oxide and said metal.

The hybrid material may contain other "neutral" elements for ionic abrasion (especially less than 30%).

The structuring method according to the invention can be easily automated and associated with other transformations of the product. The process also simplifies the production chain. The process is suitable for the manufacture of large volume and / or large scale products, especially glass products for electronics, building or automotive, including glazing. The structuring method according to the invention also makes it possible to achieve characteristic magnitudes of ever smaller patterns on larger and larger surfaces, with tolerance to acceptable texturing defects, that is to say, not adversely affecting the desired performance.

Ions can instantly provide sufficient energy for structuring (exceeding activation energy).

The abrasion process also naturally creates a heating of the oxide up to about 80 ° C or even 100 ° C (depending on the energy and the flow), progressive heating, in a few minutes, which can be sufficient only to bring the activation energy or alternatively requires additional heating as already indicated then adjusting the temperature. The heating that may be necessary is greater if the chosen rate of the species is low.

The temperature reached at the surface is variable depending on the hybrid material, the conditions of the structuring. The reference temperature is the temperature at the back of the material (opposite to the abraded surface)

More broadly, the temperature can also play a role on the structuring of the hybrid material according to the invention.

Moreover, to initiate or modify the structuring (modification of the pattern and / or acceleration), for example increasing the height of the reliefs (or pads) the aspect ratio or decrease the density, the material is heated to a temperature greater than 50 ° C, or even greater than equal to 70 ° C, preferably greater than or equal to 100 or even 120 ° C, especially ranging from 150 ° C to 300 ° C before abrasion and / or during (all or part of) l 'abrasion.

There is competition between segregation and relaxation during ionic abrasion. By heating during abrasion, preferably at a given controlled temperature surprisingly reinforces segregation rather than relaxation and thus promotes structuring.

In a configuration with reliefs, by raising the temperature, the species forms larger aggregates (on the summits of the reliefs) which are more spaced so in particular one increases the height of reliefs and one increases the spacing between relief.

It is also possible to limit the heating temperature / energy input (for reasons of energetic cost and / or resistance of the material or associated material (s), for example limited thermal resistance of an organic substrate carrying the hybrid material in a layer).

The flux level can play a role in the structuring of a hybrid material according to the invention.

To speed up the structuring, the etching flux is greater than 0.01 mA / cm ² , typically ranging from 0.05 to 0.3 mA / cm ² or even above, especially greater than or equal to 0.4 mA / cm. ² .

A sufficient increase in flux makes it possible to reduce the structuring time, but can also modify the appearance of the structures formed as a rise in temperature (increase of the relief but decrease of the density).

The energy of the incident ions can play a primordial role on the structuring of a hybrid material according to the invention.

The effect of energy is complex. It will increase the rate of abrasion, but also the depth of penetration of ions which will allow the species to diffuse more efficiently in volume. We will have both an acceleration of the formation rate of structures, but also structures of greater width and height.

By cons, beyond a certain threshold depending on the material (typically 1000 eV) too much energy will reduce the effectiveness of the mask, and to prevent structuring.

The energy can be between 200 eV and 5000 eV, typically between 300 eV and 2000 eV, or preferably between 500 eV and 1000 eV.

Of course one can combine, heat, high flux and / or high energy to obtain a wide variety of torque width / height / density.

By its effectiveness, the duration of abrasion leading to unprecedented structuring (in studs, hollow) and / or unprecedented height (greater than 50 nm) and / or at a regular spacing (...) can be less than equal to 30 min, or even less than equal to 15 min. In order to create the extended source of ions, abrasion under vacuum is carried out, for example under a vacuum defined by a pressure of less than 10-7 mbar. It can act for example a thin film deposition frame.

Said species having a lower abrasion rate than the oxide, in particular with a selected species which is silver, is abraded and the pattern is a hole that is to say that the basic pattern repeating on the surface is a depression, in particular of average maximum lateral dimension, called length L, submicron, especially with W greater than 0.3L at oblique incidence and 0.8L, or even 0.9L under normal incidence.

Said species has a lower abrasion rate than the oxide.

In particular with a chosen species which is copper, we abrade and the pattern is a relief. The relief may in particular be punctual, in the form of a cone, in particular of maximum average lateral dimension, so-called length L, submicron, in particular with W greater than 0.3L under oblique incidence and at 0.8L, or even 0.9L under normal incidence. .

Said species having a lower abrasion rate than the oxide,

Before its structuring according to the invention, the surface is not necessarily smooth and may already have a form of structuring.

In the hybrid structural material (or in the thickness underlying the structured surface), the species may be in optionally ionic form (thus oxidized) or not, may be diluted (isolated in the material) and / or in the form Aggregate preferably of (substantially) spherical shape.

This depends on the method of manufacture of the hybrid structural material, its type of incorporation in particular.

The incorporation of the species may be ion implantation (by ion bombardment), ion exchange, or incorporation of particles or growth in situ (from metal salts, etc.), as detailed later.

The species is preferably chosen from at least one of the following species, in particular:

Ag silver, in particular for an optical function (absorption induced at the UV / visible boundary) and / or for catalysis, and / or antibacterial,

copper Cu especially for an optical function,

Au gold for a grafting of biological molecules, for sensors, for optics (non-linear), and / or antibacterial

cobalt Co for a magnetic function,

iron Fe for a magnetic function, and / or catalysis,

platinum Pt for a catalysis function, nickel Ni for a magnetic function, and / or catalysis,

- Tin Sn for electrical functions,

- even gallium Ga for a function in imaging and its wide distribution as antimony Sb, indium In.

Lead Pb, Mo molybdenum may be omitted for environmental reasons.

One can have several metals capable of forming an aggregate for a given functionality, Co-Pt for a magnetic memory for example.

Other transition metals such as Ti, Nb, Cr, Cd, Zr (especially in silica), Mn are conceivable.

For more efficient structuring, the effective charge on the species is zero or less than 0.5 (known by EELS) to allow the species to aggregate.

The oxide alone can be electrical insulator and the species can bring electrical conductivity properties.

For silica in particular, aluminum Al or boron B is preferably preferred since it integrates with the silica network and will not be easily aggregated.

Transition metals or even some semi-metals are particularly preferred to earth alkalis or alkaline earths which have a too high abrasion rate. Thus, for glass, we can indicate Li and Na are not suitable because they eject and do not aggregate (fast enough).

The oxides can be further (sufficiently) transparent in the visible and even in a wider range to near or far IR or near UV depending on the intended applications.

It is possible to have a mixed oxide, the mobile species does not aggregate (under normal conditions of temperature and pressure), but still has enough mobility under ionic abrasion to form the structures

The oxide is preferably chosen from at least one of the following oxides: silica, alumina, zirconia, titanium oxide, cerium oxide, magnesium oxide, in particular a mixed oxide of aluminum and silicon, of zirconium and of silicon, titanium and silicon and preferably a glass

There are several hybrid materials according to the invention.

The hybrid material may be first a glass, in particular silicocalcic, ionically exchanged, preferably with at least one of said species, ionic at the time of exchange, the following: silver, copper.

The exchange depth is typically of the order of one micron or up to several tens of micrometers in depth. The distribution of the metal exchanged is therefore almost homogeneous in the abraded part of the material (<1 μηι). Ion exchange is the ability of certain glass ions, particularly cations such as alkali ions, to be able to exchange with other ions with different properties.

The ion exchange may be the exchange of certain ions of the glass by ions selected from, in combination or not, barium, cesium, thallium and preferably silver, copper.

Silver is very mobile in the matrix and has a strong tendency to aggregate The ion exchange rate of the hybrid material is measurable by microprobe before and after structuring.

Ion exchange is obtained by known techniques. The surface of the glass substrate to be treated in a bath of molten salts of the exchange ions, for example silver nitrate (AgNO ₃ ), is placed at a high temperature between 200 and 550 ° C. and for a correspondingly long period of time. at the desired exchange depth.

Concurrently, the glass in contact with the bath can advantageously be subjected to an electric field which is mainly a function of the conductivity of the glass and its thickness, and preferably varies between 10 and 100 V. In this case, the glass can then undergo another heat treatment, advantageously at a temperature between the exchange temperature and the glass transition temperature of the glass, in order to diffuse the ions exchanged in a direction normal to the face of the glass provided with the electrode, so as to obtain a gradient linear profile index.

The chosen glass can be extraclair. Reference WO04 / 025334 can be referred to for the composition of an extraclear glass. In particular, it is possible to choose a silicosodocalcic glass with less than 0.05% Fe III or Fe ₂ O ₃ . For example, Saint-Gobain's Diamant glass, Saint-Gobain's Albarino glass (textured or smooth), Pilkington's Optiwhite glass, and Schott's B270 glass can be chosen.

Ion exchange thus makes it possible to easily treat large areas, to be reproducible industrially. It allows to act directly and in a simple manner on the glass without the need to proceed to intermediate and / or complementary steps such as deposition of layers, etching.

For example, money is used. The diffusion depth of silver ions

Ag ⁺ in glass as a replacement for Na ⁺ sodium ions is a function of the time during which the substrate is left in the bath.

As a variant of the AgNO ₃ bath, a layer of metallic silver may be deposited. It is deposited by magnetron, CVD, inkjet or silkscreen. An electrode layer is also deposited on the opposite side. The electric field is then applied between the silver layer and the metal layer. After the exchange, the electrode layer is removed by polishing or chemical bonding. The electric field applied between the metal layer or the bath, and the electrode, therefore generates the ion exchange. The ion exchange is carried out at a temperature between 250 and 350 ° C. The exchange depth is a function of the intensity of the field, the time during which the substrate is subjected to this field and the temperature at which the exchange is carried out. The field is between 10 and 100 V.

For example, it is chosen to carry out such an ionic exchange with a glass preferably extraclear, of 2 mm, at a temperature of 300 ° C., with a duration of 10 h under a field of 10 V / mm.

To obtain nanoparticles of silver after ion exchange in the glass, a usual soda-lime glass such as Planilux glass from Saint-Gobain can be used. The size and depth of penetration of silver can be modified by changing the experimental conditions: increasing the time and temperature of the exchange gives larger particles to a greater depth and thus a more pronounced yellow coloration. The addition of an electric field during the exchange makes it possible to increase the depth of penetration without increasing the size of the particles. Thus the depth of penetration can be adjusted so that it corresponds to the depth of the abrasion so that the yellow color disappears at the end of the abrasion or be slightly greater than a few μηη so that the yellow color is lower and therefore optically acceptable at the end of the abrasion.

An example of copper-exchanged glass is the publication of

Dong et al. Titled "Ultrafast Dynamics of Copper Nanoparticles Embedded in Sodium Silicate Glass Fabricated by Thin Exchange" Thin Solid Films 517 (2009) 6046-6049 pages.

The structured exchanged glass can be monolithic, laminated, two-component. After structuring, the structured exchanged glass can also undergo various glass transformations: tempering, shaping, laminating, etc.

The hybrid material may be in bulk or as an added layer on any substrate, thick or thin, planar or curved, opaque or transparent, mineral or organic. The layer of the hybrid structural material may be reported by gluing etc. or, preferably, be deposited on a particular glass substrate. This layer can be part of a stack of layers (thin) on the substrate, including glass.

This layer of the hybrid structural material may preferably be transparent, have an optical index for example greater than that of a glass (typically around 1, 5).

The layer of the structurable hybrid material can be deposited by any known deposition techniques directly on the substrate or on one or more functional layers (thin etc.) underlying. In particular, it may be deposited on a functional (thin) layer, for example a functional oxide layer such as a transparent conductive oxide (TCO) such as ΓΙΤΟ (Indium Tin Oxide), ZnO, a mixed oxide or simple tin-based, indium or zinc or a photocatalytic layer (Ti0 ₂ anatase form for example).

This layer of the hybrid material may advantageously be deposited on an alkali barrier layer (typically Si ₃ N _4, SiO 2) to prevent the migration of the alkali ions from the glass to the layer during the various heat treatments (annealing or quenching ...).

The substrate is not necessarily mineral and may be a plastic or a hybrid material, to obtain properties of flexibility and formatting inaccessible with glass substrates. In this case, the system used must have a low activation energy because no heat treatment above 300 ° C and most often 200 ° C is possible.

It is possible to provide a step of depositing said layer in the hybrid material produced on a structuring line.

The hybrid material may be a gel sol, mass or layer especially on transparent substrate, glass (mineral or organic). Gels have the advantage of being able to withstand even high heat treatments (eg type of operation (bending) hardening) and to resist UV exposure.

In particular, it is an oxide obtained by the sol-gel process from at least one of the following elements: Si, Ti, Zr, Al, V, Mg, Sn, and Ce and incorporating said metal or semi-metal in the form of (nano) particles, optionally precipitated, especially Ag, Cu, Au.

The nanoparticles are preferably evenly distributed in the bulk material and / or the layer. Preferably, the largest dimension of the particles (formed or inserted, individualized or in a cluster, precipitate) is less than 25 nm and even more preferably less than 15 nm, and a shape ratio of less than 3 and preferably of spherical shape.

The level of nanoparticles in the sol gel material is measurable by microprobe, XPS or EDX.

Silica for example, has the advantage of being a transparent oxide, titanium oxide and zirconia to be high index. As an indication, at 600 nm, a silica layer typically has a refractive index of the order of 1.45, a titanium oxide layer has a refractive index of the order of 2, a zirconia layer. a refractive index of the order of 2.2.

The layer may be essentially silica based in particular for its adhesion and its compatibility with a glass substrate. The precursor sol of the material constituting the silica layer may be a silane or a silicate.

As a (mainly) inorganic layer, it is possible to choose a layer based on tetraethoxysilane (TEOS), or lithium, sodium or potassium silicate, for example deposited by "flow" coating ".

The silica layer can thus be based on a sodium silicate in aqueous solution, transformed into a hard layer by exposure to a CO ₂ atmosphere.

The manufacture of a hybrid mass material by sol-gel process comprises, for example, the following steps:

the hydrolysis of the precursor of the material constituting said oxide, in particular a hydrolysable compound such as a halide or an alkoxide, in a particularly aqueous and / or alcoholic solvent and then, the ripening of the soil,

- Mixing a colloidal suspension of the particles of said metals in a particular aqueous and / or alcoholic solvent, and / or salt of said metal for the in situ growth of the particles of said metals, which addition can take place at the beginning of the hydrolysis , or after sufficient ripening to avoid excessive kinetics,

the condensation of the precursor and the possible elimination of the solvent to increase the viscosity and to obtain a solid gel.

The manufacture of a layer of hybrid material by sol-gel process comprises for example the following steps:

the hydrolysis of the precursor of the material constituting said oxide, in particular a hydrolyzable compound such as a halide or an alkoxide, in a particularly aqueous and / or alcoholic solvent, then, the ripening of the sol, the mixture of a colloidal suspension of the particles of said metals in a particularly aqueous and / or alcoholic solvent, and / or salt of said metal for the in situ growth of the particles of said metals, which addition can take place at the beginning of the hydrolysis, or after a sufficient ripening to avoid a too much kinetics,

layer deposition with evaporation of the solvent, for example by spin-coating, flow coating,

a heat treatment to induce the condensation of the precursor and the possible elimination of the solvent.

The choice of the colloidal suspension makes it possible to adjust, if necessary, the size of the particles inserted. As it is redispersed in the soil, care is taken to check the compatibility of the suspension with the soil to prevent the aggregation of the particles. The addition of the salt of the said metal is simpler and presented more often in the literature. As the solvent, water or low molecular weight alcohols having a low boiling point (typically less than 100 ° C.) are preferred to allow the good dissolution of the metal salt.

The amount of nanoparticles present in the oxide / metal hybrids can be simply controlled by the synthesis conditions, and increases with the amount of metal introduced into the soil.

The formation of hybrid metal / metal oxide material from the sol-gel process is very widely described in the literature. A large variety of metal / oxide pairs in the form of layers or massive materials has thus been synthesized. The metal particles are preferentially created in situ in the matrix by adding a salt of the corresponding metal and after reducing treatment (most often heat treatment or else a reducing agent: H ₂ , hydrazine, etc.).

In the publication titled "Recent trends on nanocomposites based on Cu, Ag, and Au clusters: A doser look" (L. Armelao et al., Coordination chemitry Reviews, 2006, 250, page 1294), is reported the introduction up to at 10% by mass of silver and copper salt in sol-gel-obtained silica layers and the controlled production of Ag metal particles or Cu / CuO _x particles of a few nm, after heat treatment (at above 500 ° C). The author highlights the importance of heat treatment on the size and the oxidation state of the particles obtained. The production of other particles in metallic or oxide form in a silica matrix has been reported. Most often, a porous matrix is used as a host for the nanoparticles. However, it is possible to draw inspiration from this work to obtain a material without artificial porosity. Thus, in the publication "Insight into the properties of Fe oxide present in high concentrations on mesoporous silica" (Gervasini et al., Journal of Catalysis 2009, 262, 224), mesoporous silica (ie having a characteristic pore size of 3 -10 nm) containing up to 17% by mass of catalytic particles Fe ₂ 0 ₃ was obtained.

Nickel nanoparticles have been obtained for optical applications by thermal treatment of nickel nitrate impregnated in a silica matrix in the publication entitled "Optical properties of sol-gel fabricated Ni / SiO ₂ glass nanocomposites" (Yeshchenko OA et al. Journal of Physics and Chemistry of Solids, 2008, 69; 1615). Finally, in the publication "Synthesis and characterization of tin oxide nanoparticles dispersed in monolithic mesoporous silica" (YS Feng et al., Solid State Science, 2003 5, 729), Sn0 ₂ particles of 4-6 nm are obtained at 20 nm. % in mesoporous silica after heat treatment at 600 ° C.

Thanks to the sol-gel process other matrices than silica can be used. The most important point is the soil stability control of the organometallic precursor in the presence of the salt of the desired ion. Thus, in titanium oxide, silver nanoparticles can be used to increase conduction or photocatalytic activity. In the publication titled "Effect of incorporation of silver on the electrical properties of sol-gel-derived titanium film" (Hong Li et al, Journal of Cluster Science 2008, 19, 667-673), up to 10% of nanoparticles of 5- 15 nm of Ag are incorporated into an anatase TiO ₂ matrix. The publication entitled "Nonlinear optical and XPS properties of Au and Ag nanometer-sized particle-doped alumina films prepared by the sol-gel method" (T. Ishizaka, Optics Communication, 2001, 190, 385-389) particle incorporation Gold or silver of 5-12 nm in alumina membranes up to 1% was made for nonlinear optics. The increase in precursor would make it possible to obtain more doped matrices. Finally the publication "Structural and optical properties of silver-doped zirconia and mixed zirconia-silica matrix obtained by sol-gel processing" (F. Gonella et al., Chemistry of Materials 1999, 1 1, 814-821) up to 10 % of Ag nanoparticles could be introduced into zirconia films or zirconia mixed oxides The composition of the matrix makes it possible to control the aggregation of silver.

In addition this sol gel method allows additional functionalization of the layer. The surface structured by said process can then be functionalized to obtain new wetting properties. In particular, the patent WO00 / 64829 reports creating a hydrophobic and oleophobic coating comprising at least one fluorinated alkoxysilane of the general formula CF3 (CF2) m- (CH ₂₎ n Si (X) 3-PrP (m = 0 to 15, n = 1 to 5, p = 0, 1, 2, where X is a hydrolyzable group and R is an alkyl group), an aqueous solvent system, preferably composed of an alcohol and approximately 10% of water and at least one catalyst selected from an acid and / or a Bronsted base. This compound can be deposited on large surfaces (greater than m ² ) of glass products or functional metal oxide layers, in particular textured products, and this after a possible deposition of a silica-based primer. The combination of this process and surface texturing gives superhydrophobic properties (lotus leaf type).

The preferred deposition methods for the organic layers are dip coating (dip coating), or the spraying of the soil and the spreading of the drops by scraping or brushing or by heating as described in particular in the article entitled "Thermowetting structuring of the organic-inorganic hybrid materials »WS. Kim, K-S. Kim, Y-C. Kim, B-S Bae, 2005, Thin Solid Films, 476 (1), 181-184. The chosen method can also be a coating by spin-coating.

Naturally, an annealing at least 400 ° C. is preferred, especially beyond

500 ° C, for at least 30 minutes or even 1 hour to obtain sufficient condensation of the oxide and the decrease of the activation energy with the formation of the aggregates of said metal-type material, and less than 800 ° C especially up to 750 ° C to have sufficient reaction kinetics and not to damage the glass substrate.

This annealing may advantageously be coupled to the quenching step of the glass, which consists of heating the glass at high temperature (typically between 550 ° C. and 750 ° C.) and then cooling it rapidly.

There are other hybrid materials that can be layered.

Said hybrid material may be a layer deposited by the physical vapor phase, typically by evaporation or by sputtering (especially magnetron) on a substrate, in particular transparent, glass, including by codeposition of the species (in the aforementioned list), such as copper, silver, or gold and the oxide in particular silica, zirconia, tin oxide, alumina, with a target of the oxide element and under an oxygen atmosphere, or with a target of said oxides

Spraying will generally be preferred to evaporation due to a much higher deposition rate to make 100 nm or even micron layers faster. Thus, if by evaporation a deposition rate is generally close to 1 A min, with a maximum of 1 A / s, the magnetron deposition rates are typically between 1A / s and several tens of nm / s.

For example, for SiO2-copper mixed layer deposition, it would be possible either to use a codepot from a silicon and copper target, with the introduction of oxygen, or to directly use a copper target and a silica target.

The substrate can be glass. For the purposes of the invention, the term "glass substrate" means both an inorganic glass (silicosodocalcique, borosilicate, vitroceramic, etc.) and an organic glass (for example a thermoplastic polymer such as a polyurethane or a polycarbonate).

For the purposes of the invention, a substrate which, under normal conditions of temperature and pressure, has a modulus of at least 60 GPa for a mineral element, and at least 4 GPa for an organic element, is described as rigid.

The glass substrate is preferably transparent, in particular having a global light transmission of at least 70 to 75%.

In order to enter the composition of the glass substrate, a glass having a linear absorption of less than 0.01 mm ^-1 in the part of the spectrum useful for application, generally the spectrum ranging from 380 to 1200 nm, is preferably used.

Even more preferably, an extra-clear glass is used, ie a glass having a linear absorption of less than 0.008 mm ^-1 in the wavelength spectrum from 380 to 1200 nm. example the glass brand Diamant marketed by Saint-Gobain Glass. The substrate may be monolithic, laminated, two-component. After structuring, the substrate can also undergo various glass transformations: quenching, shaping, laminating, etc.

The glass substrate may be thin, for example of the order of 0.1 mm for mineral glasses or millimeter for organic glasses, or thicker for example with a thickness greater than or equal to a few mm or even cm.

A step of depositing a conductive, semiconductive and / or hydrophobic layer, in particular an oxide-based layer, may succeed to the first structuring.

This deposit is preferably carried out continuously.

The layer is for example metallic, silver or aluminum.

Advantageously, a step of selective deposition of a conductive layer (in particular metal, based on oxides) on the structured surface, on or between patterns, for example dielectric or less conductive, can be advantageously provided.

The layer, for example metal, in particular silver or nickel, can be deposited electrolytically. In the latter case, to form an electrode for electrolysis, the structured layer may advantageously be a layer (semiconductor) or a sol-gel type dielectric layer loaded with metal particles or a multilayer with a top layer of germination (seed layer in English) conductive.

The chemical potential of the electrolytic mixture is adapted to make the deposit preferential in areas of high curvature.

After the structuring of the layer, it is possible to envisage a transfer of the pattern network to the glass substrate and / or to an underlying layer, in particular by etching.

The structured layer may be a sacrificial layer optionally partially or completely eliminated.

In one embodiment, it is possible to structure the surface by structuring domains, structuring domains having distinct patterns (by their shape, by one of their characteristic dimensions, especially the spacing) and / or orientations. distinct patterns.

During the manufacture of the material one can differentiate the rate of the mobile species and the number of mobile species from one area to another.

Some areas of massive oxide or thin layer can be masked to avoid incorporating the mobile species or locally modify the incorporation conditions.

Naturally the structured layer can also be used as a mask for an underlayer or the adjacent substrate The invention also covers a product with surface structuring, that is to say with a set of irregularities or patterns with a submicron height and at least one (sub) micronic lateral characteristic dimension, a hybrid solid material comprising

and at least one species of nature distinct from the element or elements of the oxide and which is in particular a metal,

the molar percentage of species (s) in the material ranging from 6 mol% up to 50% and lower than the percentage of said oxide, with greater maximum characteristic dimension smaller than 50 nm obtainable by the process as described previously.

The structured product can be for an application for electronics, building or automotive, or even for a microfluidic application

There may be mentioned in particular different products, in particular glazing:

- with modified chemical properties ("super" hydrophobicity, hydrophilicity),

optics, in particular for LCD-type flat screen lighting or backlighting systems, in particular a light extraction means for an electroluminescent device, optical products for example intended for display screen, lighting, signage,

- for building, in particular a solar and / or thermal control glazing,

The function and the properties associated with structuring depend on the characteristic dimensions H, W, D.

The range of optical functionalities of nanostructured products is wide. The product may have at least one of the following characteristics:

the pattern is a relief, in particular of maximum average lateral dimension, called length L, submicron, in particular with W greater than 0.3L under oblique incidence and 0.8L under normal incidence, the material being notably richer in mobile species in the summits of the reliefs, and on a thickness less than 10 nm, said superficial thickness,

it is a glass exchanged with silver or copper, a sol gel mass or layer with said species including silver or copper and / or gold on a particularly transparent substrate,

the pattern is a hole of height h, in particular of maximum average lateral dimension, called length L, submicron, in particular with W greater than

0.3L under oblique incidence and 0.8L under normal incidence, the material being notably richer in metal in the base of the hole and in a thickness less than 10 nm, said superficial thickness,

the pattern is defined by a height H and a width W and a distance D between adjacent pattern,

the distance D being chosen less than 5 μηη in microfluidics or for wetting properties, at 2 μηη for infrared applications, at 500 nm, preferably at 300 nm, even more preferentially at 200 nm for optical applications or even widened to infrared (antireflection, light extraction, collection of light for photovoltaic or photocatalysis ...), the height H being preferably chosen to be greater than 20 nm, preferably greater than 50 nm, even more preferably greater than 100 nm for optical applications (visible and infrared), and greater than 70 nm, preferentially at 150 nm for the wetting properties (superhydrophobic or superhydrophilic),

the width W being chosen greater than D / 10, even more preferentially

D / 5 and even more preferentially at D / 2,

the distance D being chosen less than 5 μηη in microfluidic or for wetting properties, at 2 μηη for infrared applications,

the height H being preferably chosen to be greater than 70 nm, preferentially at 150 nm for the wetting properties (superhydrophobic or superhydrophilic),

the width W being chosen greater than D / 10, even more preferentially at D / 5 and even more preferentially at D / 2.

The abraded surface may form a substrate for the growth of a thin layer deposited under vacuum, the pattern is defined by a height H and a width W and a distance D between adjacent pattern:

the distance D being chosen less than 200 nm, preferably between 200 nm and 100 nm, even more preferably at 50 nm,

the height H being chosen preferably greater than 20 nm, preferably greater than 50 nm,

The relief can be particular punctual, cone-shaped. For the relief patterns, it is possible to observe at the apices of the reliefs an enrichment in said metal over a thickness called superficial thickness (less than the implantation wavelength of the beam ions), typically from 2 to 10 nm.

For the recessed patterns, it is possible to observe at the bottoms of the recesses an enrichment in said metal (over a thickness (less than the implantation wavelength of the beam ions, typically from 2 to 10 nm

The presence of the reinforced metal zones can be made by known microscopic TEM, STEM techniques and / or by chemical mapping by known microscopic or spectrometric techniques STEM, EELS, EDX.

The two main surfaces of said material may be structured with similar or distinct patterns, simultaneously or successively.

The structured product may be a solar control and / or thermal control glazing used in a microfluidic application, an optically functional glazing, such as an antireflection, a reflective polarizer in the visible and / or infra-red, an element of forward light redirection including for liquid crystal display, light extraction means for organic or inorganic electroluminescent device, or superhydrophobic or superhydrophilic glazing.

Other details and advantageous features of the invention appear on reading the examples illustrated by the following figures:

FIGS. 1a-1d show a set of 4 AFM image projections of a hybrid silica / mass metal material structured at different times in a first embodiment of the invention.

^■ Figure 2 shows schematically a sectional view of a structured glass product obtained according to the manufacturing process described in Figure 1 d. FIG. 3 represents a SEM image viewed from above of a hybrid silica / structured mass metal material obtained according to the manufacturing method described in FIG. 1 d.

^■ 4a-4b Figures represent a set of two AFM image projections at different magnifications of a hybrid material silica / metal layer structured in a second embodiment of the invention.

^■ 5a-5c represent a set of three AFM image projections at different magnifications of a hybrid material silica / copper structured layer in a third embodiment of the invention.

^■ Figure 6 shows schematically a structured glass product obtained according to the manufacturing process described in Figure 5a. ^■ 7a-7c are a set of three AFM image projections at different magnifications of a hybrid silica / copper material structured layer in a fourth embodiment of the invention.

^■ Figure 8 shows an AFM image showing an example of a comparative control material hybrid silica / copper unstructured layer.

^■ Figure 9 shows an AFM image showing an example of a hybrid material silica / copper structured layer in a fifth sample embodiment.

^■ Figure 10 shows an AFM image showing an example of a hybrid material silica / copper layer structured in a sixth sample embodiment.

^■ Figure 1 1 shows an AFM image showing an example of a comparative control material hybrid silica / copper unstructured layer

EXAMPLE OF A FIRST GLASS EXCHANGE STRUCTURE

A first 2 mm thick silver glass was obtained after ion exchange from a Planilux ^® glass from the company SAINT GOBAIN standard soda lime float glass.

It consisted in carrying out the ionic exchange between the sodium of the glass and the silver of a silver nitrate bath:

At first, the glass is immersed in pure silver nitrate at 300 ° C for 2 hours.

The resulting glass has a silver concentration profile of the surface up to several micrometers deep

It is noted that it has a weak yellow color. This color is characteristic of silver nanoparticles. Part of the silver that has penetrated the glass is reduced and aggregated to the state of nanoparticles of a few nanometers during the exchange reaction.

The silver thus penetrates to a depth of around 4 micrometers. The percentage of silica remaining constant, the surface exhibits an almost linear profile of silver. It is the sodium that was exchanged with the money and not the calcium, the potassium or any other cation of glass. The silver is probably present in the form of particles a few microns deep.

The surface contains about 15% Ag in mol.

The abrasion is in an ultrahigh vacuum pressure frame of 5.10 ^"8 mbar The ion beam Ar ⁺ energy 500eV was maintained at a flux of 0.09 mA / s.cm ² .

The AFM images of the surface of the silver glass show the appearance of a texturing composed of holes after abrasion. These holes, with a dense distribution and a few hundred nanometers in diameter appear after 30 minutes under the beam.

FIGS. 1 and 4 show the AFM images of a Planilux glass surface exchanged with silver after abrasion for 6, 12, 15, 30 minutes by an Ar ⁺ ion beam of energy 500 eV and maintained at a flux of 0. , 09 mA / s.cm ² .

The silver aggregates, diffuses towards the surface and is abraded faster than silica. This high rate of abrasion of silver is also often observed in magnetron deposition.

FIG. 2 diagrammatically represents a sectional view of a structured glass product obtained according to the manufacturing method described in FIG. 1 d, with 1: material not affected by ionic abrasion; 2: hollow; 3: zone rich in said species of metal type at the hollow; 10: structured surface.

The surface of this abraded silver glass was then imaged in SEM. We can observe the density of holes created by abrasion. FIG. 3 represents a SEM image seen from above of a hybrid silica / structured mass metal material obtained according to the manufacturing method described in FIG. 1 d.

FIG. 3 is a SEM image of a Planilux glass surface exchanged with silver after abrasion for 30 minutes by an Ar ⁺ ion beam of energy 500 eV and maintained at a flux of 0.09 mA / s. cm ²

Such images have been made at several places on the surface of the sample. It was thus possible to verify that the texturing observed in AFM took place on the entire surface exposed to the ion beam. The structuring is not related to an edge effect, the presence of platinum legs of the sample holder, or pollution.

In summary, Planilux ^® silver glass has been abraded. Holes of a few hundred nanometers in diameter formed during abrasion over the entire exposed beam surface. The holes obtained have a diameter W of 50 nm and a average height H of 20 nm. At the end of the abrasion, the yellow color is almost no longer visible on the sample.

Planilux ^® containing silver was abraded for different durations to determine the type of hole growth (Figure 1). AFM imaged the area of the abraded sample for 5 minutes. We can observe the beginning of hole formation.

We notice that the holes begin to appear between 8 and 10 min and that their size grows with the time of abrasion.

A greater and / or faster structuring can be obtained by varying at least one of the following parameters: by increasing the amount of silver present in the glass, by heating during abrasion, by increasing the flux and / or ion energy, by modifying the incident ion.

EXAMPLE OF A SECOND GLASS EXCHANGE LITTLE STRUCTURE

A Jeaner glass, containing a large quantity of alumina, underwent the same ion exchange for 2 hours in silver nitrate. The silver glass obtained has no coloring unlike the Planilux ^® . In AI0 ₂ , oxygen ions are more negatively charged than in Si0 ₂ because aluminum is more electropositive than silicon. The presence of alumina thus stabilizes the ionic form of the silver in the network and thus avoids the aggregation of metallic silver in the form of particles. The detailed profile of concentration of silver oxide, sodium and silica, was measured by EDX as for the previous glass.

Again, there is good agreement between the amounts of sodium oxides and silver. The penetration depth of the silver is however greater because it is present up to 400 micrometers deep. The surface contains about 25% Ag ₂ 0.

There is no nanometric structuring of the surface under the chosen abrasion conditions and on the contrary occurs smoothing by relaxation. The silver is spread homogeneously and in ionic form, thus not aggregated, in the glass.

EXAMPLES OF STRUCTURED SILICONE SILICONE GEL LAYER

A second type of hybrid prepared by sol-gel was prepared and abraded. The sol-gel pathway consists of synthesizing an inorganic polymer, such as silica, at room temperature from organic precursors. In a first step, this precursor is placed in the presence of water to hydrolyze. The solution obtained (called sol) can be deposited on different substrates such as glass or silicon. During the deposition, the solvent of the solution evaporates until condensation of the hydrolysed precursor into an inorganic polymeric network The oxide gel obtained can be shaped, in particular in a thin layer, until complete condensation of the polymer.

The deposition conditions (rotation speed) make it possible to control the thickness. We can play in a very wide range on the layer size (from ten nanometers to a few microns). Other compounds may be added during the hydrolysis such as dyes, dopants, surfactants that confer porosity to the layer or organic compounds that will not be altered by the synthesis because it is carried out at room temperature.

Silica layers of a few hundred nanometers thick containing 10 mol%. of silver were synthesized by sol-gel.

Preparation of the silica and silver sol: a sol of TEOS (2 g, 9.6 mmol) at 10% by weight in a pH 2 solution of HNO ₃ (18 g) was prepared and left stirring for three hours. These pH conditions allow a high rate of hydrolysis while slowing down the condensation. After evaporation under reduced pressure of the ethanol formed during the reaction, a solution of AgNO ₃ was added to the soil (1 mL, 1 mol.L ^"1 ) to have n _Ag = [Ag] / ([Ag ] + [Si]) such as 10% <n _Ag

Preparation of the silica and copper sol: a sol of TEOS (3 g, 9.6 mmol) at 15% by mass in ethanol (17 g) was prepared. Copper acetate (320 mg, 1, 6.10 ^-3 mol) and then the stoichiometric amount of water (1 g, 57.7.10 ^-3 mol) necessary for the hydrolysis of TEOS and acetate were added. After adjusting the pH to 3, the solution was left at reflux for two hours at 70 ° C. The molar ratio in the soil is n _Cu = [Cu] / ([Cu] + [Si]) = 10%.

The thickness of the sol-gel layer containing silver was measured by ellipsometry and is 250 ± 20 nm.

Sol-gel control layers of pure silica were synthesized under the same conditions as those containing silver.

Deposition and post-treatments: The silver or copper sols were deposited by spin-coating on the substrate (1000 rpm, 100 rpm for 2 min).

The samples obtained were annealed overnight at 200 ° C. to remove the solvent remaining in the layer and initiate the condensation of the silica network. Heat treatment at higher temperature T _reC uit (700 ° C) was applied. for the silver samples to finish the condensation and induce the formation of silver aggregates. Their heat treatment determines the oxidation state of silver. To obtain metallic silver, the annealing must take place between 500 ° C and 750 ° C.

The control layers before and after abrasion show little difference, regardless of the heat treatment imposed. They have a low roughness (~ 5 nm). These analyzes allow us to verify that no structuring takes place on pure silica. It is also a known result that the surface of silica, like other oxides relaxes after abrasion.

The prereduced Tp _layer cooked = 700 ° C was structured under the effect of abrasion. Holes of a few tens of nanometers have formed and are distributed over the entire surface of the material, between the degassing bubbles.

Figures 4a-4b show a set of 2 AFM image projections at different magnifications of a silica / metal hybrid material in a structured layer in a second embodiment of the invention.

FIG. 4 shows the AFM images of the silver silica layers obtained by the sol-gel route described above and abraded at ambient temperature or at 200 ° C.

We have previously seen that the layers annealed at 700 ° C contained aggregated silver metal. These holes can therefore result from the abrasion of these nanoparticles. Nevertheless, the particles usually observed in silver-containing sol-gel layers have characteristic sizes smaller than the observed holes. Silver may diffuse to these aggregates prior to abrasion.

The sol-gel layer containing 10% silver and annealed at _ReRe cooked Tp = 700 ° C were abraded to _Su bstrat T = 200 ° C.The holes appear denser after abrasion to 200 ° C. The high temperature of the abrasion makes it possible to increase the diffusion and thus goes in the direction of the formation of larger aggregates.

After treatment of the images of FIG. 4, the following characteristic sizes are observed:

The holes are thus close together when one abrades at high temperature.

Holes of a few tens of nanometers in diameter are formed after a few minutes of abrasion. By increasing the temperature, a higher density of the holes is observed. These very similar observations in the case of Planilux ^® , confirm the idea that silver nanoparticles are abraded faster than silica. The same mechanism can be considered.

EXAMPLES OF STRUCTURED COPPER SILICA GEL SOLUBLE LAYER Like silver we have made sol-silica gel layers containing 10 mol% copper. We compared the surface structure before and after 15 minutes of abrasion at room temperature.

FIGS. 5a-5c show a set of 3 AFM image projections at different magnifications of a structured layer silica / copper hybrid material in a third embodiment of the invention. The AFM images after abrasion at room temperature for 15 minutes of a layer of copper-doped silica obtained by sol-gel route are given in FIG. 5. The surface before abrasion is very slightly rough (-2 nm). The layer is homogeneous.

Unlike silver, we do not observe nanometric holes after abrasion, but reliefs. Bumps of about ten nanometers in height were formed.

Figure 6 shows schematically a structured glass product obtained according to the manufacturing method described in Figure 5a: 4: plot; 5: Zone rich in said species of metal type to the hollow. This zone can form a pure or almost pure taste in said metal type species; 10: structured surface.

They can be explained by a reverse mechanism to that of silver, where copper abrades less quickly, and remains at the top of the structures that are fed with copper, as explained in FIG.

To accentuate the formation of studs. The abrasion temperature was increased to 200 ° C to accelerate diffusion. The abrasion time has been reduced to 10 min the size seems to have increased.

FIGS. 7a-7c show a set of 3 AFM image projections at different magnifications of a structured layer silica / copper hybrid material in a fourth embodiment of the invention.

These figures show the AFM image of the surface of a copper-doped silica layer obtained by sol-gel, after ionic abrasion for 10 minutes at 200 ° C.

The copper incorporated into the silica makes it possible to quickly obtain slightly structured surfaces after abrasion with pads approximately 10 nm high. Surfaces are more homogeneous than in the case of silver. The temperature treatment reduces the density of the pads and increases their size. The characteristic sizes are given in the following table: Temperature H nm D nm W nm

25 ° C 5 75 40

200 ° C 20 150 40

A higher and / or faster structuring can be obtained by varying at least one of the following parameters: by applying a prior heat treatment, by increasing the amount of copper present in the glass, by heating during abrasion, increasing the flux and / or the energy of the ions, by modifying the incident ion.

EXAMPLES OF MAGNETRON SILICA COPPER STRUCTURED LAYER

Industrially, magnetron layer deposition is a common and well-controlled technique. Thanks to it, it is possible to form by codépôt layers of submicron thickness see micron with a well controlled composition. In addition, the ionic abrasion and magnetron deposition can be done in the same vacuum chamber, which has great advantage in terms of time and cost of structuring.

We deposited by magnetron sputtering on a glass substrate a mixed layer of silica / copper. The deposition was under a pressure of 1.6 × 10 ^-3 mbar in argon, using a pure copper target with a constant magnetic field, and a SiO 2 target with a radiofrequency magnetic field. was 0.8 A / s, and the copper deposition rate is chosen to have the desired concentration (dictated by the positions of the targets and the powers). For example, for a concentration of 20% in copper is fixed a speed deposit of 0.2A / s.

In 30 minutes, a hybrid silica layer more than 1.5 micron thick was deposited with a concentration of 20 mol%. in copper. Concentration layers slightly less than 4% (3.8%) mol were also deposited by decreasing the rate of copper deposition, illustrating the importance of a sufficient copper content for structuring (controls). XPS measurements confirmed the formation of mixed SiO 2 copper layer as well as the respective concentrations.

The samples were abraded for 15 minutes by Ar ⁺ ions of energy 500 eV, with a constant flow of 0.09mA / cm ² , at room temperature (control), and also at 175 ° C and 250 ° C. For layers with 20% copper

FIG. 8 shows an AFM image projection of a comparative control example of an unstructured layered silica / copper hybrid material. This is an AFM image of the magnetron-doped copper-doped silica layer after ionic abrasion at room temperature. At room temperature, no patterning was observed in AFM. The surface remains relatively rough, unlike a layer of pure silica which is smooth under ionic abrasion at normal incidence. The lack of structure may be due to insufficient mobility of copper in magnetron-deposited silica.

The activation energy is too important a heat treatment is required, the heating temperature is all the greater as the rate will be low.

Fig. 9 shows an AFM image projection of an example of a structured layer silica / copper hybrid material in a fifth embodiment of the sample. To increase the diffusion rate of the copper, the temperature of the sample identical to that described in Figure 8, was raised to 175 ° C during abrasion.

This time, as for the silica gel copper ground, pads of 3 nm high and 200 nm wide, and spacing D of 500 nm were formed on the surface.

Fig. 10 shows an AFM image projection of an example of a structured layer silica / copper hybrid material in a sixth embodiment of the sample. To increase the diffusion rate of the copper, the sample temperature identical to that described in Figure 8, was raised to 250 ° C during abrasion. We obtain then low density pads, but larger: 12 nm high H, 350 nm wide L, and 3 μηη spacing D.

FIG. 11 represents a projection of AFM images of a comparative control example of a hybrid silica / copper material in an unstructured layer. For layers with less than 4% copper, Figure 11 shows the area observed by AFM after abrasion at room temperature. Structural formation is not observed even with increasing temperature as in the previous examples. This illustrates that it is necessary to have a minimum amount of said metal element in the material.

The possibility of using magnetron layer deposition followed by ionic abrasion has been demonstrated. To increase the aspect ratio and / or density of the pads, layers with a higher copper concentration can be deposited. In addition, the importance of temperature has been demonstrated, which will not relax the surface but allow the formation of nanocones. The energy and flux of the incident ions can also be adjusted.

Claims

Method of structuring the surface, that is to say forming at least one set of irregularities or patterns (2, 4) with a submicron height H and at least one lateral characteristic dimension W, called width, micron or submicron , on a surface of a material (1), in particular a glass, by ionic abrasion with an optionally neutralized ion beam, characterized in that it comprises the following steps:

and at least one species, of a nature distinct from the element or elements of the oxide, and which is in particular a metal,

the molar percentage of species (s) in the material ranging from 6 mol% up to 50% and lower than the percentage of said oxide, with at least the majority of the species having a greater characteristic dimension smaller than 50 nm, in particular said hybrid material being metastable before said abrasion,

the possible heating of said hybrid material before said abrasion,

structuring the surface of said hybrid material with an abrasion time of less than one hour on an abrasion surface greater than 1 cm ² , until forming said set of patterns, the structuring being optionally accompanied by a heating of hybrid material.

Surface structuring method according to claim 1 characterized in that the material is heated to a temperature greater than equal to 70 ° C especially from 120 to 300 ° C before abrasion and / or during abrasion.

Surface structuring method according to one of the preceding claims, characterized in that the abrasion is at an etching flux greater than 0.01 mA / cm ² , in particular ranging from 0.05 to 0.3 mA / cm ² .

Surface structuring method according to one of the preceding claims, characterized in that the abrasion is at an energy ranging from 200 to 2000 eV in particular ranging from 500 to 1000 eV.

Surface structuring method according to one of claims 1 to 2 characterized in that, in particular with a selected species which is silver, is abrade, and the pattern is a hole (2) in particular of maximum average lateral dimension, so-called length L, submicron, in particular with W greater than 0,3L at oblique incidence and greater than or equal to 0,8L under normal incidence

6. surface structuring method according to one of claims 1 to 2 characterized in that, in particular with a selected species which is copper, is abrade and the pattern is a relief (2), in particular of maximum average lateral dimension, said length L, submicron, in particular with W greater than 0.3L at oblique incidence and greater than or equal to 0.8L under normal incidence.

7. surface structuring method according to one of the preceding claims characterized in that said species is in ionic form, including copper in the silica and / or aggregate, including silver in the glass and / or the species is preferably chosen from at least one of the following species, in particular metal: silver, copper, cobalt, platinum, nickel, tin, gold and preferably the effective charge on the species is zero or less than 0.5.

8. surface structuring method according to one of the preceding claims characterized in that the oxide is preferably chosen from at least one of the following oxides: silica, alumina, zirconia, titanium oxide, cerium oxide, oxide magnesium, especially a mixed oxide of aluminum and silicon, zirconium and silicon, titanium and silicon and preferably a glass.

9. surface structuring method according to one of the preceding claims characterized in that the hybrid material is a glass, in particular silicocalcique, ionically exchanged with preferably at least one of the following species: silver, copper.

10. surface structuring method according to one of the preceding claims characterized in that the hybrid material, mass or layer on a substrate, is a gel sol, in particular said oxide is at least one of the following elements Si, Ti, Zr, Al, V, Mg, Sn, and Ce and incorporating said metal in the form of particles, possibly in aggregate, in particular Ag, Cu, Au.

1 1. Surface structuring method according to one of the preceding claims characterized in that said hybrid material is a layer deposited by the physical vapor phase on a substrate by codépôt, of the species, in particular metal, such as copper, silver or gold, and oxide such as silica, zirconia, tin oxide, alumina with metal targets and oxygen atmosphere or with targets of said oxides.

12. Product with surface structuring, that is to say with a set of irregularities or patterns with submicron height and at least one submicron lateral characteristic dimension, a hybrid solid material comprising

a single or mixed oxide of element (s), the molar percentage of oxide in the material being at least 40%, especially between 40 and 94%, and at least one species of nature distinct from the element or elements of the oxide and which is in particular a metal,

the molar percentage of species (s) in the material ranging from 4 mol% up to 50% and lower than the percentage of said oxide, with a larger maximum characteristic dimension of less than 50 nm obtainable by the method according to one of previous method claims.

13. Structured product according to one of the preceding product claims characterized in that the pattern is a relief, in particular of average maximum lateral dimension, so-called length L, submicron, in particular with W greater than 0.3L at oblique incidence and at 0 , 8L at normal incidence, the material being notably richer in mobile species in the summits of the reliefs, and in a thickness less than 10 nm, said superficial thickness.

14. Structured product according to one of the preceding product claims characterized in that it is a glass exchanged in particular with silver or copper, a sol gel mass or layer with said species, including silver or copper and / or gold, on a particularly transparent substrate.

15. Structured product according to one of the preceding product claims characterized in that the pattern is a hole of height H, in particular of average maximum lateral dimension, so-called length L, submicron, in particular with W greater than 0.3L under oblique incidence. and at 0.8L under normal incidence, the material being notably richer in metal in the base of the hole and in a thickness of less than 10 nm, said surface thickness

16. Structured product according to one of the preceding product claims, characterized in that the pattern is defined by a height H and a width W and a distance D between adjacent pattern:

the distance D being chosen to be less than 500 nm, preferably 300 nm, even more preferably 200 nm for optical applications or even extended to infrared, especially antireflection, light extraction, collection of light for photovoltaic or photocatalysis,

the height H being preferably chosen to be greater than 20 nm, preferably greater than 50 nm, and even more preferentially greater than 100 nm for optical (visible and infrared) applications.

17. Structured product according to one of the preceding product claims, characterized in that the pattern is defined by a height H and a width W and a distance D between adjacent pattern: the distance D being chosen less than 5 μηι for wetting properties ,.

18. Structured product according to one of the preceding product claims, characterized in that the pattern is defined by a height H and a width W and a distance D between adjacent pattern:

the distance D being chosen less than 5 μηη in microfluidic or for wetting properties, at 2 μηη for infrared applications.

the height H being chosen preferably greater than 70 nm, preferably at 150 nm for the wetting properties (superhydrophobic or superhydrophilic).

19. Structured product according to one of the preceding product claims, characterized in that the abraded surface forms a substrate for the growth of a thin layer, in particular deposited under vacuum on the abraded layer, the pattern is defined by a height H and a width W and a distance D between adjacent pattern:

20. Structured product according to one of the preceding product claims characterized in that it is a solar control glass and / or thermal used in a microfluidic application, an optical function glazing, such as an anti-reflective, a reflective polarizer in the visible and / or infra-red, a forward light redirection element, in particular for a liquid crystal screen, an organic or inorganic light-emitting device for extracting light, or a superhydrophobic or superhydrophilic glazing unit .