p-type semiconductor element, its manufacturing method, complementary semiconductor device using the same, wireless communication device, and thin-film transistor array

Abstract

To provide a p-type semiconductor element that can achieve both high on-current and low off-current.SOLUTION: A p-type semiconductor element includes: a substrate; a first electrode and a second electrode; a semiconductor layer in contact with both of the first electrode and the second electrode; an insulating layer in contact with the semiconductor layer; a third electrode in contact with the insulating layer on a side opposite to the insulating layer with respect to the semiconductor layer; and a second insulating layer in contact with the semiconductor layer on the side opposite to the insulating layer with respect to the semiconductor layer. The semiconductor layer contains carbon nanotubes or graphene. The second insulating layer contains A: (a) an organic compound (hereinafter referred to as "compound (a)") in which the lowest unoccupied molecular orbit has an energy level of -5.8 eV or more and -3.2 eV or less and (b) a polymer, or B: a polymer containing, in its molecular structure, groups remaining after removing some atoms from a structure of the compound (a).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a p-type semiconductor element, a method for manufacturing the same, and a complementary semiconductor device, a wireless communication device, and a thin-film transistor array that use the same. [Background technology]

[0002] In recent years, field-effect transistors (FETs) using carbon nanotubes (CNTs), graphene, and organic semiconductors, which can be applied with coating techniques such as inkjet technology and screen printing, have been actively investigated with the aim of realizing low-cost, large-area, flexible, and bendable electronic products. Examples of electronic products include displays, sensors, and wireless communication devices using RFID (Radio Frequency IDentification) technology, and the above-mentioned transistors are used in the transistor arrays and drive circuits within IC chips.

[0003] The above transistors need to be made into p-type or n-type depending on their role, and their transistor characteristics need to be adjusted. For example, the drive circuits in IC chips are generally configured as complementary circuits consisting of p-type and n-type transistors to reduce power consumption.

[0004] Regarding transistors using CNTs (hereinafter referred to as CNT-FETs), techniques have been disclosed that allow for the fabrication of p-type FETs and n-type FETs by changing the work function of the source / drain electrode material or by applying an appropriate doping treatment to a semiconductor layer made of CNTs (see, for example, Non-Patent Document 1 and Patent Document 1). Additionally, techniques have been disclosed that adjust FET characteristics by forming a second insulating layer on a semiconductor layer containing CNTs (see, for example, Patent Documents 2 and 3). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-65057 [Patent Document 2] Japanese Patent Application Laid-Open No. 2009-283924 [Patent Document 3] International Publication No. 2017 / 130836 [Non-patent literature]

[0006] [Non-Patent Document 1] Surface Science Vol.28,No.1,pp.40-45,2007 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the technique described in Non-Patent Document 1 requires fine adjustment of the work function of the source and drain electrodes, making it difficult to select the source and drain electrode materials and adjust the semiconductor device characteristics.

[0008] The technique described in Patent Document 1 has the problem that the semiconductor layer needs to be doped in a complementary manner, which makes the configuration and process complicated and also makes it difficult to adjust the semiconductor element characteristics.

[0009] In the techniques described in Patent Documents 2 and 3, when an amine-based compound is contained in the second insulating layer, as disclosed in Patent Document 3, some of the characteristics of an n-type semiconductor element are exhibited, making it difficult to realize a p-type semiconductor element that combines a high on-current and a low off-current.

[0010] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a p-type semiconductor element that can achieve both a high on-current and a low off-current. [Means for solving the problem]

[0011] In order to solve the above problems, the present invention has the following configuration. That is, the present invention provides: A substrate; a first electrode and a second electrode; a semiconductor layer in contact with both the first electrode and the second electrode; an insulating layer in contact with the semiconductor layer; a third electrode in contact with the insulating layer on the opposite side of the semiconductor layer from the insulating layer; a second insulating layer in contact with the semiconductor layer on the opposite side of the insulating layer with respect to the semiconductor layer, the semiconductor layer contains carbon nanotubes or graphene; The second insulating layer is A. (a) An organic compound having an energy level of the lowest unoccupied molecular orbital of -5.8 eV or more and -3.2 eV or less (hereinafter referred to as "compound (a)"), (b) a polymer, or B. A polymer containing, in its molecular structure, the remaining groups obtained by removing some atoms from the structure of compound (a), The p-type semiconductor element is characterized by: [Effects of the Invention]

[0012] According to the present invention, a p-type semiconductor device that achieves both a high on-current and a low off-current can be obtained. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a schematic cross-sectional view showing a p-type semiconductor element according to a first embodiment of the present invention. [Figure 2] FIG. 10 is a schematic cross-sectional view showing a p-type semiconductor element according to a second embodiment of the present invention. [Figure 3] FIG. 10 is a schematic cross-sectional view showing a p-type semiconductor element according to a third embodiment of the present invention. [Figure 4] 1 is a schematic cross-sectional view showing a complementary semiconductor device according to an embodiment of the present invention; [Figure 5] FIG. 1 is a block diagram showing an example of a wireless communication device using a p-type semiconductor element according to an embodiment of the present invention. [Figure 6] Schematic diagram showing an example of the configuration of a thin-film transistor array DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, preferred embodiments of a p-type semiconductor device, a method for manufacturing the same, a complementary semiconductor device, a wireless communication device, and a thin film transistor array 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.

[0015] <p-type semiconductor device> A p-type semiconductor device according to an embodiment of the present invention includes a substrate, a first electrode and a second electrode, a semiconductor layer in contact with both the first electrode and the second electrode, and an insulating layer in contact with the semiconductor layer. A third electrode in contact with the insulating layer on the side opposite to the insulating layer with respect to the semiconductor layer, and a second insulating layer in contact with the semiconductor layer on the side opposite to the insulating layer with respect to the semiconductor layer. The p-type semiconductor device includes a semiconductor layer containing carbon nanotubes or graphene, and the second insulating layer A. (a) An organic compound (Compound (a)) having a lowest unoccupied molecular orbital energy level of -5.8 eV or more and -3.2 eV or less, and (b) a polymer, or B. A polymer containing a residue obtained by removing some atoms from the structure of Compound (a) in its molecular structure. Here, the "organic compound" is defined not to include organometallic compounds.

[0016] FIG. 1 is a schematic cross-sectional view showing a p-type semiconductor device according to Embodiment 1 of the present invention. The p-type semiconductor device 10 according to Embodiment 1 includes a gate electrode 2 formed on an insulating substrate 1, a gate insulating layer 3 covering the gate electrode 2, a source electrode 5 and a drain electrode 6 provided thereon, a semiconductor layer 4 provided between these electrodes, and a second insulating layer 8 covering the semiconductor layer. The semiconductor layer 4 includes carbon nanotubes or graphene 7.

[0017] 1, the p-type semiconductor element 10 can function as a field-effect transistor. That is, the first electrode corresponds to the source electrode 5, the second electrode corresponds to the drain electrode 6, and the third electrode corresponds to the gate electrode 2. This structure is a so-called bottom-gate / bottom-contact structure, in which the gate electrode is disposed below the semiconductor layer, and the source electrode and drain electrode are disposed on the underside of the semiconductor layer.

[0018] 2 is a schematic cross-sectional view showing a p-type semiconductor device according to a second embodiment of the present invention. The semiconductor device 20 according to the second embodiment has a second insulating layer 18 formed on an insulating substrate 11, a source electrode 15 and a drain electrode 16 formed thereon, a semiconductor layer 14 provided between these electrodes, a gate insulating layer 13 covering them, and a gate electrode 12 provided on the semiconductor layer. The semiconductor layer 14 includes carbon nanotubes or graphene 17.

[0019] 2, the p-type semiconductor element 20 can function as a field-effect transistor. That is, the first electrode corresponds to the source electrode 15, the second electrode corresponds to the drain electrode 16, and the third electrode corresponds to the gate electrode 12. This structure is a so-called top-gate bottom-contact structure in which the gate electrode is disposed above the semiconductor layer and the source electrode and drain electrode are disposed below the semiconductor layer.

[0020] When a p-type semiconductor element is made to function as a field-effect transistor, the structure of the semiconductor element may be a bottom-gate top-contact structure or a top-gate top-contact structure in addition to those shown in Figures 1 and 2.

[0021] 3 is a schematic cross-sectional view showing a p-type semiconductor device according to a third embodiment of the present invention. A p-type semiconductor device 30 according to the third embodiment has a third electrode 22 formed on an insulating base material 21, an insulating layer 23 covering the third electrode 22, a cathode 25 and an anode 26 provided thereon, a semiconductor layer 24 provided between these electrodes, a second insulating layer 28 covering the semiconductor layer, and a fourth electrode 29 electrically connecting the third electrode 22 and the first electrode 25. The semiconductor layer 24 includes carbon nanotubes or graphene 27.

[0022] 3, the p-type semiconductor element 30 can function as a diode. That is, the first electrode corresponds to the cathode 25, and the second electrode corresponds to the anode 26. This structure is a diode-connected transistor.

[0023] The structure of the semiconductor element according to the embodiment of the present invention is not limited to these, and the following description is common regardless of the structure of the semiconductor element unless otherwise specified.

[0024] (base material) The substrate may be made of any material as long as at least the surface on which the electrode system is disposed is insulating. Preferred substrates include inorganic materials such as silicon wafers, glass, sapphire, and sintered alumina, and organic materials such as polyimide, polyvinyl alcohol, polyvinyl chloride, polyethylene terephthalate, polyvinylidene fluoride, polysiloxane, polyvinylphenol (PVP), polyester, polycarbonate, polysulfone, polyethersulfone, polyethylene, polyphenylene sulfide, and polyparaxylene.

[0025] The substrate may also be a laminate of multiple materials, such as a PVP film formed on a silicon wafer or a polysiloxane film formed on polyethylene terephthalate.

[0026] (electrode) The materials used for the first, second, and third electrodes may be any conductive material commonly used for electrodes. Examples of conductive materials include, but are not limited to, conductive metal oxides such as tin oxide, indium oxide, and indium tin oxide (ITO); metals such as platinum, gold, silver, copper, iron, tin, zinc, aluminum, indium, chromium, lithium, sodium, potassium, cesium, calcium, magnesium, palladium, molybdenum, amorphous silicon, and polysilicon, as well as alloys thereof; inorganic conductive materials such as copper iodide and copper sulfide; polythiophene, polypyrrole, polyaniline; complexes of polyethylenedioxythiophene and polystyrenesulfonic acid; conductive polymers whose conductivity is improved by doping with iodine or the like; carbon materials; and materials containing an organic component and a conductor.

[0027] In particular, it is preferable that the electrode contains an organic component and a conductor, since this increases the flexibility of the electrode, provides good adhesion to the substrate and the insulating layer even when bent, and provides good electrical connection with the wiring and the semiconductor layer.

[0028] The organic component is not particularly limited, and examples thereof include a monomer, an oligomer, a polymer, a photopolymerization initiator, a plasticizer, a leveling agent, a surfactant, a silane coupling agent, an antifoaming agent, a pigment, etc. From the viewpoint of improving the bending resistance of the electrode, the organic component is preferably an oligomer or a polymer.

[0029] The oligomer or polymer is not particularly limited, and examples thereof include acrylic resin, epoxy resin, novolac resin, phenolic resin, polyimide precursor, and polyimide. Among these, acrylic resin is preferred from the viewpoint of crack resistance when the electrode is bent. This is presumably because acrylic resin has a glass transition temperature of 100°C or less, and softens during thermal curing of the conductive film, enhancing the bonding between the conductive particles.

[0030] An acrylic resin is a resin containing a repeating unit derived from at least an acrylic monomer. Specific examples of the acrylic monomer include all compounds having a carbon-carbon double bond. These acrylic monomers may be used alone or in combination of two or more.

[0031] The conductor may be any conductive material that can be generally used as an electrode, but is preferably a conductive particle that is composed entirely or partially of a conductive material and the particles themselves are conductive. By using conductive particles as the conductor, irregularities are formed on the surface of the electrode containing them. When the insulating layer penetrates into these irregularities, an anchor effect occurs, further improving the adhesion between the electrode and the insulating layer. Improved adhesion between the electrode and the insulating layer has the effect of improving the bending resistance of the electrode and the effect of suppressing fluctuations in electrical characteristics when voltage is repeatedly applied to the semiconductor element. These effects further improve the reliability of the semiconductor element.

[0032] Suitable conductive materials for the conductive particles include gold, silver, copper, nickel, tin, bismuth, lead, zinc, palladium, platinum, aluminum, tungsten, molybdenum, and carbon. More preferred conductive particles are conductive particles containing at least one element selected from the group consisting of gold, silver, copper, nickel, tin, bismuth, lead, zinc, palladium, platinum, aluminum, and carbon. These conductive particles may be used alone, as an alloy, or as a mixed particle.

[0033] Among these, gold, silver, copper, or platinum particles are preferred from the viewpoint of conductivity, with silver being more preferred from the viewpoint of cost and stability.

[0034] The width and thickness of each of the first, second, and third electrodes, as well as the distance between the first and second electrodes, can be designed to any value. For example, the electrode width is preferably 10 μm to 10 mm, the electrode thickness is preferably 0.01 μm to 100 μm, and the distance between the first and second electrodes is preferably 1 μm to 1 mm, but is not limited to these.

[0035] These materials for producing the electrodes may be used alone, or the electrodes may be formed by laminating a plurality of materials, or by mixing a plurality of materials.

[0036] Furthermore, in the p-type semiconductor element according to the third embodiment of the present invention, the material used for the fourth electrode 29 is not particularly limited, and a commonly used conductive material can be used, similar to the materials used for the first, second, and third electrodes. The third electrode 22 and the first electrode 25 can be electrically connected by any method that can ensure electrical continuity. The width and thickness of the connection portion are also optional.

[0037] (insulating layer) The material used for the insulating layer is not particularly limited as long as it ensures insulation between the semiconductor layer and the third electrode, 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 a mixture of inorganic material powder and organic material.

[0038] Among these, those containing organic compounds containing silicon-carbon bonds are preferred, with polysiloxanes being particularly preferred.

[0039] The insulating layer preferably further contains a metal compound containing a bond between a metal atom and an oxygen atom. Such metal compounds are not particularly limited, and examples include metal oxides and metal hydroxides. The metal atoms contained in the metal compound are not particularly limited as long as they form a metal chelate. Examples of metal atoms include magnesium, aluminum, titanium, chromium, manganese, cobalt, nickel, copper, zinc, gallium, zirconium, ruthenium, palladium, indium, hafnium, and platinum. Among these, aluminum is preferred in terms of availability, cost, and metal chelate stability. Examples of metal oxides include silicon oxide, titanium oxide, zirconium oxide, hafnium oxide, tin oxide, barium titanate, strontium titanate, and calcium titanate. The metal compounds may also be in the form of particles.

[0040] The thickness of the insulating layer is preferably 0.05 μm to 5 μm, more preferably 0.1 μm to 1 μm. By setting the thickness within this range, it becomes easy to form a uniform thin film. The thickness can be measured by an atomic force microscope, ellipsometry, or the like.

[0041] 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.

[0042] (semiconductor layer) The semiconductor layer contains carbon nanotubes (CNTs) or graphene. Of these, the semiconductor layer preferably contains CNTs. Furthermore, the CNTs are preferably CNT composites having a conjugated polymer attached to at least a portion of their surface. The semiconductor layer may further contain an organic semiconductor or an insulating material as long as the electrical properties are not impaired.

[0043] The thickness of the semiconductor layer is preferably 1 nm or more and 100 nm or less. Within this range, it becomes easier to form a uniform thin film. The thickness of the semiconductor layer is more preferably 1 nm or more and 50 nm or less, and even more preferably 1 nm or more and 20 nm or less. The thickness can be measured using an atomic force microscope, ellipsometry, or the like.

[0044] (CNT) CNTs can be single-walled CNTs, which are made up of a single carbon film (graphene sheet) wound into a cylindrical shape; double-walled CNTs, which are made up of two concentrically wound graphene sheets; or multi-walled CNTs, which are made up of multiple concentrically wound graphene sheets. To obtain high semiconducting properties, single-walled CNTs are preferred. CNTs can be obtained by arc discharge, CVD, laser ablation, and other methods.

[0045] Furthermore, it is more preferable that the CNTs contain 80% by weight or more of semiconducting CNTs relative to the total CNT content. Even more preferable is a content of 90% by weight or more of semiconducting CNTs, and particularly preferable is a content of 95% by weight or more of semiconducting CNTs. Known methods can be used to achieve a semiconducting CNT content of 80% by weight or more in CNTs. Examples include ultracentrifugation in the presence of a density gradient agent, selectively attaching specific compounds to the surface of semiconducting or metallic CNTs and separating them using differences in solubility, and electrophoresis or other methods using differences in electrical properties. Methods for measuring the content of semiconducting CNTs in CNTs include calculation from the absorption area ratio of visible-near-infrared absorption spectra and calculation from the intensity ratio of Raman spectra.

[0046] In the present invention, when CNTs are used in the semiconductor layer of a semiconductor element, the length of the CNTs is preferably shorter than the distance between the first electrode and the second electrode (hereinafter referred to as "inter-electrode distance"). The average length of the CNTs, although depending on the inter-electrode distance, is preferably 2 μm or less, more preferably 1 μm or less. Methods for shortening the length of CNTs include acid treatment and freeze-pulverization treatment.

[0047] The average length of CNTs is calculated as the average length of 20 randomly picked CNTs. One method for measuring the average length of CNTs is to randomly pick 20 CNTs from images obtained using an atomic force microscope, scanning electron microscope, transmission electron microscope, etc., and calculate the average length of these CNTs.

[0048] Commercially available CNTs generally have a distribution of lengths, and some CNTs may be longer than the distance between the electrodes. Therefore, it is preferable to add a process to shorten the CNTs to a length shorter than the distance between the electrodes. For example, methods such as acid treatment with nitric acid or sulfuric acid, ultrasonic treatment, or freeze-pulverization are effective for cutting CNTs into short fibers. Furthermore, it is even more preferable to use a filter to separate the CNTs in order to improve the purity of the CNTs.

[0049] The diameter of the CNT is not particularly limited, but is preferably 1 nm or more and 100 nm or less, and more preferably 50 nm or less.

[0050] In the present invention, it is preferable to provide a step of uniformly dispersing CNTs in a solvent and filtering the dispersion through a filter. By obtaining CNTs smaller than the filter pore size from the filtrate, CNTs shorter than the distance between the electrodes can be efficiently obtained. In this case, a membrane filter is preferably used as the filter. The pore size of the filter used for filtration should be smaller than the distance between the electrodes, and is preferably 0.5 μm to 10 μm.

[0051] (Graphene) The graphene may be a single-layer graphene, a double-layer graphene, a multi-layer graphene, or a graphene nanoribbon. To obtain high semiconductor properties, it is preferable to use a double-layer graphene or a graphene nanoribbon. Graphene can be obtained by CVD, reduction of graphene oxide, or the like.

[0052] (CNT composite) It is preferable that the CNTs used in the present invention have a conjugated polymer attached to at least a portion of their surface (hereinafter, the CNTs with a conjugated polymer attached are referred to as "CNT composites"). Here, the conjugated polymer refers to a compound whose repeating unit has a conjugated structure and whose degree of polymerization is 2 or more.

[0053] By attaching a conjugated polymer to at least a portion of the surface of CNTs, it becomes possible to uniformly disperse CNTs in a solution without impairing the high electrical properties of the CNTs. If a solution in which CNTs are uniformly dispersed is used, it becomes possible to form a film containing uniformly dispersed CNTs by a coating method. This makes it possible to achieve high semiconducting properties.

[0054] The state in which a conjugated polymer is attached to at least a portion of the surface of a CNT means that the conjugated polymer coats part or all of the surface of the CNT. It is presumed that the reason that a conjugated polymer can coat a CNT is because the π electron clouds derived from the conjugated structures of both polymers overlap, resulting in an interaction.

[0055] Whether or not a CNT is coated with a conjugated polymer can be determined from its reflected color. The reflected color of coated CNT differs from that of uncoated CNT and is closer to that of the conjugated polymer. Quantitatively, elemental analysis such as X-ray photoelectron spectroscopy (XPS) can be used to confirm the presence of deposits on the CNT and to measure the weight ratio of the deposits to the CNT.

[0056] In addition, the weight average molecular weight of the conjugated polymer is preferably 1,000 or more in view of ease of attachment to CNTs.

[0057] Methods for attaching a conjugated polymer to CNT include (I) adding CNT to a molten conjugated polymer and mixing, (II) dissolving a conjugated polymer in a solvent and adding CNT to the solution and mixing, (III) pre-dispersing CNT in a solvent using ultrasound or the like and adding a conjugated polymer to the solution and mixing, and (IV) placing a conjugated polymer and CNT in a solvent and irradiating the mixture with ultrasound to mix, etc. In the present invention, any of these methods may be used, or a combination of multiple methods may be used.

[0058] Examples of conjugated polymers include, but are not limited to, polythiophene polymers, polypyrrole polymers, polyaniline polymers, polyacetylene polymers, poly-p-phenylene polymers, poly-p-phenylene vinylene polymers, etc. As the above-mentioned polymers, those in which a single monomer unit is arranged are preferably used, but those in which different monomer units are block copolymerized, random copolymerized, or graft polymerized are also preferably used.

[0059] Among the above polymers, polythiophene-based polymers are preferably used in the present invention from the viewpoint of easy adhesion to CNTs and easy formation of CNT composites. Among polythiophene-based polymers, those containing a fused heteroaryl unit having a nitrogen-containing double bond in the ring and a thiophene unit in the repeating unit are more preferred.

[0060] Examples of fused heteroaryl units having a nitrogen-containing double bond in the ring include thienopyrrole, pyrrolothiazole, pyrrolopyridazine, benzimidazole, benzotriazole, benzoxazole, benzothiazole, benzothiadiazole, quinoline, quinoxaline, benzotriazine, thienoxazole, thienopyridine, thienothiazine, and thienopyrazine units. Among these, benzothiadiazole units and quinoxaline units are particularly preferred. The presence of these units increases the adhesion between CNTs and conjugated polymers, allowing for better dispersion of CNTs in the semiconductor layer.

[0061] Specific examples of the conjugated polymer include the conjugated polymers described in International Publication No. 2009 / 139339 and Japanese Patent No. 6683296.

[0062] (Second insulating layer) The second insulating layer is formed on the side of the semiconductor layer opposite to the side on which the insulating layer is formed. For example, if the insulating layer is formed on the underside of the semiconductor layer, the side opposite to the side on which the insulating layer is formed refers to the upper side of the semiconductor layer. By forming the second insulating layer, it is possible to adjust the transistor characteristics. Furthermore, it is possible to provide a p-type semiconductor device that achieves both a high on-current and a low off-current.

[0063] The thickness of the second insulating layer is preferably 500 nm or more, more preferably 1.0 μm or more, even more preferably 3.0 μm or more, and particularly preferably 10 μm or more. By setting the thickness within this range, the p-type semiconductor characteristics can be stably adjusted. The upper limit of the thickness is not particularly limited, but is preferably 500 μm or less.

[0064] The film thickness of the second insulating layer is determined by measuring the cross section of the second insulating layer using a scanning electron microscope, calculating the film thickness at 10 randomly selected locations in the obtained image from the second insulating layer portion located on the semiconductor layer, and taking the arithmetic average value.

[0065] In a p-type semiconductor device according to one embodiment of the present invention, the second insulating layer contains a compound (a) and a polymer (b).

[0066] (Compound (a)) The energy level of the lowest unoccupied molecular orbital of compound (a) is between -5.8 eV and -3.2 eV. Such compound (a) interacts electronically with the CNT or graphene in the semiconductor layer, particularly acting as an electron acceptor. This interaction increases the number of carrier holes in the valence band of the CNT or graphene, making it easier for holes to be injected from the electrode. Furthermore, it decreases the number of carrier electrons in the conduction band of the CNT or graphene, making it harder for electrons to be injected from the electrode. These effects are thought to improve the on-current and reduce the off-current, thereby adjusting the p-type semiconductor characteristics.

[0067] In particular, CNTs and graphene have narrow band gaps, and some electrons that act as carriers exist in their conduction bands, which is thought to be one of the reasons for the increase in off-state current. However, by including compound (a) in the second insulating layer, the above-mentioned action reduces the number of electrons in the conduction band, resulting in a significant reduction in off-state current.

[0068] When the energy level of the lowest unoccupied molecular orbital of compound (a) is lower than -5.8 eV, the off-state current becomes significantly larger. This is because the electron-accepting property of compound (a) is too strong, resulting in too many holes in the valence band of CNT or graphene, causing the CNT or graphene to become nearly conductive. On the other hand, when the energy level of the lowest unoccupied molecular orbital of compound (a) is higher than -3.2 eV, no improvement in on-state current or reduction in off-state current is observed. This is because the electron-accepting property of compound (a) is too weak, resulting in almost no effect on the valence band or conduction band of CNT or graphene.

[0069] The energy level of the lowest unoccupied molecular orbital of compound (a) is more preferably −5.0 eV or more and −3.7 eV or less, and particularly preferably −5.0 eV or more and −4.1 eV or less.

[0070] In the present invention, the energy level of the lowest unoccupied molecular orbital is calculated using Gaussian 16 with B3LYP as the functional and 6-311G(d) (structure optimization calculation) and 6-311++G(d,p) (energy calculation) as the basis set.

[0071] Compound (a) preferably has a structure in which at least two groups selected from halogen atoms, carbonyl groups, cyano groups, nitro groups, sulfinyl groups, sulfonyl groups, and imide groups are bonded to one carbon-carbon double bond or one conjugated system. The above structure significantly affects the electron density of the π orbital of one carbon-carbon double bond or one conjugated system. Because a structure such as one carbon-carbon double bond or one conjugated system is prone to π-π interactions or charge-transfer interactions with CNTs or graphene, it is presumed that compound (a) can have a strong electronic interaction with CNTs or graphene.

[0072] A conjugated system is a system in which two or more multiple bonds are conjugated. The π electrons in the multiple bonds interact and are delocalized through single bonds. The structure of a conjugated system is, for example, a structure in which double bonds and / or triple bonds are connected by single bonds, atoms with unshared electron pairs, or atoms with empty p orbitals, and specific examples are shown in general formulas (11) to (13).

[0073] [ka]

[0074] An example of a compound having a structure in which at least two or more groups selected from a halogen atom, a carbonyl group, a cyano group, a nitro group, a sulfinyl group, a sulfonyl group, and an imide group are bonded to one conjugated system is the compound represented by formula (14). In this compound, the corresponding conjugated system is surrounded by a dotted line. On the other hand, the compound represented by formula (15) does not have a conjugated system, and therefore does not fall under the category of compounds having a structure in which at least two or more groups selected from a halogen atom, a carbonyl group, a cyano group, a nitro group, a sulfinyl group, a sulfonyl group, and an imide group are bonded to one conjugated system.

[0075] [ka]

[0076] [ka]

[0077] Compound (a) preferably has a ring structure, presumably because the ring structure increases the planarity of compound (a), facilitating the approach and interaction between one carbon-carbon double bond or one conjugated system in compound (a) and CNT or graphene.

[0078] Compound (a) is particularly preferably a compound represented by general formula (1). This is presumably because the compound represented by general formula (1) has high planarity, which facilitates the proximity and interaction between one carbon-carbon double bond or one conjugated system in the compound and CNT or graphene.

[0079] [ka]

[0080] In the general formula (1), X represents an oxygen atom or a dicyanomethylene group. 1 ~R 4each independently represents a structure selected from a hydrogen atom, a halogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an alkoxy group, an alkylthisulfanyl group, an aryloxy group, an arylsulfanyl group, a heteroaryloxy group, a heteroarylsulfanyl group, a cyano group, a nitro group, an alkylsulfinyl group, an alkylsulfonyl group, a carboxyl group, an alkylcarbonyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkylcarbonyloxy group, an arylcarbonyloxy group, an aminocarbonyl group, an alkylimido group, an arylimido group, and a heteroarylimido group. 1 ~R 4 Any two of these may form a ring structure.

[0081] The alkyl group refers to a saturated aliphatic hydrocarbon group such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, or a tert-butyl group. The alkyl group may or may not have a substituent. When the alkyl group has a substituent, the substituent is not particularly limited, and examples thereof include an alkoxy group, an aryl group, a heteroaryl group, and a nitro group. The substituent may further have a substituent. Unless otherwise specified, the explanation regarding these substituents is common to the following descriptions. In addition, the number of carbon atoms in the alkyl group is not particularly limited, but is preferably 1 to 20, more preferably 1 to 8, from the viewpoints of ease of availability and cost.

[0082] The cycloalkyl group refers to a saturated alicyclic hydrocarbon group such as a cyclopropyl group, a cyclohexyl group, a norbornyl group, or an adamantyl group. The cycloalkyl group may or may not have a substituent. The number of carbon atoms in the cycloalkyl group is not particularly limited, but is preferably in the range of 3 to 20.

[0083] The alkenyl group refers to an unsaturated aliphatic hydrocarbon group containing a double bond, such as a vinyl group, an aryl group, or a butadienyl group. The alkenyl group may or may not have a substituent. The number of carbon atoms in the alkenyl group is not particularly limited, but is preferably in the range of 2 to 20.

[0084] The cycloalkenyl group refers to an unsaturated alicyclic hydrocarbon group containing a double bond, such as a cyclopentenyl group, a cyclopentadienyl group, or a cyclohexenyl group. The cycloalkenyl group may or may not have a substituent. The number of carbon atoms in the cycloalkenyl group is not particularly limited, but is preferably in the range of 3 to 20.

[0085] The alkynyl group refers to an unsaturated aliphatic hydrocarbon group containing a triple bond, such as an ethynyl group. The alkynyl group may or may not have a substituent. The number of carbon atoms in the alkynyl group is not particularly limited, but is preferably in the range of 2 to 20.

[0086] The aryl group refers to an aromatic hydrocarbon group such as a phenyl group, a naphthyl group, a biphenyl group, an anthracenyl group, a phenanthryl group, a terphenyl group, or a pyrenyl group. The aryl group may or may not have a substituent. The number of carbon atoms in the aryl group is not particularly limited, but is preferably in the range of 6 to 40.

[0087] The heteroaryl group refers to an aromatic group having one or more atoms other than carbon in the ring, such as a furanyl group, a thiophenyl group, a benzofuranyl group, a dibenzofuranyl group, a pyridyl group, or a quinolinyl group. The heteroaryl group may or may not have a substituent. The number of carbon atoms in the heteroaryl group is not particularly limited, but is preferably in the range of 2 to 30.

[0088] The alkoxy group refers to a functional group in which one side of an ether bond is substituted with an alkyl group, such as a methoxy group, an ethoxy group, or a propoxy group. The alkoxy group may or may not have a substituent. The number of carbon atoms in the alkoxy group is not particularly limited, but is preferably in the range of 1 to 20.

[0089] The alkylsulfanyl group refers to a functional group in which one side of a sulfanyl group is substituted with an aliphatic hydrocarbon group, such as a methylsulfanyl group, an ethylsulfanyl group, or an n-propylsulfanyl group. The alkylsulfanyl group may or may not have a substituent. The number of carbon atoms in the alkylsulfanyl group is not particularly limited, but is preferably in the range of 2 to 20.

[0090] The aryloxy group refers to a functional group in which one side of an ether bond is substituted with an aromatic hydrocarbon group, such as a phenoxy group or a naphthoxy group. The aryloxy group may or may not have a substituent. The number of carbon atoms in the aryloxy group is not particularly limited, but is preferably in the range of 6 to 40.

[0091] The arylsulfanyl group refers to a functional group in which one side of a thioether bond is substituted with an aromatic hydrocarbon group. The arylsulfanyl group may or may not have a substituent. The number of carbon atoms in the arylsulfanyl group is not particularly limited, but is preferably in the range of 6 to 40.

[0092] The heteroaryloxy group refers to a functional group in which one side of an ether bond is substituted with a heteroaromatic ring group. The heteroaryloxy group may or may not have a substituent. The number of carbon atoms in the heteroaryloxy group is not particularly limited, but is preferably in the range of 2 to 30.

[0093] The heteroarylsulfanyl group refers to a functional group in which one side of a thioether bond is substituted with a heteroaromatic ring group. The heteroarylsulfanyl group may or may not have a substituent. The number of carbon atoms in the heteroarylsulfanyl group is not particularly limited, but is preferably in the range of 2 to 30.

[0094] The alkylsulfinyl group refers to a functional group in which one side of a sulfinyl group is substituted with an aliphatic hydrocarbon group, such as a methylsulfinyl group, an ethylsulfinyl group, or an n-propylsulfinyl group. The alkylsulfinyl group may or may not have a substituent. The number of carbon atoms in the alkylsulfinyl group is not particularly limited, but is preferably in the range of 2 to 20.

[0095] The alkylsulfonyl group refers to a functional group in which one side of a sulfonyl group is substituted with an aliphatic hydrocarbon group, such as a methylsulfonyl group, an ethylsulfonyl group, or an n-propylsulfonyl group. The alkylsulfonyl group may or may not have a substituent. The number of carbon atoms in the alkylsulfonyl group is not particularly limited, but is preferably in the range of 2 to 20.

[0096] The alkylcarbonyl group refers to a functional group in which one side of the carbonyl bond is substituted with an aliphatic hydrocarbon group, such as an acetyl group or a hexanoyl group. The alkylcarbonyl group may or may not have a substituent. The number of carbon atoms in the alkylcarbonyl group is not particularly limited, but is preferably in the range of 2 to 20.

[0097] The alkoxycarbonyl group refers to a functional group in which one side of a carbonyl bond is substituted with an alkoxy group, such as a methoxycarbonyl group. The alkoxycarbonyl group may or may not have a substituent. The number of carbon atoms in the alkoxycarbonyl group is not particularly limited, but is preferably in the range of 2 to 20.

[0098] The aryloxycarbonyl group refers to a functional group in which one side of a carbonyl bond is substituted with an aryloxy group, such as a phenoxycarbonyl group. The aryloxycarbonyl group may or may not have a substituent. The number of carbon atoms in the aryloxycarbonyl group is not particularly limited, but is preferably in the range of 6 to 40.

[0099] The alkylcarbonyloxy group refers to a functional group in which one side of an ether bond is substituted with an alkylcarbonyl group, such as an acetoxy group. The alkylcarbonyloxy group may or may not have a substituent. The number of carbon atoms in the alkylcarbonyloxy group is not particularly limited, but is preferably in the range of 2 to 20.

[0100] The arylcarbonyloxy group refers to a functional group in which one side of an ether bond is substituted with an arylcarbonyl group, such as a benzoyloxy group. The arylcarbonyloxy group may or may not have a substituent. The number of carbon atoms in the arylcarbonyloxy group is not particularly limited, but is preferably in the range of 6 to 40.

[0101] The aminocarbonyl group refers to a functional group in which one side of a carbonyl bond is substituted with an amino group. The aminocarbonyl group may or may not have a substituent. The number of carbon atoms in the aminocarbonyl group is not particularly limited, but is preferably in the range of 2 to 20.

[0102] The alkylimide group is a functional group in which one side of an imide bond is substituted with an alkyl group. The alkylimide group may or may not have a substituent. The number of carbon atoms in the alkylimide group is not particularly limited, but is preferably in the range of 2 to 20.

[0103] An arylimido group is a functional group in which one side of an imide bond is substituted with an aryl group. The arylimido group may or may not have a substituent. The number of carbon atoms in the arylimido group is not particularly limited, but is preferably in the range of 8 to 20.

[0104] The heteroarylimido group refers to a functional group in which one side of an imide bond is substituted with a heteroaryl group. The heteroarylimido group may or may not have a substituent. The number of carbon atoms in the heteroarylimido group is not particularly limited, but is preferably in the range of 8 to 20.

[0105] R 1 ~R 4The case where any two of these form a ring structure is, for example, R 1 and R 2 Toya, R 1 and R 3 and bond to each other to form a conjugated or non-conjugated ring structure. The ring structure may contain, in addition to carbon atoms, nitrogen, oxygen, sulfur, phosphorus, or silicon atoms. The ring structure may also be condensed with another ring.

[0106] The compound (a) is preferably a compound represented by general formula (2).

[0107] [ka]

[0108] In general formula (2), R 5 ~R 7 each independently represents a structure selected from a hydrogen atom, a halogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an alkoxy group, an alkylthio group, an aryl ether group, an aryl thioether group, a cyano group, a nitro group, an alkylsulfinyl group, an alkylsulfonyl group, a carboxyl group, an alkylcarbonyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkylcarbonyloxy group, an arylcarbonyloxy group, an aminocarbonyl group, an alkylimide group, an arylimide group, and a heteroarylimide group. 5 ~R 7 Any two of these may form a ring structure.

[0109] Among them, R 6 or R 7 is preferably a structure represented by general formula (3).

[0110] [ka]

[0111] In general formula (3), R 8 ~R 10 each independently represents a structure selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an alkoxy group, an alkylthio group, an aryl ether group, an aryl thioether group, a cyano group, a nitro group, an alkylsulfinyl group, an alkylsulfonyl group, a carboxyl group, an alkylcarbonyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkylcarbonyloxy group, an arylcarbonyloxy group, an aminocarbonyl group, an alkylimido group, an arylimido group, and a heteroarylimido group. 8 ~R 10 At least one of R is selected from a halogen atom, a carbonyl group, a cyano group, a nitro group, a sulfinyl group, a sulfonyl group, and an imide group. 8 ~R 10 Any two of these may form a ring structure.

[0112] In addition, the compound represented by general formula (2) preferably has a ring structure, and R 5 and R 7 It is preferable that a ring structure is formed by the above, and it is more preferable that the ring structure is a conjugated system. Of the compounds represented by general formula (2), it is particularly preferable that the compound represented by general formula (4) is a compound represented by general formula (4).

[0113] [ka]

[0114] In general formula (4), R 11 ~R 15each independently represents a structure selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an alkoxy group, an alkylthio group, an aryl ether group, an aryl thioether group, a cyano group, a nitro group, an alkylsulfinyl group, an alkylsulfonyl group, a carboxyl group, an alkylcarbonyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkylcarbonyloxy group, an arylcarbonyloxy group, an aminocarbonyl group, an alkylimido group, an arylimido group, and a heteroarylimido group. 11 ~R 15 At least one of R is selected from a halogen atom, a carbonyl group, a cyano group, a nitro group, a sulfinyl group, a sulfonyl group, and an imide group. 11 ~R 15 Any two of these may form a ring structure.

[0115] Specific examples of compound (a) include 1-chloroanthraquinone, 1,5-dichloroanthraquinone, 1,4,5,8-tetrachloroanthraquinone, 2-methyl-4-nitropyridine-N-oxide, 1-nitroanthraquinone, 2,5-dimethyl-p-benzoquinone, 2,6-dimethyl-p-benzoquinone, 2,3-dichloronaphthoquinone, p-benzoquinone, 2-chloro-p-benzoquinone, 2,3-dichloro-5-nitronaphthoquinone, 2,5-dibromo-p-benzoquinone, 2,5-dichloro-p-benzoquinone, and 2,6-dichloro Examples of the compound (a) include 2,3-dichloro-5,6-dicyano-p-benzoquinone, 7,7,8,8-tetracyanoquinodimethane, tetracyanoethylene, 2,3,5,6-tetracyano-p-benzoquinone, N,N'-dicyano-2,5-dimethylbenzoquinonediimine, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene, and 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane. Compound (a) may be used alone or in combination.

[0116] ((b) Polymer) In this embodiment, the second insulating layer contains a (b) polymer along with a compound (a). The presence of the (b) polymer is thought to optimize the interaction between the compound (a) and the CNT or graphene. This is presumably because the distribution of the compound (a) in the (b) polymer allows the amount and strength of the compound (a) interacting with the CNT or graphene to be adjusted. Note that in this embodiment, if the second insulating layer does not contain a (b) polymer, it is difficult to adjust the p-type semiconductor characteristics, possibly because the interaction between the compound (a) and the CNT or graphene is too strong.

[0117] (b) Examples of polymers include polyvinyl chloride, polyethylene terephthalate, polyvinylidene fluoride, polysiloxane, polyvinylphenol, polyester, polycarbonate, polysulfone, polyethersulfone, polyethylene, polypropylene, polystyrene, cycloolefin polymer, polyphenylene sulfide, polyvinyl acetate, and acrylic resin.

[0118] The (b) polymer preferably contains at least one selected from the group consisting of ester bonds, carbonate bonds, ether bonds, siloxane bonds, sulfonyl groups, chloro groups, hydroxy groups, and carboxy groups. The reason for this is presumed to be as follows: Compound (a) and CNTs or graphene interact electronically, resulting in partial charges on each other. Therefore, the presence of a polar polymer, i.e., a polymer containing the aforementioned functional groups, surrounding compound (a) and CNTs or graphene stabilizes the interaction between compound (a) and CNTs or graphene. Furthermore, polymers containing the aforementioned functional groups have a certain degree of polarity and are highly compatible with compound (a). Therefore, compound (a) is easily distributed within the (b) polymer, making it easy to adjust the amount and strength of compound (a)'s interaction with CNTs or graphene. The effect of the (b) polymer, as described above, is thought to be effective in adjusting the aforementioned p-type semiconductor characteristics, particularly in reducing the off-state current.

[0119] In particular, the (b) polymer is preferably a polymer having an ester bond, a carbonate bond, or a hydroxy group. This is presumably because these structures have particularly strong effects. Examples of such polymers include polyester, polyvinyl acetate, acrylic resins having ester bonds such as polymethyl methacrylate and polymethyl acrylate, and celluloses such as ethyl cellulose.

[0120] In this embodiment, when the weight ratio of the compound (a) to the polymer (b) in the second insulating layer is expressed as (a):(b), it is preferable that (a):(b)=0.01:99.99 to 30:70. By being in this range, the effects of improving the on-current and reducing the off-current are more significant. More preferably, the relationships shown in (1) to (3) below are satisfied. (1) If the energy level of the lowest unoccupied molecular orbital of compound (a) is -5.8 eV or more and less than -5.0 eV, then (a):(b) = 0.01:99.99 to 0.5:99.5 (2) If the energy level of the lowest unoccupied molecular orbital of compound (a) is -5.0 eV or more and -3.7 eV or less, then (a):(b) = 0.5:99.5 to 10:90 (3) If the energy level of the lowest unoccupied molecular orbital of compound (a) is greater than -3.7 eV and less than -3.2 eV, then (a):(b) = 10:90 to 30:70 Methods for analyzing the compounds (a) and (b) polymers in the second insulating layer include analyzing samples obtained by extracting each component that makes up the second insulating layer from a p-type semiconductor element using nuclear magnetic resonance (NMR) or analyzing the second insulating layer using XPS or other methods.

[0121] In this embodiment, the second insulating layer may contain other compounds in addition to the compound (a) and the polymer (b), such as thickeners and thixotropic agents for adjusting the viscosity and rheology of the solution when the second insulating layer is formed by coating.

[0122] The second insulating layer may be a single layer or multiple layers. When the second insulating layer is multiple layers, at least the layer containing compound (a) is in contact with the semiconductor layer.

[0123] (a polymer containing in its molecular structure the remaining groups obtained by removing some of the hydrogen atoms from the structure of compound (a)) In a p-type semiconductor device according to one embodiment of the present invention, the second insulating layer includes a polymer having a functional group introduced therein that exhibits the same function as compound (a). Examples of such polymers include polymers whose molecular structure contains groups remaining after removing some atoms from the structure of compound (a). The remaining groups remaining after removing some atoms from the structure of compound (a) refer to groups in which at least one atom has been removed from the structure of compound (a) due to the substitution of compound (a) in the polymer structure. For example, when compound (a) is 1-chloroanthraquinone, the remaining groups remaining after removing some atoms from the structure refer to groups remaining after removing the hydrogen atom at the 2-position.

[0124] Here, the preferred embodiments of the compound (a) and the preferred embodiments of the polymer (b) described above can be applied to the polymer as well, if necessary.

[0125] (protective layer) The p-type semiconductor element according to the embodiment of the present invention may further include a protective layer on the second insulating layer, which serves to protect the semiconductor element from physical damage such as abrasion and from moisture and oxygen in the atmosphere.

[0126] Examples of materials for the protective layer include inorganic materials such as silicon wafer, glass, sapphire, and sintered alumina, and organic materials such as polyimide, polyvinyl alcohol, polyvinyl chloride, polyethylene terephthalate, polyvinylidene fluoride, polysiloxane, polyvinyl phenol, polyester, polycarbonate, polysulfone, polyether sulfone, polyethylene, polyphenylene sulfide, polyparaxylene, polyacrylonitrile, and cycloolefin polymer. Furthermore, the protective layer may be a laminate of multiple materials, such as a polyvinyl phenol film formed on a silicon wafer or an aluminum oxide film formed on polyethylene terephthalate.

[0127] In the p-type semiconductor element according to the embodiment of the present invention, when it is made to function as a field-effect transistor, the current flowing between the source electrode and the drain electrode (source-drain current) can be controlled by changing the gate voltage. A p-type semiconductor element with good characteristics has a large current value in the on state, i.e., when a negative voltage is applied to the gate electrode, and a small current value in the off state, i.e., when a voltage of 0 V is applied to the gate electrode.

[0128] <Complementary semiconductor device> A complementary semiconductor device according to an embodiment of the present invention includes the above-described p-type semiconductor element and an n-type semiconductor element. The n-type semiconductor element includes a substrate, a first electrode, a second electrode, a semiconductor layer in contact with both the first electrode and the second electrode, an insulating layer in contact with the semiconductor layer, and a third electrode in contact with the insulating layer on the opposite side of the semiconductor layer from the insulating layer. The semiconductor layer preferably contains CNT or graphene, and more preferably contains CNT. This is because it facilitates characteristic adjustment with the p-type semiconductor element according to an embodiment of the present invention and provides favorable characteristics as a complementary semiconductor device.

[0129] Further, the CNT used for the semiconductor layer of the n-type semiconductor element is more preferably used as a CNT composite in which a conjugated polymer is attached to at least a part of the surface. Examples of the n-type semiconductor element include the n-type semiconductor elements described in International Publication No. 2018 / 180146, International Publication 2019 / 097978, International Publication No. 2020 / 195707, and International Publication No. 2020 / 195708.

[0130] FIG. 4 is a schematic cross-sectional view showing an example of a complementary semiconductor device according to an embodiment of the present invention. On the surface of an insulating substrate 41, a p-type semiconductor element 40 and an n-type semiconductor element 50 of the present invention are formed. The configuration of the p-type semiconductor element 40 is the same as that of the p-type semiconductor element 10 according to Embodiment 1 of the present invention.

[0131] The n-type semiconductor element 50 includes a gate electrode 52 formed on the insulating substrate 41, a gate insulating layer 53 covering it, a source electrode 55 and a drain electrode 56 provided thereon, a semiconductor layer 54 provided between those electrodes, and a second insulating layer 58 covering the semiconductor layer 54. The semiconductor layer 54 contains CNT or graphene 57. The second insulating layer 57 is not particularly limited, but for example, those having the configurations described in International Publication No. 2020 / 195707 and International Publication No. 2020 / 195708 are preferable.

[0132] In the structure of FIG. 4, the n-type semiconductor element 50 can function as a field-effect transistor. That is, the first electrode corresponds to the source electrode 55, the second electrode corresponds to the drain electrode 56, and the third electrode corresponds to the gate electrode 52.

[0133] The structure of the complementary semiconductor device according to the embodiment of the present invention is not limited to this.

[0134] <Manufacturing method of p-type semiconductor element> Various methods can be used to manufacture the p-type semiconductor device according to the embodiment of the present invention, and the manufacturing method is not particularly limited, but it is preferable that the step of forming the second insulating layer includes the steps of: (P) applying a composition containing (p-1) compound (a), (b) a polymer, and a solvent, or (p-2) a composition containing a polymer and a solvent whose molecular structure contains groups remaining after removing some atoms from the structure of compound (a), and (Q) drying the applied composition. Furthermore, when forming the semiconductor layer by a coating method, it is preferable that the step of forming the semiconductor layer includes the steps of: (R) applying a solution containing carbon nanotubes or graphene and a solvent; and (S) drying the applied solution.

[0135] Examples of the method for manufacturing a semiconductor element include the method for manufacturing a semiconductor element described in WO 2018 / 180146.

[0136] When forming the second insulating layer using a coating method, the solvent for dissolving the compound (a) and the polymer (b) contained in the second insulating layer is not particularly limited, but an organic solvent is preferred. Specific examples of the solvent include ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono n-butyl ether, propylene glycol mono t-butyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, and diethylene glycol ethyl methyl ether; ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, propyl acetate, butyl acetate, isobutyl acetate, and 3-methoxybutyl acetate. esters such as acetone, 3-methyl-3-methoxybutyl acetate, methyl lactate, ethyl lactate, and butyl lactate; ketones such as acetone, methyl ethyl ketone, methyl propyl ketone, methyl butyl ketone, methyl isobutyl ketone, cyclopentanone, 2-heptanone, cyclohexanone, and γ-butyrolactone; alcohols such as butyl alcohol, isobutyl alcohol, pentanol, 4-methyl-2-pentanol, 3-methyl-2-butanol, 3-methyl-3-methoxybutanol, and diacetone alcohol; amides such as N,N-dimethylformamide and N-methylpyrrolidone; aromatic hydrocarbons such as toluene and xylene; and hydrocarbons such as hexane and decahydronaphthalene.

[0137] Two or more of these may be used as the solvent. Among them, it is preferable to use a solvent having a boiling point of 110°C to 250°C at 1 atmosphere. If the boiling point of the solvent is 110°C or higher, evaporation of the solvent is suppressed during solution application, resulting in good application properties. If the boiling point of the solvent is 250°C or lower, less solvent remains in the insulating film, resulting in a second insulating layer with better heat resistance and chemical resistance.

[0138] The formed coating film may be annealed or hot-air dried in air, under reduced pressure, or in an inert gas atmosphere such as nitrogen or argon. Specific examples of annealing conditions include 50°C to 150°C, 3 minutes to 30 minutes, and a nitrogen atmosphere. This drying step can thoroughly dry the coating film if it is not sufficiently dried.

[0139] (Applicability of semiconductor elements) The p-type semiconductor element according to the embodiment of the present invention is applicable to ICs for various electronic devices, wireless communication devices such as RFID tags, wireless power supply devices, TFT arrays for displays, sensors, tamper detection systems, and the like.

[0140] <Wireless communication device> Next, a wireless communication device according to an embodiment of the present invention, which includes a p-type semiconductor element of the present invention, will be described. This wireless communication device is a device that communicates information using radio waves, such as a product tag, an anti-shoplifting tag, various tickets, or a smart card.

[0141] The wireless communication device includes at least the p-type semiconductor element and an antenna. A more specific configuration of the wireless communication device according to the embodiment of the present invention is shown in FIG. 5, for example.

[0142] This device includes a power supply generating unit that rectifies an external modulated wave signal received by an antenna 70 and supplies power to each component; a demodulation circuit that demodulates the modulated wave signal and sends it to a control circuit; a modulation circuit that modulates 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 memory circuit and reads the data from the memory circuit and transmits it to the modulation circuit, with each circuit unit electrically connected. At least one of the power supply generating unit, demodulation circuit, control circuit, modulation circuit, and memory circuit includes a p-type semiconductor element according to an embodiment of the present invention and may further include a capacitor, a resistor, and a diode. The memory circuit may further include a read-only memory unit to which information is written during manufacturing, or a non-volatile rewritable memory unit such as an EEPROM (Electrically Erasable Programmable Read-Only Memory) or FeRAM (Ferroelectric Random Access Memory). The power supply generating unit is composed of a capacitor and a diode.

[0143] The antenna, capacitor, resistor, diode, and nonvolatile rewritable memory unit may be any commonly used material, and there are no particular limitations on the materials or shapes used. Furthermore, the material electrically connecting each of the above components may be any commonly used conductive material. The method for connecting each component may be any method that can provide electrical continuity. The width and thickness of the connection portion of each component may be any.

[0144] <Product tag> The wireless communication device can be used for any purpose, but can be applied to, for example, a product tag. Known product tags can be used, including, for example, those having a base and the wireless communication device covered by the base. When applied to product tags with an identification information return function, it becomes possible to simultaneously identify multiple products without contact at a checkout register. Therefore, payment processing can be facilitated and accelerated compared to identification using barcodes.

[0145] Furthermore, for example, when paying for a product, the reader / writer can transmit the product information read from the product tag to a POS (Point of Sale System) terminal. This function also allows the POS terminal to register the sale of a product identified by the product information, making inventory management easier and faster.

[0146] <Thin-film transistor array> A thin film transistor (hereinafter, referred to as TFT) array can be obtained using p-type semiconductor elements according to embodiments of the present invention. FIG. 6 is a schematic diagram showing an example of a TFT array. As shown in FIG. 6, a TFT array 200 includes two gate lines 250 and 260, two source lines 270 and 280, and four TFTs 210, 220, 230, and 240. The gate line 250 is electrically coupled to the gate electrodes of the TFTs 210 and 230, and the gate line 260 is electrically coupled to the gate electrodes of the TFTs 220 and 240. The source line 270 is electrically coupled to the source electrodes of the TFTs 210 and 220, and the source line 280 is electrically coupled to the source electrodes of the TFTs 230 and 240. Note that, for the sake of simplicity, FIG. 6 illustrates a TFT array 200 including four TFTs; however, the numbers of gate lines, source lines, and TFTs may be changed as desired.

[0147] The material for electrically connecting the gate lines, source lines, and TFTs is not particularly limited, and may be, for example, a commonly used conductive material. The connection method may be any method that provides electrical continuity. The width and thickness of the connection portion may be any desired value.

[0148] The TFT array according to the embodiment of the present invention can be used, for example, in an active matrix driven liquid crystal display, electronic paper, and the like.

[0149] <Sensor> The p-type semiconductor element according to the embodiment of the present invention may be used in various sensors, such as sensors for detecting temperature, moisture, gas, light, electromagnetic waves, radiation, and pressure. [Example]

[0150] The present invention will be described in more detail below based on examples. Note that the present invention is not limited to the following examples. The evaluation methods used in the examples are described in the following (1) to (2).

[0151] (1) Calculation of the energy level of the lowest unoccupied molecular orbital Calculations were performed using Gaussian 16, with the functional B3LYP and the basis set 6-311G(d) (structure optimization calculation) and 6-311++G(d,p) (energy calculation).

[0152] (2) Evaluation of p-type semiconductor device characteristics The source-drain current (Id) vs. source-drain voltage (Vsd) characteristics of the fabricated p-type semiconductor devices were measured at various gate voltages (Vg). Measurements were performed in air using a 4200-SCS Semiconductor Characterization System (Keithley Instruments, Inc.). Vsd was set to -5 V, and Vg was varied from +5 V to -10 V. Id at Vg = -10 V was defined as the on-current, and Id at Vg = 0 V was defined as the off-current. The on-current was evaluated as follows: A, B, and C were defined as high on-currents, and A, B, and C were defined as low off-currents. Devices with both high on-currents and low off-currents were deemed to have good p-type semiconductor device characteristics. (on-current) A: 50μA or more B: Less than 50 μA, 20 μA or more C: Less than 20μA, 5μA or more D: Less than 5μA, 1μA or more E: Less than 1μA (off current) A: 10nA or less B: Greater than 10nA and less than or equal to 50nA C: Greater than 50nA and less than 100nA D: Greater than 100nA and less than or equal to 1000nA E: Greater than 1000nA.

[0153] (Example of composition preparation) Composition Preparation Example 1: Second Insulation Layer Solution A 1.35 g of polymethyl methacrylate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was dissolved in 8.5 g of cyclohexanone to prepare polymer solution A. Next, 0.15 g of 1-chloroanthraquinone (manufactured by Tokyo Chemical Industry Co., Ltd.) was added to the polymer solution A, and the mixture was treated in a hybrid mixer to obtain second insulating layer solution A.

[0154] Composition Preparation Example 2: Second Insulation Layer Solution B A second insulating layer solution B was obtained in the same manner as in Composition Preparation Example 1, except that 2-methyl-4-nitropyridine-N-oxide (manufactured by Tokyo Chemical Industry Co., Ltd.) was used instead of 1-chloroanthraquinone.

[0155] Composition Preparation Example 3: Second Insulation Layer Solution C A second insulating layer solution C was obtained in the same manner as in Composition Preparation Example 1, except that 2,6-dimethyl-p-benzoquinone (manufactured by Tokyo Chemical Industry Co., Ltd.) was used instead of 1-chloroanthraquinone.

[0156] Composition Preparation Example 4: Second Insulating Layer Solution D 1.425 g of polymethyl methacrylate was dissolved in 8.5 g of cyclohexanone to prepare polymer solution D. Next, 0.075 g of 2,3-dichloronaphthoquinone (manufactured by Tokyo Chemical Industry Co., Ltd.) was added to the polymer solution D, and the mixture was treated in a hybrid mixer to obtain second insulating layer solution D.

[0157] Composition Preparation Example 5: Second Insulation Layer Solution E A second insulating layer solution E was obtained in the same manner as in Composition Preparation Example 4, except that p-benzoquinone (manufactured by Tokyo Chemical Industry Co., Ltd.) was used instead of 2,3-dichloronaphthoquinone.

[0158] Composition Preparation Example 6: Second Insulating Layer Solution F 1.485 g of polymethyl methacrylate was dissolved in 8.5 g of cyclohexanone to prepare polymer solution F. Next, 0.015 g of p-chloranil (manufactured by Tokyo Chemical Industry Co., Ltd.) was added to the polymer solution F, and the mixture was treated in a hybrid mixer to obtain second insulating layer solution F.

[0159] Composition Preparation Example 7: Second Insulation Layer Solution G 1.4985 g of polymethyl methacrylate was dissolved in 8.5 g of cyclohexanone to prepare polymer solution G. Next, 0.0015 g of 2,3-dichloro-5,6-dicyano-p-benzoquinone (manufactured by Tokyo Chemical Industry Co., Ltd.) was added to the polymer solution G, and the mixture was treated in a hybrid mixer to obtain second insulating layer solution G.

[0160] Composition Preparation Example 8: Second Insulation Layer Solution H A second insulating layer solution H was obtained in the same manner as in Composition Preparation Example 7, except that 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (manufactured by Tokyo Chemical Industry Co., Ltd.) was used instead of 2,3-dichloro-5,6-dicyano-p-benzoquinone.

[0161] Composition Preparation Example 9: Second Insulation Layer Solution I A second insulating layer solution I was obtained in the same manner as in Composition Preparation Example 6, except that polystyrene (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was used instead of polymethyl methacrylate.

[0162] Composition Preparation Example 10: Second Insulation Layer Solution J A second insulating layer solution J was obtained in the same manner as in Composition Preparation Example 6, except that polysulfone (manufactured by BASF Japan Ltd., product number "S3010") was used instead of polymethyl methacrylate.

[0163] Composition Preparation Example 11: Second Insulation Layer Solution K A second insulating layer solution K was obtained in the same manner as in Composition Preparation Example 6, except that polyvinyl chloride (manufactured by Solvay, product number "IXAN SGA-01") was used instead of polymethyl methacrylate.

[0164] Composition Preparation Example 12: Second Insulation Layer Solution L A second insulating layer solution L was obtained in the same manner as in Composition Preparation Example 6, except that polycarbonate (manufactured by Mitsubishi Gas Chemical Company, Inc., product number "Iupizeta FPC-0330") was used instead of polymethyl methacrylate.

[0165] Composition Preparation Example 13: Second Insulation Layer Solution M A second insulating layer solution M was obtained in the same manner as in Composition Preparation Example 6, except that an acrylic resin having a hydroxy group (manufactured by Kyoeisha Chemical Co., Ltd., product number "Oricox KC-7000") was used instead of polymethyl methacrylate. The polymer solution prepared during this process will be referred to as polymer solution M.

[0166] Composition Preparation Example 14: Second Insulation Layer Solution N A second insulating layer solution N was obtained in the same manner as in Composition Preparation Example 6, except that ethyl cellulose (manufactured by The Dow Chemical Company, product number "Ethocel STD-100CPS") was used instead of polymethyl methacrylate. The polymer solution prepared along the way is referred to as polymer solution N.

[0167] Composition Preparation Example 15: Second Insulation Layer Solution O A second insulating layer solution O was obtained in the same manner as in Composition Preparation Example 6, except that a copolymer of vinyl chloride, vinyl acetate, and vinyl alcohol (manufactured by Nissin Chemical Industry Co., Ltd., product number "Solvine A") was used instead of polymethyl methacrylate.

[0168] Composition Preparation Example 16: Second Insulation Layer Solution P A second insulating layer solution P was obtained by adding 0.2 g of p-chloranil to 9.8 g of cyclohexanone and treating the mixture in a hybrid mixer.

[0169] Composition Preparation Example 17: Second Insulation Layer Solution Q 0.80 g of polymethyl methacrylate was dissolved in 9.0 g of cyclohexanone to prepare polymer solution Q. Next, 0.20 g of 2-ethylanthraquinone (manufactured by Tokyo Chemical Industry Co., Ltd.) was added to the polymer solution Q, and the mixture was treated in a hybrid mixer to obtain second insulating layer solution Q.

[0170] Composition Preparation Example 18: Second Insulation Layer Solution R A second insulating layer solution R was obtained in the same manner as in Composition Preparation Example 17, except that 2-methylpyridine-N-oxide (manufactured by Tokyo Chemical Industry Co., Ltd.) was used instead of 2-ethylanthraquinone.

[0171] Composition Preparation Example 19: Second Insulation Layer Solution S 1.455 g of polymethyl methacrylate was dissolved in 8.5 g of cyclohexanone to prepare polymer solution S. Next, 0.045 g of 2,3-dichloro-5-nitronaphthoquinone (manufactured by Tokyo Chemical Industry Co., Ltd.) was added to the polymer solution S, and the mixture was treated in a hybrid mixer to obtain second insulating layer solution S.

[0172] Composition Preparation Example 20: Second Insulation Layer Solution T A second insulating layer solution T was obtained in the same manner as in Composition Preparation Example 6, except that p-fluoranil (manufactured by Tokyo Chemical Industry Co., Ltd.) was used instead of p-chloranil.

[0173] Composition Preparation Example 21: Second Insulation Layer Solution U Polysiloxane solution A (solids concentration 26.0 wt%) was obtained in the same manner as in Example 1 of the composition of WO 2018 / 180146. 4.274 g of cyclohexanone was added to 5.712 g of polysiloxane solution A, and then 0.015 g of p-chloranil was added. The mixture was treated with a hybrid exotherm to obtain second insulating layer solution U.

[0174] Example 1 A semiconductor device having the configuration shown in FIG. 1 was fabricated in the same manner as in Example 11 of International Publication No. 2019 / 065561, and a semiconductor device before the formation of a second insulating layer was obtained. Next, 5 μL of second insulating layer solution A was dropped onto semiconductor layer 4 so as to cover semiconductor layer 4, and heat treatment was performed at 110°C for 30 minutes under a nitrogen gas flow to form second insulating layer 8. In this way, a p-type semiconductor device was obtained. The obtained p-type semiconductor device was evaluated according to the above evaluation methods (1) and (2).

[0175] Examples 2 to 18, Comparative Examples 1, 5, and 6 A p-type semiconductor device was fabricated and evaluated in the same manner as in Example 1, except that second insulating layer solutions B to U, as shown in Tables 1 and 2, were used instead of second insulating layer solution A.

[0176] Comparative Examples 2 to 4 A p-type semiconductor device was fabricated and evaluated in the same manner as in Example 1, except that polymer solutions F, M, and N, as shown in Table 2, were used instead of second insulating layer solution A.

[0177] [Table 1]

[0178] [Table 2] [Explanation of symbols]

[0179] 1 Base material 2. Gate electrode 3 Gate insulating layer 4 Semiconductor layer 5. Source electrode 6 Drain electrode 7. Carbon nanotubes or graphene 8 Second insulating layer 10 p-type semiconductor element 11 Base material 12 gate electrode 13 Gate insulating layer 14 Semiconductor layer 15 Source electrode 16 Drain electrode 17 Carbon nanotubes or graphene 18 Second insulating layer 20 p-type semiconductor element 21 Base material 22 3rd electrode 23 Insulating layer 24 Semiconductor layer 25 cathode 26 anode 27 Carbon nanotubes or graphene 28 Second insulating layer 29 4th electrode 30 p-type semiconductor element 40 p-type semiconductor element 41 Base material 42 gate electrode 43 Gate insulating layer 44 Semiconductor layer 45 Source electrode 46 Drain electrode 47 Carbon nanotubes or graphene 48 Second insulating layer 50 n-type semiconductor element 52 gate electrode 53 Gate insulating layer 54 Semiconductor layer 55 Source electrode 56 Drain electrode 57 Carbon nanotubes or graphene 58 Second insulating layer 70 Antenna 200 TFT array 210 TFT 220 TFT 230 TFT 240 TFT 250 gate lines 260 gate lines 270 source lines 280 source lines

Claims

1. A substrate; a first electrode and a second electrode; a semiconductor layer in contact with both the first electrode and the second electrode; an insulating layer in contact with the semiconductor layer; a third electrode in contact with the insulating layer on the side opposite to the semiconductor layer with respect to the insulating layer; a second insulating layer in contact with the semiconductor layer on the opposite side of the insulating layer with respect to the semiconductor layer, the semiconductor layer contains carbon nanotubes or graphene; The second insulating layer is A. (a) an organic compound having an energy level of the lowest unoccupied molecular orbital of -5.8 eV or more and -3.2 eV or less (hereinafter referred to as "compound (a)"); (b) a polymer containing at least one selected from the group consisting of an ester bond, a carbonate bond, an ether bond, a siloxane bond, a sulfonyl group, a chloro group, a hydroxy group, and a carboxy group (hereinafter referred to as "(b) polymer"), or B. A polymer containing, in its molecular structure, the remaining groups obtained by removing some atoms from the structure of compound (a), A p-type semiconductor element.

2. 2. The p-type semiconductor device according to claim 1, wherein the energy level of the lowest unoccupied molecular orbital of said compound (a) is −5.0 eV or more and −3.7 eV or less.

3. 3. The p-type semiconductor device according to claim 1, wherein the energy level of the lowest unoccupied molecular orbital of said compound (a) is −5.0 eV or more and −4.1 eV or less.

4. The p-type semiconductor device according to any one of claims 1 to 3, wherein the compound (a) has a structure in which at least two or more groups selected from a halogen atom, a carbonyl group, a cyano group, a nitro group, a sulfinyl group, a sulfonyl group, and an imide group are bonded to one carbon-carbon double bond or one conjugated system.

5. The p-type semiconductor device according to claim 4 , wherein the compound (a) has a ring structure.

6. 6. The p-type semiconductor device according to claim 4, wherein the compound (a) is a compound represented by general formula (1): 【Chemical 1】 (In general formula (1), X represents an oxygen atom or a dicyanomethylene group. R １ ~R ４ each independently represents a structure selected from a hydrogen atom, a halogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an alkoxy group, an alkylsulfanyl group, an aryloxy group, an arylsulfanyl group, a heteroaryloxy group, a heteroarylsulfanyl group, a cyano group, a nitro group, an alkylsulfinyl group, an alkylsulfonyl group, a carboxyl group, an alkylcarbonyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkylcarbonyloxy group, an arylcarbonyloxy group, an aminocarbonyl group, an alkylimide group, an arylimide group, and a heteroarylimide group. １ ~R ４ Any two of these may form a ring structure.)

7. 4. The p-type semiconductor device according to claim 1, wherein the compound (a) is a compound represented by general formula (2). 【Chemistry 2】 (In general formula (2), R ５ ~R ７ each independently represents a structure selected from a hydrogen atom, a halogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an alkoxy group, an alkylsulfanyl group, an aryloxy group, an arylsulfanyl group, a heteroaryloxy group, a heteroarylsulfanyl group, a cyano group, a nitro group, an alkylsulfinyl group, an alkylsulfonyl group, a carboxyl group, an alkylcarbonyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkylcarbonyloxy group, an arylcarbonyloxy group, an aminocarbonyl group, an alkylimide group, an arylimide group, and a heteroarylimide group. ５ ~R ７ Any two of these may form a ring structure.)

8. 8. The p-type semiconductor device according to claim 1, wherein the polymer (b) is a polymer having an ester bond, a carbonate bond, or a hydroxy group.

9. The p-type semiconductor element according to any one of claims 1 to 8, wherein the second insulating layer contains the compound (a) and the polymer (b), and when the weight ratio of the compound (a) to the polymer (b) is expressed as (a):(b), (a):(b) is 0.01:99.99 to 30:

70.

10. When the second insulating layer contains the compound (a) and the polymer (b), and the weight ratio of the compound (a) to the polymer (b) is represented by (a):(b), (1) When the energy level of the lowest unoccupied molecular orbital of the compound (a) is −5.8 eV or more and less than −5.0 eV, the ratio of (a):(b) is 0.01:99.99 to 0.5:99.5 (2) When the energy level of the lowest unoccupied molecular orbital of the compound (a) is −5.0 eV or more and −3.7 eV or less, the ratio of (a):(b) is 0.5:99.5 to 10:90 (3) When the energy level of the lowest unoccupied molecular orbital of the compound (a) is greater than −3.7 eV and equal to or less than −3.2 eV, the ratio of (a):(b) is 10:90 to 30:70 10. The p-type semiconductor device according to claim 9, wherein:

11. 11. The p-type semiconductor device according to claim 1, wherein the semiconductor layer contains carbon nanotubes.

12. 12. A complementary semiconductor device comprising the p-type semiconductor element according to claim 1 and an n-type semiconductor element.

13. 13. The complementary semiconductor device according to claim 12, wherein the n-type semiconductor element comprises a substrate, a first electrode, a second electrode, a semiconductor layer in contact with both the first electrode and the second electrode, an insulating layer in contact with the semiconductor layer, and a third electrode in contact with the insulating layer on the opposite side of the semiconductor layer from the insulating layer, and the semiconductor layer contains carbon nanotubes or graphene.

14. 12. A method for manufacturing a p-type semiconductor device according to claim 1, wherein the step of forming the second insulating layer comprises the steps of: applying (P) (p-1) a composition containing compound (a), (b) a polymer and a solvent; or (p-2) a composition containing a polymer and a solvent, the molecular structure of which contains groups remaining after removing some atoms from the structure of compound (a); and (Q) drying the applied composition.

15. 12. The method for manufacturing a p-type semiconductor element according to claim 1, wherein the step of forming the semiconductor layer comprises: (R) applying a solution containing carbon nanotubes or graphene and a solvent; and (S) drying the applied solution.

16. A wireless communication device comprising at least the p-type semiconductor element according to any one of claims 1 to 11 and an antenna.

17. A thin film transistor array comprising the p-type semiconductor element according to any one of claims 1 to 11.

18. A sensor comprising the p-type semiconductor element according to any one of claims 1 to 11.

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