WO2017052202A1 - Method for forming carbon-based passivation film while reducing content of metal oxide on metal oxide-containing metal layer - Google Patents

Abstract

The present invention relates to: a method for forming a carbon-based passivation film while reducing the content of a metal oxide and/or a metal hydroxide in an interface with a metal layer containing a metal oxide and/or a metal hydroxide; a metal electrode comprising a metal layer and a carbon-based passivation film formed on the metal layer using the same; and a method for manufacturing an organic element by a solution process using the same. When the carbon-based passivation film is formed on a surface of the metal layer containing a metal oxide and/or a metal hydroxide in the annealing condition according to the present invention, the carbon-based passivation film can protect a metal surface to reduce an oxide film and/or a hydroxide film, which has already existed on a metal surface, and to prevent further oxidation and corrosion, and can be utilized as a metal electrode, on which a natural oxide film is not formed, like gold (Au), due to the low interfacial resistance.

Description

A method of forming a carbon-based passivation film while reducing the metal oxide content on the metal oxide-containing metal layer

The present invention provides a method for forming a carbon-based passivation film while reducing the content of metal oxide and / or metal hydroxide at an interface with the metal oxide and / or metal hydroxide-containing metal layer; A metal electrode having a metal layer and a carbon-based passivation film formed on the metal layer using the metal layer; And it relates to a method for manufacturing an organic device by a solution process using the same.

Because of its excellent electrical properties, strength and durability, metals are widely used throughout human life. In particular, metals occupy a very high proportion in ships, vehicles, and building materials that require durability, and all processes / reactors involving high temperature based on the high melting point and thermal stability of metals are usually made of metal. However, except for precious metals such as gold, silver, platinum, and the like, most metals tend to form natural oxide films on surfaces in air or to be corroded through moisture / acid components present in solution / atmosphere.

In general, a metal forms a native oxide and / or a metal hydroxide on its surface in a natural atmosphere containing air and moisture. In addition to metal oxides and metal hydroxides, metal chlorides may be formed.

As such, a thin metal oxide layer or metal hydroxide layer naturally formed on the metal surface in the atmosphere may prevent the metal surface from being oxidized deeper or corrosion of the metal. It is so thin that it is basically weak, and if there is a gap, the corrosion progresses even deeper.

Most metal oxides and metal hydroxides are insulators or semiconductors, and have poor electrical conductivity. Therefore, when using metal as an electrode, it becomes a factor which raises a contact resistance. In addition, when the metal oxide film or the metal hydroxide film is used as the electrode, the metal oxide film or the metal hydroxide film is a region in which scattering of electron transfer occurs a lot, and the spin property of the electron is not maintained.

Therefore, in many electronic devices using metal as an electrode, gold, which rarely forms an oxide film or a hydroxide film, may be used as an electrode, or a process may be performed without exposing the metal to air or moisture. Or it works with many constraints in an application.

Gold, on the other hand, is the material of choice for charge injection into organic semiconductors (OSCs). This is because there is an advantage in chemical stability, ease of fabrication and reproducible surface state preparation. In addition, its large work function values match Au well with p-type OSCs.

Carbon is often chosen as an electrochemical analytical material because of its attractive fabrication cost and its chemical inertness to many redox reactions. However, with the work function very sensitive to impurities (type, content) and eventual chemical state, mechanically brittle characteristics and the accompanying technical difficulties in patterning with thin electrodes are severe in the use of carbon in the connection of organic electronics. Apply constraints

In the field of research that has emerged over the last few decades, ferromagnetic electrodes have attracted interest to extend organic electronic technology to spintronics applications. For this application, a magnetic electrode is required to inject (detect) the spin polarization current, and the use of a transition magnetic metal is necessary for room temperature applications. The main constraint here is the chemical reactivity of Fe, Co, Ni surfaces with oxide surface layer growth in an environment containing oxygen or moisture at a partial pressure of 10 ⁻⁹ mbar or higher. In oxygen / moisture environments, the surface oxide (hydroxide) nickel layer has unpredictable magnetic properties such as ferromagnetic and antiferromagnetic, while making spin polarization uncontrollable. Therefore, the spin polarization of the charges injected into or in the OSC is expected to be greatly reduced, thereby reducing the reproducibility. One possibility to circumvent this problem is to use ultra high-vacuum (UHV) evaporation methods for electrode and OSC film formation to remove oxygen or moisture. However, in the case of a vertical design device using an ultra-high vacuum process, there is a problem that the effective thickness and area of the sample are uncertain due to the penetration of metal particles into the soft organic layer during the formation of the upper electrode, which is reliable and reproducible of the spin movement result. Affects.

One approach to overcome this uncertainty is that the spin implantation / detection electrode is placed on the substrate at a distance set by a controllable patterning process up to a 20 nm length scale using nanolithography, for example E-beam lithography. The horizontal structure is used. The horizontal structure is also more suitable for transmitting various external stimuli such as electric fields, (electro) magnetic fields, pressure, chemical doping, pH, etc. to control the properties of the organic layer, and the device responds to multiple independent stimuli. To do it.

Given the advantages of the chemical programmability of the physicochemical properties of molecules that cause hierarchical self-assembly in solution and at the surface, solution processable organic materials are in many ways an alternative to vacuum-processing. However, organic spintronics research using wet chemistry is inadequate and inconclusive, and the main bottleneck is the oxidation problem of magnetic electrodes.

An object of the present invention is to remove the oxide film and the hydroxide film on the metal surface without forming a thin carbon film without interfering with the inherent properties of the metal to prevent oxidation / corrosion of the metal surface, and to facilitate electron and spin transfer when used as an electrode. It is to provide a metal protective film that can be made.

A first aspect of the present invention is a method for forming a carbon-based passivation film while reducing the metal oxide and / or metal hydroxide content at an interface with a metal oxide and / or metal hydroxide-containing metal layer, the surface of the metal oxide and / or metal hydroxide-containing metal layer Applying a carbon donor precursor to some or all of the phases; And a second step of annealing under a reducing atmosphere and temperature capable of reducing the metal oxide and / or the metal hydroxide to pure metal and decomposing the carbon donor precursor. to provide.

According to a second aspect of the present invention, in a metal electrode having a metal layer and a carbon-based passivation film formed on the metal layer, a carbon-providing precursor is applied on part or all of the surface of the metal oxide and / or metal hydroxide-containing metal layer, The metal oxide and / or metal hydroxide-containing metal layer is annealed under a reducing atmosphere and temperature capable of reducing the metal oxide and / or metal hydroxide to pure metal and decomposing the carbon-providing precursor, thereby forming the metal layer and the carbon-based passivation film. Provided is a metal electrode characterized by reduced or eliminated metal oxides and / or metal hydroxides at the interface.

According to a third aspect of the present invention, there is provided a method of preparing a metal electrode including a carbon-based passivation film, the method comprising the steps of a; And it provides a method for producing an organic device comprising the step of forming an organic layer in a solution process on the carbon-based passivation film of the metal electrode.

Hereinafter, the present invention will be described in detail.

Nickel is a magnetic metal, and much research has been conducted to use it as an electrode of spintronic devices that apply magnetic properties of electrons to electronic devices. However, nickel oxide and nickel hydroxide on the surface of nickel are causing many obstacles in using nickel as an electrode material.

When a pure nickel film is deposited in a vacuum chamber and taken out into the atmosphere, it is exposed to the atmosphere and nickel nickel and nickel hydroxide are formed on the nickel surface. This is confirmed by XPS measurements (FIG. 4) and Raman spectroscopy measurements of nickel films (FIG. 5).

However, most of the anti-oxidation film is a semiconductor or non-conductor component, which acts as a factor that inhibits the characteristics of an electronic device or a spin device utilizing a metal for electron transfer.

Therefore, the present inventors apply an electrically conductive carbon-based passivation film to prevent oxidation / corrosion of the metal surface, and design a manufacturing process thereof to facilitate the electron and spin transfer in the metal to which the carbon-based passivation film is applied. Was intended. At this time, a carbon-providing precursor is applied on part or all of the surface of the metal oxide and / or metal hydroxide-containing metal layer, and the metal oxide and / or metal hydroxide-containing metal layer is reduced to pure metal. Annealing under a reducing atmosphere and at a temperature capable of decomposing the carbon-providing precursor results in the reduction of or removal of metal oxides and / or metal hydroxides at the interface between the metal layer and the carbon-based passivation film at the same time as the carbon-based passivation film formation. The surface was found to form. The present invention is based on this.

Since the present invention can form a thin carbon film on the metal surface while removing the oxide layer and the hydroxide layer of the metal surface, the thin carbon film formed on the metal surface can provide a property that the contact resistance through the metal surface is lower than the oxide layer. It is possible to improve the spin retention characteristics of the electrons, so that the metal layer on which the carbon-based passivation film is formed can increase the applicability to the organic electronic device.

In addition, the carbon-based passivation film formed according to the present invention not only acts as a metal antioxidant film and / or a corrosion protection film, but also can suppress electrical conductivity loss and ensure transparency in electron spin.

When the deposited nickel film was immersed in Nickel etchant, nickel was etched and melted away, but the nickel film on which the carbon-based passivation film was formed was not etched according to the process of one embodiment of the present invention. When operating as an anti-corrosion film, the carbon-based passivation film formed in accordance with the present invention outperformed the simple transfer of graphene onto a nickel film that acts as a protective film (Example 3).

Therefore, according to the present invention, a method of forming a carbon-based passivation film while reducing the metal oxide and / or metal hydroxide content at an interface with the metal oxide and / or metal hydroxide-containing metal layer,

Applying a carbon-providing precursor on part or all of the surface of the metal oxide and / or metal hydroxide-containing metal layer; And

And a second step of annealing under a reducing atmosphere and temperature capable of reducing the metal oxide and / or metal hydroxide to pure metal and degrading the carbon donor precursor.

The first and second steps may be performed separately or simultaneously.

The metal layer may be formed on the substrate and may also serve as an electrode. Further, the metal layer may be not only a metal but also a semiconductor material as long as an oxide film and / or a hydrate film can be formed. Non-limiting examples of the metal layer may be Ni, Cu, Fe, Al, Stainless steel, Cr, Si and other semiconductors or mixtures thereof.

The metal layer may be formed into a film on the support substrate or may be in the form of a single film. In addition, the substrate may be removed after the metal layer is placed on the support substrate and the carbon-based passivation film is formed. Furthermore, the metal layer may be patterned on the support substrate in various circuit designs.

The first step can be carried out using conventional coating methods. Typically, spin coating, dip coating, bar coating, Langmuir-Blogget film formation, self-assembly, drop-casting and the like can be.

If the material to be coated on the surface of the Nickel film is a compound including C, O, H as well as polymer materials such as PMMA, components such as O and H are lost during the heat treatment and carbon remains. Preference is given to compounds which do not leave elements other than carbon in the metal when heat treated. O and H may be separated from the compound during the heat treatment, or may be separated together with carbon to escape to the air. Carbon in the compound penetrates into the metal surface during heat treatment and excess carbon must be removed. At this time, O and H are inferred to help remove excess carbon from the metal surface. It is inferred that carbon that penetrates into the metal surface during the heat treatment process forms a carbon film as it comes to the surface during the cooling process.

The extra carbon, other than carbon that has penetrated into the metal surface, must be smoothly removed during the heat treatment process so that no carbon residues are left on the metal surface. O and H help to remove excess carbon in gaseous form.

Non-limiting examples of carbon-providing precursors usable in the present invention include synthetic polymers such as polymethylmetaacrylate (PMMA); Hydrocarbons; Graphene, graphene oxide; Organic small molecule self-assembled layer; It may be a polymer composed of carbon, hydrogen, oxygen, such as carbonates, monosaccharides, disaccharides (eg, sugars) and polysaccharides, starches and analogs, glycols, diols, polyols, various foods, and the like.

The carbon providing precursor can be appropriately selected and used depending on the kind of the metal layer.

In one embodiment of the present invention, the same effect as the carbon-based passivation film was obtained even if sugar was used instead of PMMA as the carbon providing precursor. Instead of the polymer film, graphene or a composite film of graphene and a polymer may be used to form a carbon film having excellent crystallinity. Therefore, the crystallinity of the carbon-based passivation film can be adjusted according to the carbon donor precursor selection.

Instead of the polymer film, graphene synthesized by CVD was coated on the nickel surface, then placed in a chamber, supplied with a forming gas, and the oxide and hydroxide on the nickel surface disappeared and a thin carbon film was formed even when the temperature was increased. . In this case, the crystallinity of the formed carbon film was better than that of polymer or sugar. The same results were obtained when graphene and polymer coating were used together as well as graphene synthesized by CVD.

In the second step, the reducing atmosphere may be a hydrogen containing atmosphere.

Under the appropriate temperature conditions under the provision of energy for annealing, the reducing atmosphere serves to reduce oxides on the metal surface, allowing the carbon donor precursor (polymer or chemical) coated on the metal surface to decompose. In the present specification, a gas providing such a reducing atmosphere is referred to as a forming gas, and a non-limiting example of the forming gas includes a mixed gas of hydrogen and an inert gas (eg, nitrogen and argon).

The action of temperature and forming gas is thought to decompose carbon-producing precursors such as polymers, reduce oxides and / or hydroxides on metal surfaces, and provide carbon in polymers to form thin carbon films on metal surfaces. Forming gas may be supplied only at certain parts of the treatment process.

Annealing (annealing) in the present invention is to provide a variety of energy sources, such as heat treatment or light irradiation, there is no limitation of the energy source. The energy sources that can be used are energy sources such as ovens, furnaces for simple heat treatment, halogen lamps, xenon lamps, UV lamps, etc., high energy light sources, microwave generators, laser generators, powerful mechanical energy, etc. Can be used according to the application.

The temperature range of the annealing chamber may vary depending on the type of metal layer and the carbon providing precursor, but there is no limitation as long as it can reduce the metal oxide and / or metal hydroxide to pure metal and decompose the carbon providing precursor. Preferred temperatures are those at which the carbon-providing precursor should be pyrolyzed smoothly and at such a high temperature that carbon can penetrate properly into the metal, while the carbon atoms can be properly bonded to the metal atoms by the interaction of the metal atoms with the metal atoms, The temperature should not be too high so that the shape or properties are not damaged at this too high temperature, and the temperature range should be adequate so that the carbon-providing precursor does not leave too much pyrolysis or burn-up. In addition, too high a temperature can cause carbon to soak into the metal, leaving an excessive and non-uniform carbon film later, and the surface of the metal film begins to become uneven. Therefore, it is preferable not to exceed 650 degreeC.

For PMMA, the temperature at which pyrolysis can occur is above 350 ° C. In the case of PMMA, the temperature of pyrolysis may vary slightly depending on the type or solvent, but in most cases, 400 ° C. is sufficient for pyrolysis.

Thus, the preferred temperature range of the anneal chamber may be 350 to 650 ° C.

The annealing time is preferably a time at which the carbon precursor is sufficiently pyrolyzed to remove the unnecessary carbon precursor in gaseous form. It is desirable for the time and conditions that a sufficient amount of carbon can penetrate into the metal surface before the carbon precursor is all removed in gaseous form. In other words, it is preferred that the time provided is that the carbon provided in the carbon precursor contains and maintains the amount of carbon that can hold the bond with the metal in a sufficient amount to completely cover the metal surface. Therefore, the annealing time may be 5 minutes to 60 minutes, preferably 10 minutes to 30 minutes. If the heat treatment time is prolonged in the reducing atmosphere, the surface of the metal film may be uneven due to prolonged high temperature exposure.

Therefore, in order to perform at the annealing temperature and time, the annealing method is preferably rapid thermal annealing (RTA) or the like for long exposure to high temperature.

In order to effectively remove the gas generated during annealing, the annealing chamber is preferably pumped out and kept at a low pressure. In this case, the pressure may be a pressure of about 1 torr normally. In one embodiment, the pressure was about 30-90 mTorr Gauge readin when vacuumed, and about 980 mTorr when annealing. Therefore, the pressure for performing the experiment was about 30-1000 mTorr, but it is possible outside this range.

When increasing the temperature of the annealing chamber and pumping out, forming gas is flowed to remove the oxide film and / or hydroxide film on the metal surface and to promote thermal decomposition of the carbon source.

Therefore, the annealing method in the second step may be a heat treatment in a low pressure furnace.

Carbon-based passivation film formed in the present invention is that the carbon providing precursor is oxidized on the metal surface to form a carbon, it may take the form of amorphous carbon, graphene and the like.

According to one embodiment of the present invention, it was possible to provide a nickel electrode passivated by an ultra-thin amorphous carbon film.

According to an embodiment of the present invention, the physical and chemical properties of the Ni electrode covered with a very thin carbon film were analyzed. The carbon-based overlayer prevents oxidation of Ni, and is detectable only by ToF-SIMS and is not observed in XPS. It was found that it had a negligible amount of oxide.

In addition, according to one embodiment of the present invention, Ni processed at a temperature of 550 ° C. or lower maintains the structural quality of the film and exhibits an optimal composition of Ni without oxide and carbide paper, and the resulting electrode has a charge injection capability equivalent to gold. It was confirmed to have. When temperatures higher than 600 ° C. were used, crystalline (multilayer) graphene was obtained, but degradation of the topology of the sample was observed and performance degradation of the OFET and EFET properties of the p-type organic semiconductor device was observed. Quantitative analysis of the interfacial resistance value between the active channel and the injection electrode confirmed that according to one embodiment of the present invention, a thin amorphous carbon covered nickel electrode is well suited to replace gold for organic electronic devices. This is cost-effective and is expected to be the best approach for manufacturing spin injectors and detectors for organic spintronics applications.

Therefore, the metal electrode having a metal layer and a carbon-based passivation film formed on the metal layer according to the present invention,

Applying a carbon donor precursor onto part or all of the surface of the metal oxide and / or metal hydroxide-containing metal layer and reducing the metal oxide and / or metal hydroxide-containing metal layer to pure metal and Annealing is carried out under a reducing atmosphere and a temperature capable of decomposing the carbon providing precursor, thereby reducing or removing metal oxides and / or metal hydroxides at the interface between the metal layer and the carbon-based passivation film.

At this time, by reducing or removing the metal oxide and / or metal hydroxide at the interface, the contact resistance between the metal layer and the carbon-based passivation film may be several ohms to several tens of ohms (Ohm), for example, 1 ~ 90 ohms Can be.

 On the other hand, when using a metal electrode having a carbon-based passivation film according to the present invention, since the oxidation / corrosion of the metal surface is suppressed, it is possible to form an organic layer on the carbon-based passivation film of the metal electrode by a solution process.

Accordingly, the present invention provides a method for preparing a metal electrode on which a carbon-based passivation film is formed by the method of the first aspect of the present invention; And

It can provide an organic device manufacturing method comprising a step b of forming an organic layer in a solution process on the carbon-based passivation film of the metal electrode.

As long as the metal layer in which the carbon-based passivation film is formed according to the present invention and an organic layer can be formed on the carbon-based passivation film of the metal layer by a solution process, the device in which the metal layer is not used as an electrode are also within the scope of the present invention.

According to the present invention, a metal electrode having a reduced or removed metal oxide and / or metal hydroxide at the interface between the metal layer and the carbon-based passivation film can form an organic layer thereon in a solution process, and thus a flexible plastic substrate using a coating and printing process. At low temperatures close to room temperature, functions such as a display, a circuit, a battery, and a sensor can be integrated. In addition, the wiring, the semiconductor, and the insulating film can all be made of organic material. In addition, inkjet printing can produce large-scale and inexpensive plastic electronic components, and thus can be applied to transistor circuits, photovoltanic films, OLEDs, and the like. Furthermore, various devices may be implemented by a 3D printer using ink. Therefore, as long as the solution process is introduced on the carbon-based passivation film of the metal layer, the main component dispersed in the solvent may be not only organic matter but also inorganic matter, and this case also belongs to the scope of the present invention.

Non-limiting examples of organic devices that can be fabricated in accordance with the present invention include organic semiconductor devices (OSCs), transistors, solar cells, OLEDs (organic light emitting diodes), sensors, cells, memories, bioinserts, cell culturers, and the like. .

In order to find electrode candidates for spin polarization of charge current, in one embodiment of the present invention, synthesis of graphene on Ni using Ni as a catalyst is followed by fabrication of a protected Ni electrode and these processes for wet process of OSC devices. In order to test the suitability of the graphene material growth characteristics were used. Nickel electrodes covered with multilayer graphene and amorphous carbon were used as hole injection layers for organic semiconductors. The charge carrier injection capability of the two types of electrodes of the transistor structure of the electrolyte-gate was tested and compared with pure nickel and gold electrodes. As a result, it was confirmed that the nickel electrode covered with low temperature processed amorphous carbon having an interface resistance equivalent to Au had the best performance. The purity and magnetic properties of nickel were retained, which allowed for the fabrication of devices that provide current spin injection with wet chemically processed materials.

When the carbon-based passivation film is formed on the surface of the metal oxide and / or metal hydroxide-containing metal layer under the annealing conditions according to the present invention, the metal surface is reduced so that the oxide film and / or hydroxide film already present on the metal surface is reduced and no further oxidation and corrosion occurs. In addition to protecting the, the interfacial resistance is low, it can be used as a metal electrode that does not form a natural oxide film, such as gold (Au).

The protective film technology that prevents oxidation / corrosion and deterioration of the metal can not only provide better electronic and spin devices, but also can be used to prevent metal modification in a wide range of fields such as ships, aviation, and construction. .

FIG. 1 shows a schematic diagram of a process of forming a carbon-based passivation film 3 on a surface of a metal 1 using a carbon providing precursor 2 according to an embodiment of the present invention.

2 is an XPS spectrum of pure nickel metal.

3 is an XPS spectrum of a nickel surface on which an oxide film and a hydroxide film are formed.

4 is an XPS spectrum of a deposited pure nickel film exposed to the atmosphere according to Example 1. FIG.

5 is Raman spectroscopy of pure nickel metals.

FIG. 6 is an XPS spectrum showing that the oxide film disappeared almost from the nickel surface after PMMA coating and annealing according to Example 1. FIG.

FIG. 7 is a Raman spectrum showing that a carbon thin film was formed on a nickel surface after PMMA coating and annealing according to Example 1. FIG.

8 is a Raman spectrum after coating PMMA on the surface of a nickel film according to Example 1. FIG.

FIG. 9 is an optical microscope image showing that a protective film is formed on a nickel electrode patterned on a substrate according to Example 1. FIG.

FIG. 10 is a photograph in which a nickel film having a protective film and a nickel film without a protective film are immersed in a nickel etchant solution according to Example 1;

FIG. 11 is a photograph showing the results of etching the graphene synthesized by CVD on a nickel film, and a carbon film formed according to Example 3 in a nickel etchant. FIG.

12 is an XPS Ni2p spectrum of nickel surface after coating and annealing (graphene + PMMA) according to Example 4. FIG.

FIG. 13 is Raman spectroscopy of nickel surface after coating and annealing (graphene + PMMA) according to Example 4. FIG.

14 is an optical microscope image of a Cu metal surface on which a protective film was formed in accordance with Example 5. FIG.

15 is a Raman spectrum of a Cu metal surface on which a protective film is formed in accordance with Example 5. FIG. Each graph is measured at different positions.

Figure 16 is a photograph of the change in the copper etching solution after dropping the copper etching solution and the RTA treated copper foil according to Example 5, respectively.

17A is a conceptual diagram of a device structure used for gate 4 probe measurement of contact resistance.

17B is an optical image of graphene CVD processed on top of a Ni electrode. The texture of the graphene layer lying in the same form in the catalyst zone is clearly identified.

18A is a Raman spectrum of CVD (top) multilayer graphene and RTA (bottom) amorphous carbon film on top of a 100 nm thick Ni film. Here, the inset is an optical microscope image of the sample.

18B is a topological profile of these providing additional evidence for very different surface roughness along with 3D micrographs of AFM topology scans of Ni / RTA and Ni / CVD.

19 shows (a) air exposed Ni, (b) Ni / CVD, (c) spectrum of Ni / RTA, and (d) Ni film, (e) Ni / CVD film, (f) C of Ni / RTA 1s core level spectrum.

20 is ToF-SIMS depth profile of Ni exposed to air. Characteristic fragments of nickel, oxygen and nickel oxide are shown, from the top surface (0 nm) to the depth of the nickel layer (85 nm).

FIG. 21 is a comparison of depth profiles of Ni (black), Ni / CVD (red) and Ni / RTA (blue) exposed to air for NiO- (top) and NiC _2- (bottom) fragments.

22 is a movement curve of the IIDDT-C3 OSC. For gate voltages between -1.5 and -3V, most of the polymer electrolyte was polarized to the interface. For larger negative gate voltages, volume electrochemical doping increases the effective thickness of the conductive material.

FIG. 23 is a shift curve of an IIDDT-C3 based OFET with Au, Ni / RTA, Ni / CVD, and Ni electrodes 100 nm thick.

FIG. 24 shows the width-normalized total contact resistance as a function of gate voltage for 100 nm thick Au, Ni / RTA, Ni / CVD and Ni electrodes.

25 shows the source and drain contact resistances as a function of V _G for Au (red curve) and Ni / RTA (black curve) OFETs.

Hereinafter, the present invention will be described in more detail with reference to Examples. These examples are only for illustrating the present invention more specifically, but the scope of the present invention is not limited by these examples.

Example  One: PMMA  Used Ni  Form a protective film on the metal surface

As shown in FIG. 1, a carbon-based passivation film 3 was formed on the surface of the Ni metal 1 using the PMMA 2.

 A nickel layer 1 having a thickness of 100 nm was deposited on the silicon substrate.

When the deposited pure nickel film was taken out of the vacuum chamber into the atmosphere, it was exposed to the atmosphere to form nickel oxide and nickel hydrate. As compared with FIGS. 2 and 3, the deposited nickel film may be clearly oxidized nickel film.

On the nickel film, polymethyl methacrylate (Poly (methyl methacrylate), PMMA) was spin-coated at 5000 rpm for 30 seconds using a spin coater (MIDAS SYSTEM Co., Ltd.) at room temperature (FIG. 5). It was then placed in an annealing chamber and the annealing temperature was raised above 350 ° C. so that the PMMA polymer film could be pyrolyzed. At this time, the pressure of the chamber was maintained at a low pressure (970 mTorr) while effectively removing the generated gases. At this time, a mixed gas of forming gas (hydrogen, methane) and an inert gas was flowed into the chamber. As shown in FIG. 6, it can be seen that the oxide film on the nickel surface disappeared almost in the XPS spectrum.

As compared with Raman spectroscopy (FIG. 5) of the nickel film in which the protective film is formed, the Raman spectroscopy (FIG. 5) of the nickel film shows clear carbon-related components (3).

It can be seen that the Raman spectrum (FIG. 7) of the nickel film in which the protective film was produced according to Example 1 is distinguished from the result of coating PMMA on the surface of the nickel film and measuring the Raman spectrum (FIG. 8).

As shown in FIG. 6 and FIG. 7, the nickel surface was examined by XPS and Raman spectroscopy, indicating that the nickel oxide film and the nickel hydroxide film were missing and the thin carbon film 3 was formed on the nickel surface.

Experimental Example  1: PMMA based protective film formed Nickel thin film  Corrosion stability test

Nickel etchant used TFB (by Transene Co. Inc.), and the composition is Nitric Acid 15-20%, + Potassium Perfluoroalkyl Sulfonate <1%, in Water.

As shown in FIG. 10, when the deposited nickel film was immersed in Nickel etchant, nickel was etched and melted away, but the nickel film on which the PMMA-based protective film was formed as in Example 1 was not etched.

It can be seen that the carbon layer formed according to Example 1 also acts as a corrosion protection film of the nickel film.

Example  2: Sugar solution  Used Ni  Form a protective film on the metal surface

A protective film was formed on the nickel layer in the same manner as in Example 1 except that 10 wt% sugar aqueous solution was used instead of PMMA as the carbon providing precursor.

In this case, the nickel surface was examined by XPS and Raman spectroscopy, and nickel oxide and nickel hydroxide disappeared from the nickel surface, and a thin carbon film was formed.

Example  3: Graphene  Used Ni  Forming a protective film on the metal surface

A protective film was formed on the nickel layer in the same manner as in Example 1 except that graphene synthesized by CVD instead of PMMA was used as a carbon providing precursor.

In this case, the nickel surface was examined by XPS and Raman spectroscopy, and nickel oxide and nickel hydroxide disappeared from the nickel surface, and a thin carbon film was formed. The crystallinity of the carbon film was better than that of PMMA polymer or sugar.

Experimental Example  2: Graphene  Foundation shield formed Nickel thin film  Corrosion stability test

The graphene synthesized by the CVD method was coated on a Nickel film, and the carbon film was formed according to Example 3, and subjected to an etching test in nickel etchant.

As shown in FIG. 11, coating only graphene also protected nickel from nickel etchant to some extent, but looking closely, it was confirmed that etching of the nickel film was proceeding considerably. On the other hand, the formation of the carbon film according to Example 3 was such that the etching of the nickel film was almost ignored.

That is, the carbon film formed according to Example 3 was superior as a corrosion preventing film than the simple transfer of graphene on the nickel film that acts as a protective film.

Example  4: PMMA + Graphene  Used Ni  Forming a protective film on the metal surface

A protective film was formed on the nickel layer in the same manner as in Example 1 except that graphene and PMMA synthesized by CVD instead of PMMA were used as the carbon providing precursor.

As shown in FIGS. 12 and 13, the nickel surface was examined by XPS and Raman spectroscopy. As a result, nickel oxide and nickel hydroxide disappeared from the nickel surface, a thin carbon film was formed, and the carbon film had excellent crystallinity.

Example  5: PMMA  Protective film formation on the used Cu metal surface

A 100 nm copper (Cu) layer 1 was deposited on the silicon substrate. PMMA C4 (2) was spin coated on the copper film at 2000 rpm for 30 seconds. Subsequently, it was placed in an annealing chamber, and the annealing temperature was heat-treated (rapid thermal annealing, RTA) in a hydrogen atmosphere at 600 ° C. for 1 hour so that the PMMA polymer film could be pyrolyzed.

FIG. 14 is an optical microscope image of a Cu metal surface on which a protective film is formed, and FIG. 15 is a Raman spectrum thereof. As shown in FIG. 14, it can be seen that the copper crystal is exposed on the copper surface as it is and a relatively uniform carbon film is formed. The Raman spectrum of FIG. 15 shows that the characteristic Raman peaks of the carbon thin film appear at 1300 and 1750 despite the background caused by the copper thin film. That is, copper oxide and copper hydroxide disappeared from the copper surface, and a thin carbon film was formed.

Experimental Example  3: PMMA based protective film formed Copper thin film  Corrosion stability test

As a copper etching solution, Trannsene Co. Inc., Copper Etchant CE-100 was used. The composition is Ferric Chloride 25 ~ 35%, Hydrochloric Acid 3 ~ 4%, in Water.

As in Example 5, the copper etching solution (transene 100) of the RTA treated copper foil and the untreated copper foil was dropped, respectively, and the change was observed. As shown in FIG. 16, in the case of Example 5, the carbon film formed on the copper foil because the protective film is not perfect does not prevent the etching of copper, but the etching rate is different from that of the untreated copper foil.

Example  6: Ni  Metal electrode phase Graphene  Protective film formation

6-1: electrode design and Patterning

A conceptual diagram of a device architecture with bottom contact electrodes, designed to perform four point probe gate conductance measurements, is shown in FIG. 17A. A bottom contact transistor with an upper gate, channel length L = 50 μm (width W = 1000 μm) was formed. Two thin electrodes (finger) with L = 14.5 μm and W = 2.5 μm were inserted into the channel as voltage probes. Source-drain electrodes and voltage probe electrodes were formed by photo-lithography. A 100 nm thick Ni and Au / Ti (5 nm) metal film was subjected to E-beam evaporation (deposition rate of 0.5 nm / s) on a 500 nm thermally oxidized SiO ₂ / p ⁺ -doped Si substrate. The electrode circuit was fabricated by deposition and a lift-off process.

6-2: electrode carbon passivation

Two approaches were used to cover the previously patterned nickel electrode with a thin film of carbon.

The first is to use the high temperature (850 ° C.) growth method by the CVD technique to produce a carbon thin film using a carbon-rich forming gas and its decomposition.

The second approach is to use a solid precursor made of a catalytic metal with a carbon-rich coating layer according to one embodiment of the invention, and to heat the sample using the RTA process at a lower temperature, i. .

For both bottom-up approaches, the Ni film was first exposed to a hydrogen-rich reducing gas to remove the originally existing passivation oxide layer.

For CVD graphene growth, UHV-grown nickel samples were transferred in air into a low pressure CVD wall furnace consisting of 4-inch fused silica tubes. The pressure was reduced to 800 mTorr and the samples were heated for 25 minutes at 750 ° C. in a vacuum (pressure of 1.5 to 2 × 10 ⁻³ mbar), thereby increasing the size of the grains, followed by 100 sccm Washing by annealing for 20 minutes under H ₂ flow. Then a precursor mixture of H ₂ 30 sccm and C ₂ H ₂ 30 sccm was introduced into the chamber for 30 minutes for graphene synthesis. After the growth was complete, the furnace was cooled to room temperature under 100 sccm Ar atmosphere for several hours. During the cooling process, the carbon atoms diffused out of the catalyst surface and the precipitate to form a graphene film.

FIG. 17B is an optical microscope image of a device obtained (hereinafter referred to as Ni / CVD sample) with contrast representing non-uniform multilayer type graphene as predicted by the above process conditions.

In the case of RTA graphene growth, a spin coating of about 300 nm thickness was first spin-coated at 2000 rpm for 30 seconds with PMMA-A2 resist, a solid carbon source, on top of the Ni surface used as a catalyst to convert hydrocarbon materials into graphene. Obtained film. The sample was then placed inside the quartz tube chamber of the RTA system. The chamber was heated for 15 minutes at 550 ° C. for an annealing process (degassing) under a flow of H ₂ (4%) / N ₂ mixture at a pressure of 1 mbar to remove oxides and hydroxides that passivate the Ni surface. The sample was then cooled to room temperature in H ₂ / N ₂ for 120 minutes to obtain a sample named Ni / RTA.

6-3: Transistor Fabrication and Characterization

An in-plane gate gold electrode was added to the electrode circuit by UHV deposition through a stencil mask. The organic active channel is a p-type polymer IIDDT-C3, (poly [1,1'-bis), with the main advantages of easy processability, air-stability and high mobility (> 3 cm 2 V ^-1 s ^{- 1} ). (4-decyltetradecyl) -6-methyl-6 '-(5'-methyl- [2,2'-bithiophene] -5-yl)-[3,3'-biindolinylidene] -2, 2'-dione]). . IIDDT-C3 are 1-Materials, child NC was obtained from (1-Materials Inc.), was diluted in chloroform (~ 0.25 gL ^{- 1)} by spin coating at 1000 rpm to obtain a film of about 20 nm thickness. The chips were then placed on a hotplate at 50 ° C. for 30 minutes to evaporate the solvent. All process steps for fabricating the organic layer were carried out inside the glove box under nitrogen atmosphere at room temperature.

Using a laminate of independent ion gel dielectrics, they were stacked on the IIDDT-C3 channel and side-gate electrodes to complete the device with the top gate structure. This side-gate arrangement does not require precise alignment of the gate electrode with the semiconductor channel. Ion gel was prepared by dissolving polymer P (VDF-HFP) and ionic liquid [BMIM] [PF ₆ ] in acetone at a weight ratio of 1: 4: 7, respectively.

Contact resistance measurements were performed with the Gate 4 probe method. The transfer curve is a gate voltage V _G at a constant drain voltage V _D of −0.1 V while monitoring the drain current I _SD and the probe potentials V ₁ , V _{2 of the} fingers. ) Was obtained by sweeping. V _D and V _G were added while measuring I _SD using a Keithley 2612A Source Meter. The potentials V ₁ and V ₂ of the two fingers were monitored using a second source meter. Due to the slow field-induced diffusion process of the dielectric gate ions, using a V _G sweep speed of 0.001 V / s allowed sufficient time for their movement. All measurements were performed inside an N ₂ -filled glove box at room temperature.

Experimental Example  4:

Raman analysis

Raman spectra were obtained under atmospheric conditions using a Renishaw InVia micro-Raman spectrometer equipped with a 514 nm excitation laser (E = 2.41 eV). The exposure time was 10 seconds and the spot size was about 1.5 μm.

X-ray photoelectron spectroscopy ( XPS )

XPS spectra were obtained with a photon energy of 1486.6 eV (Al K _α ) operating at a vacuum pressure of ˜10 ⁻⁷ mbar. For each sample, XPS measurements were performed on two different areas of the surface and the resulting spectra were obtained after 10 scans. The spot size of the X-ray was 400 μm and the energy step size was 0.1 eV. Spectral analysis was performed using "XPSPEAK 41" software with Gaussian-Lorentz peak form after Shirley background correction.

Ambient photoelectron yield counter

Work function values were measured with an atmospheric photoelectron yield counter spectrometer (model AC-2, RKI Instruments.). Measurements were performed in an energy range between 4.00 and 5.60 eV in 0.05 eV steps at an intensity of 100 nW. For each sample, WF was calculated from the spectrum by determining the onset of sqrt (photoelectron yield) vs. E curve.

Time-of-flight Secondary ion mass  Spectroscopic analysis ( ToF - SIMS )

Graphene-, Ni-layers and their interfaces were investigated via ToF-SIMS chemical-degradation depth profiling using a ToF-SIMS 5 instrument (ION-TOF GmbH). Interlace (interlaced) 1keV Cs ⁺ ion-sputtering (dual beam) and the combined 25 keV Bi ⁺ _1, to obtain a profile of a high mass degradation mode using primary ions. Negative secondary ions in the mass range of 1-500 mu were recorded from the top surface to a sample depth of ˜200 nm. To ensure representative reproducible results, randomly selected 1-3 scan areas of 100 × 100 μm ² were considered for each sample. Depth calibration was performed by measuring crater depth using a Dektak XT profilometer.

Atomic force  Atomic Force Microscopy

AFM terrain mapping was performed with a Bruker Dimension Edge instrument using antimony n-doped silicon tips in intermittent contact mode.

[Result analysis]

Carbon Of the adsorption layer  Raman spectroscopy and surface topography

18A shows Raman spectra of CVD and RTA graphene prepared in Example 6. FIG. The spectrum of CVD graphene shows good crystal properties indicating the presence of graphite hexagonal lattice structures on surfaces with low defect density associated with very small D peaks. Wide and sharp 2D peaks are characteristic of the formation of misoriented graphene multilayers. Optical microscopy images of the surface show patchwork of graphene flakes with different contrast, which can provide evidence for thicker areas. Raman analysis of RTA graphene shows that these surfaces consist of disordered and discontinuous layers of carbon with high and broad D peaks that are indicative of defective materials. Very small 2D peaks indicate no hexagonal structure of C atoms. However, the optical image shows a shiny, uniform surface.

Surface roughness of the Ni / CVD and Ni / RTA surfaces was investigated by recording topographic AFM images (FIG. 18B). This analysis shows that the Ni / RTA surface of FIG. 18B consists of flat granules with mean lateral size d = 118 nm, rough mean square (rms) roughness R _rms across the scanned 5 x 5 μm ² region. = 1.3 nm. However, the AFM image of the Ni / CVD film of FIG. 18B shows the formation of much larger granules with average lateral size d = 1 μm and across the scanned 5 × 5 μm ² region, up to R _rms = 41 nm. Shows a severe increase in roughness. The latter results from the recrystallization that occurs when cooling the film during the last step of the CVD process. In addition, the RTA process at temperatures above 600 ° C. led to a significant increase in the roughness of the film, with AFM images reminiscent of samples of the CVD-process. Thus, process temperature plays a key role in determining the morphology of the resulting sample.

2. Carbon / nickel interface XPS  Spectroscopic analysis

In order to determine the oxidation state of the Ni surface under the graphene layer, an exposed Ni film was used as reference material and the Ni / CVD and Ni / RTA interfaces were analyzed by XPS. For each

Spectra are shown in FIGS. 19A-19C. As expected, the spectrum for Ni (FIG. 19A) showed the characteristics of oxidized Ni due to air exposure during specimen movement.

Is, Ni ^{3 +} (Ni ₂ O having an intensity of the binding energy of the, 856.1 eV (3) and 853.8 eV (2) associated with the formation of the formed and NiO in Ni ^{2 +} ions in Ni ^{3 +} ions in the Ni surface, respectively ₃ ) and the contribution of Ni ^{2 +} (NiO) oxidation state. The main peak of 852.6 eV (1) is due to pure Ni metal. Peaks (4) and (5) are incidental peaks. For Ni / CVD

The spectrum (Fig. 19B) corresponds to the metal Ni without oxide. As can be seen clearly, the XPS oxide peaks appearing for Ni (FIG. 19A) are completely absent and the dominant peaks at 852.8 eV (1) and 853.5 eV (2) correspond to Ni metal and Ni-C solid solutions, respectively. Peaks (3) and (4) with BE near 3.7 eV (minor) and 6.0 eV (major) above the main line (at 852.8 eV) are satellites corresponding to surface and bulk plasmons, respectively. Indicates. Ni / RTA

Similar results were obtained for the spectra. A fairly large signal of Ni of similar intensity for three Ni-based samples indicates that the overlay is thin and does not exceed a few nm thickness.

Thus, CVD and RTA processed samples show Ni films that are essentially free of oxides at the carbon-Ni interface. If it is recalled that the passivation oxide film has a thickness in the nm range on the exposed Ni, the data for Ni / CVD and Ni / RTA (FIGS. 19B and 19C) were compared with the data for Ni (FIG. 19A). It will be appreciated that after the sample processing of the present invention there is a surface oxide not exceeding 1-2% of the monolayer.

These measurements performed on samples stored in an atmospheric environment for two months confirmed that the carbon film acts as an effective impermeable membrane for oxygen diffusion. C 1s spectra for the same three samples are shown in FIGS. 19D-19F. For Ni films (FIG. 19D), the main peak was observed, with two components at 284.9 eV (1) and 286.4 eV (2), interpreted as CC (and CH hydrocarbons) and CO (and C-OH), respectively . Can be divided. The peak of 288.7 eV (3) corresponds to the CC = O bond. C 1s high resolution XPS scans for Ni / CVD (FIG. 19E) and Ni / RTA (FIG. 19F) were analyzed in three components. The 284.3 eV (1) and 284.6 eV (2) peaks are the strongest peaks and they relate to sp ² CC bonds in aromatic networks such as graphene. The third component at 285.4 eV (3) shows a C = C bond with sp ³ hybridization. Another important piece of information that can be inferred from the C 1s spectrum is the absence of detectable Ni carbide (Ni ₃ C). The characteristics of Ni ₃ C in the photoelectron emission spectrum of C 1s should be shown at binding energies below 284 eV. The spectra of Figs. 19E and 19F do not have any features at this location.

3. ToF - SIMS  Thickness and Composition Analysis

ToF-SIMS was first used to assess the presence and formation of nickel oxide in the surfaces of the Ni / CVD, Ni / RTA and Ni reference samples and in the bulk nickel film.

FIG. 20 shows in-depth changes of characteristic fragments for nickel, oxygen and various forms of nickel oxide in a reference sample (Ni exposed to air). Depth was measured by profilometry after the sample was exposed to ion bombardment. A distinct layer of nickel oxide consisting mainly of NiO, NiO ₂ and Ni ₂ O ₃ was observed. This oxide layer reached ˜2 nm, after which a sharp decrease was observed up to 7% of the top content (NiO _x / Ni interface). From this, it can be seen that all the oxides decrease exponentially as the depth of the Ni layer increases. Thus, it can be seen that the metallic layer prepared as described above consists of a 2 nm-thick nickel oxide layer on top of the Ni layer, which itself contains a small fraction of the oxide diffusing from the top surface.

FIG. 21 shows a comparison of depth-by-depth changes for NiO ^- and NiC ₂ ^- in reference Ni films (black), Ni / CVD (red) and Ni / RTA (blue). The gray area represents the deposited graphene layer, has a depth scale calibrated with a thickness meter, and used a Ni / SiO ₂ interface alignment point. According to the NiO ^- profile, as with XPS surface data, both deposition methods effectively prevent the formation of a nickel oxide layer on top of nickel. In addition to complete inhibition of the top oxide layer, a 97.6% reduction in Ni / RTA was observed at the graphene / Ni interface. As the nickel layer became deeper, the tendency of the oxide in Ni / RTA was similar to that of the reference Ni film and similar to the oxide content at about half the depth of the Ni layer. In Ni / CVD, the trend was less clear. After the initial low level of oxide at the surface, the oxide content seemed to increase with the depth of the Ni layer. This can be explained by the oxide diffusion from the buried Ni / Si interface triggered by higher processing temperatures. Thus, lower temperature RTA processing has been shown to outperform CVD processing in terms of effective oxide formation and diffusion prevention.

In addition, the NiC ₂ ^- ToF-SIMS profile informs about carbon layer thickness and carbon / Ni film interface quality. In the case of Ni / RTA, a sharp decrease was observed after a short plateau. This shows a graphene layer thickness of ˜5 nm and also shows no or little diffusion of carbon in the Ni layer (<1% after 10 nm). In contrast, Ni / CVD samples showed much thicker carbon-rich layers (named above 40 nm) and large diffusion in the entire Ni layer. No clear graphene / Ni interface was observed. The profile of the reference Ni film showed no graphene deposition as there was no carbon on or inside the Ni layer. The long tail in the negative thickness range of FIG. 21 for CVD samples quantifies the roughness of samples of the same order as the AFM-reference data. Low temperature RTA deposition forms a good quality graphene layer in terms of interface clarity and minimal carbon diffusion compared to CVD processing.

4. Work function  Measure

Work function (WF) values can affect the electrode / organic charge injection probability. Low WF values relate to a relatively high barrier to the injection of holes into the highest occupancy molecule orbital (HOMO), which typically lies at 5.52 eV for IIDDT-C3. WF measurements for Au, Ni and Ni / C were performed through an atmospheric optoelectronic yield counter as described above with a light source intensity of 100 nW in an energy range between 4.00 and 5.60 eV in steps of 0.05 eV. The measurements of WF for Au, Ni, Ni / RTA and Ni / CVD films were 5.10 eV, 4.85 eV, 5.0 eV and 5.11 eV, respectively. The observed Ni value was below the value of the pure Ni surface.

5. Organic field effect transistor OFET Characterization

22 illustrates the principle of the electrolyte gate operation. The polyelectrolyte gate can control the OSC's conductivity very effectively on-off with a ratio exceeding 10 ⁷ . The huge hysteresis apparently observed in very large ON conductivity values and shift curves indicates that electrochemical doping of the OSC occurs at the highest applied gate voltage value. The plot of the square root of I _SD (red curve) shows two distinct voltages. The onset voltage V ₀ (first slope in FIG. 22) is the gate voltage (device turn-on voltage) at which negative ions begin to accumulate at the ion-gel / OSC interface and acts as the large electric field gate of the device. Only the first nanometer at the interface between the active channel and the gate medium contributes to the conductivity in this regime of electric field doping. The threshold voltage (V _Th ) is associated with an increase in slope at onset of electrochemical doping of the bulk OSC layer. Since the active channel can be related to the overall thickness of the OSC, this electrochemically doped FET (EFET) section is expected to lead to significantly smaller interfacial resistance values. Interfacial resistance is generally expressed as resistance per unit length, ie R _C W, where W relates to the width of the active OSC channel. Comparing the four types of samples, FIG. 23 clearly shows that a difference is observed in the source-drain current and electrochemical threshold voltage values. Au and Ni / RTA samples show the highest conductivity values, while negative Ni electrodes clearly exhibit much smaller currents and larger electrochemical threshold voltages. The latter is expected to result from significantly lower work functions measured for exposed (oxidized) Ni.

Taking the advantage of a four-probe arrangement, derive the width-normalized total contact resistance (R _c W) and sheet resistance (R _sheet ) for four different metal electrodes as a function of applied V _G as shown in FIG. 24. It was.

For all devices, a typical drop in R _c W was observed with an increase in the gate voltage. In the range of high applied V _G (> -3V), the contact resistance of Ni / CVD and Ni / RTA devices is 1st and 2nd lower than the values for Ni devices, respectively. This clearly illustrates the role of carbon passivation on the Ni surface in improving the metal / OSC interface.

FIG. 25 shows a comparison of contact resistances R _S and R _D at the source and drain as a V _G function for devices with Au (red line) and Ni / RTA (black line) electrodes. This shows how advantageous Ni / RTA is in comparison to a good Au electrode. For both devices, R _S and R _D have the same order and exhibit the same behavior, and Au works marginally better than Ni / RTA. At low V _G , both the contact resistances of the source and drain exhibit somewhat larger values, and R _D is significantly larger than R _S. As V _G decreases, R _S decreases slightly, but R _D decreases significantly and eventually falls off the line. In addition, FIG. 25 shows that a large gate bias made R _S similar to R _D , indicating that charge injection is fully optimized. Table 1 below shows the main observed conductivity / resistance values of the four irradiated samples. This quantitatively shows how Au and Ni / RTA electrodes outperform the other two types of samples.

electrode	WF [eV]	R C [Ωcm] (Vg = -3.2V)	R C [Ωcm] Max Vg	R Sheet [KΩ]	V Th [V]
Au	5.1	4.9	3.7	1.9	-2.71
Ni / RTA	5.0	9.3	8.4	1.6	-2.79
Ni / CVD	5.11	129.4	129.4	4.6	-2.75
Ni	4.85	6.6 × 10 3	1.6 × 10 3	48.7	-3.12

Claims (18)

1. A method of forming a carbon-based passivation film while reducing the content of metal oxides and / or metal hydroxides at an interface with a metal oxide and / or metal hydroxide-containing metal layer,

   Applying a carbon-providing precursor on part or all of the surface of the metal oxide and / or metal hydroxide-containing metal layer; And

   A second step of annealing under a reducing atmosphere and temperature capable of reducing the metal oxides and / or metal hydroxides to pure metals and decomposing the carbon providing precursors

   Carbon-based passivation film forming method comprising a.
2. The method of claim 1, wherein the reducing atmosphere is a hydrogen-containing atmosphere.
3. The method of claim 1, wherein the carbon providing precursor comprises C, O, and H. 6.
4. The carbon providing precursor of claim 1, wherein the carbon providing precursor is selected from the group consisting of synthetic polymers, graphene, graphene oxide, organic low molecular weight self-assembled layer, carbonate, hydrocarbons, sugars, starch, glycol, diol, polyol and foods. Method of forming a passivation film.
5. The method according to claim 1, wherein the crystallinity of the carbon-based passivation film is adjusted according to the selection of the carbon donor precursor.
6. The method of claim 1, wherein the first and second steps are performed simultaneously.
7. The method of claim 1, wherein the metal is at least one selected from the group consisting of Ni, Cu, Fe, Al, Stainless steel, Cr, Si, and semiconductors.
8. The method of claim 1, wherein the annealing method in the second step is rapid thermal annealing (RTA).
9. The method of claim 1, wherein the annealing method in the second step is a heat treatment in a low pressure furnace.
10. The method of claim 1, wherein the annealing temperature in the second step is a temperature at which carbon may penetrate into the metal as the carbon providing precursor is pyrolyzed, and the time of the annealing is such that the carbon provided in the carbon providing precursor maintains a bond with the metal. A method of forming a carbon-based passivation film, characterized in that it is time to contain an amount of carbon that can cover the surface.
11. The method of claim 1, wherein the annealing in the second step is performed at a temperature of 350 to 650 ° C. and a time of 5 to 60 minutes.
12. In a metal electrode having a metal layer and a carbon-based passivation film formed on the metal layer,

    Applying a carbon donor precursor onto part or all of the surface of the metal oxide and / or metal hydroxide-containing metal layer and reducing the metal oxide and / or metal hydroxide-containing metal layer to pure metal and A metal electrode characterized by annealing under a reducing atmosphere and temperature capable of decomposing a carbon donor precursor, thereby reducing or eliminating metal oxides and / or metal hydroxides at the interface between the metal layer and the carbon-based passivation film.
13. The metal electrode of Claim 12 manufactured by the method of any one of Claims 1-11.
14. 13. The metal electrode according to claim 12, wherein the metal oxide is not detectable by XPS at the interface between the metal layer and the carbon-based passivation film.
15. 13. The metal electrode according to claim 12, wherein metal carbide is not detectable by XPS at the interface between the metal layer and the carbon-based passivation film.
16. The metal electrode according to claim 12, wherein the contact resistance between the metal layer and the carbon-based passivation film is 1 to 90 ohms.
17. The metal electrode according to claim 12, wherein the carbon-based passivation film is graphene.
18. A step of preparing a metal electrode on which a carbon-based passivation film is formed by the method according to any one of claims 1 to 11; And

    Step b of forming an organic layer by a solution process on the carbon-based passivation film of the metal electrode

    Organic device manufacturing method characterized in that it comprises a.

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