EP2237697B1 - Object comprising a graphics element transferred onto a support wafer and method of producing such an object - Google Patents

Description

TECHNICAL AREA

The invention relates to an object, such as a massive object, for example of jewel type, stone, watch (for example a watch glass, a dial or a case back), nomadic electronic equipment (for example a window or a window). screen) or any other solid support, including a graphic element, or graphics, such as a decoration, typographic characters, a drawing or a photo, for example of micrometric and / or nanometric dimensions. The invention also relates to a method for producing such an object.

The invention has applications in various industrial, cultural or artistic fields. For the watch industry, watch glasses or case backs can be manufactured according to this invention to produce semi-transparent graphics or decorations of very high visual quality and very robust.

The invention can also be applied in the field of jewelery, in particular for the production of stones comprising decorations or texts with micrometric and / or nanometric dimensions, for example used to make pendants, rings, or loops. hear.

The invention can also be used to carry out the storage of a large amount of information in small volumes (for example a few cm ² of surface for less than 2 mm thick) with very good durability (several thousand or millions years).

PRIOR ART

It is known to produce objects comprising decorations or graphics of micrometric size obtained by the implementation of techniques derived from microtechnologies, for example by photolithography on an object. However, the durability and mechanical strength of these decorations made on the surface of objects are generally poor.

A method of protecting a graphic made on an object is described in the document FR 2 851 496 . In this document, the graphic is first made by photolithography on a transparent substrate. The substrate is then returned and secured to the desired object by gluing or crimping.

Such a method has several disadvantages. Indeed, the adhesives used to secure the substrate to the object comprise organic materials having a limited life. The objects thus produced therefore have a limited life. On the other hand, the optical properties of its glues deteriorate over time, which alters the readability of the graphics made on the substrate. The crimping allows a solid mechanical assembly of the substrate to the object, but does not ensure a good integrity of the object and its graphics because the crimping can be dismantled without destroying the object, which poses a problem if the we want to make an object with an inviolable graphic.

EP-A-0627 763 describes an object provided with a graphic element and a method of producing it.

STATEMENT OF THE INVENTION

An object of the present invention is to provide an object comprising one or more graphic elements, as well as a method for producing such an object, not having the disadvantages of the prior art described above.

For this purpose, the present invention proposes an object provided with at least one graphic element, comprising at least one layer etched according to a pattern of the graphic element, a first face of said layer being arranged opposite a face of at least one at least partially transparent substrate, a second face, opposite to the first face, of said layer being covered by at least one passivation layer secured to at least one face of at least one support by molecular adhesion and forming, with the support, a monolithic structure.

Said layer etched according to the pattern of the graphic element may be based on at least one metal. In addition, said layer etched according to the pattern of the graphic element may comprise, at least at the level of the second face, at least one zone based on said metal and at least one semiconductor.

Thus, the graphic element, which may be of micrometric and / or nanometric dimensions, is produced on the object in a robust, durable and integrated manner (uncoupling impossible without degrading the object) thanks to the molecular adhesion bonding achieved between the layer of passivation and the support of the object.

The graphics, or texts, formed by the graphic element, are thus hermetically enclosed between two solid solid components, on one side the substrate and on the other side the support, thanks to the bonding by molecular adhesion achieved. This hermetic seal forms in particular a barrier to the diffusion of moisture or any gaseous or liquid chemical product (except products possibly capable of destroying the substrate or the support).

Molecular adhesion bonding makes it possible to form a monolithic and robust structure from the substrate and from the support of the object, in which the graphic element is enclosed. The adhesion forces between the substrate and the support are greater than the cohesive forces of the materials. Thus, any attempt to detach the substrate with the support would lead to a complete destruction of the object.

In addition, molecular bonding allows the use of inorganic materials whose optical properties are stable over time. The structure produced therefore does not undergo degradation of its optical qualities (in particular the visibility of the graphic element) due to time.

The graphic element is mechanically protected by the entire thickness of the substrate on one side and the support of the other. These must be abraded or fully worn before destroying the graphic element. This protection can therefore be maximized by choosing very hard materials, for example sapphire for the substrate which can only be scratched by silicon carbide or diamond.

This object can be realized independently of the density of the patterns of the graphic element.

When the graphic element is made in a metal layer, the graphics or texts can be made with a valuable material and very stable, that is to say, not sensitive to corrosion or degradation in time.

Thanks to the metal and semiconductor-based zone formed in the layer comprising the graphic element, a very good adhesion of the passivation layer to the layer comprising the graphic element is obtained, this adhesion making it possible to prevent a deterioration of the object for example when a subsequent cutting of the layers forming the object (wafer cutting).

The substrate may be based on at least one amorphous or crystalline material and / or the passivation layer may be based on at least one mineral material.

The object may further comprise an adhesion layer disposed between the first face of the layer, in which the graphic element is formed, and the face of the substrate.

In this case, the graphic element can also be etched in the adhesion layer.

The adhesion layer may be based on at least one metal and / or one metal nitride and / or one metal oxide.

The object may further comprise at least one adhesion layer disposed between the face of the support and the passivation layer, the molecular adhesion being able to be formed between the adhesion layer and the passivation layer.

Thanks to the adhesion layer deposited on the support before the molecular bonding, the support can be of any kind or based on any material. This material may in particular be compatible with a possible annealing to consolidate the molecular adhesion.

The object may be for example a jewel, a watch, or an electronic device.

Said zone of the layer may be based on silicide.

1. a) dépôt d'au moins une couche au-dessus, ou en regard, d'une face d'au moins un substrat au moins partiellement transparent,
2. b) gravure de ladite couche selon un motif de l'élément graphique,
3. c) dépôt d'au moins une couche de passivation au moins sur ladite couche comportant l'élément graphique gravé et sur des portions de la face du substrat non recouvertes par la couche comportant l'élément graphique gravé,
4. d) solidarisation de la couche de passivation à au moins une face d'au moins un support par adhésion moléculaire, formant une structure monolithique.

The invention also relates to a method for producing an object provided with at least one graphic element, comprising at least the steps of:

1. a) deposition of at least one layer above or opposite one side of at least one at least partially transparent substrate,
2. b) etching said layer in a pattern of the graphic element,
3. c) depositing at least one passivation layer at least on said layer comprising the engraved graphic element and on portions of the face of the substrate not covered by the layer comprising the engraved graphic element,
4. d) joining the passivation layer to at least one side of at least one support by molecular adhesion, forming a monolithic structure.

1. a) dépôt d'au moins une couche au-dessus, ou en regard, d'une face d'au moins un substrat au moins partiellement transparent,
2. b) gravure de ladite couche selon un motif de l'élément graphique,
3. c) formation dans ladite couche, au moins au niveau d'une seconde face de ladite couche opposée à une première face de ladite couche se trouvant du côté du substrat, d'au moins une zone à base dudit métal et d'au moins un semi-conducteur,
4. d) dépôt d'au moins une couche de passivation au moins sur ladite couche comportant l'élément graphique gravé et sur des portions de la face du substrat non recouvertes par la couche comportant l'élément graphique gravé,
5. e) solidarisation de la couche de passivation à au moins une face d'au moins un support par adhésion moléculaire, formant une structure monolithique.

The invention furthermore relates to a method of producing an object provided with at least one graphic element, comprising at least the steps of:

1. a) deposition of at least one layer above or opposite one side of at least one at least partially transparent substrate,
2. b) etching said layer in a pattern of the graphic element,
3. c) forming in said layer, at least at a second face of said layer opposite to a first face of said layer lying on the substrate side, at least one zone based on said metal and at least one semiconductor,
4. d) depositing at least one passivation layer at least on said layer comprising the etched graphic element and on portions of the face of the substrate not covered by the layer comprising the etched graphic element,
5. e) joining the passivation layer to at least one side of at least one support by molecular adhesion, forming a monolithic structure.

The method may further comprise, before step a) of depositing the layer, a step of depositing an adhesion layer on the face of the substrate, said layer being then deposited, during step a), on the adhesion layer.

The graphic element can also be etched, during step b), in the adhesion layer.

The method may further comprise, between step d) of depositing the passivation layer and the step e) of joining, an annealing step, at a temperature between about 400 ° C and 1100 ° C, of the substrate having the passivation layer.

The method may further comprise, between step d) of depositing the passivation layer and the step e) of joining, a step of planarization of the passivation layer.

Step b) of etching the graphic element can be obtained by the implementation of masking, lithography and etching steps in said layer and / or in an adhesion layer disposed between the face of the substrate and said layer, or at least one laser ablation step directly in said layer and / or in an adhesion layer disposed between the face of the substrate and said layer.

The method may further comprise, before the step e) of joining, a step of deposition of at least one adhesion layer at least on the face of the support, the step e) of securing being obtained by the implementation bonding by molecular adhesion between said adhesion layer and the passivation layer.

The method may further comprise, between the step of depositing the adhesion layer and step e) solidarization, a step of planarization of the adhesion layer.

The method may furthermore comprise, between the step of depositing the adhesion layer and the step e) of joining, an annealing step, at a temperature of between about 400 ° C. and 1100 ° C., of the support comprising the adhesion layer.

The method may further comprise, after the step e) of joining, a heat treatment step by annealing the object consolidating the molecular adhesion.

Step c) of forming the zone based on said metal and a semiconductor is obtained by carrying out a step of siliciding said layer.

BRIEF DESCRIPTION OF THE DRAWINGS

• les figures 1A à 1H représentent les étapes d'un procédé de réalisation d'un objet, objet de la présente invention, selon un mode de réalisation particulier.

The present invention will be better understood on reading the description of exemplary embodiments given purely by way of indication and in no way limiting, with reference to the appended drawings in which:

• the Figures 1A to 1H represent the steps of a method of producing an object, object of the present invention, according to a particular embodiment.

Identical, similar or equivalent parts of the different figures described below bear the same numerical references so as to facilitate the passage from one figure to another.

The different parts shown in the figures are not necessarily in a uniform scale, to make the figures more readable.

The different possibilities (variants) must be understood as not being exclusive of each other and can be combined with one another.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

An exemplary method of producing an object 100 comprising a graphic element carried on a support 20, for example a solid object such as a jewel, a watch, or an electronic equipment, will be described in connection with the Figures 1A to 1H .

As shown on the Figure 1A first, a deposit is made on a flat face of a substrate 2, for example transparent or at least partially transparent, and based on an amorphous material, such as glass, or crystalline, such as sapphire or diamond, an adhesion layer 4 on which is deposited a layer 6. The thickness of the substrate 2 is for example equal to a few hundred micrometers, or between about 100 microns and 1 mm. The thickness of the support 20 (shown on the Figures 1F to 1H ) may in particular be greater than or equal to the thickness of the substrate 2.

The layers 4 and 6 are for example obtained by PVD type deposits (evaporation or sputtering). In the embodiment described here, the layer 6 is metal-based, for example example of gold, platinum, tungsten, titanium, metal oxide, etc. The material of the layer 6 may in particular be opaque to light. The thickness of this layer 6 is for example between about 50 nm and 100 nm. The thickness of the layer 6 can in particular be chosen according to the nature of the material forming the layer 6, the thickness chosen being sufficient to obtain a certain opacity of the layer 6. Thus, since the graphic element that the it is desired to achieve will be etched in the layer 6 and that this graphic element will be visible through the substrate 2 on the object 100, the opacity of the material of the layer 6 will visually highlight the graphic element made in the layer 6. The adhesion layer 4 is for example based on titanium, titanium nitride, titanium oxide or any other material to obtain a good adhesion between the layer 6 and the substrate 2. The nature of the adhesion layer 4 may in particular be chosen depending on the nature of the substrate 2 and the layer 6. The thickness of this adhesion layer 4 may for example be between about 1 nm and 10 nm.

In a variant, the layer 6 can be deposited directly on the substrate 2 without using an intermediate adhesion layer 4 between the substrate 2 and the layer 6.

A mask 8, whose pattern corresponds to that of the graphic element to be produced, is then formed on the layer 6 ( Figure 1B ). For this, a layer of photoresist is for example deposited on the layer 6. One or more steps of lithography and etching are then implemented to form the mask 8. In the embodiment described here, the mask 8 is formed by remaining portions of the photosensitive resin layer deposited on the layer 6. The resin layer Thus, in the example described here, the photosensitive resin is positive, the pattern of the graphic element being formed by the portions of the mask 8. However, it is also possible to use a negative photoresist.

As shown on the figure 1C the layer 6, as well as the adhesion layer 4, are then etched by an isotropic or anisotropic or dry chemical route (plasma mode, reactive ion etching or ionic machining). The etching mask 8 is then eliminated. The pattern of the graphic element is therefore transferred to the layer 6 and formed by remaining portions 6 'and 6 "of the layer 6, as well as remaining portions 4' and 4" of the adhesion layer 4.

In an alternative embodiment, it is possible for the mask 8 to be formed in a layer, for example of mineral type (for example based on silicon dioxide), deposited on the layer 6, and on which the layer to be deposited is then deposited. photosensitive resin base. The pattern of the graphic element is then formed by lithography and etching in the resin layer. This pattern is then transferred into the mineral layer by etching. Finally, the remaining portions of the resin layer are then removed by engraving. The mask 8 is in this case formed by the remaining portions of the mineral layer. This variant may in particular be used to produce an etching mask resistant to certain etching agents used to etch the layer 6 and / or the adhesion layer 4, which may damage a resin-based mask (for example water regia). The choice of one or the other embodiment of the mask can be made according to the material to be etched (material of the layers 6 and 4).

In a variant of the method described, it is possible not to use an etching mask. In this case, the pattern of the graphic element is produced directly in the layer 6, and possibly in the adhesion layer 4 if it is present between the layer 6 and the substrate 2, for example by laser ablation which can in particular be performed by a femtosecond laser.

The remaining portions of the etched layer 6 are then formed (portions 6 'and 6 "on the figure 1C ), a zone 10 based on the metal of the layer 6 and a semiconductor. For this, siliciding of the etched portions 6 ', 6 "is carried out for example, This silicidation is for example obtained by a silane decomposition (SiH ₄ , or more generally any type of gas Si _n H _{2n + 2} ) under a controlled atmosphere. at a temperature for example between about 200 ° C and 450 ° C and preferably about 300 ° C. The gas thus decomposed reacts with the metal of the layer 6 to form the zone 10. For example, when the layer 6 is based on Pt, the zone 10 obtained after the silicidation is then based on PtSi. It is also possible that the zone 10 is based on a semiconductor other than silicon. This zone 10 is for example made to a thickness between about 1 nm and 50 nm, or, if the metal layer 6 has a thickness greater than 50 nm, to a thickness of between about 1 nm and the entire thickness of the layer. 6.

On the figure 1D a passivation layer 12 is then deposited, for example by CVD (chemical vapor deposition) or PVD. This passivation layer 12 is for example based on a mineral material, such as silicon dioxide or silicon nitride. The material of this passivation layer 12 is chosen in particular to be able to subsequently produce a molecular bonding with the support 20. This passivation layer 12 is also intended to provide protection for the pattern formed by the remaining portions 6 ', 6 "of the layer 6.

In a variant, it is also possible to first deposit the anti-reflective layer and / or other layers on the remaining portions 6 ', 6 "of the layer 6 and on the face of the substrate 2 comprising these remaining portions 6 ', 6 ", then depositing the passivation layer 12 on this anti-reflective layer and / or on the other layers.

Thanks to the presence of the area 10 at the surface of the remaining portions 6 'and 6 "of the metal layer 6, the adhesion of the passivation layer 12 is improved on these portions 6' and 6". Preferably, the formation of the zone 10, for example obtained by a silicidation step, can be implemented in situ, that is to say carried out in the equipment used to deposit the passivation layer 12, without implementing other steps between the step of producing the zone 10 and the deposition of the passivation layer 12, which makes it possible not to expose the zone 10 to the external environment and thus to retain better adhesion properties of the zone 10 vis-à- screw of the passivation layer 12.

The passivation layer 12 is then planarized, for example by a chemical-mechanical polishing step, thus making it possible to eliminate the relief formed by the remaining portions 6 ', 6''of the layer 6 and the remaining portions of the coating layer. adhesion 4 ', 4 "relative to the surface of the substrate 2 on which are formed the remaining portions 6', 6" of the layer 6 and the remaining portions 4 ', 4''of the adhesion layer 4. thus forms a passivation thin film 12 ', having a flat surface, above the remaining portions 6', 6 "( figure 1E ). The passivation thin film 12 'may for example have a thickness between about 100 nm and 1 micron.

An assembly 14 is thus obtained, formed here by the substrate 2, the remaining portions 6 ', 6 "of the layer 6, the remaining portions 4', 4" of the adhesion layer 4 and the thin passivation film 12 ' , comprising the pattern of the graphic element that is to be transferred to the support 20 of the object 100.

It is possible to subject the assembly 14 stabilization annealing, for example to a temperature of between about 400 ° C. and 1100 ° C., in order to avoid any degassing by the oxides present in the assembly 14 during the molecular bonding carried out subsequently during the production method described here, and therefore to consolidate the adhesion molecular.

In parallel with the realization of the assembly 14, the support 20 can be prepared to receive the report of the assembly 14.

For this, as shown on the figure 1F an adhesion layer 22 is deposited, for example by a CVD or PVD type deposit, on one side of the support 20 intended to receive the assembly 14. This adhesion layer 22 may be based on a mineral material such as silicon dioxide or silicon nitride, and / or of a similar nature to that of the passivation layer 12. The material of the adhesion layer 22 is chosen in particular so that a molecular bonding with the assembly 14 and more particularly with the passivation layer 12 '. It is also possible to cover the other faces of the support 20 with the material of the adhesion layer 22 so as to provide mechanical protection for the support 20 during the subsequent steps of the process.

It is possible to subject the support 20 and the adhesion layer 22 to a stabilizing anneal, for example at a temperature of between about 400 ° C. and 1100 ° C., in order to avoid any degassing, for example when the adhesion layer 22 is based on silicon dioxide, during the molecular bonding carried out subsequently during the production method described here, and therefore to consolidate the molecular adhesion.

A surface treatment of the adhesion layer 22 is then carried out, for example a chemical-mechanical polishing of the surface 22 'of the adhesion layer 22, making it possible to eliminate the possible roughness of the support 20 which may end up at the face 22 'of the adhesion layer 22 ( figure 1G ). This gives a flat face 22 '.

Finally, as represented on the figure 1H , the assembly 14, or part of the assembly 14 comprising the graphic element, is transferred to the support 20 by molecular bonding, without addition of material. In the embodiment described here, the molecular bonding is performed between the adhesion layer 22 and the passivation thin film 12 'which are here based on the same material. When the support 20 is based on a material capable of adhesion by molecular bonding with the passivation layer 12 ', the adhesion layer 22 may be omitted. The roughness of the molecular bonded surfaces may be less than about 1 nm or 0.5 nm.

It is then possible to carry out a step of heat treatment of the object (support + assembly carried forward) making it possible to consolidate the molecular adhesion achieved. This heat treatment may in particular be an annealing carried out at a temperature of between about 250 ° C. and 1200 ° C. Advantageously, this annealing can be carried out at a temperature greater than about 850 ° C. in order to obtain the best possible strength between the layers 12 and 22 (at least equivalent to that of a solid material).

This produces the object 100 comprising the graphic element formed by the portions 4 ', 4 ", 6', 6" visible through the substrate 2 and / or the support 20 and buried in the monolithic structure thus formed.

Claims (19)

1. Object (100) provided with at least one graphic element, including at least one layer (6, 6', 6") composed of at least one metal and etched according to a pattern of the graphic element, a first face of said layer (6, 6', 6") being positioned opposite a face of at least one at least partly transparent substrate (2), a second face, opposite to the first face, of said layer (6, 6', 6") being covered with at least one passivation layer (12, 12') fixed to at least one face of at least one support (20) by wafer bonding and forming with the support (20), a monolithic structure, and said layer (6, 6', 6") including, at least at the second face, at least one area (10) composed of said metal and of at least one semiconductor.
2. Object (100) according to claim 1, wherein the substrate (2) is composed of at least one amorphous or crystalline material and/or the passivation layer (12, 12') being composed of at least one mineral material.
3. Object (100) according to any of the preceding claims, further including an adherence layer (4, 4', 4") positioned between the first face of the layer (6, 6', 6"), in which the graphic element is formed, and the face of the substrate (2).
4. Object (100) according to claim 3, wherein the graphic element is also etched in the adherence layer (4, 4', 4").
5. Object (100) according to any of claims 3 or 4, wherein the adherence layer (4, 4', 4") is composed of at least one metal and/or of a metal nitride and/or a metal oxide.
6. Object (100) according to any of the preceding claims, further including at least one adhesion layer (22) positioned between the face of the support (20) and the passivation layer (12, 12'), the wafer bonding being formed between the adhesion layer (22) and the passivation layer (12, 12').
7. Object (100) according to any of the preceding claims, said object (100) being a jewel, a watch or an electronic device.
8. Object (100) according to any of the preceding claims, wherein said area (10) of the layer (6, 6', 6") is composed of silicide.
9. Method for making an object (100) provided with at least one graphic element, including at least the steps of:

   a) depositing at least one layer (6, 6', 6") composed of at least one metal above a face of at least one at least partly transparent substrate (2),

   b) etching said layer (6, 6', 6") according to a pattern of the graphic element,

   c) forming in said layer (6, 6', 6"), at least at a second face of said layer (6, 6', 6") opposite to a first face of said layer (6, 6', 6") located on the side of the substrate (2), at least one area (10) composed of said metal and of at least one semiconductor,

   d) depositing at least one passivation layer (12, 12') at least onto said layer (6, 6', 6") including the etched graphic element and onto portions of the face of the substrate (2) not covered by the layer (6, 6', 6") including the etched graphic element,

   e) fixing the passivation layer (12, 12') to at least one face of at least one support (20) by wafer bonding, forming a monolithic structure.
10. Method according to claim 9, further including, before the step a) for depositing the layer (6, 6', 6"), a step for depositing an adherence layer (4, 4', 4'') onto the face of the substrate (2), said layer (6, 6', 6") being then deposited, during step a), onto the adherence layer (4, 4', 4").
11. Method according to claim 10, wherein the graphic element is also etched during step b), in the adherence layer (4, 4', 4'').
12. Method according to any of claims 9 to 11, further including between the step d) for depositing the passivation layer (12, 12') and the fixing step e), a step for annealing at a temperature comprised between about 400°C and 1,100°C, the substrate (2) including the passivation layer (12, 12').
13. Method according to any of claims 9 to 12, further including between the step d) for depositing the passivation layer (12, 12') and the fixing step e), a step for planarization of the passivation layer (12, 12').
14. Method according to any of claims 9 to 13, wherein the step b) for etching the graphic element is obtained by applying masking, lithographic and etching steps in said layer (6, 6', 6") and/or in an adherence layer (4, 4', 4") positioned between the face of the substrate (2) and said layer (6, 6', 6"), or at least one laser ablation step directly in said layer (6, 6', 6") and/or in an adherence layer (4, 4', 4'') positioned between the face of the substrate (2) and said layer (6, 6', 6'').
15. Method according to any of claims 9 to 14, further including, before the fixing step e), a step for depositing at least one adhesion layer (22) at least onto the face of the support (20), the fixing step e) being obtained by applying bonding by wafer bonding between said adhesion layer (22) and the passivation layer (12, 12').
16. Method according to claim 15, further including, between the step for depositing the adhesion layer (22) and the fixing step e), a step for planarization of the adhesion layer (22).
17. Method according to any of claims 15 or 16, further including, between the step for depositing the adhesion layer (22) and the fixing step e), a step for annealing, at a temperature comprised between about 400°C and 1,100°C, the support (20) including the adhesion layer (22).
18. Method according to any of claims 9 to 17, further including, after the fixing step e), a step for heat treatment by annealing the object (100) consolidating wafer bonding.
19. Method according to any of claims 9 to 18, wherein the step c) for forming the area (10) composed of said metal and of a semiconductor is obtained by applying a step for siliconizing said layer (6,6',6").

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