Elemental metal porous structure arrangement and method for homogeneous galvanic deposition of an elemental metal into a porous structure down to a predefined pore depth

Abstract

The invention relates to an elemental metal porous structure arrangement having an elemental metal and a layer made of a hydrophobic, porous structure and is characterised in that the elemental metal is deposited down to a predefined pore depth of the hydrophobic, porous structure, wherein the predefined pore depth is smaller than the total pore depth, the elemental metal is formed as a layer several micrometres thick and suitable for a lift-off process on the hydrophobic, porous structure, wherein the elemental metal and the hydrophobic, porous structure have mechanically stable and electrically conductive contacts in the pores. The invention further relates to a method for the homogeneous galvanic deposition of an elemental metal into a porous structure down to a predefined pore depth by manipulating the wetting properties.

Description

[0001] Christian-Albrechts-University of Kiel CAU IPR_2024_0126 - DESC, CLMS, ABST

[0002] August 27, 2025

[0003] 1

[0004] Element metal porous structure arrangement and method for the homogeneous galvanic separation of an element metal into a porous structure down to a predefined pore depth

[0005] The invention relates to an element metal porous structure arrangement and a method for the homogeneous electroplating of an element metal into a porous structure to a predefined pore depth by manipulating the wetting properties.

[0006] Thin, large-area layers of semiconductor material find many applications in industry. These layers are often deposited onto other semiconductors in a process called layer transfer.

[0007] In other applications, such as solar cells and battery anodes, the semiconductor layers are used directly with a metallic conductive layer as a back contact. The mechanical adhesion and stability of the metallic backing are typically used to delaminate the semiconductor layer. Delamination is often induced at a highly porous layer that has been etched beneath a low-porosity layer (the actual layer). Crucially, in this combination of semiconductor porosity and metal deposition, the metal deposition must not completely fill the porous semiconductor layer. Otherwise, the highly porous separating layer would be filled again and would no longer represent a mechanical weak point for lift-off.Furthermore, the porous areas that are filled with metal are not active material for either solar cells or battery applications, meaning that the porous semiconductor layer should only be filled with metal to a depth necessary for mechanical stability.

[0008] German patent application DE 10 2020 103469 A1 discloses a process for manufacturing a silicon anode for secondary batteries, characterized by the steps of providing a monocrystalline silicon wafer with (100)-oriented flat sides, contacting the back of the wafer with a planar first electrode, placing the front of the wafer in an etching bath comprising a hydrofluoric acid-containing electrolyte and a second electrode, electrochemically etching mesopores of at least 4 micrometers pore depth into the front of the silicon wafer by setting a predetermined etching current density while generating a porosity between 40% and 80% in the mesoporous layer, generating a microporous delamination layer below the mesoporous layer by increasing the etching current density, and placing the etched wafer in an electroplating bath.Electroplating of an elemental metal into the etched mesopores to a predetermined pore depth of less than 2 micrometers, deposition of a layer at least a few micrometers thick. Christian-Albrechts-University of Kiel CAU IPR_2024_0126 - DESC, CLMS, ABST

[0009] August 27, 2025

[0010] 2

[0011] The invention involves depositing a metal layer onto the etched front surface of the wafer, creating electrically conductive and mechanically adhesive contacts between the metal layer and the elemental metal in the mesopores, and then removing the metal layer and the mesoporous, monocrystalline, (100)-oriented silicon layer, which is partially filled with elemental metal in the mesopores, while mechanically destroying the microporous release layer. The invention further relates to a silicon anode for secondary batteries.

[0012] Furthermore, publication EP 2 460214 B1 discloses an electrode for lithium-ion batteries comprising a metal film inert to lithium ions and a plurality of silicon nanowires arranged on at least one flat side of the film and projecting from the film, wherein sections of the nanowires are enclosed by the metal film, characterized in that the metal film is at least 1 micrometer thick, and a method for producing an electrode for lithium-ion batteries. The method is characterized by the steps: a. Electrochemical etching of a silicon wafer to create pores in a pre-selected arrangement up to a predetermined pore depth P, b. Conversion of the pore walls into standing nanowires of predetermined thickness attached to the wafer by over-etching the pores, c.Forming a film of predetermined thickness D from a metal inert to lithium ions by electroplating on the etched side of the wafer, wherein the metal film encloses the attached ends of the nanowires and the nanowires protrude from the flat side facing away from the wafer by approximately the length P - D.

[0013] The problems with the prior art essentially involve ensuring a homogeneous penetration depth of an electrolyte into a porous structure down to a predefined pore depth for electrochemical metal deposition, thus guaranteeing good electrical and mechanical contact and uniform nucleation in all pores. Typically, with standard variations in pore diameter, pores are usually completely filled with metal, even though a large proportion of the pores are filled with metal to an "acceptable" degree. Even this small proportion of completely metal-filled pores is unacceptable for many applications, as it can, for example, lead to local short circuits, hinder the layer-transfer process, or, in the case of battery applications as electrodes, cause severe local stresses during charging.

[0014] Furthermore, according to the state of the art, several industrially applicable methods exist that achieve reliable wettability on smooth semiconductor surfaces. However, a cost-effective, industrially applicable method for porous semiconductor surfaces is still lacking.

[0015] The object of the invention is to provide a cost-effective, industrially applicable method for producing a mechanically stable and electrically conductive interface between a porous semiconductor substrate and an elemental metal. Christian-Albrechts-University of Kiel CAU IPR_2024_0126 - DESC, CLMS, ABST

[0016] August 27, 2025

[0017] 3

[0018] Interlocking allows for a mechanically stable and electrically conductive connection between the metal and a porous layer. The pores of a porous layer are typically not smooth and channel-like, but rather exhibit diameters that vary with pore depth and lateral protrusions or branches that are perpendicular to the pore direction and act as undercuts. When such pores are filled with solid material, the material cannot be pulled out; instead, it is mechanically interlocked by positive locking. This makes it virtually impossible to detach a filled area of ​​a porous layer from a film of solid material that is also deposited in the pores.

[0019] The task is therefore to provide a mechanically stable and electrically conductive interface between a porous structure, in particular a semiconductor substrate, and an elemental metal, the pores of which are filled with elemental metal to a defined depth.

[0020] Another object of the invention is to provide a method that ensures a homogeneous penetration depth of an electrolyte for electrochemical metal deposition.

[0021] The problem is solved by an element metal porous structure arrangement according to the main claim and a method for the homogeneous electroplating of an element metal into a porous structure to a predefined pore depth by manipulating the wetting properties according to the dependent claim.

[0022] The elemental metal-porous structure arrangement with an elemental metal and a layer of a hydrophobic, porous structure is characterized by the fact that

[0023] - the elemental metal is deposited down to a predefined pore depth of the hydrophobic, porous structure, whereby the predefined pore depth is smaller than the total pore depth;

[0024] - the element metal is formed as a layer a few micrometers thick and suitable for a lift-off process on the hydrophobic, porous structure; wherein the element metal and the hydrophobic, porous structure have mechanically stable and electrically conductive contacts in the pores.

[0025] The hydrophobic, porous structure can be formed in particular from etched, predominantly H-terminated porous silicon.

[0026] In a preferred embodiment, the predefined pore depth of the hydrophobic, porous structure can be at least twice the wall thickness and twice the pore diameter. Christian-Albrechts-University of Kiel CAU IPR_2024_0126 - DESC, CLMS, ABST

[0027] August 27, 2025

[0028] 4

[0029] The process for the homogeneous electroplating of an elemental metal into a porous structure to a predefined pore depth by manipulating the wetting properties is characterized by the following steps: a. Providing a hydrophobic, porous structure, b. Surface oxidation of the structure to the predefined pore depth with the

[0030] Steps:

[0031] - Introducing a film of water of homogeneous thickness at room temperature onto the surface of the structure and

[0032] - Intensive, homogeneous heating of the surface of the structure; c. Placing the etched structure in an electroplating bath with an aqueous, polar, surfactant-free electrolyte; d. Electroplating of an elemental metal into the porous structure to the predefined pore depth; e. Deposition of a metal layer at least a few micrometers thick, suitable for a lift-off process, onto the etched front surface of the structure, creating electrically conductive and mechanically adhesive contacts between the metal layer and the elemental metal in the pores.

[0033] After step a. and before step b., the following step can also be added:

[0034] - Cleaning and removal of existing HF residues by rinsing with pure ethanol and subsequent drying.

[0035] In a preferred embodiment, a hydrophilic surface can be created at the beginning of step b. by an ozone treatment lasting 20 seconds.

[0036] Furthermore, step b. can be performed iteratively and repeated several times until the predefined pore depth is reached.

[0037] In particular, in step b. the introduction of the water film of homogeneous thickness onto the surface of the structure can be carried out via a moist carrier material or a cold fog (droplet size < 6 pm) or an aerosol (droplet size < 25 pm) or a condensate from a supercooled gas phase.

[0038] Preferably, in step b., the water film can be completely evaporated in < 10 seconds during intensive, homogeneous heating.

[0039] The water film in step b. can also consist of deionized water or contain polar additives.

[0040] Furthermore, the intensive, homogeneous heating in step b. can be carried out using infrared radiation or hot air. Christian-Albrechts-University of Kiel CAU IPR_2024_0126 - DESC, CLMS, ABST

[0041] August 27, 2025

[0042] 5

[0043] In a particularly preferred embodiment, the deposition of the metal layer in step e. can be carried out by applying a series of current pulses or very small current densities or sub-potential deposition.

[0044] The method according to the invention can in particular be carried out as an inline process.

[0045] Furthermore, the process can be used in particular to form the previously described element metal porous structure arrangement.

[0046] When using etched, predominantly H-terminated porous silicon as a hydrophobic, porous structure, the process takes advantage of the fact that after RF etching, the silicon surface is largely H-terminated and therefore hydrophobic. This holds true for at least 15 minutes after the surface has dried. The lifetime of the F-termination depends on the humidity and temperature. In a dry environment, the processing time would be somewhat longer. However, even with atmospheric oxygen, a gradual oxidation and the formation of a native oxide occur. This native oxide can be removed by immersion in a hydrofluoric acid-containing electrolyte, restoring the hydrophobicity. The wetting of such a structure with water can be described by the Cassie-Baxter model, which means that a heterogeneous interface of hydrophobic silicon and air-filled pores has an enhancing effect on the hydrophobicity.As a result, water cannot penetrate the pores, and they remain filled with air. This hydrophobicity manifests itself in the fact that the hydrophobic, porous structure, for example, a wafer, can be completely dried by briefly shaking it after immersion in water. The water does not penetrate the pores and simply beads up on the surface.

[0047] The hydrophobic, porous structure used in the process according to the invention can include, in addition to mesoporous silicon, all porous materials whose wetting properties can be changed from hydrophobic to hydrophilic by oxidation with an aqueous electrolyte and which have a porosity in which the cavities remain air-filled in contact with water (Cassie-Baxter model).

[0048] Electroplating is also applicable to all metals whose deposition potential does not lead to oxidation of the semiconductor surface. These include nickel and iron, as well as other metals such as tin and copper. Nickel is also considered a good adhesion promoter. Thicker layers, for example of copper, can easily be deposited on such a layer.

[0049] In the optional step of cleaning and removing existing HF residues directly after pore etching or later after an additional HF dip, the porous layers are washed in pure ethanol and then completely dried. (Christian-Albrechts-Universität zu Kiel CAU IPR_2024_0126 - DESC, CLMS, ABST)

[0050] August 27, 2025

[0051] 6

[0052] If cleaning were to take place in water-based liquids, an oxide would form on the surface during the cleaning step. Prolonged storage in humid air also leads to the formation of a native oxide, and the surface becomes wettable again.

[0053] Deposition of metal onto hydrophobic, air-filled pores leads to poor adhesion between the metal and the porous material, as the pores are either not filled with metal or only very close to the surface. Targeted oxidation (hydrophilization) of the pore entrances to a defined depth allows the electrolyte to penetrate and the metal to be deposited to that depth. For good electrical and mechanical contact, the embedding depth should be at least twice the wall thickness and twice the pore diameter.

[0054] Several industrially applicable methods exist for achieving reliable wettability on smooth semiconductor surfaces. One method involves contact with ozone (a gas) in a chamber. Another is contact with liquids containing a strong oxidizing chemical (sometimes at elevated temperatures), such as potassium hydroxide, sodium hydroxide, or sulfuric acid.

[0055] However, liquids containing a strong oxidizing chemical have the disadvantage that they quickly hydrophilize the originally hydrophobic, porous layers from the surface to the pore tips. This process begins with wetting at the surface. At each interface where the surface is wetted, oxidation occurs, leading rapidly and uncontrollably to further penetration of the liquids and oxidation to ever greater depths.

[0056] Furthermore, pore wall oxidation is strongly dependent on the pore diameter: Oxidation to the depths of large-diameter pores occurs significantly faster. Therefore, under the conditions described above, with typical variations in pore diameter, pores are always found to be completely filled with metal, even though a large proportion of the pores are filled with metal to an "acceptable" degree. Even this small proportion of completely metal-filled pores is, as already explained, unacceptable for most applications, as it can, for example, lead to a local short circuit, hinder the layer-transfer process, or, in the case of a battery application as an electrode, cause severe local stresses during charging.

[0057] At room temperature, distilled water hardly oxidizes a silicon surface. In contrast, it is known that distilled water significantly oxidizes a silicon surface at elevated temperatures around 80°C.

[0058] On hydrophilic surfaces, it is possible to apply defined thin films of water to (smooth) surfaces using known techniques, for example from offset printing. These techniques are described in Christian-Albrechts-Universität zu Kiel CAU IPR_2024_0126 - DESC, CLMS, ABST.

[0059] August 27, 2025

[0060] Seven methods can fail on hydrophobic surfaces because, due to surface tension, the thin films can quickly re-accumulate into droplets with a significantly larger diameter than the original layer thickness, covering only a portion of the surface. It is often observed that the interface beneath the droplets becomes hydrophilic due to the "forced" water wetting. Repeated application of a thin film can then gradually lead to wettability of the surface. In other cases, however, the droplets may preferentially accumulate at the same positions where they randomly formed during an initial application.

[0061] The teaching of the invention utilizes this effect in a two-stage step, which is preferably repeated several times.

[0062] First, a film of homogeneous thickness of deionized water at room temperature is applied to the surface, for example, over a moist carrier material, without time constraints. The carrier material should preferably consist of a very fine, hydrophilic, non-fibering fabric (e.g., silk). The relatively low degree of wettability of the carrier material must be refreshed before each application, preferably by a self-regulating process such as the (multiple) transfer of moisture from one layer of fabric to another. In this process, the first layer of fabric draws moisture from a large water reservoir, and the last layer of fabric is used to wet the porous substrate. Depending on their properties, the individual layers of fabric will self-limit and absorb the maximum amount of moisture, allowing only a small excess to be transferred to the next layer.This ensures that the final fabric is not too moist and always has the same moisture content. It is also possible to wet the porous substrate with a cold mist (droplet size < 6 pm) or an aerosol (droplet size < 25 pm), for example, through a spray process following ozone treatment or through condensate from a supercooled gas phase.

[0063] The water film is then heated by intensive homogeneous heating of the surface, for example with infrared emitters, and completely evaporates in less than 10 seconds.

[0064] Heating the water to its boiling point intensifies its oxidative effect. Contact with the hot water leads to progressive oxidation of the silicon surface and a shift in the wetting boundary beyond the originally wetted surface. The oxidative effect of pure deionized water can be further enhanced by adding polar additives such as acids or bases, although additives with wetting properties, such as acetic acid or ethanol, should be avoided. These would cause the liquid to penetrate the pores completely. Increasing the pH to pH 9, for example by adding sodium hydroxide, results in a similar effect. (Christian-Albrechts-Universität zu Kiel CAU IPR_2024_0126 - DESC, CLMS, ABST)

[0065] August 27, 2025

[0066] 8. Five times faster oxidation and penetration process compared to pure deionized water. However, a change in pH can make the application of the liquid layer time-critical, as the liquid then has an oxidizing effect at room temperature.

[0067] The subsequent rapid evaporation and volatilization of the water prevents the self-reinforcing effect of oxidation at ever greater depths. The wettability of surfaces, determined by thermodynamic equilibrium conditions as described, for example, in the Cassie-Baxter model, is replaced by a kinetic limitation of all relevant processes. Several known technical solutions exist for ensuring the homogeneity and intensity of water heating, such as infrared radiation or hot air application. Since uniform and simultaneous evaporation is easier to achieve with thin water films than with thicker ones, a smaller variance in penetration depth can be expected when using numerous weak wetting steps compared to applying thicker water films with less oxidizing properties.

[0068] The penetration depth per iteration step increases with increasing water film thickness. Depending on the selected wettability of the support material, the penetration depth per iteration can be set between approximately 30 nm and 120 nm (even greater depths are possible with oxidizing additives). The amount of water applied, in combination with the selected heating power, determines the residence time of the hot water on the sample surface and thus the progressive oxidation depth. However, since the surface is hydrophobic before the first iteration step, wetting does not occur on all surfaces during the initial iterations. Instead, the formation of a carpet of tiny, randomly distributed droplets is observed. Only after approximately three iterations are all surface areas readily wettable. This leads to an inhomogeneity in the depth of wettability of up to three times the average penetration depth.

[0069] An advantageous first step is therefore the brief exposure of the surface to ozone. This makes the direct (outer) surface hydrophilic, but not the inner pore walls. The outer surface is then completely covered with a thin film of water in this first step. Three iterations are avoided, and the homogeneity of the thickness of the final metallization layer is significantly improved by approximately 90 nm.

[0070] Complete surface wettability can be achieved, for example, by a 20-second ozone treatment using a UVC ozone lamp (60W) in an air-filled volume of approximately 75 liters. The high-energy UV radiation enables the partial conversion of oxygen to ozone, a strong oxidizing agent. Prolonged ozone treatment is not recommended, as the oxidation process is further compromised. (Christian-Albrechts-Universität zu Kiel CAU IPR_2024_0126 - DESC, CLMS, ABST)

[0071] August 27, 2025

[0072] 9. Ozone degradation occurs at different rates locally. Larger pore diameters are oxidized to greater depths significantly faster than smaller pore diameters. For an ideally porous sample (all pore diameters are the same and the pore distribution is uniform), it is conceivable to control the oxidation to greater depths solely through time and ozone concentration.

[0073] Tests conducted on the hydrophobicity of a hydrophobic, porous structure made of mesoporous silicon showed that a film forms on the entire surface upon contact with water, which cannot be easily shaken off (the water barely penetrates the pores). However, the film can be removed with compressed air / nitrogen, allowing the sample to dry. If the pores are already (partially) oxidized and wetted from the inside, a two-stage drying process can be observed (recognizable by color gradients). First, the surface of the sample dries. Subsequently, the pores themselves dry.

[0074] Following the targeted oxidation of the pore entrances, the hydrophilic pore entrances are filled with a metal. Here again, the Cassie-Baxter effect is utilized. When using an aqueous, polar electrolyte without surfactant-like, wetting additives such as ethanol and acetic acid, the hydrogen-terminated pores remain air-filled. The electrolyte can only penetrate the hydrophilic, previously oxidized pore entrances.

[0075] In the subsequent electrochemical metal deposition process, it is essential to ensure uniform nucleation in all pores. Those skilled in the art know that this is most easily achieved by applying a series of current pulses. Other approaches based on very low current densities or sub-potential deposition are also possible. Pulsing allows for post-nucleation in still unfilled pore openings before these are sealed by lateral layer growth on the surface of the porous material, creating a seamless seal.

[0076] Good results regarding uniform nucleation in all pores for a mesoporous silicon structure can be achieved, for example, with short current pulses of 100 ms, pause times of 1 s and a pulse intensity of approximately 80 mA / cm². 2This can be achieved for a nickel-Watts type electrolyte without flow at approximately 50°C. The pulse intensity must be adjusted to the electrolyte and flow conditions. Those skilled in the art know that a high flow rate and high electrolyte conductivity require increased pulse intensities to create transport limitation at the interface.

[0077] Instead of, for example, first passing a sample through the ozone chamber and then repeatedly through a two-stage process chamber, it is possible to move the sample on a conveyor belt through a system where the process chambers are repeatedly set up and thus processed inline. Christian-Albrechts-University of Kiel CAU IPR_2024_0126 - DESC, CLMS, ABST

[0078] August 27, 2025

[0079] 10

[0080] The invention is described below with reference to the accompanying figures in the figure description, which are intended to illustrate the invention and are not to be considered limiting. They show:

[0081] Fig. 1 is a scanning electron microscope (SEM) image of a homogeneous nickel embedding of approximately 300 nm after 10 deionized water applications;

[0082] Fig. 2 shows a scanning electron microscope (SEM) image of a nickel embedding approximately 500 nm deep after 3 applications of an aqueous sodium hydroxide solution with pH 9;

[0083] Fig. 3 shows a scanning electron microscope (SEM) image of a mesoporous silicon layer in cross-section, in which the pore openings were pretreated with the above-described method without ozone treatment using 2 deionized water applications and subsequently sealed with nickel by 30 current pulses and

[0084] Fig. 4 shows a scanning electron microscope (SEM) image of an approximately 400 nm deep iron embedding after a 20-second ozone treatment and 4 deionized water applications.

[0085] Fig. 1 shows a scanning electron microscope (SEM) image of a homogeneous nickel embedding of approximately 300 nm after 10 deionized water applications. The cross-section shows: nickel at the top, nickel-silicon interlocking in the middle, and porous silicon at the bottom.

[0086] Figure 2 shows a scanning electron microscope (SEM) image of a nickel embedding approximately 500 nm deep after 3 applications of an aqueous sodium hydroxide solution with pH 9, with nickel in cross-section at the top, nickel-silicon interlocking in the middle and porous silicon at the bottom.

[0087] Figures 1 and 2 clearly show that increasing the pH value by introducing a polar additive into the water film leads to a faster oxidation and penetration process.

[0088] Fig. 3 shows a scanning electron microscope (SEM) image of a mesoporous silicon layer in cross-section, in which the pore openings were pretreated with 2 deionized water applications using the above-described method without ozone treatment and subsequently sealed with nickel by 30 current pulses.

[0089] Furthermore, Fig. 4 shows a scanning electron microscope (SEM) image of an approximately 400 nm deep iron embedding after a 20-second ozone treatment and 4 deionized water applications. An iron chloride solution was used.

Claims

Christian-Albrechts-University of Kiel CAU IPR_2024_0126 - DESC, CLMS, ABST August 27, 2025 11 REQUIREMENTS 1. Element metal-porous structure arrangement comprising an element metal and a layer of a hydrophobic, porous structure, characterized in that the element metal extends to a predefined pore depth of the hydrophobic, porous layer. The structure is formed by deposits, with the predefined pore depth being smaller than the total pore depth; - the element metal is formed as a layer a few micrometers thick and suitable for a lift-off process on the hydrophobic, porous structure; wherein the element metal and the hydrophobic, porous structure have mechanically stable and electrically conductive contacts in the pores.

2. Element metal porous structure arrangement according to claim 1, characterized in that - the hydrophobic, porous structure consists of etched, predominantly H-terminated porous silicon is formed and / or - the predefined pore depth of the hydrophobic, porous structure corresponds to at least twice the wall thickness and twice the pore diameter. Christian-Albrechts-University of Kiel CAU IPR_2024_0126 - DESC, CLMS, ABST August 27, 2025 12 3. A method for the homogeneous electroplating of an elemental metal into a porous structure to a predefined pore depth by manipulating the wetting properties, characterized by the steps: a. Providing a hydrophobic, porous structure; b. Surface oxidation of the structure to the predefined pore depth with the steps: - Introducing a film of water of homogeneous thickness at room temperature onto the surface of the structure and - Intensive, homogeneous heating of the surface of the structure; c. Placing the etched structure in an electroplating bath with an aqueous, polar, surfactant-free electrolyte; d. Electroplating of an elemental metal into the porous structure to the predefined pore depth; e. Deposition of a metal layer at least a few micrometers thick, suitable for a lift-off process, onto the etched front surface of the structure, creating electrically conductive and mechanically adhesive contacts between the metal layer and the elemental metal in the pores.

4. Method according to the preceding claim, characterized in that after step a. and before step b. the following additional step is performed: - Cleaning and removal of existing HF residues by rinsing with pure ethanol and subsequent drying.

5. Method according to the two preceding claims, characterized in that in step b. a hydrophilic surface is initially produced by an ozone treatment lasting 20 seconds.

6. Method according to the three preceding claims, characterized in that Step b. is performed iteratively and repeated several times until the predefined pore depth is reached. Christian-Albrechts-University of Kiel CAU IPR_2024_0126 - DESC, CLMS, ABST August 27, 2025 13 7. Method according to the four preceding claims, characterized in that in step b. - the introduction of a water film of homogeneous thickness onto the surface of the structure via a moist carrier material or a cold fog (droplet size < 6 pm) or an aerosol (droplet size < 25 pm) or a condensate from a supercooled gas phase and / or - during intensive, homogeneous heating, the water film completely evaporates in < 10 seconds and / or - the water film is formed from deionized water and / or - the water film is composed of polar additives and / or - intensive, homogeneous heating is carried out using infrared radiation or hot air application.

8. Method according to the five preceding claims, characterized in that the deposition of the metal layer in step e. by - Applying a series of electrical pulses or - very low current densities or - Underpotential separation is performed.

9. Method according to the six preceding claims, characterized in that the method is carried out as an inline process.

10. Method according to the seven preceding claims, characterized in that the method for forming an element metal porous structure arrangement is carried out according to one of claims 1 or 2.

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