Elements and methods for manufacturing the same, as well as electronic devices and wireless communication devices.

Abstract

To provide an element that is excellent in electrical connection between an upper electrode and a lower electrode and has a low wiring resistance of the upper electrode.SOLUTION: An element has: a substrate 1; a lower electrode 2 placed on the substrate 1; and an upper electrode 4 having an area in contact with the lower electrode 2. Standard oxidation-reduction potential of a metallic component forming the lower electrode 2 is -0.40 V or more and 0.50 V or less. The upper electrode 4 includes at least a first metallic component, a second metallic component, and an organic component. When standard oxidation-reduction potential of the second metallic component is E° (M2), the standard oxidation-reduction potential of the metallic component forming the lower electrode is E° (M), and standard oxidation-reduction potential of the first metallic component is E° (M1), their relationship is E° (M2)<E° (M)≤E° (M1).SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an element, a method for manufacturing the same, an electronic device, and a wireless communication device.

Background Art

[0002] In recent years, wireless communication systems using RFID (Radio Frequency Identification) technology have attracted attention. An RFID tag has an IC chip having a circuit composed of a field effect transistor (hereinafter referred to as FET) or the like, and an antenna for wireless communication with a reader / writer. An antenna installed in the tag receives a carrier wave transmitted from the reader / writer, and a drive circuit in the IC chip operates.

[0003] RFID tags are expected to be used in various applications such as logistics management, product management, and theft prevention, and some introductions have started for IC cards such as transportation cards and product tags.

[0004] In the future, in order to use RFID tags for all products, it is necessary to reduce the manufacturing cost. Therefore, in the manufacturing process of RFID tags, it has been considered to eliminate processes using vacuum or high temperature and use a flexible and inexpensive process using coating / printing technology. As an example, using a conductive paste containing a conductor and a photosensitive organic component, electrodes (upper electrodes and lower electrodes) of elements such as FETs and capacitors constituting the RFID circuit are formed using coating / printing technology, and the upper electrodes and lower electrodes of each element are electrically connected according to the circuit configuration (for example, see Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, when forming an electrode layer using a conductive paste as described in Patent Document 1, there was a problem that it was difficult to obtain electrical connection between the lower electrode and the upper electrode.

[0007] Therefore, an object of the present invention is to provide an element that is excellent in electrical connection between the upper electrode and the lower electrode and has a low wiring resistance of the upper electrode.

Means for Solving the Problems

[0008] In order to solve the above problems, the present invention has the following configuration.

[0009] That is, the present invention has the following configuration. (1) An element including a substrate, a lower electrode disposed on the substrate, and an upper electrode having a region in contact with the lower electrode, wherein the standard oxidation-reduction potential of the metal component constituting the lower electrode is -0.40 V or more and 0.50 V or less, the upper electrode includes at least a first metal component, a second metal component, and an organic component, and when the standard oxidation-reduction potential of the second metal component is E°(M2), the standard oxidation-reduction potential of the metal component constituting the lower electrode is E°(M), and the standard oxidation-reduction potential of the first metal component is E°(M1), it is an element characterized by the relationship E°(M2) < E°(M) ≤ E°(M1). (2) Further having an insulating layer disposed on the lower electrode, the upper electrode is disposed on the insulating layer, and the region where the lower electrode and the upper electrode are in contact is provided in the insulating layer and is a contact hole where the lower electrode and the upper electrode are in contact, the element according to (1). (3) The element according to (1) or (2), wherein the difference between E°(M2) and E°(M) is 1.10 V or less. (4) The element according to any one of (1) to (3), wherein E°(M1) is 0.60 V or more and 1.50 V or less. (5) The element according to any one of (1) to (4), wherein the specific gravity difference between the first metal component and the second metal component is 3 or less. (6) The element according to any one of (1) to (5), wherein the upper electrode on the insulating layer and the upper electrode in the contact hole are in a continuous phase. (7) The element according to any one of (1) to (6), wherein the element is a field-effect transistor. (8) The element according to any one of (1) to (7), wherein the semiconductor layer of the field-effect transistor contains carbon nanotubes. (9) An electronic device having an element as described in any of (1) to (8). A method for manufacturing an element according to any one of (10)(1) to (8), characterized in that the upper electrode is formed by applying a paste containing at least a first metal component, a second metal component, and an organic component, followed by a process including drying, exposure, and development. (11) A wireless communication device having at least one of the elements described in any of (1) to (8), and an antenna. [Effects of the Invention]

[0010] According to the present invention, it is possible to obtain an element that has excellent electrical connection between the upper electrode and the lower electrode and low wiring resistance of the upper electrode. [Brief explanation of the drawing]

[0011] [Figure 1] A schematic cross-sectional view showing an element according to Embodiment 1 of the present invention. [Figure 2] A schematic cross-sectional view showing an element according to Embodiment 2 of the present invention. [Figure 3] A schematic cross-sectional view showing an element according to Embodiment 3 of the present invention. [Figure 4] A schematic diagram showing a manufacturing method for an element according to Embodiment 2 of the present invention. [Figure 5] Block diagram showing an example of a wireless communication device using an element according to an embodiment of the present invention. [Figure 6] Schematic diagram showing the element fabricated in the example. [Figure 7A] Schematic diagram of a photomask for fabricating a pattern in the element in the example. [Figure 7B] Schematic diagram of a photomask for fabricating a pattern in an element in an embodiment [Figure 8A] Schematic diagram showing an element fabricated in an embodiment [Figure 8B] Schematic diagram showing an element fabricated in an embodiment [Figure 9] Schematic diagram showing a manufacturing method of an element fabricated in an embodiment

Mode for Carrying Out the Invention

[0012] Hereinafter, preferred embodiments of an element, a method for manufacturing the element, and a wireless communication device according to the present invention will be described in detail. However, the present invention is not limited to the following embodiments, and can be variously modified and implemented according to the purpose and application. Also, the description of the specific embodiment shown in the drawings can be understood as the description of the present invention as a superior concept.

[0013] <Element> One aspect of an element according to an embodiment of the present invention is an element including a base material, a lower electrode disposed on the base material, and an upper electrode having a region in contact with the lower electrode, wherein the standard oxidation-reduction potential of the metal component constituting the lower electrode is -0.40 V or more and 0.50 V or less, the upper electrode includes at least a first metal component, a second metal component, and an organic component, and when the standard oxidation-reduction potential of the second metal component is E°(M2), the standard oxidation-reduction potential of the metal component constituting the lower electrode is E°(M), and the standard oxidation-reduction potential of the first metal component is E°(M1), they are in the relationship of E°(M2) < E°(M) ≤ E°(M1).

[0014] Another aspect of the device according to an embodiment of the present invention further has an insulating layer disposed on the lower electrode, the upper electrode is disposed on the insulating layer, and a region where the lower electrode and the upper electrode are in contact is provided within the insulating layer and is a contact hole where the lower electrode and the upper electrode are in contact. That is, such a device includes a substrate, a lower electrode disposed on the substrate, an insulating layer disposed on the lower electrode, an upper electrode disposed on the insulating layer, and a contact hole provided within the insulating layer where the lower electrode and the upper electrode are in contact. The standard oxidation-reduction potential of the metal component constituting the lower electrode is -0.40 V or more and 0.50 V or less. The upper electrode includes at least a first metal component, a second metal component, and an organic component. When the standard oxidation-reduction potential of the second metal component is E°(M2), the standard oxidation-reduction potential of the metal component constituting the lower electrode is E°(M), and the standard oxidation-reduction potential of the first metal component is E°(M1), they are in the relationship of E°(M2) < E°(M) ≤ E°(M1).

[0015] The electrode in the present invention is a member or region used to create an electric field, conduct an electric current, or extract an electric signal. As this electrode, in addition to members generally called "electrodes" such as the source, drain, and gate electrodes of a transistor, the upper and lower electrodes of a capacitor, and the pair of electrodes of a rectifying element, in a multilayer circuit, a region where different conductors are joined to make an electrical connection between layers can be cited.

[0016] [Embodiment 1] FIG. 1 is a schematic cross-sectional view showing a device according to Embodiment 1 of the present invention. The device according to this embodiment includes a substrate 1, a lower electrode 2 disposed on the substrate 1, an insulating layer 3 disposed on the lower electrode 2, an upper electrode 4 disposed on the insulating layer 3, and a contact hole 5 provided within the insulating layer 3 where the lower electrode 2 and the upper electrode 4 are in contact. The upper electrode 4 includes at least a first metal component, a second metal component, and an organic component, which are not shown in the figure.

[0017] In the element according to this embodiment, the organic components contained in the upper electrode 4 improve the adhesion between the upper electrode 4 and the insulating layer 3 and the lower electrode 2, as well as the flexibility of the element. Further, between the standard oxidation-reduction potential E°(M1) of the first metal component contained in the upper electrode 4 on the insulating layer 3 and the standard oxidation-reduction potential E°(M2) of the second metal component, and the standard oxidation-reduction potential E°(M) of the metal component constituting the lower electrode 2, there is a relationship of E°(M2) < E°(M) ≤ E°(M1), and E°(M) is -0.40 V or more and 0.50 V or less, whereby an element excellent in electrical connection between the lower electrode 2 and the upper electrode 4, excellent in electrical connection, and having a low wiring resistance of the upper electrode 4 can be obtained.

[0018] Although the detailed mechanism thereof is unknown, it is presumed as follows. As a cause for the difficulty in obtaining electrical connection between the lower electrode 2 and the upper electrode 4, it is conceivable that the organic components contained in the upper electrode 4 oxidize the lower electrode 2 in contact therewith, and an oxide film is formed on the lower electrode 2. When the oxide film is present, the resistance (contact resistance) value between the upper electrode and the lower electrode 2 increases.

[0019] Therefore, by including a second metal component, which is a metal component having a lower standard oxidation-reduction potential than the metal component constituting the lower electrode 2, in the upper electrode 4, the second metal component is more easily oxidized than the lower electrode, and oxidation of the lower electrode 2 can be suppressed. Further, by further having a first metal component having a standard oxidation-reduction potential equal to or higher than that of the metal component constituting the lower electrode 2 in the upper electrode 4, even if the second metal component is oxidized, conductivity can be maintained by the first metal component.

[0020] Due to the above-described action, oxidation of the lower electrode 2 by the organic components contained in the upper electrode 4 is suppressed or reduced, and it is considered that good electrical connection between the lower electrode 2 and the upper electrode 4 can be obtained.

[0021] The standard redox potential is calculated as the potential difference with respect to the normal hydrogen electrode (NHE) when the metal component identified by elemental analysis of the upper electrode and the lower electrode is used as an electrode by itself. Since the standard redox potential is a value specific to a substance, the numerical value is referred to from the 6th revised edition of the Basic Edition of the Kagaku Binran published by Maruzen Co., Ltd. as the standard redox potential in the present invention.

[0022] (Metal component) From the viewpoint of achieving conductivity between the upper and lower electrodes, each of the metal components constituting the lower electrode and each of the metal components contained in the upper electrode in the present invention is preferably selected from materials having an electrical conductivity of 1.0×10 6 S / m or more.

[0023] The difference between E°(M2) and E°(M) is not particularly limited as long as E°(M2) < E°(M) is satisfied, but it is preferably 1.10V, and more preferably 0.70V or less. This makes it easier to suppress the deterioration of the contact resistance between the upper and lower electrodes over time. Further, the difference between E°(M2) and E°(M) is more preferably 0.10V or more. This makes it even easier to suppress the deterioration of the contact resistance between the upper and lower electrodes over time.

[0024] E°(M1) is preferably 0.60V or more and 1.50V or less. This makes it less likely for the oxidation of the first metal component to occur, and it is easier to obtain a good and stable electrical connection between the lower electrode 2 and the upper electrode 4. More preferably, E°(M1) is 0.60V or more and 1.00V or less. The higher the standard redox potential, the more the oxidation of the first metal component can be suppressed. However, when performing a processing process such as etching when forming the upper electrode in a desired pattern, the deterioration of processability and the increase in manufacturing cost are likely to occur.

[0025] E°(M) is -0.40V or more and 0.50V or less, but preferably 0.00V or more and 0.50V or less. This makes it easier to further suppress the oxidation of the metal component of the lower electrode over time, and thus the electrical connection between the lower electrode 2 and the upper electrode 4 becomes more stable.

[0026] The material used for the lower electrode can be any conductive material that is commonly used as an electrode and has a standard oxidation-reduction potential of -0.40V to 0.50V. Examples of conductive materials include, but are not limited to, metal components containing elements selected from the group consisting of copper, iron, tin, indium, cobalt, molybdenum, nickel, lead, and bismuth. Among these, metal components containing elements selected from the group consisting of copper, tin, and nickel are preferred as conductive materials because they can be deposited on a film by vacuum deposition and are easy to apply to the roll-to-roll method.

[0027] The material used for the upper electrode contains at least a first metallic component, a second metallic component, and an organic component. The first metallic component may include elements selected from the group consisting of gold, silver, copper, nickel, tin, bismuth, lead, palladium, platinum, and molybdenum. The second metallic component may include elements selected from the group consisting of nickel, tin, bismuth, lead, molybdenum, chromium, and zinc.

[0028] A more preferred metallic component is a first metallic component containing an element selected from the group consisting of gold, silver, copper, nickel, tin, bismuth, and lead, and a second metallic component containing an element selected from the group consisting of nickel, tin, bismuth, lead, zinc, and molybdenum. The first and second metallic components may be particulate, i.e., metallic particles.

[0029] The first metal component is particularly preferably silver particles, from the viewpoint of easily obtaining a conductive film and conductive pattern with excellent conductivity and stability. The second metal component is particularly preferably nickel particles or molybdenum particles, from the viewpoint of easily obtaining a conductive film and conductive pattern with excellent flexibility and conductivity of the upper electrode, when the first metal component is silver particles.

[0030] Furthermore, when the metal component of the lower electrode is copper, it is particularly preferable that the first and second metal components be silver particles and nickel particles, respectively. This makes it easier to obtain more stable conductivity.

[0031] It is preferable that the first and second metal components exist independently and dispersed within the upper electrode. This makes it easier to maintain the film strength of the upper electrode. The dispersion of each metal component can be confirmed by observing the cross-section of the upper electrode using a scanning electron microscope (SEM) or transmission electron microscope (TEM).

[0032] Furthermore, as long as the effects of the present invention are achieved, it is acceptable for a portion of the first metal component and the second metal component to be alloyed.

[0033] Furthermore, it is preferable that the total volume ratio of the second metal component to the total volume of the first and second metal components in the upper electrode film is 10% to 35%. By setting the volume ratio within this range, it becomes easier to further suppress the deterioration of contact resistance over time due to external influences such as temperature and humidity, and it becomes easier to obtain stable conductivity.

[0034] Furthermore, if the volume resistivity of the second metal component is higher than that of the first metal component, it is even more preferable to set the total volume ratio of the second metal component to the total volume of the first and second metal components in the upper electrode film to 10% or more and 20% or less. By setting the volume ratio within this range, it is possible to lower the initial contact resistance while suppressing the deterioration of contact resistance over time due to external influences such as temperature and humidity.

[0035] The volume ratio of the first and second metallic components in the upper electrode film is determined by observing a 200 μm wide area of ​​the upper electrode cross-section using a scanning electron microscope (SEM), distinguishing the first and second metallic components from organic components through X-ray elemental analysis (SEM-EDX), and then performing image analysis to calculate the area ratio of the first and second metallic components in the upper electrode, which is considered the volume ratio.

[0036] One method for detecting metallic components in the upper and lower electrodes is to cut a cross section perpendicular to the electrode film surface in the area including the contact hole and its surroundings, and perform elemental analysis using energy-dispersive X-ray spectroscopy (TEM-EDX) with a transmission electron microscope.

[0037] It is preferable that the difference between the specific gravity of the first metal component and the specific gravity of the second metal component in the upper electrode is not too large, from the viewpoint of improving the film strength and flexibility of the upper electrode. Therefore, it is preferable that the difference in specific gravity between the first metal component and the second metal component is 3 or less.

[0038] (organic ingredients) There are no particular restrictions on the organic components, but examples include monomers, oligomers, polymers, photopolymerization initiators, compounds having carboxyl groups, polymerization inhibitors, plasticizers, leveling agents, surfactants, silane coupling agents, defoamers, and pigments.

[0039] The oligomer or polymer is not particularly limited, and can be acrylic resin, epoxy resin, novolac resin, phenolic resin, polyimide precursor, polyimide, etc. Among these, acrylic resin is preferred from the viewpoint of crack resistance when the electrode is bent. This is presumed to be because the glass transition temperature of acrylic resin is 100°C or lower, and it softens during the thermal curing of the conductive film, increasing the bonding between them.

[0040] Acrylic resin is a resin whose repeating units contain structures derived from at least acrylic monomers. Specific examples of acrylic monomers include methyl acrylate, methyl methacrylate, acrylic acid, methacrylic acid, 2-hydroxyethyl acrylate, and isovonyl acrylate. These acrylic monomers may be used individually or in combination of two or more.

[0041] Compounds having a carbon-carbon double bond can be used as monomers. Specific examples of monomers include the aforementioned acrylic monomers, as well as styrene, α-methylstyrene, maleic acid, and fumaric acid.

[0042] Examples of compounds containing a carboxyl group include acrylic resins using unsaturated acids such as unsaturated carboxylic acids as part of their constituent monomers, surfactants containing a carboxyl group, and other additives containing a carboxyl group.

[0043] Preferably, the organic components include at least a compound having a carbon-carbon double bond and a compound having a carboxyl group. By including at least these compounds, curing reactivity through polymerization reactions such as radical polymerization, cationic polymerization, and anionic polymerization, as well as solubility in alkaline developers, can be imparted, thereby enabling the production of a photosensitive conductive paste and allowing for fine pattern processing by photolithography.

[0044] (Continuous phase) It is preferable that the upper electrode on the insulating layer and the upper electrode in the contact hole are in a continuous phase. A continuous phase means that the material constituting the upper electrode on the insulating layer and the material constituting the upper electrode in the contact hole are mixed together and integrated in such a way that the concentration of each material changes in steps, or that the material constituting the upper electrode on the insulating layer and the material constituting the upper electrode in the contact hole are the same and there is no connection surface at the connection between the two.

[0045] The continuous phase can be confirmed by observing the cross-section of the connection using a scanning electron microscope (SEM) or transmission electron microscope (TEM). By creating a continuous phase, the increase in resistance in the region between the upper electrode on the insulating layer and the upper electrode in the contact hole can be suppressed. One method for forming the continuous phase is to use the aforementioned photosensitive conductive paste to form the upper electrode on the insulating layer and the upper electrode in the contact hole simultaneously.

[0046] (base material) The substrate 1 can be made of any material as long as at least the surface on which the electrode system is placed is insulating. As the substrate, for example, an inorganic substrate such as silicon wafer, glass, sapphire, or alumina sintered body, or an organic substrate such as polyimide, polyvinyl alcohol, polyvinyl chloride, polyethylene terephthalate, polyvinylidene fluoride, polysiloxane, polyvinylphenol (PVP), polyester, polycarbonate, polysulfone, polyethersulfone, polyethylene, polyphenylene sulfide, or polyparaxylene can be used. However, in order to adopt a less expensive manufacturing process, a material with a low cost per unit area and excellent flexibility is preferred.

[0047] Furthermore, the substrate may be a laminate of multiple materials, such as a PVP film formed on a silicon wafer or a polysiloxane film formed on polyethylene terephthalate.

[0048] (Insulating layer) The material used for the insulating layer 3 is not particularly limited as long as insulation between the lower electrode 2 and the upper electrode 4 can be ensured, but examples include inorganic materials such as silicon oxide and alumina; organic polymer materials such as polyimide, polyvinyl alcohol, polyvinyl chloride, polyethylene terephthalate, polyvinylidene fluoride, polysiloxane, and polyvinylphenol (PVP); or mixtures of inorganic material powder and organic material.

[0049] Among these, those containing organic compounds that include a silicon-carbon bond are preferred, and polysiloxanes are particularly preferred.

[0050] The insulating layer preferably contains a photosensitive organic component to provide pattern processing capabilities by photolithography. Examples of photosensitive organic components include radical polymerizable compounds, photopolymerization initiators, photoacid generators, sensitizers, chain transfer agents, and polymerization inhibitors.

[0051] The thickness of the insulating layer is preferably 0.05 to 5 μm, and more preferably 0.1 to 1 μm. A thickness within this range facilitates the formation of a uniform thin film. The film thickness can be measured by atomic force microscopy, ellipsometry, spectroscopic reflectance, or other methods.

[0052] The insulating layer may be a single layer or multiple layers. Furthermore, one layer may be formed from multiple insulating materials, or multiple insulating layers may be formed by laminating multiple insulating materials.

[0053] A contact hole 5 is provided within the insulating layer for connecting the lower electrode and the upper electrode. Common processing methods such as photolithography, dry etching, and wet etching can be used to form the contact hole.

[0054] The size of the contact hole is not particularly limited as long as the upper electrode fills the contact hole and an electrical connection can be made between the upper and lower electrodes. However, it is preferable that the aspect ratio (the ratio of the contact depth to the contact diameter) is at least less than 1, that is, that the diameter of the contact hole is larger than the depth of the contact hole, from the viewpoint of facilitating the embedding of the upper electrode.

[0055] [Embodiment 2] Figure 2 is a schematic cross-sectional view showing an element according to Embodiment 2 of the present invention. This Embodiment 2 is similar to the features of Embodiment 1, except that it is an example in which the element according to Embodiment 1 is combined with a field-effect transistor (FET).

[0056] The FET shown within the dotted line in Figure 2(a) comprises an insulating substrate 1, a gate electrode 12 which is a lower electrode formed on the substrate 1, a gate insulating layer 13 which is an insulating layer disposed on the gate electrode 12, a source electrode 14a and a drain electrode 14b which are upper electrodes provided thereon, and a semiconductor layer 16 provided between the source electrode 14a and the drain electrode 14b. The source electrode 14a and the drain electrode 14b contain at least a first metallic component and a second metallic component and an organic component (not shown).

[0057] This structure is a so-called bottom-gate, top-contact structure, in which the gate electrode is located on the underside of the semiconductor layer, and the source and drain electrodes are located on the top surface of the semiconductor layer.

[0058] Note that the portion outside the dotted line in Figure 2(a) (the portion on the right) has the same structure as the element according to Embodiment 1. In the element of Figure 2(a), the drain electrode 14b and the upper electrode 4 are in a continuous phase.

[0059] The FET shown within the dotted line in Figure 2(b) comprises an insulating substrate 1, a source electrode 22a and a drain electrode 22b which are lower electrodes formed on the substrate 1, a semiconductor layer 26 provided between the source electrode 22a and the drain electrode 22b, a gate insulating layer 23 which is an insulating layer disposed on the source electrode 22a, the drain electrode 22b and the semiconductor layer 26, and a gate electrode 24 which is an upper electrode provided thereon.

[0060] This structure is a so-called top-gate, bottom-contact structure in which the gate electrode is located on the upper side of the semiconductor layer, and the source electrode and drain electrode are located on the lower side of the semiconductor layer.

[0061] Note that the portion outside the dotted line in Figure 2(b) (the portion on the right) has the same structure as the element according to Embodiment 1. In the element in Figure 2(b), the drain electrode 22b and the lower electrode 2 are in a continuous phase.

[0062] The semiconductor layer constituting the FET is not particularly limited as long as it is a material exhibiting semiconducting properties, but materials with high carrier mobility are preferably used. Furthermore, the material for the semiconductor layer 16 is preferably one to which a low-cost and simple coating process can be applied, and organic semiconductors and carbon materials are examples of preferred materials.

[0063] As organic semiconductors used in semiconductor layer 16, known materials such as pentacene, polythiophenes, compounds containing thiophene units in the main chain, polypyrroles, poly(p-phenylenevinylene) compounds, polyanilines, polyacetylenes, polydiacetylenes, polycarbazoles, polyfurans, polyheteroaryls with nitrogen-containing aromatic rings as constituent units, condensed polycyclic aromatic compounds, heteroaromatic compounds, aromatic amine derivatives, biscarbazole derivatives, pyrazoline derivatives, stilbene compounds, hydrazone compounds, metal phthalocyanines such as copper phthalocyanine, metal porphyrins such as copper porphyrin, distyrylbenzene derivatives, aminostyryl derivatives, aromatic acetylene derivatives, condensed ring tetracarboxylic acid diimides, and organic dyes can be used. The above organic semiconductors may contain two or more of these.

[0064] Carbon materials used in the semiconductor layer 16 include carbon nanotubes (CNTs), graphene, and fullerenes. Among these, CNTs are preferred as the carbon material because they can be formed at low temperatures of 200°C or below and are highly suitable for coating processes. Furthermore, unlike organic semiconductors, crystallization is not required, high mobility can be achieved through the network structure of CNTs, and the FET characteristics can be changed according to the work function of the electrode material. For this reason, CNTs are preferred as the carbon material because they make it easier to adjust the FET characteristics by changing the combination and content of metal component 1 and metal component 2 contained in the upper electrode, as in the present invention.

[0065] As the carbon nanotube (CNT), any of the following may be used: single-walled carbon nanotubes (WNTs) in which a single carbon film (graphene sheet) is wound in a cylindrical shape, double-walled carbon nanotubes (DWNTs) in which two graphene sheets are wound concentrically, or multi-walled carbon nanotubes (WNTs) in which multiple graphene sheets are wound concentrically. Two or more of these may also be used. Among these, single-walled carbon nanotubes are preferred from the viewpoint of exhibiting semiconductor properties, and it is more preferable that the single-walled carbon nanotubes contain 90% by weight or more of semiconductor-type single-walled carbon nanotubes. Even more preferable is that the single-walled carbon nanotubes contain 95% by weight or more of semiconductor-type single-walled carbon nanotubes.

[0066] Furthermore, CNTs with a conjugated polymer attached to at least a portion of their surface (hereinafter referred to as CNT composites) exhibit excellent dispersion stability in solution and high mobility, making them particularly preferable as carbon materials for the semiconductor layer 16. Here, a conjugated polymer refers to a compound in which repeating units adopt a conjugated structure and has a degree of polymerization of 2 or more. In addition, by using a solution in which CNTs are uniformly dispersed, a film in which CNTs are uniformly dispersed (a film constituting the semiconductor layer 4) can be formed by a coating method such as an inkjet method.

[0067] The phrase "a state in which a conjugated polymer is attached to at least a portion of the surface of a CNT" means a state in which part or all of the CNT surface is covered by a conjugated polymer. It is presumed that the conjugated polymer can cover the CNT because interactions occur due to the overlapping of π-electron clouds originating from each conjugated structure. Whether or not a CNT is covered with a conjugated polymer can be determined by observing that the reflected color of the target CNT approaches the color of the conjugated polymer from the color of an uncovered CNT. Quantitatively, the presence of the deposit and the mass ratio of the deposit to the CNT can be identified by elemental analysis such as X-ray photoelectron spectroscopy (XPS).

[0068] The conjugated polymer attached to the CNT can be used regardless of its molecular weight, molecular weight distribution, or structure. From the viewpoint of ease of attachment to the CNT, it is preferable that the conjugated polymer has a weight-average molecular weight of 1000 or more.

[0069] Methods for attaching a conjugated polymer to CNTs include, for example, the first to fourth methods described below. The first method involves adding and mixing CNTs into a molten conjugated polymer. The second method involves dissolving the conjugated polymer in a solvent and then adding and mixing CNTs into this solution. The third method involves pre-dispersing CNTs in a solvent using ultrasound or the like before adding and mixing the conjugated polymer. The fourth method involves placing the conjugated polymer and CNTs in a solvent and then irradiating this mixture with ultrasound to mix it. In this invention, a combination of these methods may be used.

[0070] In the present invention, the length of the CNTs is preferably shorter than the distance between the source electrode 14a and the drain electrode 14b (channel length). The average length of the CNTs depends on the channel length, but is preferably 2 μm or less, and more preferably 0.5 μm or less. Generally, commercially available CNTs have a length distribution, and may contain CNTs longer than the channel length. For this reason, it is preferable to add a step to shorten the CNTs to be shorter than the channel length in the process of forming the semiconductor layer 4. Effective methods for shortening the CNTs to be shorter than the channel length include, for example, acid treatment with nitric acid or sulfuric acid, ultrasonic treatment, or freeze-drying to cut the CNTs into short fibers. Furthermore, combining this with separation by filtration is even more preferable from the viewpoint of improving the purity of the CNTs. The diameter of the CNTs is not particularly limited, but is preferably 1 nm to 100 nm, and more preferably 50 nm or less.

[0071] Examples of conjugated polymers used to coat the above-mentioned CNTs include polythiophene polymers, polypyrrole polymers, polyaniline polymers, polyacetylene polymers, poly-p-phenylene polymers, poly-p-phenylenevinylene polymers, and thiophene-heteroarylene polymers having thiophene units and heteroaryl units in repeating units. Two or more of these conjugated polymers may also be used. The above-mentioned conjugated polymers can be those consisting of a series of single monomer units, those obtained by block copolymerization of different monomer units, those obtained by random copolymerization, or those obtained by graft polymerization.

[0072] Furthermore, the semiconductor layer 16 may be a mixture of a CNT composite and an organic semiconductor. By uniformly dispersing the CNT composite in the organic semiconductor, it is possible to achieve high mobility while maintaining the properties of the organic semiconductor itself.

[0073] Furthermore, the semiconductor layer 16 may also contain an insulating material. Examples of insulating materials used here include, but are not limited to, the insulating material composition of the present invention, or polymer materials such as poly(methyl methacrylate), polycarbonate, and polyethylene terephthalate.

[0074] The semiconductor layer 16 may be a single layer or multiple layers. The thickness of the semiconductor layer 16 is preferably 1 nm to 200 nm, and more preferably 100 nm or less. By making the semiconductor layer 4 thickness within this range, uniform thin film formation becomes easier, and the current between the source and drain electrodes, which cannot be controlled by the gate voltage, is suppressed, and the on / off ratio of the FET can be made higher. The thickness of the semiconductor layer 16 can be measured by atomic force microscopy or ellipsometry.

[0075] [Embodiment 3] Figure 3(a) is a schematic diagram showing an element according to Embodiment 3 of the present invention. The element according to Embodiment 3 of the present invention comprises a base material 1, a lower electrode 32 disposed on the base material 1, and an upper electrode 34 having a region in contact with the lower electrode 32. Since Embodiment 3 does not have the insulating layer 3 of the element according to Embodiment 1, the lower electrode 32 and the upper electrode 34 can be contacted without passing through the contact hole 5. Except for being electrically connected, the features are the same as those of Embodiment 1. By taking on a desired planar shape, the element according to Embodiment 3 can be given various functions. For example, an element according to Embodiment 3 with a coil-like planar shape can function as an antenna.

[0076] Figure 3(b) shows a rectifier element utilizing the element according to Embodiment 3 of the present invention. The rectifier element comprises the element according to Embodiment 3 of the present invention, an insulating layer 33 disposed on a part of the lower electrode 32, an upper electrode 35 disposed on the insulating layer 33, and a semiconductor layer 36 provided between the upper electrode 34 and the upper electrode 35.

[0077] While embodiments for carrying out the present invention have been described so far, the present invention should not be limited to the embodiments described above. For example, when electrically connecting the lower wiring and the upper wiring through the contact holes of the insulating layer, or when electrically connecting the upper electrode and the lower wiring through the contact holes of the insulating layer, a similar configuration can be used to achieve superior electrical connection and lower wiring resistance.

[0078] <Method of manufacturing the element> The method for manufacturing an element according to an embodiment of the present invention will be specifically described below, using the example of manufacturing an element with the structure shown in Figure 2(a).

[0079] First, as shown in Figure 4(a), a group of lower electrodes (lower electrodes 2, gate electrodes 12) are formed on the insulating substrate 1. There are no particular limitations on the method for forming the group of lower electrodes, and examples include known techniques such as resistance heating deposition, electron beam deposition, sputtering, plating, chemical vapor deposition (CVD), ion plating coating, inkjet printing, and printing. Another example of an electrode formation method is to apply a paste containing organic components and a conductor onto an insulating substrate using known techniques such as spin coating, blade coating, slit die coating, screen printing, bar coating, mold method, print transfer method, and immersion pulling method, and then dry it using an oven, hot plate, infrared rays, etc.

[0080] Furthermore, as a method for forming the electrode pattern, the electrode thin film fabricated by the above method may be patterned into a desired shape using a known photolithography method, or the pattern may be formed by using a mask of the desired shape during the deposition or sputtering of the electrode material.

[0081] Next, as shown in Figure 4(b), insulating layers 3 and 13 are formed on the lower electrode group. There are no particular limitations on the method for producing the insulating layers 3 and 13, but for example, a method can be used in which a composition containing a material for forming the insulating layer is applied to a substrate, the coating film obtained by drying is formed by photolithography, and then heat-treated as necessary. Known coating methods include spin coating, blade coating, slit die coating, screen printing, bar coating, mold method, print transfer, immersion and pull-up method, and inkjet method. The heat treatment temperature of the coating film is preferably in the range of 100 to 300°C.

[0082] Next, as shown in Figure 4(c), a semiconductor layer 16 is formed on top of the insulating layer 13. While dry methods such as resistance heating deposition, electron beam deposition, sputtering, and CVD can be used to form the semiconductor layer 16, coating methods are preferable from the viewpoint of manufacturing cost and suitability for large areas. Specifically, spin coating, blade coating, slit die coating, screen printing, bar coating, mold method, print transfer, immersion and pull-up, and inkjet methods are preferred. From these, it is preferable to select a coating method according to the desired coating characteristics, such as coating thickness control and orientation control. Furthermore, the formed coating may be subjected to annealing treatment under air, reduced pressure, or an inert gas atmosphere such as nitrogen or argon.

[0083] Next, as shown in Figure 4(d), an upper electrode group (upper electrode 4, source electrode 14a, drain electrode 14b) is formed on top of the insulating layers 3, 13, the lower electrode 2, and the semiconductor layer 16. More preferably, the upper electrode group is formed by applying a paste containing at least a first metal component, a second metal component, and an organic component, followed by drying, exposure, and development.

[0084] Known coating methods include spin coating, blade coating, slit die coating, screen printing, bar coating, mold casting, print transfer, and immersion-pull methods. Drying methods include those using ovens, hot plates, and infrared radiation.

[0085] The most common exposure method is to expose the material through a photomask, as is done in conventional photolithography. Alternatively, a method of direct drawing with laser light or the like may be used. Examples of exposure equipment include stepper exposure machines and proximity exposure machines. Examples of active light sources used in this process include near-ultraviolet light, ultraviolet light, electron beams, X-rays, or laser light, but ultraviolet light is preferred. Examples of ultraviolet light sources include low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, halogen lamps, or germicidal lamps, but ultra-high-pressure mercury lamps are preferred.

[0086] Development methods include spraying the substrate with an alkaline developer such as tetramethylammonium hydroxide, potassium hydroxide, or sodium carbonate while the substrate is stationary or rotating, or immersing the substrate in the developer. The pattern obtained by development may be rinsed with water or an alcohol aqueous solution.

[0087] Furthermore, it is preferable to cure the obtained pattern as needed. Curing methods include, for example, heating and drying using an oven, inert oven, hot plate, or infrared, or vacuum drying. This formation method allows for the easy formation of fine wiring patterns.

[0088] Among these methods, it is preferable to apply a photosensitive conductive paste and form a pattern by photolithography. A method for forming an upper electrode group (upper electrode 4, source electrode 14a, drain electrode 14b) on top of the insulating layers 3, 13, lower electrode 2, and semiconductor layer 16 using a photosensitive conductive paste preferably includes the steps of applying a photosensitive conductive paste to a substrate to form a coating film, exposing the coating film to light, developing the exposed coating film, and further curing the coating film to bring about the conductivity of the corresponding pattern.

[0089] At this time, by ensuring sufficient cure temperature and time of the coating film, conductivity is likely to be exhibited, but at the same time, oxidation of the lower electrode is also likely to occur. Therefore, by having a relationship of E°(M2) < E°(M) ≤ E°(M1) between the metal component constituting the lower electrode and the first metal component and the second metal component contained in the upper electrode, oxidation of the lower electrode can be suppressed in the curing process, and stable conductivity is likely to be obtained.

[0090] Further, by including copper in the lower electrode material, nickel as the second metal component in the upper electrode material, and a compound having a carboxyl group as an organic component, the adhesion between the lower electrode and the upper electrode is improved, and oxidation of copper in the curing process of the coating film is likely to be suppressed.

[0091] The photosensitive conductive paste preferably contains at least the above-mentioned first metal component and second metal component as conductive particles, a compound having a carbon-carbon double bond as a photosensitive organic component, and further a monomer, oligomer or polymer having a carboxyl group. Examples of the polymerizable unsaturated group include ethylenically unsaturated groups such as vinyl group, allyl group, acrylate group, methacrylate group, etc. or acrylamide group.

[0092] After mixing the necessary materials, the photosensitive conductive paste is produced using a disperser or kneader such as a three-roll mill, ball mill or planetary ball mill.

[0093] (Photoinitiator·Sensitizer) In order to photocure the photosensitive organic component as described above by a photoreaction, the conductive paste preferably contains a photoinitiator. Examples of the photoinitiator include a photo radical polymerization initiator or a photo cationic polymerization initiator, which may be appropriately selected according to the light used in the exposure process.

[0094] Further, by using a sensitizer together with the photoinitiator in the conductive paste, the sensitivity can be improved and the effective wavelength range for the reaction can be expanded.

[0095] (solvent) The photosensitive conductive paste preferably contains an organic solvent from the viewpoint of viscosity adjustment and improvement of surface smoothness of the coated film. The viscosity of the conductive paste (value measured at 3 rpm with a Brookfield viscometer) is preferably 10 to 100 Pa·s, and more preferably 10 to 50 Pa·s, from the viewpoint of preventing poor coating due to sedimentation of conductive particles, preventing dripping, and improving coverage.

[0096] Examples of organic solvents include methyl ethyl ketone, dioxane, acetone, cyclohexanone, cyclopentanone, isobutyl alcohol, isopropyl alcohol, tetrahydrofuran, γ-butyrolactone, bromobenzene, chlorobenzene, dibromobenzene, dichlorobenzene, bromobenzoic acid, chlorobenzoic acid, etc., diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether, diethylene glycol monobutyl ether acetate, 2-methyl-2,4-pentanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, terpineol, 3-methyl-3-methoxybutanol, texanol, benzyl alcohol, dipropylene glycol monoethyl ether, tripropylene glycol monomethyl ether, or propylene glycol monomethyl ether acetate.

[0097] (Other ingredients) The conductive paste may contain additives such as organic or inorganic pigments, glass powder, fillers, plasticizers, leveling agents such as special vinyl polymers or special acrylic polymers, surfactants, silane coupling agents, defoamers, or antioxidants.

[0098] <Electronic Devices> The elements according to embodiments of the present invention can be suitably used as elements in electronic circuits used in touch panels, displays, organic electroluminescent lighting, solar cells, and various sensors. Examples of various sensors include sensors that detect temperature, moisture, gas, light, electromagnetic waves, radiation, pressure, and the like.

[0099] <Wireless communication equipment> Next, a wireless communication device according to an embodiment of the present invention having the above-mentioned elements will be described. The wireless communication device according to an embodiment of the present invention has at least the above-mentioned elements and an antenna.

[0100] This wireless communication device is a device that operates using radio waves received by an antenna. Examples of wireless communication devices are not particularly limited, but include: (1) a power supply device that provides energy contactlessly without using a wired connection via an adapter; (2) a device that performs telecommunications by partially modulating a carrier wave used for sensing; and (3) a device that exchanges information by receiving a carrier wave transmitted from an antenna mounted on a reader / writer. More specific examples of (3) include RFID (Radio Frequency Identification) tags, which are contactless tags such as product tags, anti-theft tags, various tickets, and smart cards.

[0101] The specific operation of a wireless communication device will be explained using an RFID tag as an example. For example, one can be seen as shown in Figure 5. This device consists of a power generation unit that rectifies the externally modulated wave signal received by the antenna 50 and supplies power to each part, a demodulation circuit that demodulates the above modulated wave signal and sends it to the control circuit, a modulation circuit that modulates the data sent from the control circuit and sends it to the antenna, and a control circuit that writes the data demodulated by the demodulation circuit to a storage circuit, and reads the data from the storage circuit and transmits it to the modulation circuit, with each circuit part being electrically connected.

[0102] The above-mentioned demodulation circuit, control circuit, modulation circuit, and memory circuit may include the above-mentioned FETs, and may also include capacitors, resistors, and diodes. The above-mentioned power generation unit is composed of a capacitor and a diode.

[0103] The antenna, capacitor, resistor, and diode can be any commonly used components, and their materials and shapes are not particularly limited. Furthermore, any commonly used conductive material can be used to electrically connect the above components. Any method of connecting the components is acceptable as long as electrical conductivity can be achieved. The width and thickness of the connection points for each component are arbitrary.

[0104] <Product Tag> Next, a product tag containing a wireless communication device according to an embodiment of the present invention will be described. This product tag has, for example, a substrate and the wireless communication device covered by this substrate.

[0105] The substrate is formed from a non-metallic material such as paper, for example, in the shape of a flat plate. For example, the substrate has a structure in which two flat sheets of paper are glued together, and the wireless communication device is placed between these two sheets of paper. Individual identification information for identifying individual products is pre-stored in the memory circuit of the wireless memory device.

[0106] Wireless communication is performed between this product tag and the reader / writer. The reader / writer is a device that reads and writes data to the product tag wirelessly. The reader / writer exchanges data with the product tag during the distribution process and at the time of payment. Readers / writers can be portable or fixed and installed at the cash register. For product tags according to the embodiments of the present invention, known readers / writers can be used.

[0107] The product tag according to an embodiment of the present invention is equipped with an identification information reply function. This function allows the product tag to wirelessly reply with its stored individual identification information when it receives a command from a predetermined reader / writer requesting the transmission of individual identification information. With a single command from the reader / writer, individual identification information for each tag is transmitted from multiple product tags. This function makes it possible, for example, to identify a large number of products simultaneously and without contact at a checkout counter. Therefore, it is possible to simplify and speed up payment processing compared to identification using barcodes.

[0108] Furthermore, for example, during product checkout, the reader / writer can transmit product information read from the product tag to a POS (Point of Sale) terminal. This function allows the POS terminal to register the sale of the product identified by that product information, thereby simplifying and speeding up inventory management. [Examples]

[0109] The present invention will be described in more detail below based on examples. However, the present invention is not limited to the following examples. Each evaluation method in the examples is described in [1] to [4] below.

[0110] [1] Contact resistance of the upper and lower electrodes Five of the element 100 shown in Figure 6 were prepared, and the contact resistance was measured using the Kelvin pattern 110 in each element. Figures 6(b) and (c) are cross-sections along the I-I' and II-II' lines in Figure 6(a), respectively. The white area in the figure is the upper electrode 4, and the black area is the lower electrode 2. The dashed line in the figure indicates that a contact hole 5 exists within the dashed line. The measurement was performed using a semiconductor characterization system 4200-SCS (manufactured by Keithley Instruments, Inc.) in air. The voltage between pad 2 and pad 3 was measured using the four-terminal method when the current between pad 1 and pad 4 in Figure 6 was varied from 0 to 10 μA, and the contact resistance was calculated from the voltage value at a current of 10 μA. A total of five Kelvin patterns were measured, and their average value was calculated as the initial contact resistance. After that, the measured elements were placed in an 85°C, 85% RH constant temperature and humidity chamber SH-661 (manufactured by ESPEC Corporation) for 24 hours. Afterward, the element was removed, and the contact resistance value (average value of five Kelvin patterns) was calculated again in the same manner. The following criteria were used for the evaluation. (Evaluation of resistance) A (Good): The contact resistance of the element with a contact hole size of 100 μm × 100 μm is 50 Ω or less. B (Acceptable): The contact resistance of the element with a contact hole size of 100 μm × 100 μm is 100 Ω or less. C (Not acceptable): The contact resistance of an element with a contact hole size of 100 μm × 100 μm is greater than 100 Ω. (Evaluation of resistance increase after constant temperature and humidity testing) A (Good): The increase in contact resistance after constant temperature and humidity testing for an element with a contact hole size of 100 μm × 100 μm is 30 Ω or less. B (Acceptable): The increase in resistance after constant temperature and humidity testing of the contact resistance of an element with a contact hole size of 100 μm × 100 μm is 100 Ω or less. C (Not acceptable): The increase in contact resistance after constant temperature and humidity testing of an element with a contact hole size of 100 μm × 100 μm is greater than 100 Ω. D (Unable to evaluate): The initial contact resistance of the element with a contact hole size of 100 μm × 100 μm is greater than 100 Ω.

[0111] [2] Wiring resistance of the upper electrode Five of the elements 100 shown in Figure 6 were prepared, and the wiring resistance was measured using the wiring resistance measurement pattern 120 in each element. The fine wire portion of the resistance measurement pattern 120 had a length of 500 μm and a line width of 100 μm. The measurement was performed using a semiconductor characterization system 4200-SCS (manufactured by Keithley Instruments, Inc.) in air. The voltage between pads 5 and 6 was measured using the four-terminal method when the current between pads 5 and 6 was varied from 0 to 10 μA, and the wiring resistance was calculated from the voltage value at a current of 10 μA. The average value obtained for each of the five wiring resistance measurement patterns was taken as the wiring resistance.

[0112] [3] Flexibility Using the Kelvin pattern 110 used in evaluation [1], the pattern was folded in a mountain fold, and a bending operation was performed by bringing sides A and B of the substrate, as shown in Figure 6, closer together until the distance between them was 10 mm, and then returning them to their original position. The Kelvin patterns 110 before and after the bending were observed with an optical microscope to check for peeling, breakage, etc., and evaluated according to the following criteria. A (Good): No peeling or breakage was observed even after 300 bending cycles. B (Acceptable): No peeling or breakage was observed even after 100 bending cycles. C (Unacceptable): Peeling or disconnection was observed after fewer than 100 bending cycles.

[0113] (Preparation of polysiloxane solution A) 13.12 g (0.05 mol) of 3-trimethoxysilylpropyl succinic anhydride (SucSi), 93.73 g (0.40 mol) of 3-acryloxypropyltrimethoxysilane (AcrSi), and 109.06 g (0.55 mol) of phenyltrimethoxysilane (PheSi) were dissolved in 215.91 g of propylene glycol monomethyl ether acetate (PGMEA, boiling point 146°C). To this, 54.90 g of water and 0.864 g of phosphoric acid were added while stirring. The resulting solution was heated in a bath at 105°C for 2 hours, and the internal temperature was raised to 90°C to distill off the component mainly consisting of methanol, which was a by-product. Then, the solution was heated in a bath at 130°C for 2 hours, and the internal temperature was raised to 118°C to distill off the component mainly consisting of water and methanol. After cooling to room temperature, a polysiloxane solution A with a solid content of 26.0% by mass was obtained. 10 g of the obtained polysiloxane solution A was weighed out, 0.83 g of PGMEA was mixed in, and the mixture was stirred at room temperature for 2 hours to obtain polysiloxane solution A (solid content concentration 24% by mass).

[0114] (Preparation of insulating layer material solution B) 10 g of polysiloxane solution A was weighed out, and 1.04 g of DPHA (trade name "KAYARAD", manufactured by Nippon Kayaku Co., Ltd.; dipentaerythritol hexaacrylate), 0.15 g of OXE-01 (trade name "Irgacure", manufactured by BASF Ltd.) and 4.60 g of PGMEA were mixed together. The mixture was stirred at room temperature for 2 hours to obtain a negative-type photosensitive insulating layer material solution B (solid content concentration 23% by mass).

[0115] (Synthesis of compound C containing a carboxyl group) Copolymerization ratio (by mass): Ethyl acrylate (hereinafter, "EA") / 2-ethylhexyl methacrylate (hereinafter, "2-EHMA") / styrene (hereinafter, "St") / glycidyl methacrylate (hereinafter, "GMA") / acrylic acid (hereinafter, "AA") = 20 / 40 / 20 / 5 / 15.

[0116] 150 g of diethylene glycol monoethyl ether acetate (hereinafter referred to as "DMEA") was charged into a reaction vessel under a nitrogen atmosphere, and the temperature was raised to 80°C using an oil bath. A mixture consisting of 20 g of EA, 40 g of 2-EHMA, 20 g of St, 15 g of AA, 0.8 g of 2,2'-azobisisobutyronitrile, and 10 g of DMEA was added dropwise over 1 hour. After the addition was complete, the polymerization reaction was carried out for a further 6 hours. Subsequently, 1 g of hydroquinone monomethyl ether was added to stop the polymerization reaction. Subsequently, a mixture consisting of 5 g of GMA, 1 g of triethylbenzylammonium chloride, and 10 g of DMEA was added dropwise over 0.5 hours. After the addition was complete, the addition reaction was carried out for a further 2 hours. Unreacted impurities were removed from the resulting reaction solution by purifying it with methanol, and compound C having a carboxyl group was obtained by vacuum drying for 24 hours.

[0117] (Conductive particles) • Ag particles: Ag particles with a particle size (D50) of 0.5 μm, specific gravity of 10.5, and standard oxidation-reduction potential of 0.799 V (vs NHE). • Ni particles: Ni particles with a particle size (D50) of 0.3 μm, specific gravity of 8.9, and standard oxidation-reduction potential of -0.257 V (vs NHE). • Mo particles: Mo particles with a particle size (D50) of 0.3 μm, specific gravity of 10.2, and standard oxidation-reduction potential of -0.20 V (vsNHE). • Cr particles: Cr particles with a particle size (D50) of 0.3 μm, specific gravity of 7.2, and standard oxidation-reduction potential of -0.74 V (vs NHE).

[0118] (Preparation of photosensitive conductive paste E) Preparation Example 1; Photosensitive conductive paste E In a 100ml clean bottle, 10g of compound C obtained above, 1.5g of light acrylate BP-4EA (manufactured by Kyoeisha Chemical Co., Ltd.), a compound having a carbon-carbon double bond, 0.5g of photopolymerization initiator OXE-01 (manufactured by BASF Japan Ltd.), and 10g of γ-butyrolactone (manufactured by Mitsubishi Gas Chemical Company, Inc.) were added and mixed using a rotation-orbit vacuum mixer "Awatori Rentaro" (registered trademark) (ARE-310; manufactured by Thinky Co., Ltd.) to obtain 22g of photosensitive resin solution. 13.0g of the obtained photosensitive resin solution was mixed with 29.5g of Ag particles as the first metal component and 0.5g of Ni particles as the second metal component, and kneaded using a three-roller mixer "EXAKT M-50" (product name, manufactured by EXAKT Corporation) to obtain 43g of photosensitive conductive paste E.

[0119] Adjustment Examples 2-6; Photosensitive Conductive Paste F-K Photosensitive conductive pastes F to K were obtained in the same manner as in Example 1, except that the composition of the conductive particles was changed to that shown in Table 1.

[0120] [Table 1]

[0121] (Preparation of semiconductor solution) First, 1.0 mg of CNTs (CNI, single-walled CNTs, 95% purity) were added to a chloroform solution (10 ml) containing 2.0 mg of P3HT (Aldrich Corporation, poly(3-hexylthiophene)). The mixture was then ultrasonically stirred for 4 hours at 20% output using an ultrasonic homogenizer (Tokyo Rikakikai Co., Ltd., VCX-500) while being cooled with ice. This yielded CNT dispersion A11 (with a CNT complex concentration of 0.96 g / l relative to the solvent).

[0122] Next, the CNT dispersion A11 was filtered using a membrane filter (pore size 10 μm, diameter 25 mm, Millipore Omnipore membrane) to remove CNT complexes longer than 10 μm. 5 ml of o-DCB (Wako Pure Chemical Industries, Ltd.) was added to the resulting filtrate, and the low-boiling point solvent, chloroform, was removed using a rotary evaporator. This replaced the solvent with o-DCB, yielding CNT dispersion B11. 3 ml of o-DCB was added to CNT dispersion B11 (1 ml) to obtain semiconductor solution A (with a CNT complex concentration of 0.03 g / l relative to the solvent).

[0123] (Example of creating the second insulating layer) Polymer solution A was prepared by dissolving 2.5 g of polymethyl methacrylate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) in 7.5 g of N,N-dimethylformamide. Next, compound solution A was prepared by dissolving 1 g of N,N,N',N'-tetramethyl-1,4-phenylenediamine (manufactured by Tokyo Chemical Industry Co., Ltd.) in 9.0 g of N,N-dimethylformamide. Compound solution A was prepared by adding 0.30 g of compound solution A to 0.68 g of polymer solution A to obtain second insulating layer solution A.

[0124] Example 1 Element 100, shown in Figure 6, was fabricated. Copper (standard oxidation-reduction potential 0.340V) was vacuum-deposited to a thickness of 100 nm onto a PET film (thickness 0.15 mm) using the resistance heating method. Next, a positive-type photoresist LC140-10cP (manufactured by Rohm & Haas Electronic Materials Co., Ltd.) was spin-coated onto the copper deposition film and dried at 100°C for 5 minutes. The dried film was then exposed and developed through the photomask shown in Figure 7(a). Next, the film was etched using a copper-specific mixed acid etching solution (Cu-01; manufactured by Kanto Chemical Co., Ltd.), followed by washing and drying to obtain the lower electrode pattern. Exposure was performed using an exposure apparatus "PEM-8M" (product name, manufactured by Union Optical Co., Ltd.) with an exposure dose of 50 mJ / cm². 2Full-line exposure was performed at a wavelength of 365 nm. Development was carried out by immersion development in a 2.38 wt% TMAH aqueous solution for 40 seconds, followed by rinsing with ultrapure water. Photoresist removal was performed by immersion in AZ Remover 100 (product name, manufactured by AZ Electronic Materials) for 2 minutes, followed by rinsing with ultrapure water, and then removing water droplets with an air knife.

[0125] Next, insulating layer material solution B was spin-coated onto the substrate and dried at 100°C for 2 minutes. Then, the dried film was exposed and developed through the photomask shown in Figure 7(b) to form contact holes, and then heat-treated at 150°C for 30 minutes under a nitrogen atmosphere to form the insulating layer. The exposure was performed using an exposure device "PEM-8M" (product name, manufactured by Union Optical Co., Ltd.) with an exposure dose of 200 mJ / cm². 2 Full-line exposure was performed at a wavelength of 365 nm. Development was carried out by immersion development in a 2.38 wt% TMAH aqueous solution for 20 seconds, followed by rinsing with ultrapure water. The size of each contact hole was set to 100 μm × 100 μm in plan view.

[0126] Next, photosensitive conductive paste E was applied to the substrate by screen printing and dried in a drying oven at 100°C for 10 minutes. The dried film was exposed and developed through the photomask shown in Figure 7(c) to obtain a pattern. Subsequently, the obtained pattern was heat-treated at 140°C for 30 minutes to form the upper electrode. Exposure was performed using an exposure device "PEM-8M" (product name, manufactured by Union Optical Co., Ltd.) with an exposure dose of 200 mJ / cm². 2 Full-line exposure was performed at a wavelength of 365 nm. Development was carried out by immersion development in a 0.2 wt% Na2CO3 solution for 45 seconds, followed by rinsing with ultrapure water.

[0127] The resulting contact resistance and wiring resistance measurement patterns were then evaluated using the methods described in [1] to [3]. The results of [1] to [3] are shown in Table 2.

[0128] Examples 2-6, Comparative Example 1 The patterns were formed and evaluated in the same manner as in Example 1, except that the photosensitive conductive pastes listed in Table 2 were used instead of photosensitive conductive paste E. The evaluation results are shown in Table 2.

[0129] [Table 2]

[0130] Example 7 In Example 7, an inverter was formed that included a p-type FET and an n-type FET, and this inverter was used to fabricate a ring oscillator, which is an oscillation circuit.

[0131] Figure 8(a) is a schematic plan view showing the configuration of the ring oscillator in this embodiment 7. This ring oscillator 28 is constructed by connecting 21 stages of inverters 27 in series. In Figure 8(a), in order to simplify the configuration of the ring oscillator 28, the inverters 27 that have a repeating configuration are not shown among the 21 inverters 27. In addition, the multiple sets of FETs that make up each of these inverters 27 are connected by wiring (not shown).

[0132] Figure 8(b) is a schematic diagram of the two-stage inverter 27 enclosed by the dashed line III in Figure 8(a), and Figures 8(c) and (d) are cross-sections along the IV-IV' and V-V' lines in Figure 8(b), respectively. The white areas in the figures represent the upper electrode 4, and the black areas represent the lower electrode 2. The dashed lines in Figure 8(b) indicate that the contact holes 5 are located within the dashed lines.

[0133] The specific method for manufacturing the ring oscillator will be explained with reference to Figure 9. Figure 9 shows the manufacturing process of the ring oscillator in this embodiment 7, using cross-sectional views along the lines IV-IV' and V-V' in Figure 8(b).

[0134] First, copper (standard oxidation-reduction potential 0.340V) was vacuum-deposited to a thickness of 100nm onto a PET film (thickness 0.15mm), which was substrate 1, using resistance heating. Next, positive-type photoresist LC140-10cP (manufactured by Rohm & Haas Electronic Materials Co., Ltd.) was spin-coated onto the copper deposition film and dried at 100°C for 5 minutes. The fabricated photoresist film was exposed to light at an exposure dose of 40mJ / cm² through a photomask designed with a lower electrode and gate electrode. 2 Full-line exposure was performed at a wavelength of 365 nm. The gate electrode width designed on the photomask was 50 μm. After exposure, the photomask was developed with a 2.38 wt% tetramethylammonium hydroxide aqueous solution for 30 seconds, followed by washing with water for 1 minute. Then, it was etched with mixed acid (product name SEA-5, manufactured by Kanto Chemical Co., Ltd.) for 30 seconds, followed by washing with water for 30 seconds. The resist was removed by immersion in photoresist stripping solution (product name AZ Remover 100, manufactured by Merck Performance Materials K.K.) for 2 minutes, washed with water for 30 seconds, and water droplets were removed with an air knife. Subsequently, the lower electrode 2 and gate electrode 12 were formed by heating and drying in a hot air drying oven at 80°C for 60 seconds (Figure 9(a)).

[0135] Subsequently, insulating layer material solution B was spin-coated onto the substrate 1 and dried at 100°C for 2 minutes. Next, the dried film was exposed and developed through a photomask with contact holes designed in it to form the contact holes. Then, heat treatment was performed at 150°C for 30 minutes under a nitrogen atmosphere to form the insulating layer 3 and the gate insulating layer 13. The exposure was performed using an exposure device "PEM-8M" (product name, manufactured by Union Optical Co., Ltd.) with an exposure dose of 200 mJ / cm². 2 Full-line exposure was performed at a wavelength of 365 nm, and development was carried out by immersion development in a 2.38 wt% TMAH aqueous solution for 20 seconds, followed by rinsing with ultrapure water. The size of each contact hole 5 was set to 100 μm × 100 μm in a plan view (Figure 9(b)).

[0136] On the substrate 1 on which the gate insulating layer 3 was formed as described above, 100 pl of semiconductor solution A was applied by inkjet method to the gate insulating layer located in a projection relative to the gate electrode 12, and a semiconductor layer 16 was formed by heat treatment in an IR drying oven at 150°C for 30 minutes under a nitrogen atmosphere (Figure 9(c)).

[0137] Next, a photosensitive conductive paste F was applied to the substrate by screen printing and dried in a drying oven at 100°C for 10 minutes. The dried film was exposed and developed through a photomask on which the upper electrode, source electrode, and drain electrode were designed to obtain a pattern. Subsequently, the obtained pattern was heat-treated at 140°C for 30 minutes to form the upper electrode 4, source electrode 14a, and drain electrode 14b. Exposure was performed using an exposure device "PEM-8M" (product name, manufactured by Union Optical Co., Ltd.) with an exposure dose of 200 mJ / cm². 2 Full-line exposure was performed at a wavelength of 365 nm, and development was carried out by immersion development in a 0.2 wt% Na2CO3 solution for 45 seconds, followed by rinsing with ultrapure water (Figure 9(d)).

[0138] Next, 5 μL of the second insulating layer solution A was dropped onto a PET film substrate on which the semiconductor layer described above was formed, using a drop-casting method, so as to cover a portion of the semiconductor layer 16. Subsequently, the substrate was heat-treated at 110°C for 30 minutes under a nitrogen atmosphere to form the second insulating layer 17 (Figure 9(e)). The thickness of the second insulating layer 17 was 20 μm.

[0139] For the obtained ring oscillator, with a power supply voltage of 5.0V applied to the ring oscillator circuit, an oscilloscope (Keysight Technology, DSOX6002A) was connected to the output of the ring oscillator circuit, and the waveform was observed to confirm the oscillation operation of the ring oscillator circuit.

[0140] Furthermore, five p-type FETs were extracted from the ring oscillator circuit, and the source-drain current (Id)-source-drain voltage (Vsd) characteristics were measured when the gate voltage (Vg) was varied. A semiconductor characterization system 4200-SCS (manufactured by Keithley Instruments, Inc.) was used for the measurements, and the measurements were taken under atmospheric conditions. When Vg was varied from +5V to -5V, the average value of Id at Vsd = -5V was measured, and the result was 14.6 μA.

[0141] Comparative Example 2 A ring oscillator was formed in the same manner as in Example 7, except that photosensitive conductive paste K was used instead of photosensitive conductive paste F, and the same evaluation was performed. As a result, the ring oscillator circuit did not oscillate due to poor conductivity between the upper and lower electrodes. In addition, the operation of the p-type FET extracted from the ring oscillator circuit was confirmed, but the average Id value was 10.8 μA, which was lower than the current value in Example 7. [Explanation of Symbols]

[0142] 1 Base material 2 Lower electrode 3. Insulating layer 4 Upper electrode 5 Contact Holes 12 gates 13 Gate insulating layer 14a Source electrode 14b Drain electrode 16 Semiconductor layer 17. Second insulating layer 22a Source electrode 22b Drain electrode 23 Gate Insulation Layer 24 gate 26 Semiconductor layer 27 Inverter 28 Ring Oscillator 32 Lower electrode 33 Insulating layer 34 Upper electrode 35 Upper electrode 36 Semiconductor layer 50 Antennas 100 elements 110 Kelvin pattern 120 Wiring Resistance Measurement Patterns

Claims

1. An element comprising a substrate, a lower electrode disposed on the substrate, and an upper electrode having a region in contact with the lower electrode, wherein the standard oxidation-reduction potential of the metal component constituting the lower electrode is -0.40V or more and 0.50V or less, the upper electrode contains at least a first metal component, a second metal component, and an organic component, and when the standard oxidation-reduction potential of the second metal component is E°(M2), the standard oxidation-reduction potential of the metal component constituting the lower electrode is E°(M), and the standard oxidation-reduction potential of the first metal component is E°(M1), the relationship E°(M2) < E°(M) ≤ E°(M1) holds, and the difference between E°(M2) and E°(M) is 1.10V or less.

2. An element comprising a substrate, a lower electrode disposed on the substrate, and an upper electrode having a region in contact with the lower electrode, wherein the standard oxidation-reduction potential of the metal component constituting the lower electrode is -0.40V or more and 0.50V or less, and the upper electrode contains at least a first metal component, a second metal component, and an organic component, and when the standard oxidation-reduction potential of the second metal component is E°(M2), the standard oxidation-reduction potential of the metal component constituting the lower electrode is E°(M), and the standard oxidation-reduction potential of the first metal component is E°(M1), the relationship E°(M2) < E°(M) ≤ E°(M1) holds, and E°(M1) is 0.60V or more and 1.50V or less.

3. An element comprising a substrate, a lower electrode disposed on the substrate, and an upper electrode having a region in contact with the lower electrode, wherein the standard oxidation-reduction potential of the metal component constituting the lower electrode is -0.40V or more and 0.50V or less, the upper electrode contains at least a first metal component, a second metal component, and an organic component, and when the standard oxidation-reduction potential of the second metal component is E°(M2), the standard oxidation-reduction potential of the metal component constituting the lower electrode is E°(M), and the standard oxidation-reduction potential of the first metal component is E°(M1), the relationship E°(M2) < E°(M) ≤ E°(M1) holds, and the difference in specific gravity between the first metal component and the second metal component is 3 or less.

4. The element according to any one of claims 1 to 3, further comprising an insulating layer disposed on the lower electrode, the upper electrode disposed on the insulating layer, and a region in contact between the lower electrode and the upper electrode provided within the insulating layer, which is a contact hole in which the lower electrode and the upper electrode make contact.

5. The element according to claim 2 or 3, wherein the difference between E°(M2) and E°(M) is 1.10V or less.

6. The element according to claim 1 or 3, wherein E°(M1) is 0.60V or more and 1.50V or less.

7. The element according to claim 1 or 2, wherein the difference in specific gravity between the first metal component and the second metal component is 3 or less.

8. The element according to claim 4, wherein the upper electrode on the insulating layer and the upper electrode in the contact hole are in a continuous phase.

9. The element according to any one of claims 1 to 3, wherein the element is a field-effect transistor.

10. The device according to claim 9, wherein the semiconductor layer of the field-effect transistor contains carbon nanotubes.

11. An electronic device having the element described in any one of claims 1 to 3.

12. A method for manufacturing an element according to any one of claims 1 to 3, A method for manufacturing an element, characterized by forming the upper electrode by applying a paste containing at least a first metal component, a second metal component, and an organic component, followed by a process including drying, exposure, and development.

13. A wireless communication device comprising at least an element according to any one of claims 1 to 3 and an antenna.

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