EP0934553A1

EP0934553A1 - Method to prepare the production of structured metal coatings using proteins

Info

Publication number: EP0934553A1
Application number: EP97945795A
Authority: EP
Inventors: Stefan Fiedler; Dieter Oesterhelt; Heinrich Meyer; Wolfgang Scheel; Herbert Reichl
Original assignee: Fraunhofer Gesellschaft zur Forderung der Angewandten Forschung eV
Current assignee: Fraunhofer Gesellschaft zur Forderung der Angewandten Forschung eV; Atotech Deutschland GmbH and Co KG
Priority date: 1996-10-25
Filing date: 1997-10-27
Publication date: 1999-08-11
Also published as: DE19747377A1; US6197387B1; WO1998019217A1

Abstract

The aim of the invention is to produce thin metal coatings and such structures on substrate supports of different structures. The lateral expansion of a metallic coating on each support can be predetermined with micrometer and submicrometer precision. The disclosed method enables flat and three-dimensional structures to be produced on smooth, planar or curved surfaces such as those required to reproduce letters or drawings. The method does not use any stamp printing techniques.

Description

Process for preparing the production of structured metal layers with the help of proteins

The invention relates to the production of thin metallic layers and structures on substrate carriers with a planar or three-dimensional structure, such as are required, for example, for imaging lettering or drawings. The process avoids stamp printing techniques.

The field of application of the described invention relates to the

Manufacture of finely structured elements on decorative foils or other thin or thick materials that are flexible or rigid at room temperature. Such materials provided with thin metal layers are usually used as packaging material or for other decorative purposes, as advertising media, in optical signal and information processing or in semiconductor technology and microelectronics as printed circuit board and IC chip material or for rewiring e.g. usable on semiconductor substrates.

State of the art, disadvantages of the prior art:

Known methods and processes for producing such metallic structures on the materials mentioned can be roughly classified into basic types. The division into direct and indirect methods here relates to the first electrically conductive layer, which is structured or applied in a structured manner on a substrate with significantly lower conductivity. The known processes work either directly and subtractively (e.g. laser-induced blation), directly and additively (chemical deposition from the gas phase - CVD, also laser-induced) or indirectly and with the help of a complex combination of different process steps from the range of microlithographic structuring processes (e.g.

Etching process in aqueous or gas phase). These processes are widely used in semiconductor technology. Those techniques that use only a few process steps are based on a closed metal layer or a closed metal film on the respective substrate. These can be, for example, layers obtained by lamination for thick layers (> 5 μm) or chemical and physical vapor deposition processes or combinations thereof for thin layers. The latter typically require vacuum conditions and high voltages or chemically aggressive gases and reagents.

After covering the areas (structural elements) that are to be retained because required (structural elements) with a protective layer, a part corresponding to the negative image of the desired image is removed by etching from a closed metal pad, however produced. (See:

Menz, W .; Bley, P. (1993) Microsystem Technology for Engineers, Weinheim, New York, Basel, Cambridge: VCH). Coarser structures can be obtained by simply cutting or punching them out of a metal foil and gluing them to the corresponding surface.

Likewise, starting from a closed metallic layer by masking with opaque lacquer or paint, the negative image can be concealed, overprinted, pasted over or - covered differently, while the image elements stand out clearly in a metallic sheen. The latter technique limits the applicability of the created patterns and structures solely for decoration and packaging purposes.

The technically usable generation of complex metallic

Structures in the micrometer and submicrometer range by means of a direct lamination or sputtering process are not known. However, laser-induced chemical deposition can produce high-resolution planar and even three-dimensional metallic structures on different materials (laser-assisted deposition - LAD, synonymous chemical vapor deposition - CVD). However, as mentioned, these processes are subject to special pressure or atmospheric conditions and are reserved for the production of small series up to lot size 1.

Combined methods can also be used. These are either printing processes, such as screen printing techniques, in which a metal paste containing auxiliary substances is applied to the material and then attached to the substrate surface by remelting at an elevated temperature (about 200 - over 800 degrees Celsius). The resolution (smallest structure width) of such processes and thus the quality of the images obtained is limited. The relatively high temperature required for the remelting process for pastes to produce metallizations that can be subjected to permanent loads limits the range of materials usable here to correspondingly stable materials, such as ceramics and glasses.

Stamp printing and molding techniques have successfully found their way into the range of microstructuring processes via the LIGA technique (Becker, E.W., et al., Microelectronic Engineering 4: 35-56 (1986)). They are embedded in a complex cascade of individual steps. Their highest lateral resolution is also limited to structure widths in the m range due to the stamp materials to be used.

A method using stamp impressions was presented by a working group led by Hockberger for finely structured biomolecule deposition on glass surfaces for the purpose of cell growth control (Soekarno, A. et al.,

Neuroimage, 1, 129-144 (1994); Lom, B., et al. , J. Neuroscience Methods, 50, 385-397 (1993)). A microlithographically created stamp can be used to make chemical surface modifications with a lateral resolution in the μm range. Using a mask-based photochemical activation process - Pritchard et al. (Angew. Chemie, 107, 84-86 (1995)) Protein web widths of 1.5 μm on a SiO 2 surface.

The separation of inorganic molecules and their ordered landfill in crystalline form is a principle used in biology by "primitive" microorganisms. Highly developed beings provide themselves in the same way with a protective shell, a supporting skeleton or teeth. The use of these principles for technical applications is u. a. by Mann et al. (Science 261, 1286-1292 (1993)). The authors mentioned above also present a method of iron oxide enrichment on ferritin monolayers. However, the known methods have not hitherto led to the crystallization of metals at locally limited deposition locations specified by proteins.

Metallizations of supramolecular lipid structures are also known. It was possible to superficial metallize helical superstructures (Schnur, J.M., Science 262, 1669-1676 (1993)).

It is the object of the present invention to provide a method in which the necessary metallic, already reduced or reducible material is selectively and very precisely at the location of the deposition to produce laterally very finely structurable metallic layers on any materials with a flat or three-dimensional surface can be brought. The use of environmentally harmful components should preferably be avoided.

The object is achieved in that a layer consisting of or containing proteins is applied to the substrate to be coated, the layer or proteins under exposure to light (exposure to light) in a corresponding environment causing a vectorial gradient of a physical or chemical property between two builds up the layer formed compartments and the resulting change in the physical or chemical property in one of the two compartments causes metal ions to be reduced to metal or accessible for later reduction, after which the substrate provided with the proteinaceous layer is exposed at those locations where the metal is to be deposited (positive exposure), or the change in property mentioned causes an already existing metal deposit on the exposed areas of the layer to be removed (etched away) (negative exposure).

The subclaims relate to preferred configurations of the

Invention.

The proteins used according to the invention are those which as

“Pump” can act to build up a gradient of a physical or chemical property directed against the usually established equilibrium. The "property" can be physical, e.g. on

Electron gradient, but is preferably chemical in nature.

Examples of chemical gradients are pH or ion (cation or anion) gradients. The proteins can be natural proteins, naturally derived (e.g. - genetically or chemically modified) proteins or artificial

Be proteins.

The structure of the concentration gradient should be inducible with the help of light (photons). Such proteins are found in nature, for example. Bacteriorhodopsin is a

Molecule that acts as a "proton pump" when exposed to light, while an example of an anion pump is halorhodopsin (see Oesterheld, D., Israel J. of Cheistry 1995, 35: 475-494). Such proteins are commonly referred to as "retinal proteins". In principle, they use a cis-trans transition of a chromophore with light absorption, as found in alkenals such as the retinal of rhodopsin (visual purple of mammals) or the retinal of bacteriorhodopsin o was. Some "retinal proteins" use the energy obtained to build up a concentration gradient, for example the aforementioned, bacteriorhodopsin and halorhodopsin.

As already mentioned above, the proteins to be used according to the invention can be genetically modified proteins derived from natural proteins. Small changes in the structure of the amino acid chain of the protein can possibly already bring about a significant change in function here: for example, a bacterial mutant is known that produces a bacteriorhodopsin modified by only one amino acid, which transports chloride ions (Sasahi et al., Science ( 1995), 269: 73-75).

To the necessary compartmentalization of the environment of the

To obtain protein, it is necessary that either a closed layer of protein is deposited on the substrate or that a closed layer of a carrier material in which the protein molecules are embedded is deposited. Since molecular pumps consisting of protein usually also have to be effective at phase boundaries in nature and these usually consist of membranes, it is expedient to use lipids as the carrier material. In principle, there are no restrictions on the selection thereof; phospholipids are preferred. For cost reasons, fabrics such as

Soybean lecithin or azolecitin. Of course, in principle all phosphatidylcholines and their derivatives are suitable.

The lipids can be deposited as a two-dimensional layer on the substrate, in which the protein (or different types of protein) are embedded. The advantage of using lipids is their spatial composition of the hydrophilic head and hydrophobic tail, which causes the lipids to be arranged in parallel (head-head and tail-tail). The protein, for example bacteriorhodopsin, will be arranged in such a layer with a preferred direction. In order to maintain the effect of the molecular pump in the macro range, it is understandably imperative that more than half of the molecular pumps operate in one direction. A stochastic distribution would lead to the cancellation of the effect.

It is particularly preferred that the protein-containing layer consists of or comprises lipid vesicles (liposomes) in which the protein is embedded. Here are the compartments between which the gradient is built, the outer environment of the vesicles and their interior. Bacteriorhodopsin gets into the

If the vesicle is installed, it is arranged in the artificial membrane in such a way that the pump function - unlike in nature - can also be "inside-out". In this way, metal ions can either be reduced either in the immediate vicinity of the vesicles or in their interior, or changed in such a way that they are amenable to reduction. The result is the locally defined deposition of these metal atoms. Instead of reducing the metal ions (direct reduction or modification of the metal-containing molecule, e.g. an organometallic complex so that it becomes accessible for the reduction), other methods which are customary in the technology of metal deposition can also be followed, e.g. A sensitization (example: tin (II) chloride is converted into tin (II) hydroxide, which precipitates in a pallidum (II) salt bath with the oxidation of palladium metal).

If the proton or other chemical pump works in the opposite direction (e.g. by lowering the pH value), its exposure will lead to the opposite effect. Therefore such arrangements for etching are already available

Suitable metal layers on the substrate. Instead of direct etching, a metallic or non-metallic auxiliary, for example another alkali or acid-unstable compound, can also be activated in this variant, which in turn then causes the etching. O

The protein molecules must remain fixed in place from the time of exposure. This can be ensured by embedding them in the layer applied to the substrate. In a particularly preferred embodiment, the proteins additionally have an "anchor", i.e. they are replaced by Van der Waals or other, e.g. chemical forces held on the substrate.

The layer consisting of or containing proteins must be arranged in an environment which allows the concentration gradient to be formed. When using a proton pump, it is necessary that a sufficient amount of water molecules is present in both compartments. An aqueous solution which contains the metal ions in is preferably located within the vesicles or below the two-dimensional layer (by "two-dimensional" is meant a layer which consists only of particles which are essentially arranged next to one another, but which can be formed both in one layer and in multiple layers) Contains form of a metal salt. The outside of the vesicles (or the side of the two-dimensional layer facing away from the substrate) should also be covered by an aqueous solution which can contain the corresponding metal ions. It is sufficient if this solution covers the vesicles in a thin layer, which can be ensured - if necessary with the help of a "moist chamber".

If vesicles are used, the local one

Concentration gradient as described above, depending on the selected conditions inside or on the outside of the vesicles, be suitable for effecting or preparing for the reduction or etching. If the former is the case, of course they have to

Vesicles are destroyed or opened so that the desired one

Effect is achieved. This can be done with the help of conventional methods, such as the removal of the lipids and

Proteins. The metal ions which can be used according to the invention can be selected depending on the material to be deposited. Tin or transition metals, which can be complexed, for example, are preferably selected. In addition to inorganic complexes, organometallic compounds can also be used. Protonation of such compounds leads to radicals that decompose to metal or metal oxide. Such radicals may be hydrolyzed relatively slowly, so they may be relatively long-lived. Otherwise, or in addition, they can be stabilized, for example by packing them in micelles.

According to the invention, it is also possible to increase the viscosity of the metal ion solution. This measure can contribute to the stability of the proteins. The viscosity can be increased using conventional means, e.g. by adding polyvinyl pyrrolidone or polyvinyl alcohol.

The surface of the substrate can be electrically conductive or non-conductive; the effect of metal deposition or etching is independent of this.

The metal deposition that prepares the production of structured metal layers does not have to be a comprehensive deposition. It is sufficient to deposit crystal nuclei of the metal on the substrate surface. Here are high

Precision of the deposition limits achievable (in the range of the wavelength of the light used). The crystal nuclei can be catalytically active in the subsequent steps in the deposition of further material.

Furthermore, it is possible with the method according to the invention to arrive at three-dimensional structures of the metal to be deposited.

In the method according to the invention, starting from a homogeneous covering, the substrate surface is covered with a light-sensitive protein layer as stated above, followed by the desired imaging pattern or the desired one Structure is written / drawn by appropriate exposure, if necessary with a focused light source or projected with a suitable photo mask.

The process according to the invention can in many cases be carried out at room temperature. If proteins occurring in nature are used, it is preferred to carry them out at a temperature which corresponds to the natural environment of the protein.

In the subsequent process step of a specific embodiment of the invention, which may also be carried out only after the prepared (exposed) materials have been temporarily stored, a metallic layer is deposited from the liquid at the locations (picture elements) of the material which have been changed by the exposure. After suitable intermediate steps to avoid unwanted layer deposition at areas of the substrate which are not provided for this purpose - to increase the contrast - this layer is used for further metallization.

The method of metallization with the aid of molecules whose properties can be changed optically or complex mixtures of these is also suitable for generating spatial structures. These structures, which can be viewed from several complexly interconnected individual planes or components thereof, can be produced by specifically guiding focused light on the three-dimensional substrate that is homogeneous or inhomogeneous in its material composition and / or structure for metal deposition. Such a substrate can be, for example, a sol, a gel, a glass or a monolithic or porous solid, such as, for example, a crystal compact similar to a piece of sugar cubes. From a complex, three-dimensional one created in this way

Layer structure in the sense described can completely or partially remove the underlying substrate, the surface of which was used for the layer deposition (for example by Dissolve in a suitable solvent). What remains - in the case of simply removing a planar substrate - is a finely structured planar layer of the deposited material, or else a spatially complex structure. This structure then consists of a metallic material or a material containing a metallic component.

In any case, for this embodiment of the invention there is a layer of molecules and possibly auxiliary substances applied to the surface or in the substrate, which leads to the formation of locations of preferred metal deposition in the course of subsequent processes by means of a light-addressed change in the properties of an essential component of this layer .

A further embodiment of the invention uses the special properties of a substance which acts as a molecular pump, for example the bacteriorhodopsin molecule, which can be obtained from bacterial biomass. The directional deposition of a monolayer of such molecules is used for locally high-resolution corrosion or modification of the substrate used as a base in a liquid medium. The molecule referred to here as the "pump" has the property of selectively transporting substances such as - for example protons (H ⁺ ) or ions from the solution side to the substrate side through a layer which simultaneously serves as a support and barrier, under the action of light. These factors are structured in close proximity to the substrate surface. The structuring can lead to the creation of otherwise undetectable defects. In a subsequent process step, which does not follow until the layer containing the optically partially activated "pumps" is removed, a further structuring or other modification of the material is carried out. This can be isotropic or anisotropic etching or the formation of a layer, for example by crystallization a substance that comes into contact with the substrate from ^• a solution, a suspension or a gas.

Advantages of the method according to the invention can be summarized as follows: The locally high-resolution deposition of the primary metallic layer which is later to act catalytically or directly as a nucleation at the location of previously optically modified molecules allows precision in the range of the wavelength of the light used, but at least in the range of if necessary Vesicle size. The use of focused light, such as that of a laser beam, and the simplicity of the process control also allow metallization to be carried out in and under porous layers. The same or different planar metallizations, one on top of the other in several levels, can be electrically conductively connected to one another via predetermined bridges. By combining suitable parameters, structures made of two or more different metals can be constructed planar and three-dimensional. Such complex metallization structures can be used as high-density wiring structures. Process-determining parameters result from the optical absorption properties of various proteins or other light-sensitive substances in their mixture, and / or the time-delayed incubation with solutions of different metals, or the controlled reaction kinetics in complex solutions and mixtures. The lateral extent of a metallic layer on the respective substrate can be specified with precision in the micrometer and sub-micrometer range. With the described method, it is possible to produce flat and spatial metal structures on smooth planar or curved, even electrically non-conductive surfaces,

The latter preferred embodiment of the method according to the invention (generation of structured

Materials or layers) is based on the same principle of optically addressable targeted modification of a suitable layer on a surface. With the method according to the invention it is possible, for example, to achieve a decorative metallic gloss for labeling surfaces.

The embodiments of the invention mentioned can be used to build up complex layers and structures. The material that ultimately dominates the structure produced can be of a different material composition than the underlying substrate surface or the substrate itself.

The attached figures are intended to clarify the basic procedures described, in which

FIG. 1 shows the sequence of steps of a photo-addressed metallicization,

Figure 2 illustrates the precision of the layer deposition and

FIG. 3 shows the sequence of steps of a fine etching technique mediated by a “molecular pump”.

In FIG. 1, 1 denotes a support / fixation auxiliary (e.g. lipid), 2 a photoactivatable molecule, such a molecular compound or cluster, 3 the substrate; 4 represents crystallization nuclei, and 5 a grown metal layer. The sequence of steps shows, from top to bottom, the substrate 3 alone, the substrate with a layer of photoactivatable molecules deposited thereon in a supporting matrix, the selective exposure (hv) of a photoactivatable molecule or group of molecules (dry or wet), the primary metallization caused thereby with the formation of

Crystallization nuclei, and - in the bottom row - the secondary metal deposition.

The etching process is also illustrated in FIG. 3, from top to bottom, the substrate (drawn in dashed lines) with a metal layer deposited thereon ("primary layer", drawn as a continuous thicker black line) in the second row with monolayers of photoactivatable molecules in one Carrier (support function) are coated. The selective exposure induces local pH gradients, recognizable by defects in the metal layer, which are enlarged by biomimetic corroding (4th row). The corrosion is stopped by removing the photoactivatable molecules (last row).

The invention will be explained in more detail below on the basis of exemplary embodiments.

1. General

Liposomes are produced which contain metal ions stabilized in solution in the enclosed internal liquid pool and bacteriorhodopsin molecules (BR) oriented in a preferred direction (vectorially) in their lipid membrane. A dispersion of such liposomes is applied as a closed thin layer to the substrate to be provided with a metal structure and partially exposed with the aid of an appropriate photomask. At locations of exposure, the pH of the liquid encapsulated in the liposomes changes as a result of the activity of the molecular proton pump BR. The temporary shifts in pH thus triggered are used to modify the solution of the encapsulated metal salt. Metal salts of the type of complex compounds can be destabilized and partially or completely changed in this way. The associated modifications of the liposome content are used in subsequent process steps to partially activate the substrate in accordance with common processes of chemical (= autocatalytic = external currentless) metallization. This activation consists in the separation of metal nuclei. Such metal nuclei are then used with customary methods of chemical or galvanic metallization to produce electrically conductive structures - also from metals other than those of the salts and / or complexes initially used.

The principle described, using light-driven molecular proton pumps to optically manipulate components of known activation or metallization baths encapsulated in liposomes in such a way that this leads to partial chemical contrasts which correspond to the optical ones used for manipulation, can - depending on the components used and theirs Orientation in the liposome membrane (eg BR) - provide both negative and positive images of the exposure pattern.

2. Typically, the following work steps can be used:

The amount of lipid required for the preparation of a 0.1-0.5% lipid suspension is weighed into a test tube and together with a 0.01-1 mM salt or complex salt solution of a metal (for example 100 μM palladium (II) chloride ) in a 0.01 - 5 M salt solution of a chloride, sulfate, carbonate, nitrate or phosphate whose pH value can be adjusted to sizes around or below pH 8 (for example 0.5 M potassium sulfate) with the aid of a

Ultrasonic generator suspended according to common procedures. With constant cooling in the (tap water) cooling bath, depending on the power used, a clear, slightly opalescent liposome dispersion can be obtained within about 10 minutes. A solution of the BR (bacteriorhodopsin) intended for reconstitution in the liposome membrane is added to the prepared liposome preparation. The "incorporation" of the BR into the liposomes is again carried out using the titanium horn of an ultrasound generator within about 3 minutes, but can also be done - in other ways - as is common in biochemistry, biophysics or medicine in various variants. To evaluate the (oriented reconstitution of the BR in the) BR metal salt liposome preparation obtained, an aliquot is irradiated with continuous mixing in a glass cuvette with - yellow light (1> 500 nm). The change in the pH value in the external volume (pH single-rod electrode), which is easily accessible from a measurement point of view, turns into the effective one

Preferred orientation of the BR molecules in the vesicle membrane and the achieved pumping rate closed. Suitable preparations are those which induce pH jumps of 0.1 pH units when exposed to light. To increase the viscosity of the dispersion, polymers, ^■ for example, polyvinylpyrrolidone (PVP) or polyvinyl alcohol (PVA) may be added. For example, a 7.5% PVP - liposome dispersion can be applied to the substrate as a thin film - for example with one in the

Microelectronic technologies commonly used spin coater. The substrate prepared in this way is then exposed to yellow light (1> 500 nm) through the photomask in a moist atmosphere (so-called "moist chamber"). The exposed substrate is then dried in a hot air oven and is then available for conventional chemical metallization, for example with a nickel-boron layer (NiB).

3. Execution example

5 mg of azolectin (Sigma-Aldrich) in 5 ml of an aqueous 100 μM tetrammine palladate solution in 0.5 M potassium sulfate in a test tube are sonicated with the titanium horn of an ultrasound generator (Branson Sonifier W 450) over the course of 15 minutes. The clear, slightly opalescent dispersion is mixed with a bacteriorhodopsin solution to a molar ratio of lipid: protein such as 700: 1 and sonicated for a further 3 minutes while avoiding strong cavitation. Polyvinylpyrrolidone (molecular weight approx. 350,000 - SERVA) is reduced to 7.5

Percentages by weight added and completely dissolved with stirring (vortex). This slightly syrupy solution is applied to the substrate to be coated - for example a glass fiber reinforced epoxy material (FR-4 circuit board base material) in a thin layer. With a suitable optical arrangement, a photo mask with yellow light (Schott filter OG 515) is projected onto this layer. In order to prevent the liposome layer from drying out, the latter step is carried out in a water vapor-saturated atmosphere. The substrate lies in one

"damp chamber". After exposure, the substrate is dried in a hot air oven. This is followed by a conventional NiB deposition. lo

The invention is to be summarized again below, additional specific configurations being mentioned:

It concerns a method of generating structured

Metal layers on surfaces or their preparation, in which, starting from protein molecules adhering to the surface of a solid, these properties change locally and thus compared to the unchanged protein molecules of the layer at the location of metal deposition from a solution or suspension and / or the binding of colloidal metal particles or become atomic clusters from a liquid or a gas or a gas mixture containing them, a protein layer ordered with molecular resolution or components thereof serves as an initiator of a reaction on a surface which is wetted by a solution or brought into contact with a defined gas composition, a local concentration gradient of at least one component in the liquid or gas phase in the immediate vicinity of certain protein molecules can be an important influencing variable for controlling the deposition process, light one Discrete wavelength from the spectrum of visible light is a factor that modifies the peculiarity of the protein molecules adhering to the surface

Conformational state of a polymeric component located at the location provided for metal deposition and which contains various amino acid residues as structural units represents a parameter determining the metallization process.

The invention further encompasses those configurations in which structured metal layers are produced on surfaces in contact with a liquid phase, as set out above, in which bacteriorhodopsin or a derivative derived therefrom or a variation thereof the protein component in represents the layer or constitutes an essential constituent thereof, a protein mixture or a mixture of proteins with other molecules capable of different conformational states is used for the layer structure,

- The layer is stabilized by a type of molecule which is chemically inert under the other conditions, staggered or synchronously, discrete areas of the primary protein-containing layer absorb light of different wavelengths, discrete areas of a primary non-metallic layer are excited by light of a defined wavelength and / or their properties are changed locally , the liquid phase can contain the salt of a metal to be deposited in dissolved form, the liquid phase is a colloidal solution of the smallest (<200 nm diameter), a separate load of carrying particles, the liquid phase can contain a metal colloid, - the composition of the liquid Phase changes over the duration of contact with the substrate, the properties of the components in the liquid leading to the metal layer formation stabilized by the presence of other solutes or for the intended purpose of the layer Deposition is improved, the surface provided for metal layer deposition can be covered by a porous layer, the surface provided for metal layer deposition can represent the inner surface of a porous material, the surface provided for metal deposition represents the surface of a material which can be formed at room temperature or at a higher temperature, which for the layer structure as a basis serving under the conditions of layer deposition solid substrate in a subsequent process step without the complete destruction of the deposited metallic structure partially or completely removed, can be replaced or supplemented by another material, a laterally structured metal layer specifies the superficial arrangement of a primary substance that mediates the deposition of a further metal, the fine-structured metal layer obtained serves for the purposes of circuit construction and power conduction, the fine-structured metal layer obtained as graphic image element or text component is used, the metal structure obtained is used for measured value acquisition or sensor technology, the metal structure obtained is used in the field of automobile or vehicle construction, the metal structure by means of a molecular pump activated by selective exposure or another which generates a local concentration gradient Principle is created, the structure of the metallic layer takes place at locations of the protein molecules whose properties have previously been activated by light.

Claims

Expectations :

1. A method for preparing the production of structured metal layers on substrate surfaces, comprising the following steps:

(a) applying a layer consisting of or containing proteins to the substrate surface, the protein or proteins of this layer being selected from those proteins which, when exposed to light in a corresponding environment, have a vectorial gradient of a physical or chemical property between two formed by the layer Build compartments and the resulting change in physical or chemical

Property in one of the two compartments causes metal ions or compounds present there to be reduced to metal or to be accessible for later reduction, and

(b) partial exposure of the substrate provided with the protein-containing layer.

2. A process for the preparation of the production of structured ^'metal layers on substrate surfaces, comprising the steps of:

(a) applying a layer consisting of or containing proteins to a metal-coated substrate surface, the protein or proteins thereof

Layers are selected from those proteins which, when exposed to light in an appropriate environment, build up a vectorial gradient of a physical or chemical property between two compartments formed by the layer and which in this way brings about a change in the physical or chemical property in one of the two compartments, that metal is oxidized from the coating and brought into solution, and

A method according to claim 1 or 2, wherein the gradient of the chemical or physical property is a concentration gradient, in particular a pH gradient.

Method according to one of the preceding claims, wherein the protein-containing layer consists of or contains retinal protein.

5. The method according to claim 4, wherein the retinal protein is selected from natural or modified bacteriorhodopsin and / or halorhodopsin.

6. The method according to any one of the preceding claims, wherein the exposure using light of a discrete

Wavelength is effected.

7. The method according to any one of the preceding claims, wherein the protein-containing layer contains a mixture of lipids and proteins.

8. The method of claim 7, wherein the proteinaceous layer is a two-dimensional layer of lipids with proteins contained therein.

9. The method according to claim 7, wherein the protein-containing layer consists of or contains lipid vesicles or liposomes, in the wall of which proteins are incorporated.

10. The method according to any one of the preceding claims, wherein the metal or metal ions are selected from tin and the group of transition metals or their ions.

11. The method according to claim 10, wherein the metal or the metal ions are selected from tin, iron, chromium, - rhodium, nickel, palladium, platinum, iridium, gold and / or rhenium ions or the corresponding metals.

12. The method according to any one of the preceding claims, wherein the metal ions are in the form of inorganic or organic complexes or organometallic compounds.

13. The method according to claim 12, wherein the metal ions are present as protonatable organometallic compounds of nickel, palladium and / or platinum.