EP1230674A1 - Crosslinked resin and method for making oxides using same - Google Patents

Crosslinked resin and method for making oxides using same

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Publication number
EP1230674A1
EP1230674A1 EP01954061A EP01954061A EP1230674A1 EP 1230674 A1 EP1230674 A1 EP 1230674A1 EP 01954061 A EP01954061 A EP 01954061A EP 01954061 A EP01954061 A EP 01954061A EP 1230674 A1 EP1230674 A1 EP 1230674A1
Authority
EP
European Patent Office
Prior art keywords
ceramic
alkoxide
glass
manufacturing
crosslinked resin
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP01954061A
Other languages
German (de)
French (fr)
Inventor
Philippe c/o Thales Intellectual Prop. GAUCHER
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Thales SA
Original Assignee
Thales SA
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Filing date
Publication date
Application filed by Thales SA filed Critical Thales SA
Publication of EP1230674A1 publication Critical patent/EP1230674A1/en
Withdrawn legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/02104—Forming layers
    • H01L21/02107—Forming insulating materials on a substrate
    • H01L21/02225—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer
    • H01L21/0226—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer formation by a deposition process
    • H01L21/02282—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer formation by a deposition process liquid deposition, e.g. spin-coating, sol-gel techniques, spray coating
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
    • H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
    • H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
    • H01L21/31—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to form insulating layers thereon, e.g. for masking or by using photolithographic techniques; After treatment of these layers; Selection of materials for these layers
    • H01L21/314—Inorganic layers
    • H01L21/316—Inorganic layers composed of oxides or glassy oxides or oxide based glass
    • H01L21/31691—Inorganic layers composed of oxides or glassy oxides or oxide based glass with perovskite structure
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/02104—Forming layers
    • H01L21/02107—Forming insulating materials on a substrate
    • H01L21/02109—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates
    • H01L21/02112—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates characterised by the material of the layer
    • H01L21/02172—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates characterised by the material of the layer the material containing at least one metal element, e.g. metal oxides, metal nitrides, metal oxynitrides or metal carbides
    • H01L21/02197—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates characterised by the material of the layer the material containing at least one metal element, e.g. metal oxides, metal nitrides, metal oxynitrides or metal carbides the material having a perovskite structure, e.g. BaTiO3
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L28/00—Passive two-terminal components without a potential-jump or surface barrier for integrated circuits; Details thereof; Multistep manufacturing processes therefor
    • H01L28/40—Capacitors
    • H01L28/55—Capacitors with a dielectric comprising a perovskite structure material

Definitions

  • the field of the invention is that of thin layer oxides and more specifically oxides in the form of glass or ceramic obtained by sol gel processes.
  • the sol gel process makes it possible, from a colloidal solution based on metal alkoxides or silicon alkoxide, to manufacture powders or thin layers of oxides in the form of glass or ceramic. More precisely, the alkoxides are dissolved in a solvent, their hydrolysis leads to the condensation of polymer networks of oxides and hydroxides. However, it is not easy to control the rate and kinetics of hydrolysis when it comes to the synthesis of complex phases containing a large number of elements with different properties.
  • the cations are dissolved in a solution where polymerization (or maturation) is caused by the reaction of two organic compounds: acetylacetone (ACAC) and hexamethylenetetramine (HMTA). More precisely these two compounds brought into contact with hot acid lead to a polymeric species.
  • the assembly thus formed is therefore a binder comprising grains of metal oxides.
  • This resin can then be deposited on a substrate, to be brought to high temperature and lead to obtaining a ceramic in a thin layer.
  • the resin deposited on the substrate is first of all brought to a calcination temperature of the order of 500 ° C. During this operation, the solvent is evaporated and certain chemical species are calcined to obtain amorphous oxides.
  • a rapid annealing operation is then carried out at approximately 700 ° C. in order to obtain the desired crystalline phase from the corresponding ceramic.
  • the invention proposes to use a crosslinked resin, which can be calcined subsequently so as to reduce the stresses caused during this heating for the manufacture of ceramic or glass.
  • this crosslinked resin makes it possible to obtain very direct ceramic patterns of very small dimensions compared to the solutions of the prior art.
  • the resin disclosed in patent application No. 431999 can advantageously be exposed by ultraviolet radiation to result in a crosslinked resin whose performance is improved.
  • the invention more specifically relates to a crosslinked resin characterized in that it comprises a material obtained from the mixture of one or more simple or complex alkoxides of metal or silicon, acetylacetone and hexamethylene tetramine, then heating and exposure of said mixture.
  • the simple metal alkoxides are of the titanium alkoxide or zirconium alkoxide type.
  • the metal complex alkoxide is produced from lead carboxylate, from titanium alkoxide. and zirconium alkoxide.
  • the mixture also comprises photo-initiating agents to increase the performance of the crosslinked resin obtained.
  • These agents can in particular be radical photoinitiators of the Irgacure 184 or 1800 type from the company Ciba, or alternatively benzophenone or diphenylketone.
  • the solvent is of type 2 ethyl hexanol and / or acetic acid.
  • the subject of the invention is also a method of manufacturing a ceramic or a glass comprising:
  • the exposure of the photosensitive resin by ultraviolet radiation leads to a denser gel and therefore to thicker layers of glass or ceramic oxides than according to the prior art.
  • the substrate is glass.
  • Another subject of the invention is a process for manufacturing ceramic or glass patterns on the surface of a substrate, characterized in that:
  • the insolation is carried out through a mask so as to define insolated patterns and non-insolated patterns;
  • Ceramic patterns are used in particular in ferroelectric memory type applications, integrated capacitors, pyroelectric detectors for infrared imaging or detection, or else piezoelectric sensors and microsystems, etc.
  • the invention finally relates to components of the capacitor, piezoelectric transducer or ferroelectric memory type. obtained from the process for manufacturing a ceramic or a glass according to the invention.
  • a photosensitive resin can be deposited on the surface of a ceramic layer previously produced on the surface of a substrate.
  • the photosensitive resin is exposed through a substrate through a mask, then the insolated or non-insolated resin (depending on whether it is a negative or positive resin) is dissolved using a solvent.
  • Figure 1 illustrates the different stages of a photolithography process for defining ceramic patterns. More precisely, FIG. 1a represents a layer of ceramic 1 on a substrate 0, covered with a layer of photosensitive resin 2.
  • FIG. 1b shows diagrammatically the photosensitive resin 2 exposed through a mask 3. The exposed parts of the resin may become insoluble in certain solvents while the non-insoluble parts remain soluble in said solvents.
  • a mask is thus defined which makes it possible, for example, to engrave the unmasked parts of FIG. 1c, with an acid of HCI / HF type in the case of a thin layer of PZT, to obtain the patterns illustrated in FIG.
  • This chemical attack is isotropic and does not allow very fine resolution. Typically, it is difficult to produce patterns with a width of less than 10 ⁇ m.
  • the crosslinked resin according to the invention allows ceramic or glass patterns to be produced directly, bypassing the need to use a masking resin and an isotropic etching process.
  • FIG. 1a-1d illustrate the steps of the masking process according to the known art for defining ceramic patterns
  • FIG. 2a-2c illustrate the process steps according to the invention for defining ceramic patterns
  • FIGS. 3a and 3b illustrate a layer of metal oxides a few microns thick on a silicon substrate before and after sintering
  • FIG. 4a and 4b illustrate patterns of metal oxides a few microns thick on a silicon substrate before and after sintering, obtained according to the invention.
  • n zirconium butoxide 0.5 mole of n zirconium butoxide, and 0.5 mole of n titanium butoxide, are mixed at 60 ° C.
  • a heavy carboxylate, 2 ethyl hexanoate is chosen to obtain a resin sufficiently viscous for deposition on the substrate leading to sufficient thickness.
  • a solvent of heavy alcohol type for example 2 ethyl hexanol, to adjust the viscosity of said solution.
  • a solution A is thus obtained based on lead, zirconium, titanium and ACAC oxides.
  • HMTA hexamethylene tetramine
  • Solutions A and B are brought together and are heated to form the resin.
  • a PZT resin is thus obtained in which the grains of PZT oxides are taken up in a polymer matrix formed from HMTA and ACAC.
  • the resin 11 formed in step 3 may typically have a kinematic viscosity of the order of 25 centistokes and be deposited by conventional methods of centrifugation or soaking on the surface of a substrate 01 ( Figure 2a).
  • the resin is then exposed to the sun by ultraviolet radiation, typically at 335 nm, making it possible to densify the resin and make it insoluble in certain solvents, including 2 ethyl hexanol and / or dilute acetic acid.
  • the exposure can advantageously be carried out through a mechanical mask 31 so as to define soluble patterns 11 and insoluble patterns 12 in the resin layer (FIG. 2b).
  • the resin layers beyond a thickness of the order of 2 microns, deposited on plates of about 10 cm in diameter tend to fail during the sintering step due to the stresses generated between the layer and the substrate during the reduction in volume linked to the passage of a porous gel to a dense oxide .
  • the substrate may tend to bend.
  • the initial gel is denser due to ultraviolet radiation
  • the surface under which these stresses are exerted is lower and these can relax on the edges of the pattern as illustrated in Figures 3 and 4 which respectively represent Figures 3a and 3b an oxide layer 13 of a few microns on a substrate silicon 03 before sintering and after sintering and Figures 4a and 4b of the oxide patterns 14 previously made a few microns thick on a silicon substrate 04 before sintering and after sintering.
  • the ceramic patterns thus defined without deformation can have dimensions less than a few microns as well as dimensions of a few tens or even a few hundred microns.
  • the photolithography, sunstroke and dissolution stages allow in particular the production of very fine patterns, unlike the isotropic chemical etching operations of ceramic of the prior art.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Manufacturing & Machinery (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Power Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Materials Engineering (AREA)
  • Glass Compositions (AREA)
  • Formation Of Insulating Films (AREA)

Abstract

The invention concerns a crosslinked resin and its use for making ceramic or glass patterns at the surface of a substrate. Said resin is obtained by mixing in a solvent one or several simple or complex metal or silicon alkoxides, acetylacetone and hexamethylene tetramine, then heating and subjecting said mixture to an exposure. The invention is applicable to ferroelectric storage units, integrated capacitors, piezoelectric transducers.

Description

RESINE RETICULEE ET PROCEDE DE FABRICATION D'OXYDES UTILISANT CETTE RESINE RETICULEE CROSSLINKED RESIN AND PROCESS FOR PRODUCING OXIDES USING THE CROSSLINKED RESIN
Le domaine de l'invention est celui des oxydes en couche mince et plus précisément des oxydes sous forme de verre ou de céramique obtenus par des procédés sol gel.The field of the invention is that of thin layer oxides and more specifically oxides in the form of glass or ceramic obtained by sol gel processes.
De manière classique, le procédé sol gel permet à partir d'une solution colloïdale à base d'alcoxydes métalliques ou d'alcoxyde de silicium de fabriquer des poudres ou des couches minces d'oxydes sous forme de verre ou de céramique. Plus précisément les alcoxydes sont mis en solution dans un solvant, leur hydrolyse mène à la condensation de réseaux polymériques d'oxydes et d'hydroxydes. Néanmoins, il n'est pas évident de contrôler le taux et la cinétique d'hydrolyse lorsqu'il s'agit de la synthèse de phases complexes contenant un grand nombre d'éléments aux propriétés différentes.Conventionally, the sol gel process makes it possible, from a colloidal solution based on metal alkoxides or silicon alkoxide, to manufacture powders or thin layers of oxides in the form of glass or ceramic. More precisely, the alkoxides are dissolved in a solvent, their hydrolysis leads to the condensation of polymer networks of oxides and hydroxides. However, it is not easy to control the rate and kinetics of hydrolysis when it comes to the synthesis of complex phases containing a large number of elements with different properties.
On peut difficilement contrôler à la fois l'homogénéité chimique que permet l'abaissement de la température de synthèse et la rhéologie souhaitable pour l'obtention d'un dépôt en couche mince.It is difficult to control both the chemical homogeneity that allows the lowering of the synthesis temperature and the rheology desirable for obtaining a thin layer deposit.
Il est possible de modifier la viscosité et l'élasticité des solutions préparées par ajout d'agents tels que des polyalcools, des polyacides conduisant à des résines polymères. Cependant ces additifs ne sont pas forcément compatibles avec les cations et conduisent à des solutions dont l'adhérence sur des substrats n'est pas bien adaptée à des dépôts par centrifugation ou par trempage sur des substrats. Dans ce contexte, la demanderesse a déposé une demande de brevet publiée sous le numéro 431999 proposant un procédé de dépôt d'une composition céramique en couche mince à partir d'une solution homogène dont la rhéologie peut être adaptée au dépôt par centrifugation ou par trempage. Les cations sont solubilisés dans une solution où une polymérisation (ou maturation) est provoquée par la réaction de deux composés organiques : l'acétylacétone (ACAC) et l'hexaméthylènetétramine (HMTA). Plus précisément ces deux composés mis en présence à chaud d'un acide conduisent à une espèce polymérique. L'ensemble ainsi constitué est donc un liant comprenant des grains d'oxydes métalliques.It is possible to modify the viscosity and the elasticity of the solutions prepared by adding agents such as polyalcohols, polyacids leading to polymer resins. However, these additives are not necessarily compatible with cations and lead to solutions whose adhesion to substrates is not well suited to deposits by centrifugation or by soaking on substrates. In this context, the applicant has filed a patent application published under number 431999 proposing a method for depositing a ceramic composition in a thin layer from a homogeneous solution, the rheology of which can be adapted to deposit by centrifugation or by soaking. . The cations are dissolved in a solution where polymerization (or maturation) is caused by the reaction of two organic compounds: acetylacetone (ACAC) and hexamethylenetetramine (HMTA). More precisely these two compounds brought into contact with hot acid lead to a polymeric species. The assembly thus formed is therefore a binder comprising grains of metal oxides.
Cette résine peut ensuite être déposée sur un substrat, pour être portée à haute température et conduire à l'obtention d'une céramique en couche mince.This resin can then be deposited on a substrate, to be brought to high temperature and lead to obtaining a ceramic in a thin layer.
Plus précisément la résine déposée sur le substrat est tout d'abord portée à une température de calcination de l'ordre de 500° C. Lors de cette opération on évapore le solvant et l'on calcine certaines espèces chimiques pour obtenir des oxydes amorphes.More precisely, the resin deposited on the substrate is first of all brought to a calcination temperature of the order of 500 ° C. During this operation, the solvent is evaporated and certain chemical species are calcined to obtain amorphous oxides.
On procède alors à une opération de recuit rapide à environ 700° C pour obtenir la phase cristalline désirée de la céramique correspondante.A rapid annealing operation is then carried out at approximately 700 ° C. in order to obtain the desired crystalline phase from the corresponding ceramic.
Durant l'opération de calcination on génère de nombreuses contraintes dues à l'évaporation du solvant et à la calcination de certains composés.During the calcination operation, numerous stresses are generated due to the evaporation of the solvent and the calcination of certain compounds.
L'invention propose d'utiliser une résine réticulée, pouvant être calcinée ultérieurement de manière à réduire les contraintes occasionnées lors de ce chauffage pour la fabrication de céramique ou de verre. De plus cette résine réticulée permet d'obtenir de manière très directe des motifs céramiques de très petites dimensions par rapport aux solutions de l'art antérieur.The invention proposes to use a crosslinked resin, which can be calcined subsequently so as to reduce the stresses caused during this heating for the manufacture of ceramic or glass. In addition, this crosslinked resin makes it possible to obtain very direct ceramic patterns of very small dimensions compared to the solutions of the prior art.
En effet la résine divulguée dans la demande de brevet N° 431999 peut avantageusement être insolée par rayonnement ultraviolet pour conduire à une résine réticulée dont les performances sont améliorées.Indeed, the resin disclosed in patent application No. 431999 can advantageously be exposed by ultraviolet radiation to result in a crosslinked resin whose performance is improved.
C'est pourquoi l'invention a plus précisément pour objet une résine réticulée caractérisée en ce qu'elle comprend un matériau obtenu à partir du mélange d'un ou plusieurs alcoxydes simples ou complexes de métal ou de silicium, d'acétylacetone et d'hexaméthylène tetramine, puis chauffage et insolation dudit mélange.This is why the invention more specifically relates to a crosslinked resin characterized in that it comprises a material obtained from the mixture of one or more simple or complex alkoxides of metal or silicon, acetylacetone and hexamethylene tetramine, then heating and exposure of said mixture.
Selon une variante de l'invention, les alcoxydes simples métalliques sont de type alcoxyde de titane ou alcoxyde de zirconium.According to a variant of the invention, the simple metal alkoxides are of the titanium alkoxide or zirconium alkoxide type.
Selon une autre variante de l'invention, l'alcoxyde complexe métallique est élaboré à partir de carboxylate de plomb, d'alcoxyde de titane. et d'alcoxyde de zirconium. Selon une variante de l'invention, le mélange comprend en outre des agents photo-initiateurs pour augmenter les performances de la résine réticulée obtenue.According to another variant of the invention, the metal complex alkoxide is produced from lead carboxylate, from titanium alkoxide. and zirconium alkoxide. According to a variant of the invention, the mixture also comprises photo-initiating agents to increase the performance of the crosslinked resin obtained.
Ces agents peuvent être notamment des photo-initiateurs radicalaires de type l'Irgacure 184 ou 1800 de la société Ciba, ou bien encore de la benzophénone ou de la diphenylcétone.These agents can in particular be radical photoinitiators of the Irgacure 184 or 1800 type from the company Ciba, or alternatively benzophenone or diphenylketone.
Selon une variante de l'invention le solvant est de type 2 éthyl hexanol et/ou acide acétique.According to a variant of the invention, the solvent is of type 2 ethyl hexanol and / or acetic acid.
L'invention a aussi pour objet un procédé de fabrication d'une céramique ou d'un verre comprenant :The subject of the invention is also a method of manufacturing a ceramic or a glass comprising:
- la réalisation d'une solution d'alcoxydes métalliques dans de l'acétylacétone ;- the production of a solution of metal alkoxides in acetylacetone;
- l'obtention d'une résine photosensible par réaction à chaud d'un acide et d'hexaméthylène tetramine avec ladite solution ; - le dépôt de la résine photosensible sur un substrat ;- Obtaining a photosensitive resin by hot reaction of an acid and hexamethylene tetramine with said solution; - depositing the photosensitive resin on a substrate;
- l'insolation de la résine photosensible par un rayonnement ultraviolet ;- exposure of the photosensitive resin by ultraviolet radiation;
- la calcination de la résine réticulée.- calcination of the crosslinked resin.
L'insolation de la résine photosensible par rayonnement ultraviolet conduit à un gel plus dense et donc à des couches d'oxydes de verre ou de céramique plus épaisses que selon l'art antérieur.The exposure of the photosensitive resin by ultraviolet radiation leads to a denser gel and therefore to thicker layers of glass or ceramic oxides than according to the prior art.
Selon une variante de l'invention le substrat est du verre. L'invention a encore pour objet un procédé de fabrication de motifs céramique ou de verre à la surface d'un substrat, caractérisé en ce que :According to a variant of the invention the substrate is glass. Another subject of the invention is a process for manufacturing ceramic or glass patterns on the surface of a substrate, characterized in that:
- l'insolation est effectuée au travers d'un masque de manière à définir des motifs insolés et des motifs non insolés ;- the insolation is carried out through a mask so as to define insolated patterns and non-insolated patterns;
- il comprend la dissolution des motifs non insolés dans un solvant. De tels motifs céramiques sont notamment utilisés dans des applications de type mémoires ferroélectriques, condensateurs intégrés, détecteurs pyro-électriques pour l'imagerie ou la détection infrarouge, ou bien encore capteurs et microsystèmes piézo-électriques etc..- It includes the dissolution of non-insolated patterns in a solvent. Such ceramic patterns are used in particular in ferroelectric memory type applications, integrated capacitors, pyroelectric detectors for infrared imaging or detection, or else piezoelectric sensors and microsystems, etc.
C'est pourquoi l'invention a enfin pour objet des composants de type condensateur, transducteur piézoélectrique ou mémoire ferroélectrique obtenus à partir du procédé de fabrication d'une céramique ou d'un verre selon l'invention.This is why the invention finally relates to components of the capacitor, piezoelectric transducer or ferroelectric memory type. obtained from the process for manufacturing a ceramic or a glass according to the invention.
Selon l'art antérieur, il est possible de déposer une couche d'oxyde à la surface d'un substrat au moyen de procédés de type pulvérisation cathodique ou procédé de dépôt chimique en phase vapeur d'organo-métalliques (MOCVD), puis de définir des motifs sur ladite couche d'oxyde au moyen de procédés de photolithographie classiques.According to the prior art, it is possible to deposit an oxide layer on the surface of a substrate by means of cathodic sputtering type processes or chemical organic metal vapor deposition (MOCVD) process, then defining patterns on said oxide layer using conventional photolithography methods.
Ainsi, on peut déposer une résine photosensible à la surface d'une couche de céramique préalablement réalisée à la surface d'un substrat. On insole au travers d'un substrat ladite résine photosensible au travers d'un masque, puis on dissout la résine insolée ou non insolée (selon qu'il s'agit d'une résine négative ou positive) à l'aide d'un solvant. La Figure 1 illustre les différentes étapes d'un procédé de photolithographie permettant de définir des motifs céramiques. Plus précisément la Figure 1 a représente une couche de céramique 1 sur un substrat 0, recouvert d'une couche de résine photosensible 2. La Figure 1b schématise la résine photosensible 2 insolée au travers d'un masque 3. Les parties insolées de la résine peuvent devenir insolubles dans certains solvants alors que les parties non insolées demeurent solubles dans lesdits solvants. On définit ainsi un masque permettant par exemple de graver les parties non masquées de la Figure 1c, par un acide de type HCI/HF dans le cas de couche fine de PZT, pour obtenir les motifs illustrés en Figure 1d. Cette attaque chimique est isotrope et n'autorise pas une résolution très fine. Typiquement il est difficile de réaliser des motifs d'une largeur inférieure à 10 μm.Thus, a photosensitive resin can be deposited on the surface of a ceramic layer previously produced on the surface of a substrate. The photosensitive resin is exposed through a substrate through a mask, then the insolated or non-insolated resin (depending on whether it is a negative or positive resin) is dissolved using a solvent. Figure 1 illustrates the different stages of a photolithography process for defining ceramic patterns. More precisely, FIG. 1a represents a layer of ceramic 1 on a substrate 0, covered with a layer of photosensitive resin 2. FIG. 1b shows diagrammatically the photosensitive resin 2 exposed through a mask 3. The exposed parts of the resin may become insoluble in certain solvents while the non-insoluble parts remain soluble in said solvents. A mask is thus defined which makes it possible, for example, to engrave the unmasked parts of FIG. 1c, with an acid of HCI / HF type in the case of a thin layer of PZT, to obtain the patterns illustrated in FIG. This chemical attack is isotropic and does not allow very fine resolution. Typically, it is difficult to produce patterns with a width of less than 10 μm.
La résine réticulée selon l'invention permet de réaliser directement des motifs céramique ou verre, en s'affranchissant de la nécessité d'utiliser une résine de masquage et un procédé de gravure isotrope.The crosslinked resin according to the invention allows ceramic or glass patterns to be produced directly, bypassing the need to use a masking resin and an isotropic etching process.
L'invention sera mieux comprise et d'autres avantages apparaîtront à la lecture de la description qui va suivre donnée à titre non limitatif et grâce aux figures annexées parmi lesquelles :The invention will be better understood and other advantages will appear on reading the description which follows given without limitation and thanks to the appended figures among which:
- les Figures 1a-1d illustrent les étapes de procédé de masquage selon l'art connu pour définir des motifs céramiques ; - les Figures 2a-2c , illustrent les étapes de procédé selon l'invention pour définir des motifs céramiques ;- Figures 1a-1d illustrate the steps of the masking process according to the known art for defining ceramic patterns; - Figures 2a-2c illustrate the process steps according to the invention for defining ceramic patterns;
- les Figures 3a et 3b, illustrent une couche d'oxydes métalliques de quelques microns d'épaisseur sur un substrat silicium avant et après frittage ;- Figures 3a and 3b illustrate a layer of metal oxides a few microns thick on a silicon substrate before and after sintering;
- les Figures 4a et 4b illustrent des motifs d'oxydes métalliques de quelques microns d'épaisseur sur un substrat silicium avant et après frittage, obtenus selon l'invention.- Figures 4a and 4b illustrate patterns of metal oxides a few microns thick on a silicon substrate before and after sintering, obtained according to the invention.
Nous allons décrire l'invention dans le cadre d'un exemple d'oxyde de plomb, de zirconium et de titane (PZT) mais l'invention s'applique tout aussi bien à la fabrication de silice, ou d'oxydes réfractaires de type Ti02, Zi02...We will describe the invention in the context of an example of lead, zirconium and titanium oxide (PZT) but the invention applies equally well to the manufacture of silica, or of refractory oxides of the type Ti0 2 , Zi0 2 ...
Première étape :First stage :
Elaboration d'une solution A à base d'alcoxydes métalliquesDevelopment of a solution A based on metal alkoxides
1 mole de 2 éthyl-hexanoate de plomb1 mole of 2 lead ethyl hexanoate
0,5 mole de n butoxyde de zirconium, et 0,5 mole de n butoxyde de titane, sont mélangés à 60° C. on choisit un carboxylate lourd, le 2 éthyl-hexanoate pour obtenir une résine suffisamment visqueuse pour un dépôt sur le substrat conduisant à une épaisseur suffisante.0.5 mole of n zirconium butoxide, and 0.5 mole of n titanium butoxide, are mixed at 60 ° C. a heavy carboxylate, 2 ethyl hexanoate, is chosen to obtain a resin sufficiently viscous for deposition on the substrate leading to sufficient thickness.
Le mélange précédent est mis en présence d'acétylacetone à raison d'1 mole d'ACAC par mole de Pb.The above mixture is placed in the presence of acetylacetone at a rate of 1 mole of ACAC per mole of Pb.
On peut avantageusement y ajouter un solvant de type alcool lourd par exemple du 2 éthyl-hexanol pour ajuster la viscosité de ladite solution.It is advantageous to add thereto a solvent of heavy alcohol type, for example 2 ethyl hexanol, to adjust the viscosity of said solution.
On obtient ainsi une solution A à base d'oxydes de plomb, de zirconium, de titane et d'ACAC.A solution A is thus obtained based on lead, zirconium, titanium and ACAC oxides.
Deuxième- étape :Second step :
Réalisation d'une solution B à base d'HMTACreation of a solution B based on HMTA
Parallèlement on réalise le mélange de 0,5 mole d'hexaméthylène tetramine (HMTA) en présence de 100 cm3 d'acide acétique à 60° C. Il est tout aussi possible de remplacer l'acide acétique, par de l'acide propanoïque ou de l'acide trifluoroacétique.At the same time, a mixture of 0.5 mol of hexamethylene tetramine (HMTA) is produced in the presence of 100 cm 3 of acetic acid at 60 ° C. It is just as possible to replace acetic acid, by propanoic acid or trifluoroacetic acid.
Troisième étape : Réalisation d'une résine photosensible à base d'alcoxydes métalliquesThird step: Realization of a photosensitive resin based on metal alkoxides
Les solutions A et B sont mises en présence et sont chauffées pour former la résine.Solutions A and B are brought together and are heated to form the resin.
Typiquement on peut chauffer à 118° C durant environ 15 minutes. Plus la température est élevée plus la résine est visqueuse.Typically, it can be heated to 118 ° C for about 15 minutes. The higher the temperature, the more viscous the resin.
On obtient ainsi une résine de PZT dans laquelle les grains d'oxydes PZT sont pris dans une matrice polymère formée à partir de HMTA et d'ACAC.A PZT resin is thus obtained in which the grains of PZT oxides are taken up in a polymer matrix formed from HMTA and ACAC.
Quatrième étape :Fourth step:
Insolation de la résine photosensible pour former la résine réticuléeExposure of the photosensitive resin to form the crosslinked resin
La résine 11 formée en étape 3 peut typiquement avoir une viscosité cinématique de l'ordre de 25 centistokes et être déposée par des méthodes classiques de centrifugation ou de trempage à la surface d'un substrat 01 (Figure 2a).The resin 11 formed in step 3 may typically have a kinematic viscosity of the order of 25 centistokes and be deposited by conventional methods of centrifugation or soaking on the surface of a substrate 01 (Figure 2a).
On procède alors à l'insolation de la résine par un rayonnement ultraviolet typiquement à 335 nm permettant de, densifier la résine et la rendre insoluble à certains solvants dont le 2 éthyl hexanol et/ou acide acétique dilué.The resin is then exposed to the sun by ultraviolet radiation, typically at 335 nm, making it possible to densify the resin and make it insoluble in certain solvents, including 2 ethyl hexanol and / or dilute acetic acid.
L'insolation peut avantageusement être réalisée au travers d'un masque mécanique 31 de manière à définir des motifs solubles 11 et des motifs insolubles 12 dans la couche de résine (Figure 2b).The exposure can advantageously be carried out through a mechanical mask 31 so as to define soluble patterns 11 and insoluble patterns 12 in the resin layer (FIG. 2b).
Il est particulièrement intéressant de définir les motifs d'oxydes préalablement à l'étape de cuisson ou frittage correspondant à la densification. Les motifs solubles dans du 2 éthyl hexanol et/ou acide acétique sont ensuite éliminés pour ne laisser en place que les motifs insolubles 12 (Figure 2c).It is particularly advantageous to define the patterns of oxides prior to the cooking or sintering step corresponding to the densification. The units soluble in 2 ethyl hexanol and / or acetic acid are then eliminated to leave in place only the insoluble units 12 (Figure 2c).
En effet selon les procédés de l'art antérieur, les couches de résine au-delà d'une épaisseur de l'ordre de 2 microns, déposées sur des plaques d'environ 10 cm de diamètre par exemple ont tendance à failler lors de l'étape de frittage en raison des contraintes générées entre la couche et le substrat lors de la diminution de volume lié au passage d'un gel poreux à un oxyde dense. Pour les mêmes raisons, le substrat peut avoir tendance à fléchir.Indeed according to the methods of the prior art, the resin layers beyond a thickness of the order of 2 microns, deposited on plates of about 10 cm in diameter for example tend to fail during the sintering step due to the stresses generated between the layer and the substrate during the reduction in volume linked to the passage of a porous gel to a dense oxide . For the same reasons, the substrate may tend to bend.
Lorsque les motifs sont définis photochimiquement dans la couche de résine avant frittage, les contraintes sont diminuées pour deux raisons :When the patterns are photochemically defined in the resin layer before sintering, the constraints are reduced for two reasons:
- le gel initial est plus dense du fait du rayonnement ultraviolet ;- the initial gel is denser due to ultraviolet radiation;
- la surface sous laquelle s'exercent ces contraintes est plus faible et celles-ci peuvent relaxer sur les bords du motif comme illustré en Figures 3 et 4 qui représentent respectivement Figures 3a et 3b une couche d'oxyde 13 de quelques microns sur un substrat silicium 03 avant frittage et après frittage et Figures 4a et 4b des motifs d'oxydes 14 préalablement réalisés de quelques microns d'épaisseur sur un substrat silicium 04 avant frittage et après frittage. Typiquement les motifs céramiques ainsi définis sans déformation, peuvent avoir aussi bien des dimensions inférieures à quelques microns que des dimensions de quelques dizaines voir quelques centaines de microns. En effet selon l'invention les étapes de photolithographie, insolation puis dissolution permettent notamment l'obtention de motifs très fins contrairement aux opérations de gravure chimique isotrope de céramique de l'art antérieur. - The surface under which these stresses are exerted is lower and these can relax on the edges of the pattern as illustrated in Figures 3 and 4 which respectively represent Figures 3a and 3b an oxide layer 13 of a few microns on a substrate silicon 03 before sintering and after sintering and Figures 4a and 4b of the oxide patterns 14 previously made a few microns thick on a silicon substrate 04 before sintering and after sintering. Typically the ceramic patterns thus defined without deformation, can have dimensions less than a few microns as well as dimensions of a few tens or even a few hundred microns. In fact, according to the invention, the photolithography, sunstroke and dissolution stages allow in particular the production of very fine patterns, unlike the isotropic chemical etching operations of ceramic of the prior art.

Claims

REVENDICATIONS
1. Résine réticulée caractérisée en ce qu'elle comprend un matériau obtenu à partir du mélange d'au moins, un ou plusieurs alcoxydes simples ou complexes de métal ou de silicium, de l'acétylacetone, de l'hexaméthylène tetramine et d'un acide, puis chauffage et insolation dudit mélange.1. Crosslinked resin characterized in that it comprises a material obtained from the mixture of at least one or more simple or complex alkoxides of metal or silicon, acetylacetone, hexamethylene tetramine and a acid, then heating and exposure of said mixture.
2. Résine réticulée selon la revendication 1 , caractérisée en ce que l'alcoxyde métallique est de type alcoxyde de titane.2. Crosslinked resin according to claim 1, characterized in that the metal alkoxide is of the titanium alkoxide type.
3. Résine réticulée selon la revendication 2, caractérisée en ce que l'alcoxyde métallique est de type alcoxyde de zirconium.3. Crosslinked resin according to claim 2, characterized in that the metal alkoxide is of the zirconium alkoxide type.
4. Résine réticulée selon la revendication 1 , caractérisée en ce qu'elle comprend un alcoxyde complexe de plomb/zirconium et titane.4. Crosslinked resin according to claim 1, characterized in that it comprises a complex alkoxide of lead / zirconium and titanium.
5. Résine réticulée selon la revendication 4, caractérisée en ce que l'alcoxyde complexe de plomb, zirconium et titane est obtenu à partir de carboxylate de plomb, d'alcoxyde de zirconium et d'alcoxyde de titane.5. Crosslinked resin according to claim 4, characterized in that the complex alkoxide of lead, zirconium and titanium is obtained from lead carboxylate, zirconium alkoxide and titanium alkoxide.
6. Résine réticulée selon l'une des revendications 1 à 5, caractérisée en ce que l'acide est de l'acide acétique.6. Crosslinked resin according to one of claims 1 to 5, characterized in that the acid is acetic acid.
7. Résine réticulée selon l'une des revendications 1 à 5, caractérisée en ce que l'acide est de l'acide propanoïque.7. Crosslinked resin according to one of claims 1 to 5, characterized in that the acid is propanoic acid.
8. Résine réticulée selon l'une des revendications 1 à 5, caractérisée en ce que l'acide est de l'acide trifluoroacétique.8. Crosslinked resin according to one of claims 1 to 5, characterized in that the acid is trifluoroacetic acid.
9. Résine réticulée selon l'une des revendications 1 à 8, caractérisée en ce qu'elle comprend en outre au moins un agent photo-initiateur. 9. Crosslinked resin according to one of claims 1 to 8, characterized in that it further comprises at least one photo-initiating agent.
10. Procédé de fabrication d'une céramique ou d'un verre comprenant :10. A method of manufacturing a ceramic or a glass comprising:
- la réalisation d'une solution d'alcoxydes simples ou complexes métalliques ou de silicium dans de l'acétylacetone ; - l'obtention d'une résine par réaction à chaud d'un acide et d'hexaméthylène tetramine à ladite solution ;- the production of a solution of simple or complex metal or silicon alkoxides in acetylacetone; - Obtaining a resin by hot reaction of an acid and hexamethylene tetramine to said solution;
- le dépôt de la résine sur un substrat ;- depositing the resin on a substrate;
- l'insolation de la résine par un rayonnement ultraviolet ;- exposure of the resin by ultraviolet radiation;
- la calcination de la résine insolée, pour obtenir la céramique ou le verre.- calcination of the exposed resin, to obtain the ceramic or the glass.
11. Procédé de fabrication d'une céramique ou d'un verre selon la revendication 10, caractérisé en ce que la solution d'alcoxydes simples ou complexes métalliques ou de silicium est réalisée en présence d'un alcool lourd, de type 2 éthyl-hexanol.11. A method of manufacturing a ceramic or a glass according to claim 10, characterized in that the solution of simple or complex metal or silicon alkoxides is carried out in the presence of a heavy alcohol, type 2 ethyl- hexanol.
12. Procédé de fabrication de céramique ou de verre selon l'une des revendications 10 ou 11 , caractérisé en ce que les alcoxydes simples métalliques sont de l'alcoxyde de zirconium ou de l'alcoxyde de titane.12. A method of manufacturing ceramic or glass according to one of claims 10 or 11, characterized in that the simple metal alkoxides are zirconium alkoxide or titanium alkoxide.
13. Procédé de fabrication de céramique ou de verre selon l'une des revendications 10 ou 11 , caractérisé en ce qu'il comprend une étape d'élaboration d'alcoxyde métallique complexe à partir de carboxylate de plomb, d'alcoxyde de zirconium et d'alcoxyde de titane.13. A method of manufacturing ceramic or glass according to one of claims 10 or 11, characterized in that it comprises a step of preparation of complex metal alkoxide from lead carboxylate, zirconium alkoxide and titanium alkoxide.
14. Procédé de fabrication de motifs céramique ou de verre à la surface d'un substrat selon l'une des revendications 10 à 13, caractérisé en ce que :14. Method for manufacturing ceramic or glass patterns on the surface of a substrate according to one of claims 10 to 13, characterized in that:
- l'insolation est effectuée au travers d'un masque de manière à définir des motifs insolés et des motifs non insolés ;- the insolation is carried out through a mask so as to define insolated patterns and non-insolated patterns;
- il comprend la dissolution des motifs non insolés dans un solvant. - It includes the dissolution of non-insolated patterns in a solvent.
15. Procédé de fabrication de motifs céramique ou de verre selon la revendication 14, caractérisé en ce que le solvant est de type 2 éthyl hexanol et/ou acide acétique dilué.15. A method of manufacturing ceramic or glass patterns according to claim 14, characterized in that the solvent is of type 2 ethyl hexanol and / or dilute acetic acid.
16. Procédé de fabrication d'une céramique ou d'un verre selon l'une des revendications 10 à 15, caractérisé en ce que le substrat est du verre.16. A method of manufacturing a ceramic or a glass according to one of claims 10 to 15, characterized in that the substrate is glass.
17. Procédé de fabrication d'une céramique ou d'un verre selon l'une des revendications 10 à 15, caractérisé en ce que le substrat est du silicium.17. A method of manufacturing a ceramic or a glass according to one of claims 10 to 15, characterized in that the substrate is silicon.
18. Condensateur caractérisé en ce qu'il est obtenu à partir du procédé de fabrication d'une céramique ou d'un verre selon l'une des revendications 10 à 15.18. Capacitor characterized in that it is obtained from the process for manufacturing a ceramic or a glass according to one of claims 10 to 15.
19. Transducteur piézo-électrique caractérisé en ce qu'il est obtenu à partir du procédé de fabrication d'une céramique ou d'un verre selon l'une des revendications 10 à 15.19. Piezoelectric transducer characterized in that it is obtained from the process for manufacturing a ceramic or a glass according to one of claims 10 to 15.
20. Mémoire ferroélectrique caractérisée en ce qu'elle est obtenue à partir du procédé de fabrication d'une céramique ou d'un verre selon l'une des revendications 10 à 15. 20. Ferroelectric memory characterized in that it is obtained from the process for manufacturing a ceramic or a glass according to one of claims 10 to 15.
EP01954061A 2000-07-07 2001-07-06 Crosslinked resin and method for making oxides using same Withdrawn EP1230674A1 (en)

Applications Claiming Priority (3)

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FR0008920A FR2811317B1 (en) 2000-07-07 2000-07-07 CROSSLINKED RESIN AND PROCESS FOR PRODUCING OXIDES USING THE CROSSLINKED RESIN
FR0008920 2000-07-07
PCT/FR2001/002189 WO2002005340A1 (en) 2000-07-07 2001-07-06 Crosslinked resin and method for making oxides using same

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