JP2018093198A - Semiconductor film and semiconductor element using the same, and dispersion liquid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor film which can be manufactured in a vacuum process and a low temperature process and which can develop higher mobility; and provide a semiconductor element using the semiconductor film; and provide a dispersion liquid.SOLUTION: In a semiconductor film including metal oxide particles and an organic compound, with respect to the entire semiconductor film of 100 mass%, a content of the metal oxide is not less than 55 mass% and not more than 95 mass% and a content of the organic compound is not less than 5 mass% and not more than 45 mass%; and a ratio (S2/S1) between a peak area S1 attributed to Oions of the metal oxide and a peak area S2 attributed to Oions of oxygen defect of o1s spectra observed by XPS measurement of the semiconductor film is not less than 0.25 and not more than 0.60.SELECTED DRAWING: None

Description

  The present invention relates to a semiconductor film, a semiconductor element using the semiconductor film, and a dispersion.

  In recent years, with the development of thin and light display elements such as organic electroluminescence (organic EL) elements, development of materials having high carrier mobility (hereinafter referred to as mobility) as semiconductor elements is required. Currently, metal oxides such as indium, gallium, and zinc oxide, which are high mobility metal oxides, have been developed (Patent Document 1).

  Moreover, the current semiconductor element is mainly silicon, and the process requires an expensive vacuum apparatus and a high temperature process. Further, since photolithography is used, it is necessary to go through a plurality of steps. For this reason, there exists a problem that the manufacturing cost of a semiconductor element is high. Therefore, as a method for forming a layer made of inorganic semiconductor particles having high mobility, a non-vacuum process such as a coating method has been actively studied.

International Publication No. 2005/088726

  By the way, in the case of an inorganic semiconductor film, a high temperature of about 300 ° C. or higher is required as a thin film formation temperature. For this reason, a glass substrate or a silicon wafer must be used as the substrate for forming the inorganic semiconductor film, and application to a resin substrate or the like for which impact resistance and flexibility are desired is extremely difficult.

  Accordingly, an object of the present invention is to propose a semiconductor film that can be manufactured by a non-vacuum process and a low-temperature process and can exhibit higher mobility, a semiconductor element using the semiconductor film, and a dispersion liquid. To do.

  As a result of intensive studies to solve the above problems, the present inventors have completed the present invention.

That is, the present invention is a semiconductor film containing metal oxide particles and an organic compound, and the content of the metal oxide is 55% by mass or more and 95% by mass with respect to 100% by mass of the entire semiconductor film. % Or less, the content of the organic compound is 5% by mass or more and 45% by mass or less, and the peak of the O1s spectrum in the XPS measurement of the semiconductor film is attributed to the O ²⁻ ion of the metal oxide. The ratio (S2 / S1) between the area S1 and the peak area S2 attributed to oxygen deficient O ²⁻ ions is 0.25 or more and 0.60 or less.

  The present invention is a semiconductor film containing indium oxide particles and an organic compound, and the content of the indium oxide is 55% by mass or more and 95% by mass or less with respect to 100% by mass of the entire semiconductor film. The organic compound content is 5% by mass or more and 45% by mass or less, and is present in the peak area S1 existing from 528 eV to 530 eV and from 530 eV to 533 eV in the O1s spectrum in the XPS measurement of the semiconductor film. The ratio (S2 / S1) to the peak area S2 is 0.25 or more and 0.60 or less.

The present invention is a semiconductor film containing zinc oxide particles and an organic compound, wherein the content of the zinc oxide is 55% by mass or more and 95% by mass or less with respect to 100% by mass of the entire semiconductor film. The organic compound content is 5% by mass or more and 45% by mass or less, and the peak area S1 attributed to the O ²⁻ ion of zinc oxide in the O1s spectrum in the XPS measurement of the semiconductor film and oxygen The ratio (S2 / S1) to the peak area S2 attributed to the deficient O ²⁻ ions is 0.25 or more and 0.60 or less.

  In this invention, it is preferable that the said organic compound is a dielectric material and a dielectric constant is 5-100.

  In the present invention, the organic compound is preferably a cyano group-containing organic compound.

  In the present invention, the relative element concentration of Na in the XPS measurement of the semiconductor film is preferably 1.0 atomic% or less.

  A semiconductor element according to the present invention includes an electrode and the semiconductor film described above in contact with the electrode.

  In the semiconductor element according to the present invention, the thickness of the semiconductor film is preferably 1 nm or more and 1000 nm or less.

  The semiconductor element in the present invention is preferably a transistor element.

Mobility of the semiconductor device in the present invention, 0.001 cm ² / Vs or more is preferably not more than 10 cm ² / Vs.

Further, the present invention is a dispersion containing metal oxide particles, an organic compound, and a solvent, and the content of the metal oxide particles is 0.1% with respect to 100% by mass of the whole dispersion. The organic compound content is 0.1% by mass or more and 20% by mass or less, and the solvent content is 20% by mass or more and 99.98% by mass or less. Yes, the area S1 of the peak attributed to the O ²⁻ ion of the metal oxide and the area S2 of the peak attributed to the O ²⁻ ion of oxygen deficiency in the O1s spectrum in the XPS measurement after drying the dispersion The ratio (S2 / S1) is 0.25 or more and 0.60 or less.

  Further, the present invention is a dispersion containing indium oxide particles, an organic compound, and a solvent, and the content of the indium oxide particles is 0.01% by mass with respect to 100% by mass of the entire dispersion. The content of the organic compound is 0.01% by mass or more and 20% by mass or less, and the content of the solvent is 20% by mass or more and 99.98% by mass or less, The ratio (S2 / S1) of the peak area S1 existing from 528 eV to 530 eV and the peak area S2 present from 530 eV to 533 eV in the O1s spectrum in the XPS measurement after drying of the dispersion is 0.25 or more. 0.60 or less.

Further, the present invention is a dispersion containing zinc oxide particles, an organic compound, and a solvent, and the content of the zinc oxide particles is 0.1% by mass relative to 100% by mass of the entire dispersion. The content of the organic compound is 0.1% by mass or more and 20% by mass or less, and the content of the solvent is 20% by mass or more and 99.98% by mass or less, Ratio of peak area S1 attributed to O ²⁻ ions of zinc oxide and peak area S2 attributed to O ²⁻ ions of oxygen deficiency in the O1s spectrum in XPS measurement after drying of the dispersion ( S2 / S1) is 0.25 or more and 0.60 or less.

  According to the semiconductor film of the present invention and the semiconductor element using the semiconductor film, it can be manufactured by a non-vacuum process and a low-temperature process, and can exhibit higher mobility.

  By using the dispersion liquid of the present invention, the semiconductor film can be formed by a non-vacuum process and a low temperature process.

It is sectional drawing which shows typically an example of the semiconductor element in this Embodiment. It is sectional drawing which shows typically an example of the semiconductor element in this Embodiment. It is sectional drawing which shows typically an example of the semiconductor element in this Embodiment. It is sectional drawing which shows typically an example of the semiconductor element in this Embodiment. It is sectional drawing which shows the manufacturing method of the semiconductor element in this Embodiment in order of a process.

  Hereinafter, an embodiment of the present invention (hereinafter abbreviated as “embodiment”) will be described in detail.

(Semiconductor film)
The semiconductor film according to the present embodiment will be described in detail. The semiconductor film according to this embodiment includes metal oxide particles and an organic compound.

  The semiconductor film may be a film composed only of metal oxide particles and an organic compound, or may be a film composed of metal oxide particles and an organic compound and other components. Examples of other components include any one or more of a solvent, a binder component, and an inorganic component.

The semiconductor film (also referred to as a composite body) in this embodiment has the following characteristics.
(1) The content of the metal oxide is 55% by mass to 95% by mass with respect to 100% by mass of the entire semiconductor film.
(2) The content of the organic compound is 5% by mass or more and 45% by mass or less with respect to the total mass% of the semiconductor film 100.
(3) Ratio of peak area S1 attributed to O ²⁻ ions of metal oxide and peak area S2 attributed to O ²⁻ ions of oxygen deficiency in O1s spectrum in XPS measurement of semiconductor film ( S2 / S1) is 0.25 or more and 0.60 or less.

  First, materials and physical properties of metal oxide particles and organic compounds will be described.

<Metal oxide particles>
The metal oxide particles are particles composed of at least one metal and oxygen.

Examples of the metal oxide particles that can be used include aluminum oxide, bismuth oxide, cerium oxide, cobalt oxide, fornium oxide, magnesium oxide, silicon oxide, yttrium oxide, zirconium oxide, iron oxide, spinel (MgAl ₂ O ₄ ), BaTiO 3. ₃ , FeTiO ₃ , copper oxide (I), copper oxide (II), iron oxide, zinc oxide, silver oxide, titanium oxide (for example, including titanium oxide (IV) having a rutile type and anatase type crystal form), Aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), indium tin oxide (ITO), tin oxide, fluorine-doped tin oxide (FTO), antimony-doped tin oxide, indium oxide, indium Gallium / zinc oxide, nickel oxide, vanadium oxide, titanium Include _{strontium, CuAlO 2, CuGaO 2, SrCu} 2 O 2, LaCuOS, LaCuOSe, CuInO 2, ZnRh 2 O 4, 12CaO · 7Al 2 O 3 (C12A7), Ga 2 O 3, SrCuO like or similar metal oxides It is done.

  The metal oxide particles are preferably zinc oxide, indium oxide, indium / gallium / zinc oxide, and particularly preferably indium oxide, from the viewpoint of transparency and carrier mobility. In addition, from the viewpoint of low cost, titanium oxide (for example, titanium oxide (IV) including rutile type and anatase type) or zinc oxide, zinc oxide doped with aluminum (AZO), oxidation doped with gallium Zinc (GZO) is preferred. These metal oxides used for the metal oxide particles may be used in combination of two or more.

  In the X-ray diffraction spectrum of the metal oxide particles, the half width of the main peak is a measure representing the crystallinity of the metal oxide. When the X-ray diffraction measurement of the metal oxide particles is performed, the full width at half maximum can be measured from the main peak. The half width obtained from X-ray diffraction showing the crystallinity of the metal oxide is preferably 5.0 ° or less, more preferably 3.0 ° or less, from the viewpoint of carrier mobility in the metal oxide particles. 0 ° or less is more preferable, and 1.0 ° or less is most preferable. Further, since the film formability is deteriorated because the crystallinity of the metal oxide particles is too high, the half width is preferably 0.004 ° or more, more preferably 0.01 ° or more, and further preferably 0.1 ° or more. Preferably, 0.2 ° or more is most preferable.

  A typical method for producing metal oxide particles is to neutralize and precipitate metal ions, such as aqueous metal chloride solutions, by adding alkali such as ammonia or caustic soda to produce metal hydroxides or metal carbonates. Alternatively, a method of crystallizing by heat treatment (baking) at a high temperature of 500 ° C. or higher in a reducing atmosphere has been proposed.

  In addition, as a method for producing metal oxide particles, for example, a sol-gel method is used in which a metal alkoxide is hydrolyzed and polycondensed under acidic or basic conditions to form a sol, and the sol is dried to gel. It is done. Other production methods include, for example, a method in which a metal is directly heated to vaporize and burned with air, or a metal sulfuric acid or metal nitric acid is thermally decomposed.

  As another manufacturing method, a metal oxide produced by sputtering or the like may be used after being pulverized. The method for pulverization may be either dry pulverization or wet pulverization, and both methods may be used. For the dry pulverization, a Hammar crusher or the like can be used. For wet grinding, a ball mill, a planetary ball mill, a bead mill, a homogenizer, or the like can be used. The following are mentioned as a solvent at the time of wet grinding.

  That is, as a solvent, water, pentane, hexane, peptane, octane, nonane, decane, 2-methylhexane, decalin, tetralin, methanol, ethanol, n-propanol, 2-propanol, n-butanol, t-butanol, ethylene Glycol, diethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monobutyl ether, ethylene glycol monobutyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, ethylene glycol mono 2-ethylhexyl ether, propylene glycol n-butyl ether, dipropylene glycol n -Butyl ether, tripropylene glycol n-butyl ether, Propylene glycol methyl ether, tripropylene glycol methyl ether, ketones such as glycerin acetone, methyl ethyl ketone, aromatics such as benzene, xylene, toluene, phenol, aniline, diphenyl ether, dimethyl sulfoxide, dimethylformamide, acetonitrile, methyl acetate, tetrahydrofuran, Examples include butyl lactate and N-methylpyrrolidone. It is also possible to use a mixture of these.

  The surface of the metal oxide particles may be modified with an organic functional group. By modifying the surface with an organic functional group, dispersibility in an organic solvent is improved, and a uniform film can be produced. Examples of the method for modifying the organic functional group include cyanoethylation.

  The average particle diameter of the metal oxide particles is measured using a transmission electron microscope or a scanning electron microscope.

  The average particle diameter of the metal oxide particles is preferably 1 nm or more and 500 nm or less. The average particle diameter of the metal oxide particles is preferably 1 nm or more, more preferably 3 nm or more, still more preferably 5 nm or more, and most preferably 10 nm or more from the viewpoint of reducing contact resistance. Further, from the viewpoint of film formability, the average particle diameter of the metal oxide particles is preferably 500 nm or less, more preferably 300 nm or less, still more preferably 100 nm or less, and most preferably 50 nm or less.

  The metal oxide particles used in the present embodiment preferably have a relative standard deviation σ of the particle size distribution of 0.1 nm to 5.0 nm. From the viewpoint of reducing resistance, the relative standard deviation σ is more preferably 3.0 nm or less, further preferably 2.0 nm or less, and most preferably 1.0 nm or less.

  Among metal oxide particles, indium oxide will be described. The types of indium oxide that can be used include indium oxide (III) nanopowder, <100 nm particle size (TEM), indium oxide (III) 99.9% trace metals basis, indium oxide (III) 99.998% trace metals basis, 99.99% trace metals basis, indium (III) oxide 99.5 + CAS13143-2, molar mass 277.64 g / mol. , 99.5+ (EMD Millipore) (above, manufactured by Sigma-Aldrich), indium oxide / 99.9%, indium (III) oxide 99.999% -In PURATREM, indium oxide 99.99% metals basis (above, (Wako Pure Chemical Industries, Ltd.), Indium Oxide Nanoparticulars (SkySpring Nanomaterials Inc), Indium Oxide (SP) (Rare Metal Co., Ltd.), and the like, are not limited thereto.

  As a typical method for producing indium oxide particles, indium ions such as an indium chloride aqueous solution are neutralized and precipitated by adding an alkali such as ammonia or caustic soda to produce indium hydroxide in an atmospheric or reducing atmosphere. A method of crystallizing by heat treatment (baking) at a high temperature of 500 ° C. or higher has been proposed. As another production method, a method of adding an additive such as hexadecyltrimethylammonium bromide in order to prevent sintering during heating has been proposed.

  The crystal type of indium oxide is a cubic or bixbyte type and can be identified by X-ray diffraction measurement.

  Among the metal oxide particles, zinc oxide will be described. The types of zinc oxide particles that can be used include hexagonal plate-like zinc oxide, plate-like integrated spherical zinc oxide, large particle zinc oxide, ultrafine zinc oxide, ultrafine zinc oxide dispersion (above, Sakai Chemical Industry Co., Ltd.), FZO-50 (manufactured by Ishihara Sangyo Co., Ltd.), MZ-300, MZY-303S, MZ-306X, MZ-500, MZY-505S, MZY-510M3S, MZ-506X, MZ-510HPSX (above, manufactured by Teika), Zinc oxide dispersion (Product Nos .: 720107, 721093, 721107, 72085, 633844, and more, manufactured by Sigma-Aldrich), zinc oxide nanoparticles, <100 nm particle size, zinc oxide nanoparticles, 40 wt% in ethanol, <130 nm part size; zinc oxide nanoparticles, <110 nm particle size, 40 wt% in butylacetate (manufactured by Sigma-Aldrich), zinc oxide 0.02 μm, zinc oxide nanoparticles 20 nm, zinc oxide −5 μm, 99.9%, oxide Zinc 99.999% -Zn PURATREM, zinc oxide 99.999% metal basis (above, Wako Pure Chemical Industries, Ltd.) etc. are mentioned.

  As a typical method for producing zinc oxide particles, metal zinc is heated and vaporized and burned with air, or zinc sulfate or zinc nitrate is thermally decomposed. As another production method, a production method in which basic zinc carbonate is precipitated from an aqueous zinc chloride solution and baked is also used.

<Organic compounds>
The organic compound used in this embodiment is expected to improve the adhesion between particles and the adhesion between the particles and the substrate by being present between the metal oxide particles and on the surface of the metal oxide particles. Is done.

  From the viewpoint of preventing carrier recombination and high mobility, the relative dielectric constant of the organic compound is preferably 5 or more and 100 or less, more preferably 7 or more and 70 or less, and further preferably 8 or more and 50 or less, and most preferably. Is 10 or more and 30 or less. Thus, the organic compound functions as a dielectric.

  Moreover, the organic compound can improve the film formability by being present around the metal oxide particles.

  As an organic compound, as a general resin, polyvinylidene chloride, acrylic resin, acetyl cellulose, aniline resin, ABS resin, ebonite, vinyl chloride resin, acrylonitrile resin, aniline formaldehyde resin, aminoalkyl resin, urethane, AS resin, Epoxy resin, vinyl butyral resin, silicone resin, vinyl acetate resin, styrene butadiene rubber, silicone rubber, cellulose acetate, styrene resin, dextrin, nylon, soft vinyl butyral resin, fluorine resin, furfural resin, polyamide, polyester resin, polycarbonate Examples thereof include resins, phenol resins, furan resins, polyacetal resins, melamine resins, urea resins, polysulfide polymers, and polyethylene. Also, acetone, methyl alcohol, isobutyl alcohol, ethyl alcohol, aniline, isobutyl methyl ketone, ethylene glycol, propylene glycol, polyethylene glycol, polypropylene glycol, glycerin, cresol glycol, diall phthalate, dextrin, pyranol, phenol, bakelite varnish, formalin Thioglycerol, chloropyrene, succinic acid, succinic nitrile, nitrocellulose, ethyl cellulose, hydroxyethyl cellulose, starch, hydroxypropyl starch, pullulan, glycidol pullulan, polyvinyl alcohol, sucrose, sorbitol, organic compounds containing cyano group, etc. It is done.

  Here, the cyano group-containing organic compound is a compound containing one or more cyano groups. The cyano group-containing organic compound is more preferably a cyanoethyl group-containing organic compound. Specific examples of the cyano group-containing organic compound include cyanoethyl pullulan, cyanoethyl polyvinyl alcohol, cyanoethyl saccharose (cyanoethyl sucrose), cyanoethyl cellulose, cyanoethyl hydroxyethyl cellulose, cyanoethyl starch, cyanoethyl hydroxypropyl starch, cyanoethyl glycidol pullulan, cyanoethyl sorbitol and the like. .

Specific examples of fluorine-based resin, a _{C 2 F 4-n H n} (n is 0 to 3) a polymer as a skeleton, specifically, polyvinyl fluoride, polyvinylidene fluoride, polytetrafluoroethylene, etc. Is mentioned. Moreover, these may be copolymerized, and based on the fluororesin, it may be copolymerized with another resin. In addition, a part of hydrogen in the chemical formula may be substituted with chlorine. For example, polychlorotrifluoroethylene and the like can be mentioned.

Furthermore, a fluorine-type ion exchange resin is mentioned as a specific example of a fluorine-type resin. Specifically, the general formula _{CF 2 = CF-O (CF} 2 CF X) n O- (CF 2) m and fluorinated vinyl compound represented by -W, fluorinated olefin of the formula _CF 2 = CFZ And consisting of at least a binary copolymer. Here, X is F or a perfluoroalkyl group having 1 to 3 carbon atoms, n is an integer of 0 to 3, m is an integer of 1 to 5, Z is H, Cl, F, or carbon It is a perfluoroalkyl group of number 1-3. W is any of the groups represented by COOH, SO ₃ H, SO ₂ F, SO ₂ Cl, SO ₂ Br, COF, COCl, COBr, CO ₂ CH ₃ , and CO ₂ C ₂ H _5. .

In particular, in the case of an organic compound, an organic compound containing a highly polar atom or a functional group is preferable because of its large dielectric constant. The dipole moment that serves as an index of polarity can be estimated by the sum of the coupling moments. As the organic compound having a relative dielectric constant of 2 or more, a compound having a substituent having a bond moment of 1.4D (D = 3.333564 × 10 ⁻³⁰ Cm) or more is preferable. Examples of the substituent having a bond moment of 1.4D or more include OH, CF, CCl, C═O, N═O, and CN. Examples of organic compounds having these substituents and having a relative dielectric constant of 2 or more include fluorine-based resins, glycerin, thioglycerol, and cyano group-containing organic compounds. From the viewpoint of mobility, fluorine-based resins and cyano group-containing organic compounds are preferred. In particular, a cyano group-containing organic compound is preferable, and a cyanoethyl group-containing organic compound is more preferable.

  The organic compound in the semiconductor film is preferably an organic compound having a molecular weight of 600 or more from the viewpoint of functioning as a binder for metal oxide particles.

By the way, when the present inventors prepared a semiconductor film by mixing metal oxide particles and an organic compound together with the contents of the feature points (1) and (2) listed above, XPS measurement of the semiconductor film was performed. The ratio (S2 / S1) of the area S1 of the peak attributed to the O ²⁻ ion of the metal oxide to the area S2 of the peak attributed to the O ²⁻ ion having an oxygen deficiency in the O1s spectrum at 0. It has been found that the semiconductor characteristics are remarkably improved when controlled to 25 or more and 0.60 or less (the above characteristic point (3)). This range can be controlled by, for example, the annealing temperature and time for the oxide semiconductor particles before the formation of the semiconductor film. If the annealing temperature is increased and the annealing time is increased, the ratio (S2 / S1) is decreased. Further, the ratio (S2 / S1) can be controlled to be smaller by performing the baking treatment in the presence of ozone.

  On the other hand, the ratio (S2 / S1) increases due to the interaction due to the addition of the organic compound, and as a result, the ratio (S2 / S1) can be controlled to 0.25 or more and 0.60 or less.

In other words, the semiconductor film in this embodiment is used for a semiconductor element using an oxide semiconductor as described later, but in order to improve semiconductor characteristics, oxygen defects of the semiconductor element should be appropriately controlled. is necessary. Therefore, as a result of intensive studies by the inventors, in order to appropriately control oxygen defects of the semiconductor element, the area of the peak attributed to the O ²⁻ ion of the metal oxide in the O1s spectrum in the XPS measurement of the semiconductor film. It has been found that it is important that the ratio (S2 / S1) between S1 and the peak area S2 attributed to oxygen deficient O ²⁻ ions is 0.25 or more and 0.60 or less. .

  This ratio (S2 / S1) is based on the interaction between the metal oxide particles and the organic compound. The peak area S1 is made of oxygen inside the semiconductor film, and the peak area S2 is the oxygen of the semiconductor film. It is considered that the defect is caused by an interaction between oxygen and organic compounds on the surface of the semiconductor film. Therefore, by adjusting the ratio (S2 / S1) between the peak area S1 and the peak area S2, oxygen defects can be appropriately controlled.

  In the present embodiment, from the viewpoint of carrier mobility of semiconductor characteristics, the ratio (S2 / S1) between the peak area S1 and the peak area S2 in the O1s spectrum in XPS measurement of the semiconductor film is 0.25 or more. Is preferably 0.30 or more, more preferably 0.31 or more, and most preferably 0.32 or more. Similarly, the ratio (S2 / S1) is preferably 0.60 or less, more preferably 0.50 or less, and more preferably 0.40 or less from the viewpoint of semiconductor characteristics, particularly from the viewpoint of reducing off-state current of transistor elements. More preferred is 0.35 or less.

  Moreover, the flexibility of a semiconductor film can be improved by setting it as the semiconductor film which mixes a metal oxide particle and an organic compound. In order to improve flexibility, the interaction between the metal oxide particles and the organic compound is important.

  In addition, mixing the metal oxide particles and the organic compound has an effect of increasing the carrier conduction path. When a semiconductor film is formed using only metal oxide particles, that is, when a semiconductor film is formed using 100% metal oxide, a large number of portions where the metal oxide particles are not connected to each other are generated. Therefore, by mixing the metal oxide particles and the organic compound, the contact between the metal oxide particles can be increased in a pseudo manner. In addition, even if the metal oxide particles are not actually closely connected, it is presumed that carriers can pass through the inside of the semiconductor film when the organic compound enters at intervals of several nm. Moreover, when there are too many metal oxide particles in a semiconductor film, there exists a problem that the film formability to a board | substrate falls.

  In addition, by compositing metal oxide particles and an organic compound, surrounding oxygen (that is, air existing on the empty wall at the particle interface) can be blocked. As a result, the number of carriers deactivated by oxygen can be reduced, so that carrier density and mobility can be improved.

  The content of the metal oxide particles in the semiconductor film containing the metal oxide particles and the organic compound is preferably 55% by mass or more and 65% by mass from the viewpoint of semiconductor characteristics when the entire semiconductor film is 100% by mass. The above is more preferable, 80% by mass is further preferable, and 90% by mass is most preferable. Further, from the same viewpoint, the content of the metal oxide particles is preferably 95% by mass or less, more preferably 94% by mass or less, still more preferably 93% by mass or less, and most preferably 92% by mass or less.

  The content of the metal oxide particles in the semiconductor film containing the metal oxide particles and the organic compound is preferably 15% by volume or more and 21% by volume from the viewpoint of semiconductor characteristics when the entire semiconductor film is 100% by mass. The above is more preferable, 36% by volume is more preferable, and 56% by volume is most preferable. From the same viewpoint, the content of the metal oxide particles is preferably 73% by volume or less, more preferably 69% by volume or less, still more preferably 65% by volume or less, and most preferably 62% by volume or less.

  The content of the organic compound in the semiconductor film is preferably 5% by mass or more, more preferably 6% by mass or more, still more preferably 7% by mass, and most preferably 8% by mass from the viewpoint of flexibility. From the same viewpoint, the content of the organic compound is preferably 45% by mass or less, more preferably 35% by mass or less, still more preferably 20% by mass or less, and still more preferably 10% by mass or less.

  From the same viewpoint, it is preferably 27% by volume or more, more preferably 31% by volume or more, still more preferably 35% by volume, and most preferably 38% by volume. From the same viewpoint, the content of the organic compound is preferably 85% by volume or less, more preferably 79% by volume or less, still more preferably 64% by volume or less, and still more preferably 44% by volume or less.

  It has been found that when the relative element concentration of impurities in XPS measurement of a semiconductor film is controlled to 1.0 atomic% or less, the semiconductor characteristics, particularly the off-state current and hysteresis characteristics when used as a transistor, are remarkably improved. From the same viewpoint, the relative element concentration of the impurity is more preferably 0.8 atomic% or less, further preferably 0.5 atomic% or less, and particularly preferably 0.1 atomic% or less. Examples of the impurity element include Na, Cl, Ca, and the like, but are not limited thereto.

  In order to reduce the amount of impurities, the metal oxide particles can be washed and used. There are wet cleaning methods and dry cleaning methods, which can be used in appropriate combination.

  The wet cleaning includes three steps: impregnation of the metal oxide particles into the cleaning liquid, migration of impurities from the metal oxide particles to the cleaning liquid, and recovery of the metal oxide particles. In the step of impregnating the metal oxide particles into the cleaning liquid, the cleaning liquid is not particularly limited, but ultrapure water, citric acid aqueous solution, sodium hydrogen carbonate aqueous solution alone or in combination can be used. A commercially available surfactant can also be used for the cleaning liquid.

  In the step of transferring impurities from the metal oxide particles to the cleaning liquid, manual stirring or an ultrasonic cleaning machine can be used. In particular, the ultrasonic cleaner can transfer a large amount of impurities to the cleaning liquid by physical actions such as ultrasonic cavitation, vibration acceleration, and straight flow. Further, the chemical reaction of the cleaning liquid is promoted by the ultrasonic wave, and a large amount of impurities can be transferred to the cleaning liquid.

  In the metal oxide particle recovery step, the metal oxide containing a large amount of solids can be recovered by membrane distillation or centrifugal separation in order to separate the cleaning liquid and particles containing impurities. By repeating the above three steps, impurities in the metal oxide particles can be further reduced.

  Dry cleaning includes UV-ozone cleaning and oxygen plasma treatment. By dry cleaning, molecules and elements strongly chemisorbed on the metal oxide surface, which was difficult to remove by wet cleaning, can be reduced.

(Semiconductor element)
The semiconductor element in this embodiment includes an electrode and the semiconductor film formed in contact with the electrode.

  Examples of the semiconductor element include a diode, a transistor, a thin film transistor, a memory, a photodiode, a light emitting diode, a light emitting transistor, and a sensor.

  Transistors and thin film transistors (hereinafter collectively referred to as transistor elements) include various display devices such as active matrix display, liquid crystal display, distributed liquid crystal display, electrophoretic display, electrochromic display, organic light emitting display, and electronic paper. It can be used for various display elements such as a particle rotation type display element.

  In these display devices, the transistor element is used for a display pixel switching transistor, a signal driver circuit element, a memory circuit element, a signal processing circuit element, and the like.

  A switching transistor of a display device or a display element (hereinafter collectively referred to as a display device) is disposed in each pixel of the display device and switches a display state of each pixel. Since such an active drive element does not require patterning of the opposing conductive substrate, depending on the circuit configuration, the pixel wiring is simplified compared to a passive drive type display device that does not have a transistor that switches the display state of the pixel. Can be Usually, one to several switching transistors are arranged per pixel. Such a display device has a structure in which a data line and a gate line which are two-dimensionally formed on a substrate surface intersect each other, and the data line and the gate line are respectively joined to the gate electrode, the source electrode and the drain electrode of the transistor. ing. It is possible to divide the data line and the gate line, and to add a current supply line and a signal line.

  Each pixel of the display device can be provided with a function of recording a signal by adding a capacitor in addition to the pixel wiring and the transistor. Furthermore, a driver circuit for data lines and gate lines, a memory circuit for pixel signals, a pulse generator, a signal divider, a controller, and the like can be mounted on the substrate over which the display device is formed.

  When the semiconductor element is a thin film transistor, the element structure may be, for example, a structure of substrate / gate electrode / insulator layer (dielectric layer) / source electrode / drain electrode / semiconductor layer (bottom contact structure), substrate / Semiconductor layer / source electrode / drain electrode / insulator layer (dielectric layer) / gate electrode structure (top gate structure), substrate / gate electrode / insulator layer (dielectric layer) / semiconductor layer / source electrode / drain electrode (Top contact structure) and the like. The insulator layer (dielectric layer) is a gate insulating film, and is made of, for example, an organic compound film having a relative dielectric constant of 3 to 150. A plurality of source electrodes, drain electrodes, and gate electrodes may be provided. Further, a plurality of semiconductor layers may be provided in the same plane or may be provided in a stacked manner.

Mobility of the semiconductor element (e.g., mobility of the thin film transistor described above), in order to use the device for displaying an image is preferably at least 0.001 cm ² / Vs, more preferably at least 0.01 cm ² / Vs, more preferably at least 0.1 cm ² / Vs, most preferably at least ^{1 cm} 2 / Vs. For the same viewpoint, preferably 10 cm ² / Vs or less, more preferably more than ^{8 cm} 2 / Vs, more preferably at least ^{6 cm} 2 / Vs, most preferably at least ^{4 cm} 2 / Vs.

  As a configuration of the transistor element, in addition to the thin film transistor, any of a MOS (metal-oxide (insulator layer) -semiconductor) type transistor and a bipolar type transistor can be employed. Examples of the element structure of the bipolar transistor include a structure of n-type semiconductor layer / p-type semiconductor layer / n-type semiconductor layer and a structure of p-type semiconductor layer / n-type semiconductor layer / p-type semiconductor layer. An electrode is connected to the semiconductor layer. A semiconductor film containing the metal oxide particles and the organic compound of this embodiment is used for at least one of the p-type semiconductor layer and the n-type semiconductor layer.

  When the semiconductor element is a diode, the element structure includes, for example, a structure of electrode / n-type semiconductor layer / p-type semiconductor layer / electrode. A semiconductor film containing the metal oxide particles and the organic compound of this embodiment is used for the p-type semiconductor layer or the n-type semiconductor layer.

  The semiconductor film containing the metal oxide particles and the organic compound is in contact with the electrode, and at least a part of the bonding surface between the semiconductor film and the electrode can be a Schottky junction and / or a tunnel junction. Examples of such a junction structure include, for example, an electrode / Schottky junction (tunnel junction) / semiconductor layer / electrode structure, an electrode / semiconductor layer / tunnel junction / semiconductor layer / electrode structure, and an electrode / Schottky junction ( (Tunnel junction) / semiconductor layer / tunnel junction / semiconductor layer / electrode.

  These Schottky junctions and tunnel junctions are not only usable for adjustment of diode characteristics and tunnel junction elements. If a magnetic material or a photoresponsive material is used for the Schottky junction and the tunnel junction, a more sophisticated semiconductor element can be manufactured.

  Further, a diode can be formed only by applying a Schottky junction and / or a tunnel junction to the semiconductor film containing the metal oxide particles and the organic compound of this embodiment. A semiconductor element having such a junction structure is preferable because a diode or a transistor can be manufactured with a simple structure. Furthermore, various elements such as an inverter, an oscillator, a memory circuit, and a sensor can be formed by bonding a plurality of semiconductor elements having such a bonded structure.

  The semiconductor element of this embodiment can also be used as an arithmetic element or a storage element in an electronic device such as an IC card, a smart card, or an electronic tag. In that case, even if these are a contact type or a non-contact type, they can be applied without any problem.

  These IC cards, smart cards, and electronic tags are composed of a memory, a pulse generator, a signal divider, a controller, a capacitor, and the like, and may further include an antenna and a battery.

  Furthermore, the semiconductor element of this embodiment can be used as a sensor, and can be applied to various sensors such as a gas sensor, a biosensor, a blood sensor, an immune sensor, an artificial retina, and a taste sensor.

  Next, a specific example of a semiconductor element using the semiconductor film of this embodiment will be described.

  FIG. 1 is a cross-sectional view showing an example of a configuration example of a semiconductor element 100 according to the present embodiment. As shown in FIG. 1, the semiconductor element 100 is a thin film transistor having a bottom contact structure, and includes a substrate 110, a gate electrode 120 formed on the substrate 110, and an insulation formed on the substrate 110 to cover the gate electrode 120. The body layer 130, the source electrode 140, the drain electrode 150, and the semiconductor layer 160 are included. The source electrode 140 is formed on the substrate 110 and covers one end of the gate electrode 120 with the insulator layer 130 interposed therebetween. The drain electrode 150 is formed on the substrate 110 and covers the other end of the gate electrode 120 with the insulator layer 130 interposed therebetween. The semiconductor layer 160 is formed on the gate electrode 120 with the insulator layer 130 interposed therebetween. From the insulator layer 130 that appears between the source electrode 140 and the drain electrode 150 (ie, a gap), the semiconductor layer 160 is formed on the source electrode 140. And over the drain electrode 150.

  Examples of the material of the substrate 110 include glass or resin. Examples of the material for the gate electrode 120, the source electrode 140, and the drain electrode 150 include metals, conductive ceramic materials, carbon, and conductive organic materials. Each material of the gate electrode 120, the source electrode 140, and the drain electrode 150 is more preferably gold, silver, aluminum, copper, indium tin oxide (ITO) from the viewpoint of obtaining good bonding and adhesion with metal oxide or silicon. Or an indium-gallium alloy. The semiconductor layer 160 is a body layer of a thin film transistor (that is, a layer in which a channel is formed), and is formed using a semiconductor film containing metal oxide particles and an organic compound of this embodiment.

  FIG. 2 is a cross-sectional view schematically showing an example of the semiconductor element 200 according to the present embodiment. As shown in FIG. 2, the semiconductor element 200 is a thin film transistor having a top gate structure, and includes a substrate 210, a source electrode 240 and a drain electrode 250 formed on the substrate 210, and a source electrode formed on the substrate 210. 240, the semiconductor layer 260 covering the drain electrode 250, the insulator layer 230 formed on the semiconductor layer 260, and the gate electrode 220 formed on the insulator layer 230. As shown in FIG. 2, the source electrode 240 and the drain electrode 250 are arranged apart from each other. The semiconductor layer 260 is formed from the substrate 210 appearing between the source electrode 240 and the drain electrode 250 (that is, the gap) to the source electrode 240 and the drain electrode 250. The semiconductor layer 260 is formed using a semiconductor film containing the metal oxide particles of this embodiment and an organic compound. The gate electrode 220 is formed over the semiconductor layer 260 with the insulator layer 230 interposed therebetween, and the gate electrode 220, the source electrode 240, and the drain electrode 250 connect the insulator layer 230 and the semiconductor layer 260. Are provided so as to face each other.

  FIG. 3 is a cross-sectional view schematically showing an example of the semiconductor element 300 according to the present embodiment. As shown in FIG. 3, the semiconductor element 300 is a thin film transistor having a top contact structure, and includes a substrate 310, a gate electrode 320 formed on the substrate 310, and an insulation formed on the substrate 310 to cover the gate electrode 320. The semiconductor device includes a body layer 330, a semiconductor layer 360 formed over the insulator layer 330, and a source electrode 340 and a drain electrode 350. The semiconductor layer 360 is formed using a semiconductor film containing the metal oxide particles and the organic compound of this embodiment. The source electrode 340 is formed on the substrate 310 and covers one end of the semiconductor layer 360. The drain electrode 350 is also formed on the substrate 310 and covers the other end of the semiconductor layer 360. The source electrode 340 and the drain electrode 350 are arranged apart from each other. The gate electrode 320, the source electrode 340, and the drain electrode 350 are provided so as to partially face each other with the insulator layer 330 and the semiconductor layer 360 interposed therebetween.

  FIG. 4 is a cross-sectional view schematically showing an example of the semiconductor element in the present embodiment. A semiconductor element 400 illustrated in FIG. 4 is a thin film transistor having a bottom contact structure that serves as the substrate 110 and the gate electrode 120 in FIG. The semiconductor element 400 includes a gate electrode 420 that also serves as a substrate, an insulator layer 430, a source electrode 440, a drain electrode 450, and a semiconductor layer 460. The semiconductor layer 460 is formed over the gate electrode 420 with the insulator layer 430 interposed therebetween. From the insulator layer 430 that appears between the source electrode 440 and the drain electrode 450 (ie, a gap), the semiconductor layer 460 is formed on the source electrode 440. And over the drain electrode 250.

  Examples of the material of the gate electrode 420 that also serves as the substrate include p-type silicon and n-type silicon.

  Although not illustrated, the semiconductor element according to this embodiment may be a transistor in which a semiconductor layer is interposed between a source electrode and a drain electrode and these three layers are stacked in the film thickness direction. At this time, the gate electrode is preferably disposed in the semiconductor layer or in the vicinity of the source electrode (drain electrode).

  Next, the material of each layer of the semiconductor elements 100, 200, 300, and 400 will be described. Examples of the material for the substrates 110, 210, and 310 include glass or resin. Further, as materials of the gate electrodes 120, 220, 320, source electrodes 140, 240, 340, 440 and drain electrodes 150, 250, 350, 450, metals, conductive ceramic materials, carbon, conductive organic materials, etc. Is mentioned. Each material of the gate electrodes 120, 220, 320, the source electrodes 140, 240, 340, and 440 and the drain electrodes 150, 250, 350, and 450 is from the viewpoint of obtaining good bonding and adhesion with a metal oxide or silicon. More preferably, gold, silver, aluminum, copper, ITO, or an indium-gallium alloy is used. In addition, the semiconductor layers 160, 260, 360, and 460 are thin film transistor body layers, and are formed of a semiconductor film containing metal oxide particles and an organic compound as described above. Since metal oxide particles and organic compounds have already been described, please refer to them. 1 to 4, the expression “semiconductor layer” is used for the semiconductor elements 100, 200, 300, and 400. However, the “semiconductor layer” is formed from a “semiconductor film”. The two are not particularly distinguished.

  The layer thickness (film thickness) of the semiconductor layers 160, 260, 360, 460 (semiconductor film) is preferably 0.001 μm (1 nm) or more, more preferably 0.01 μm or more, from the viewpoint of electrical characteristics. 02 μm or more is more preferable, and 0.05 μm or more is most preferable. From the same viewpoint, the thickness of the semiconductor layers 160, 260, 360, 460 (semiconductor film) is preferably 1 μm (1000 nm) or less, more preferably 0.4 μm or less, still more preferably 0.2 μm or less, 0 .1 μm or less is most preferable.

(Semiconductor element manufacturing method)
As a method for manufacturing the semiconductor element described above, for example, a semiconductor layer-forming dispersion liquid (described later) is applied in a predetermined pattern on a predetermined pattern on each electrode or on an insulator layer. The method of forming a layer is mentioned. As another method for manufacturing a semiconductor element, there is a method in which after forming a semiconductor film on a substrate, the semiconductor film is patterned to form a semiconductor layer, and further, an electrode is formed and an insulator layer is formed. . As a patterning method of the semiconductor film at this time, for example, a method of forming a pattern using a method such as screen printing, gravure printing, offset printing, ink jet printing, or spraying can be employed.

  In this embodiment mode, a semiconductor element can be formed over a substrate such as glass or resin. In addition, since the semiconductor film can be formed by a simple method such as printing or application of a solution, a large number of semiconductor elements can be easily formed on a large area at a time. Therefore, a semiconductor element and a device using the semiconductor element (the above-described display element, arithmetic element, memory element, and the like) can be manufactured at low cost. In addition, manufacturing a semiconductor element using a semiconductor film is effective in reducing the thickness and weight of an apparatus using the semiconductor element.

  Next, a method for manufacturing the semiconductor elements 100, 200, 300, and 400 shown in FIGS. 1 to 4 will be described with reference to the drawings.

  5A to 5C are cross-sectional views showing the method of manufacturing the semiconductor element 100 according to the present embodiment in the order of steps. As shown in FIG. 5A, first, the gate electrode 120 is formed on the substrate 110.

  Next, as illustrated in FIG. 5B, the upper surface and side surfaces of the gate electrode 120 are covered with an insulator layer 130. Then, as shown in FIG. 5C, a source electrode 140 and a drain electrode 150 are formed from the substrate 110 to the insulator layer 130, respectively. Thereafter, the semiconductor layer 160 is formed, and the gap between the source electrode 140 and the drain electrode 150 is filled with the semiconductor layer 160. Thereby, the semiconductor element 100 shown in FIG. 1 is completed.

  The semiconductor element 200 shown in FIG. 2 can be manufactured in the following process order. That is, the source electrode 240 and the drain electrode 250 are formed on the substrate 210. Next, the semiconductor layer 260 is formed over the substrate 210 to cover the space between the source electrode 240 and the drain electrode 250 and the source electrode 240 and the drain electrode 250. Then, the insulator layer 230 is formed over the semiconductor layer 260. Thereafter, the gate electrode 220 is formed over the insulator layer 230. Thereby, the semiconductor element 200 shown in FIG. 2 is completed.

  Also, the semiconductor element 300 shown in FIG. 3 can be manufactured in the following process order. That is, the gate electrode 320 is formed on the substrate 310. Next, an insulator layer 330 is formed over the substrate 310 to cover the upper surface and side surfaces of the gate electrode 320. Then, a semiconductor layer 360 is formed over the insulator layer 330. After that, the source electrode 340 and the drain electrode 350 are formed over the substrate 310 and the semiconductor layer 360. Thereby, the semiconductor element 300 shown in FIG. 3 is completed.

  Further, the semiconductor element 400 shown in FIG. 4 can be manufactured in the following process order. That is, the insulator layer 430 is formed over the gate electrode 420 that also serves as a substrate to cover the upper surface of the gate electrode 420 that also serves as a substrate. Then, the source electrode 440 and the drain electrode 450 are formed over the insulator layer 430. After that, the semiconductor layer 460 is formed from the insulator layer 430 appearing between the source electrode 440 and the drain electrode 450 (that is, the gap) to the source electrode 440 and the drain electrode 450. Thereby, the semiconductor element 400 shown in FIG. 4 is completed.

  The gate electrode, the source electrode, the drain electrode, the insulator layer, and the semiconductor layer, which are components of these semiconductor elements (for example, thin film transistors), can be formed by a method such as printing or coating. For this reason, it is not necessary to manufacture a semiconductor element under vacuum, and it can be performed under normal pressure.

  Examples of materials for the gate electrode, source electrode, and drain electrode (hereinafter referred to as electrode materials) include metals, conductive ceramic materials, carbon, and conductive organic materials. The electrode material is preferably gold, silver, aluminum, copper, indium tin oxide (ITO), or indium-gallium alloy from the viewpoint of good bonding and adhesion to metal oxide or silicon.

  Further, in order to form the gate electrode, the source electrode, and the drain electrode by a method such as printing and coating, the electrode material needs to be in a liquid state. Therefore, a liquid electrode material can be used alone as an electrode material, but a non-liquid electrode material needs to be dispersed in a liquid. Examples of using non-liquid electrode materials dispersed in liquid include powders of gold, silver, copper, indium tin oxide (ITO), osmium, palladium, nickel, cobalt, iron, aluminum, etc. dispersed in liquid An electroconductive paste is mentioned, More preferably, they are gold, aluminum, copper, and indium tin oxide (ITO). Since indium-gallium is a liquid alloy at room temperature, printing can be performed as it is, and the liquid can be fixed with a sealing material or the like.

  Alternatively, for the electrode material, the precursor can be used as long as the precursor is in a liquid form or is easily made into a solution. Examples of such electrode materials include organic metal complexes such as gold, silver, nickel, and indium, and solutions of inorganic metal complexes.

  The material of the insulator layer preferably has a high dielectric constant, and an insulating ceramic material, an organic compound, a polymer, or the like is used. However, since the material of the insulator layer needs to be liquid like the electrode material, a solution, dispersion, or precursor of these materials may be used. For example, an alcoholate, an acetylacetone complex, or a solution thereof can be applied or printed to form a thin film, and the thin film can be converted into an oxide or sulfide by radiation energy such as heat or light to form an insulator layer. As the material for the insulator layer, polymers such as polyvinylidene fluoride, polyacrylonitrile, polyester, liquid crystal polymer, and organic compounds having polarity can be preferably used. Furthermore, a material in which a high dielectric material such as a ceramic material is dispersed in these organic compounds can be used as a material for the insulator layer.

  Further, as the substrates 110, 210, 310, glass substrates, PET (polyethylene terephthalate), PEN (polyethylene naphthalate), PC (polycarbonate), PP (polypropylene), polyethersulfone, polyimide, cycloolefin polymer, acrylic resin, Any commonly used substrate such as a plastic substrate such as a fluorine-based resin, a melamine resin, or a phenol resin, an aluminum substrate, a stainless steel (SUS) substrate, a clay substrate, or a paper substrate can be used. PET (polyethylene terephthalate), PC (polycarbonate), PP (polypropylene), PEN (polyethylene naphthalate), polyethersulfone, polyimide, cycloolefin polymer, acrylic resin, fluorine resin, melamine from the viewpoint of light weight, flexibility, and low cost A plastic substrate such as a resin or a phenol resin or a paper substrate is preferable.

  Furthermore, if a plurality of printing devices and / or coating devices arranged in series in the order of the manufacturing process are used, a coating solution for forming a semiconductor layer is continuously printed and / or coated on a continuous substrate (or sheet). be able to. Thereby, an electrode, a dielectric material layer, and a semiconductor layer can be continuously formed on a substrate (or sheet), and a semiconductor element can be manufactured.

  For example, in the case of manufacturing a thin film transistor having a structure (bottom contact structure) of substrate / gate electrode / insulator layer (dielectric layer) / source electrode / drain electrode / semiconductor layer, they are arranged in series in the order of the manufacturing process. The strip-shaped substrate is sequentially passed through the gate electrode printer, the insulator layer printer, the source / drain electrode printer, and the semiconductor layer printer. The strip-shaped substrate is, for example, the above-described sheet. Thereby, the constituent elements of the above-described thin film transistor are continuously formed on the substrate, and the thin film transistor is efficiently manufactured.

  Such a continuous thin film transistor manufacturing method has advantages such as a small equipment load, a shortened process, a significant reduction in the number of workers, and a low cost. In addition, since a large number of thin film transistors can be easily formed on a large-area substrate at a time, a large-area display device can be manufactured at low cost.

  As the printing method and coating method, known methods such as screen printing, gravure printing, offset printing, ink jet printing, spraying method, blade coating and the like can be used. In a plurality of printing devices and / or coating devices, the same printing method and coating method may be employed, or different printing methods and coating methods may be employed for each component.

  In forming the semiconductor film in this embodiment, coating or printing is performed on a substrate or the like using a dispersion liquid described below, and then drying or the like is performed as necessary.

(Dispersion)
Since the dispersion according to the present invention is applied on a substrate, it may be called a coating liquid. The dispersion according to the present invention includes metal oxide particles, an organic compound, and a solvent. Further, a dispersant may be included. As a solvent, water, pentane, hexane, peptane, octane, nonane, decane, 2-methylhexane, decalin, tetralin, methanol, ethanol, n-propanol, 2-propanol, n-butanol, t-butanol, terpineol, ethylene glycol , Diethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monobutyl ether, ethylene glycol monobutyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, ethylene glycol mono 2-ethylhexyl ether, propylene glycol n-butyl ether, dipropylene glycol n- Butyl ether, tripropylene glycol n-butyl ether , Ketones such as dipropylene glycol methyl ether, tripropylene glycol methyl ether, glycerin acetone, methyl ethyl ketone, aromatics such as benzene, xylene, toluene, phenol, aniline, diphenyl ether, dimethyl sulfoxide, dimethylformamide, acetonitrile, methyl acetate, Tetrahydrofuran, butyl lactate, N-methylpyrrolidone and the like can be mentioned.

  In particular, a solvent having a high polarity is preferable as the solvent because the dispersibility of the metal oxide particles becomes high. The highly polar solvent is preferably a solvent having a polarity parameter of Rohrschneider of 4 or more, more preferably 5 or more, still more preferably 6 or more, and even more preferably 7 or more.

  Specific examples of preferred solvents include terpineol, dimethyl sulfoxide, dimethylformamide, N-methylpyrrolidone and the like. It is also possible to use a mixture of these.

  Since the metal oxide particles and the organic compound in the dispersion have been described in the above (semiconductor film), please refer to them.

  Examples of the dispersant include an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a nonionic surfactant. Specifically, examples of the anionic surfactant include fatty acid sodium, monoalkyl sulfate, alkyl benzene sulfonate, and monoalkyl phosphate. Examples of the cationic surfactant include alkyltrimethylammonium salts, dialkyldimethylammonium salts, and alkylbenzylmethylammonium salts. Examples of amphoteric surfactants include alkyl dimethylamine oxide and alkyl carboxybetaine. Examples of the nonionic surfactant include polyoxyethylene alkyl ether, fatty acid sorbitan ester, alkyl polyglycoside, fatty acid ethanolamide, and alkyl monoglyceryl ether. Further, as other dispersants, “Disperbyk-102”, “Disperbyk-111”, “Disperbyk-142”, “Disperbyk-145”, “Disperbyk-110”, “Disperbyk-180”, “Disperbyk” manufactured by BYK Chemie. -2013 "," Byk-9076 "," ANTI-TERRA-U "," Plysurf M208F "," Plysurf DBS "manufactured by Daiichi Kogyo Seiyaku. Also, Triton X-45, Triton X-100, Triton X, Triton A-20, Triton X-15, Triton X-114, Triton X-405, Tween # 20, Tween # 40, Tween # 60, Tween # 80 , Tween # 85, Pluronic F-68, Pluronic F-127, Span 20, Span 40, Span 60, Span 80, Span 83, Span 85, "Surflon S-211", "Surflon S-221" manufactured by AGC Seimi Chemical "Surflon S-231", "Surflon S-232", "Surflon S-233", "Surflon S-242", "Surflon S-243", "Surflon S-611", "No. 3" manufactured by 3M “vecFC-4430”, “NovecFC-4432”, “MegaFuck F-444”, and “MegaFuck F-558” manufactured by DIC are listed.

  In terms of improving the dispersibility of metal oxide particles in a solvent, phosphoric acid polyester-based dispersants, alkylammonium salt-based dispersants, alkylolamine salt-based dispersants, and copolymer-based dispersants having pigment affinity Specifically, it is preferable to use “Disperbyk-111”, “Disperbyk-145”, “Disperbyk-180”, and “Disperbyk-2013” manufactured by Big Chemie.

  Further, from the viewpoint of improving the affinity between the metal oxide particles and the organic compound, a phosphoric acid polyester-based dispersant and a pigment-based copolymer dispersant are preferable, and specifically, “Disperbyk” manufactured by BYK Chemie. -111 "and" Disperbyk-2013 "are preferably used. The interaction of the metal oxide particles and the organic compound in the solvent can be confirmed by an infrared absorption spectrum method. It can also be confirmed by Raman spectroscopy or UV-visible spectroscopy. These dispersing agents may be used alone or in combination.

  The addition amount of the dispersant is preferably 0.1% by mass or more and 20% by mass, more preferably 0.2% by mass or more and 10% by mass or less, based on the total dispersion, from the viewpoint of the stability of the dispersion. The mass% is more preferably 5% by mass or less, and most preferably 0.5% by mass or more and 5% by mass or less.

  As a method for producing the dispersion, a ball mill, a planetary ball mill, a bead mill, a homogenizer, or the like can be used. Moreover, you may add a dispersing agent etc. suitably.

  As the concentration of the dispersion, the content of the metal oxide particles is preferably 0.1% by mass or more and 60% by mass or less, and more preferably 1% by mass or more and 55% by mass or less with respect to 100% by mass of the entire dispersion. Yes, more preferably 10 mass% or more and 50 mass% or less, and most preferably 20 mass% or more and 48 mass% or less.

  Further, the content of the organic compound is preferably 0.1% by mass or more and 20% by mass or less, more preferably 1% by mass or more and 15% by mass or less, and further preferably 2% by mass or more and 10% by mass. Or less, and most preferably 2.5% by mass or more and 5% by mass or less.

  Further, the content of the solvent is preferably 20% by mass or more and 99.98% by mass or less, more preferably 30% by mass or more and 90% by mass or less, and still more preferably 30% by mass or more and 80% by mass. %, Most preferably 40% by mass or more and 70% by mass or less. The average particle diameter of the metal oxide particles is preferably 1 nm or more and 500 nm or less. The average particle diameter of the metal oxide particles is preferably 1 nm or more, more preferably 3 nm or more, and further preferably 5 nm or more from the viewpoint of reducing contact resistance. Further, from the viewpoint of film formability, the average particle diameter of the metal oxide particles is more preferably 200 nm or less, still more preferably 100 nm or less, and most preferably 50 nm or less.

  Further, in the dispersion liquid of the present embodiment, when XPS measurement is performed after the dispersion liquid is dried, from the viewpoint of carrier mobility of semiconductor characteristics, the peak area S1 existing from 528 eV to 530 eV in the O1s spectrum in XPS measurement is obtained. The ratio (S2 / S1) to the peak area S2 existing from 530 eV to 533 eV is preferably 0.25 or more, more preferably 0.30 or more, still more preferably 0.31 or more, and 0.32 The above is most preferable. Similarly, the ratio (S2 / S1) is preferably 0.60 or less, more preferably 0.50 or less, and further preferably 0.40 or less from the viewpoint of semiconductor characteristics, particularly from the viewpoint of reducing off-state current of the transistor element. Preferably, 0.35 or less is even more preferable.

(Semiconductor film manufacturing process)
The manufacturing method of a semiconductor film in this embodiment includes a coating process in which a dispersion containing metal oxide particles, an organic compound, and a solvent is applied to a substrate to obtain a coating film, And a drying step of removing at least a part of the solvent from the coating film by drying at a drying temperature of 0 ° C. or lower.

  When the semiconductor film is formed by a printing method or a coating method, it is preferable to perform the coating process and the drying process to form the semiconductor film.

  In addition, the step of preparing the dispersion liquid used in the coating process (that is, the preparation step of the dispersion liquid) may be performed on the same production line as the coating process, or a production line different from the coating process or another manufacturing factory. You may go on. Moreover, you may make it purchase a dispersion liquid from the outside. In this embodiment, printing is one mode of application, and the dispersion (coating liquid) can be rephrased as a printing liquid, and the application process can be rephrased as a printing process. Hereinafter, the dispersion preparation process, the coating process, and the drying process will be described.

(1) Dispersion preparation step The dispersion preparation step is a step of preparing a dispersion from metal oxide particles, an organic compound, and a solvent. The solvent is preferably an organic solvent for dissolving or dispersing the metal oxide particles and the organic compound. Metal oxide particles, an organic compound, and a solvent are mixed to obtain a dispersion for forming a semiconductor film.

  The metal oxide particles can be used after being annealed in advance before being mixed with an organic compound in a solvent. The annealing atmosphere can be annealed in oxygen gas, in an inert gas such as nitrogen, or in a mixed gas of nitrogen and oxygen such as air. The annealing temperature is preferably 300 ° C. or higher, more preferably 400 ° C. or higher, and most preferably 600 ° C. or higher from the viewpoint of controlling oxygen defects. Moreover, 2000 degreeC or less is preferable with the same viewpoint, 1500 degreeC or less is more preferable, and 1200 degreeC or less is the most preferable.

  When the dispersion for forming a semiconductor film contains a cyano group-containing organic compound as the organic compound, the content of the cyano group-containing organic compound is 0.1% by mass or more and 20% by mass or less with respect to 100% by mass of the entire dispersion. More preferably, it is 1 to 15% by mass, more preferably 2 to 10% by mass, and most preferably 2.5 to 5% by mass. .

  The content of the metal oxide contained in the dispersion for forming a semiconductor film is 100% by mass of the dispersion as a concentration of the dispersion, and the content of the metal oxide particles is 0.1% by mass or more and 60% by mass. % Or less, more preferably 1% by mass or more and 55% by mass or less, still more preferably 10% by mass or more and 50% by mass or less, and most preferably 20% by mass or more and 48% by mass or less.

(2) Application process An application process is a process of apply | coating a dispersion liquid to a board | substrate and obtaining a coating film. For example, in the case of manufacturing a thin film transistor having a structure (bottom contact structure) of substrate / gate electrode / insulator layer (dielectric layer) / source electrode / drain electrode / semiconductor layer, the coating step uses the coating liquid as the source electrode and drain. Applying to a substrate on which an electrode is formed to obtain a coating film.

(3) Drying process A drying process is a process of drying a coating film and removing all or one part of the organic solvent from a coating film. This drying process is a low temperature process different from the conventional high temperature sintering. The low temperature process means a temperature region of 20 ° C. or more and 300 ° C. or less in the present embodiment. The temperature in this region is a very important temperature region for industrial processes because the resin substrate can be used. The temperature range of this drying step is preferably 20 ° C. or higher and 300 ° C. or lower, more preferably 20 ° C. or higher and 200 ° C. or lower, and further preferably 20 ° C. or higher and 150 ° C. or lower. When the temperature is 150 ° C. or lower, it is optimal because inexpensive general-purpose resin substrates such as PET films and PC films can be used.

  According to the present embodiment, the metal oxide particles and the organic compound are mixed to form the semiconductor film containing the metal oxide particles and the organic compound. In this semiconductor film, there are many carrier conduction paths, and carrier trapping and recombination are further suppressed. In addition, this semiconductor film can block surrounding oxygen. As a result, the amount of carrier flow increases and the moving speed of the carrier increases. Accordingly, it is possible to provide a semiconductor element that has high mobility and is stable even in the air (that is, the chemical change hardly occurs and does not easily deteriorate even when it is in contact with the air).

  In addition, a semiconductor film containing metal oxide particles and an organic compound does not require a vacuum process and can be formed by a low-cost and low-temperature process, and a non-vacuum process such as a coating method or a printing method. Can be formed. Thereby, the manufacturing cost of the semiconductor element can be reduced.

  Thus, according to the present embodiment, it is possible to provide a semiconductor element that can be manufactured by a non-vacuum process and can exhibit higher mobility.

  Hereinafter, the present invention will be described in more detail with reference to specific examples.

<Evaluation method>
Hereinafter, unless otherwise specified, the evaluation was performed under conditions of 25 ° C. and a humidity of 45%.

(1) Average particle diameter The average particle diameter was measured using a field emission scanning electron microscope SU-8820 (manufactured by Hitachi, Ltd.). After cutting around the observation position of the semiconductor film formed on the substrate, the cross section was processed by irradiation with an argon ion beam while cooling using an ion milling device E-3500 Plus (manufactured by Hitachi, Ltd.). The cross section of the semiconductor film was observed, and the particle diameters at a total of 10 points were measured, and the average value was taken as the average particle diameter.

(2) XPS measurement The XPS measurement was performed by X-ray photoelectric spectroscopy at a measurement temperature of 23 ° C. Specifically, a metal mask (2 mmφ) was put on, and measurement was performed under the following measurement conditions using X-ray photoelectric spectroscopy (equipment used: VersaProbe II manufactured by ULVAC-PHI).
Excitation source: monoAl Kα 25W × 15kV
Analysis size: about 200μmφ
Pass Energy
Survey scan: 117.4 eV
Narrow scan: 23.5 eV

  The peak separation is performed by performing background correction on the 1s spectrum of oxygen, and then separating the peaks of In—O bonds appearing from 528 eV to 530 eV into peaks such as OH groups appearing from 530 eV to 533 eV, and the areas of the respective peaks. Asked. Peak separation was performed by a curve fitting method by a nonlinear least square method using a Gauss-Lorentz complex function. At that time, the upper limit of the possible value of the full width at half maximum of the three peaks was 2.0 eV.

  The relative element concentration of Na on the surface of the sample was calculated from the area calculation using the survey scan result, and the ratio of the total element was calculated. Tables 1, 2, and 3 show the amounts of impurities in the samples of the examples and comparative examples.

(3) Film thickness The layer thickness of the semiconductor film was measured at the step portion of the film measured by a stylus profiling system (Dektak XTL, manufactured by Bruker Corporation).

(4) Mobility of semiconductor film The mobility was measured using a parameter analyzer (4200-SCS manufactured by Keithley). There are no particular restrictions on the measurement parameters, but unless otherwise noted, the drain current measured when the source voltage is swept from -60V to 100V in increments of 1V and further measured to 60V under vacuum conditions. The change was measured, and the mobility was calculated from the field effect mobility formula.

<Substrate with electrode>
The element structure is not particularly limited, but unless otherwise noted, a 2 nm-thick Ti film is formed on an n-type silicon wafer with 200 nm thermal oxide film (electric resistivity is 0.001 to 0.0015 Ω · cm). An adhesion layer was formed, and Au having a thickness of 22 nm was deposited thereon to form a source electrode and a drain electrode. The size of the source electrode and the drain electrode was 200 μm × 500 μm, the channel length was 50 μm, and the channel width was 500 μm.

  Before use, the substrate with electrodes is impregnated in semi-clean 56, ultrapure water, acetone, and 2-propanol, treated with an ultrasonic cleaner for 5 minutes, and then a tabletop ultraviolet cleaning and reforming apparatus PL21-200. UV ozone treatment was performed for 10 minutes using (Sen Special Light Source Co., Ltd.).

[Example 1]
As the metal oxide particles, indium oxide (III) nanopowder <100 nm particle size (TEM), 99.9% trace metals basis (manufactured by Sigma-Aldrich) was used, and 5.0 g of indium oxide particles were used in a muffle furnace SSTR-11K. (ISUZU Co., Ltd.) was used for annealing at 600 ° C. for 1 hour in the air.

  3.33 g of indium oxide particles subjected to the above treatment, 1.67 g of cyanoethyl saccharose (manufactured by Shin-Etsu Chemical), 5.00 g of dimethyl sulfoxide and 5.0 g of spherical zirconium oxide having a diameter of 0.3 mm are put in a container, and a planetary ball mill apparatus P- 6 (manufactured by Fritsch) was processed at 600 rpm for 30 minutes to prepare a coating liquid (dispersion) containing cyanoethyl saccharose and indium oxide particles.

  The coating solution is formed on a substrate with electrodes using a spin coater MS-B1000 (Mikasa Co., Ltd.) under the conditions of 2000 rpm and 30 seconds, and then dried on a 120 ° C. hot plate for 10 minutes. A semiconductor film (composite body) containing indium oxide and an organic compound was formed to obtain a semiconductor element. At that time, the spherical zirconium oxide having a diameter of 0.3 mm moved out of the system and did not remain in the semiconductor film.

[Example 2]
A semiconductor element was obtained in the same manner as in Example 1 except that 3.75 g of indium oxide particles and 1.25 g of cyanoethyl saccharose were changed.

[Example 3]
As the metal oxide particles, indium (III) oxide nanopowder <100 nm particle size (TEM), 99.9% trace metals basis> (manufactured by Sigma-Aldrich) was used. In order to wash the indium oxide particles, 10 times the amount of 1 mol / L sodium hydrogen carbonate aqueous solution was added to the indium oxide particles, and the mixture was stirred well and allowed to settle in a centrifuge 5 times, and then 10 times the amount. The operation of adding ultrapure water, stirring well, and precipitating with a centrifuge was repeated 5 times. Thereafter, the mixture was heated on a 150 ° C. hot plate for 2 hours to obtain indium oxide particles.

  Thereafter, 5.0 g of indium oxide particles were placed on a baking dish and placed in a tubular furnace connected to a tabletop ultraviolet cleaning and reforming apparatus PL21-200 (manufactured by Sen Special Light Company), and ozone was allowed to flow at 2.0 L / min. In this state, treatment was performed at 300 ° C. for 1 hour.

  4.00 g of the indium oxide particles subjected to the above treatment, 1.00 g of cyanoethyl saccharose (manufactured by Shin-Etsu Chemical), 5.00 g of dimethyl sulfoxide and 5.0 g of 0.3 mm diameter spherical zirconium oxide are put in a container, and a planetary ball mill apparatus P- 6 (manufactured by Fritsch) was processed at 600 rpm for 30 minutes to prepare a coating liquid (dispersion) containing cyanoethyl saccharose and indium oxide particles.

  A semiconductor element was obtained by depositing the coating solution under the same conditions as in Example 1.

[Example 4]
Instead of placing 5.0 g of indium oxide particles on a baking dish, placing it in a tubular furnace connected to a UV ozone cleaner and flowing ozone at 2.0 L / min for 1 hour at 300 ° C., A semiconductor element was obtained in the same manner as in Example 3 except that 5.0 g of indium oxide particles were annealed at 600 ° C. for 1 hour in the air using a muffle furnace SSTR-11K (manufactured by ISUZU).

[Example 5]
A semiconductor element was obtained in the same manner as in Example 3 except that 4.55 g of indium oxide particles and 0.45 g of cyanoethyl saccharose were changed.

[Example 6]
A semiconductor element was obtained in the same manner as in Example 5 except that the cleaning treatment of indium oxide particles was not performed.

[Example 7]
Cyanoethyl saccharose (manufactured by Shin-Etsu Chemical) was mixed with 2-methoxyethanol to prepare a 20% by mass solution. The cyanoethyl saccharose solution was printed on an electrode-attached substrate using an inkjet printer DMP-2831 (manufactured by Fujifilm) so that the film thickness after drying was about 400 nm.

  As the metal oxide particles, indium (III) oxide nanopowder <100 nm particle size (TEM), 99.9% trace metals basis> (manufactured by Sigma-Aldrich) was used. In order to wash the indium oxide particles, 10 times the amount of 1 mol / L sodium hydrogen carbonate aqueous solution was added to the indium oxide particles, and the mixture was stirred well and allowed to settle in a centrifuge 5 times, and then 10 times the amount. The operation of adding ultrapure water, stirring well, and precipitating with a centrifuge was repeated 5 times. Thereafter, the mixture was heated on a 150 ° C. hot plate for 2 hours to obtain particles.

  Thereafter, 5.0 g of indium oxide particles were annealed at 600 ° C. for 1 hour in air using a muffle furnace SSTR-11K (manufactured by ISUZU).

  It is composed of a composite body of indium oxide and organic compound by placing indium oxide particles that have been cleaned and annealed on a substrate with electrodes printed with cyanoethyl saccharose, pressing with a spatula, and drying on a hot plate at 120 ° C for 10 minutes. A semiconductor element provided with the semiconductor film thus obtained was obtained.

[Example 8]
A semiconductor element was obtained in the same manner as in Example 7 except that the cleaning treatment of indium oxide particles was not performed.

[Example 9]
Indium oxide particles were synthesized by the following method. Indium chloride 99.99% (Transmetal Corp.) 8.00 g was dissolved in dehydrated ethanol 160 ml. Dehydrated triethylamine (Sigma-Aldrich) was added thereto, and after stirring for 1 hour, the solid content was collected by filtration. It was rinsed with 50 ml of dehydrated ethanol and dried under reduced pressure at 40 ° C. for 12 hours. The recovered solid amount was 1.59 g, and the yield was 22%. In a 100 ml flask, 0.36 g of hexadecyltrimethylammonium bromide (Sigma-Aldrich) was dissolved in 20 ml of dehydrated ethanol. 0.62 g of the above solid content was added, and 60 ml of ultrapure water was further added. Ammonium hydroxide (manufactured by Wako Pure Chemical Industries, Ltd.) was added thereto so that the pH was 10. This was subjected to a homogenizer treatment in the air at 100 W / cm, 2.20 kHz, 1.5 hours, and then a solid content was collected by filtration. It was washed with 100 ml of ultrapure water, and the solid content was recovered by filtration. Washing with ultrapure water was repeated 5 times. The recovered solid content was calcined in a muffle furnace SSTR-11K (manufactured by ISUZU) at 350 ° C. for 1 hour to obtain 0.34 g of yellow indium oxide particles.

  When ultrama-IV (manufactured by Rigaku Corporation) XRD measurement was performed on the indium oxide particles obtained by synthesis, it was identified to be indium oxide and the crystallite diameter was 13.0 nm.

  Thereafter, 0.50 g of indium oxide particles were annealed in the air at 400 ° C. for 1 hour using a muffle furnace SSTR-11K (manufactured by ISUZU).

  Cyanoethyl saccharose (manufactured by Shin-Etsu Chemical Co., Ltd.) was mixed with 2-methoxyethanol to prepare a 20% by mass solution. The cyanoethyl saccharose solution was printed on an electrode-attached substrate using an inkjet printer DMP-2831 (manufactured by Fujifilm) so that the film thickness after drying was about 400 nm.

  Indium oxide particles that have been washed and annealed are placed on a substrate with electrodes printed with cyanoethyl saccharose, pressed with a spatula, and dried on a hot plate at 120 ° C. for 10 minutes to form a composite of indium oxide and an organic compound. A semiconductor element provided with the configured semiconductor film was obtained.

[Example 10]
A semiconductor element was obtained in the same manner as in Example 8 except that the annealing treatment of indium oxide particles was not performed.

[Example 11]
A semiconductor element was obtained in the same manner as in Example 8 except that cyanoethyl polyvinyl alcohol (manufactured by Shin-Etsu Chemical Co., Ltd.) was used instead of cyanoethyl saccharose.

[Example 12]
A semiconductor element was obtained in the same manner as in Example 8 except that cyanoethyl pullulan (manufactured by Shin-Etsu Chemical Co., Ltd.) was used instead of cyanoethyl saccharose.

[Example 13]
A semiconductor device was obtained in the same manner as in Example 8 except that glycerin (manufactured by Wako Pure Chemical Industries, Ltd.) was used instead of cyanoethyl saccharose.

[Example 14]
A semiconductor element was obtained in the same manner as in Example 8, except that polyvinyl alcohol (Wako Pure Chemical Industries, average polymerization degree: about 1500 to 1800) was used instead of cyanoethyl saccharose, and 2-methoxyethanol was replaced with water. .

[Example 15]
Cyanoethyl saccharose (manufactured by Shin-Etsu Chemical) was mixed with 2-methoxyethanol to prepare a 10% by mass solution. The cyanoethyl saccharose solution was printed on an electrode-attached substrate using an ink jet printer DMP-2831 (manufactured by Fuji Film) so that the film thickness after drying was about 200 nm.

  As the metal oxide particles, indium (III) oxide nanopowder <100 nm particle size (TEM), 99.9% trace metals basis> (manufactured by Sigma-Aldrich) was used.

  Thereafter, 5.0 g of indium oxide particles were annealed at 600 ° C. for 1 hour in air using a muffle furnace SSTR-11K (manufactured by ISUZU).

  Indium oxide particles that have been washed and annealed are placed on a substrate with electrodes printed with cyanoethyl saccharose, pressed with a spatula, and dried on a hot plate at 120 ° C. for 10 minutes to form a composite of indium oxide and an organic compound. A semiconductor element provided with the configured semiconductor film was obtained.

[Example 16]
A semiconductor element was obtained in the same manner as in Example 1 except that zinc oxide nanopowder <100 nm particle size (manufactured by Sigma-Aldrich) was used in place of the indium oxide particles.

[Example 17]
A semiconductor element was obtained in the same manner as in Example 6 except that zinc oxide nanopowder <100 nm particle size (manufactured by Sigma-Aldrich) was used in place of the indium oxide particles.

[Example 18]
A semiconductor element was obtained in the same manner as in Example 8 except that zinc oxide nanopowder <100 nm particle size (manufactured by Sigma-Aldrich) was used in place of the indium oxide particles.

[Example 19]
A semiconductor element was obtained in the same manner as in Example 10 except that zinc oxide nanopowder <100 nm particle size (manufactured by Sigma-Aldrich) was used in place of the indium oxide particles.

[Comparative Example 1]
Cyanoethyl saccharose (manufactured by Shin-Etsu Chemical) was mixed with 2-methoxyethanol to prepare a 20% by mass solution. By forming a cyanoethyl saccharose solution on a substrate with an electrode using a spin coater MS-B1000 (manufactured by Mikasa Co., Ltd.) under the condition of 2000 rpm for 30 seconds and drying on a hot plate at 120 ° C. for 10 minutes. A cyanoethyl saccharose membrane was obtained.

[Comparative Example 2]
A semiconductor device was obtained in the same manner as in Example 1 except that the indium oxide particles were changed to 2.50 g and the cyanoethyl saccharose was changed to 2.50 g.

[Comparative Example 3]
For the metal oxide particles, indium oxide Nanopowder, 99.99%, 20-70 nm (manufactured by SkySprings Nanomaterials) was used, and 5.0 g of indium oxide particles were used in the air using a muffle furnace SSTR-11K (manufactured by ISUZU). Annealing treatment was performed at 600 ° C. for 1 hour.

  4.00 g of the indium oxide particles subjected to the above treatment, 1.00 g of cyanoethyl saccharose (manufactured by Shin-Etsu Chemical), 5.00 g of dimethyl sulfoxide and 5.0 g of 0.3 mm diameter spherical zirconium oxide are put in a container, and a planetary ball mill apparatus P- The coating liquid (dispersion liquid) containing cyanoethyl saccharose and indium oxide particles was prepared by treating for 30 minutes at 6 rpm (manufactured by Fritsch) at 600 rpm.

  A semiconductor element was obtained by depositing the coating solution under the same conditions as in Example 1.

[Comparative Example 4]
A semiconductor device was obtained in the same manner as in Comparative Example 3 except that indium oxide (III) (manufactured by Wako Pure Chemical Industries, Ltd.) was used instead of indium oxide Nanopowder, 99.99%, 20-70 nm (manufactured by SkySprings Nanomaterials). It was.

[Comparative Example 5]
Indium oxide particles were synthesized by the following method. 8.00 g of indium chloride 99.99% (manufactured by Transmetal) was dissolved in 160 ml of dehydrated ethanol. Dehydrated triethylamine (Sigma-Aldrich) was added thereto, and after stirring for 1 hour, the solid content was collected by filtration. It was rinsed with 50 ml of dehydrated ethanol and dried under reduced pressure at 40 ° C. for 12 hours. The recovered solid amount was 1.59 g, and the yield was 22%. In a 100 ml flask, 0.36 g of hexadecyltrimethylammonium bromide (Sigma-Aldrich) was dissolved in 20 ml of dehydrated ethanol. 0.62 g of the above solid content was added, and 60 ml of ultrapure water was further added. Ammonium hydroxide (manufactured by Wako Pure Chemical Industries, Ltd.) was added thereto so that the pH was 10. This was subjected to a homogenizer treatment in the air at 100 W / cm, 2.20 kHz, 1.5 hours, and then a solid content was collected by filtration. It was washed with 100 ml of ultrapure water, and the solid content was recovered by filtration. Washing with ultrapure water was repeated 5 times. The recovered solid content was calcined at 350 ° C. for 1 hour using a muffle furnace SSTR-11K (manufactured by ISUZU) to obtain 0.34 g of yellow indium oxide particles.

  When the ultra-IV (made by Rigaku Corporation) XRD measurement of the indium oxide particle obtained by synthesis was performed, it was identified as indium oxide, and the crystallite diameter was 13.0 nm.

  Thereafter, 0.50 g of indium oxide particles were annealed at 1000 ° C. for 1 hour in air using a muffle furnace SSTR-11K (manufactured by ISUZU).

  Cyanoethyl saccharose (manufactured by Shin-Etsu Chemical) was mixed with 2-methoxyethanol to prepare a 20% by mass solution. The cyanoethyl saccharose solution was printed on an electrode-attached substrate using an inkjet printer DMP-2831 (manufactured by Fujifilm) so that the film thickness after drying was about 400 nm.

  It is composed of a composite body of indium oxide and organic compound by placing indium oxide particles that have been cleaned and annealed on a substrate with electrodes printed with cyanoethyl saccharose, pressing with a spatula, and drying on a 120 ° C hot plate for 10 minutes. A semiconductor element provided with the semiconductor film thus obtained was obtained.

[Comparative Example 6]
A semiconductor element was obtained in the same manner as in Example 1 except that the indium oxide particles were changed to 4.85 g and the cyanoethyl saccharose was changed to 0.15 g.

[Comparative Example 7]
As the metal oxide particles, indium (III) oxide nanopowder <100 nm particle size (TEM), 99.9% trace metals basis> (manufactured by Sigma-Aldrich) was used. Indium oxide was annealed at 600 ° C. for 1 hour in air using a muffle furnace SSTR-11K (manufactured by ISUZU).

  The annealed indium oxide particles were placed on the wafer with gold electrode, pressed with a spatula, and dried on a 120 ° C. hot plate for 10 minutes to obtain a lump of indium oxide particles.

[Comparative Example 8]
A semiconductor element was obtained in the same manner as in Comparative Example 2 except that zinc oxide nanopowder <100 nm particle size (manufactured by Sigma-Aldrich) was used in place of the indium oxide particles.

[Comparative Example 9]
A semiconductor element was obtained in the same manner as in Comparative Example 6 except that zinc oxide nanopowder <100 nm particle size (manufactured by Sigma-Aldrich) was used in place of the indium oxide particles.

  Hereinafter, the results of evaluation for the samples of each Example and Comparative Example are shown in Tables 1, 2, and 3 below.

  The film formability is observed by observing the surface of the semiconductor film with a 50 × magnification microscope, where the semiconductor film is formed in an area of 80% or more, and the semiconductor film is formed in an area of less than 80%. The state was set to x.

The mobility is 0.1 cm ² / Vs or more, ◎, 1.0E-3 cm ² / Vs or more and less than 0.1 cm ² / Vs, ○, or less than 1.0E-3 cm ² / Vs becomes a transistor. Those that did not become transistors were marked with x.

  The off-state current is less than 1.0E-10A, and 1.0E-10A or more is x. As for the hysteresis, the difference between Vg at the time of return and return at Id = 1.0 nA was less than 10V, and ○ was 10V or more.

  As shown in Tables 1, 2, and 3, in each Example, the film forming property and the mobility were both good. In particular, Examples 5, 6, 7, 8, and 18 were found to be good in terms of mobility. In addition, Examples 5, 7, 9, 17, and 18 were found to be favorable in terms of off current. Furthermore, Examples 7, 9, 17, and 19 were found to be good in terms of hysteresis. On the other hand, in Comparative Example 1 and Comparative Example 2, both became insulators and a transistor element could not be manufactured. Furthermore, in Comparative Example 1, the film forming property was poor.

  In addition, this invention is not limited to embodiment described above or each Example. Based on the knowledge of those skilled in the art, design changes and the like may be added to the embodiments and examples, and the embodiments and examples may be arbitrarily combined, and such changes are added. Embodiments are also within the scope of the present invention.

  According to the present invention, it is possible to provide a semiconductor film that can be manufactured by a non-vacuum process and a low-temperature process and can exhibit higher mobility, a semiconductor element using the semiconductor film, and a dispersion.

100, 200, 300, 400 Semiconductor element 110, 210, 310 Substrate 120, 220, 320, 420 Gate electrode 130, 230, 330, 430 Insulator layer (gate insulating film)
140, 240, 340, 440 Source electrode 150, 250, 350, 450 Drain electrode 160, 260, 360, 460 Semiconductor layer

Claims (13)

A semiconductor film comprising metal oxide particles and an organic compound, wherein the content of the metal oxide is 55% by mass or more and 95% by mass or less with respect to 100% by mass of the entire semiconductor film, The content of the organic compound is 5% by mass or more and 45% by mass or less,
Ratio of peak area S1 attributed to O ²⁻ ions of metal oxide and peak area S2 attributed to oxygen deficient O ²⁻ ions (O ² / S2 / O2s spectrum in XPS measurement of the semiconductor film) A semiconductor film characterized in that S1) is 0.25 or more and 0.60 or less.   A semiconductor film containing indium oxide particles and an organic compound, wherein the content of the indium oxide is 55% by mass or more and 95% by mass or less with respect to 100% by mass of the entire semiconductor film, and the organic compound Is 5 mass% or more and 45 mass% or less, and the peak area S1 existing from 528 eV to 530 eV and the peak area S2 existing from 530 eV to 533 eV in the O1s spectrum in the XPS measurement of the semiconductor film. (S2 / S1) is a semiconductor film characterized by having a ratio of 0.25 to 0.60. A semiconductor film comprising zinc oxide particles and an organic compound, wherein the content of the zinc oxide is 55% by mass or more and 95% by mass or less with respect to 100% by mass of the entire semiconductor film, and the organic compound Is 5 mass% or more and 45 mass% or less, and the area S1 of the peak attributed to the O ²⁻ ion of zinc oxide in the O1s spectrum in the XPS measurement of the semiconductor film and the oxygen deficient O ^{2. -} the ratio of the peak area S2, which is attributed to the ion (S2 / S1) is 0.25 or more, a semiconductor film, characterized in that it is 0.60 or less.   The semiconductor film according to claim 1, wherein the organic compound is a dielectric and has a relative dielectric constant of 5 or more and 100 or less.   The semiconductor film according to claim 1, wherein the organic compound is a cyano group-containing organic compound.   6. The semiconductor film according to claim 1, wherein a relative element concentration of Na in XPS measurement of the semiconductor film is 1.0 atomic% or less. Electrodes,
A semiconductor element comprising: the semiconductor film according to claim 1, which is in contact with the electrode.   The semiconductor element according to claim 7, wherein the semiconductor film has a thickness of 1 nm to 1000 nm.   9. The semiconductor element according to claim 7, wherein the semiconductor element is a transistor element. Mobility 0.001 cm ² / Vs or more, and equal to or less than 10 cm ² / Vs, the semiconductor device according to claim 7 of claim 9. A dispersion containing metal oxide particles, an organic compound, and a solvent, wherein the content of the metal oxide particles is 0.1% by mass or more and 60% by mass with respect to 100% by mass of the entire dispersion. The content of the organic compound is 0.1% by mass or more and 20% by mass or less, and the content of the solvent is 20% by mass or more and 99.98% by mass or less. Ratio of the area S1 of the peak attributed to the O ²⁻ ion of the metal oxide and the area S2 of the peak attributed to the O ²⁻ ion of oxygen deficiency in the O1s spectrum in the XPS measurement after drying (S2 / S1 ) Is 0.25 or more and 0.60 or less. A dispersion containing indium oxide particles, an organic compound, and a solvent, wherein the content of the indium oxide particles is 0.01% by mass to 60% by mass with respect to 100% by mass of the entire dispersion. Yes, the content of the organic compound is 0.01% by mass or more and 20% by mass or less, and the content of the solvent is 20% by mass or more and 99.98% by mass or less,
The ratio (S2 / S1) of the peak area S1 existing from 528 eV to 530 eV and the peak area S2 present from 530 eV to 533 eV in the O1s spectrum in the XPS measurement after drying of the dispersion is 0.25 or more. , 0.60 or less. A dispersion containing zinc oxide particles, an organic compound, and a solvent, wherein the content of the zinc oxide particles is 0.1% by mass or more and 60% by mass or less with respect to 100% by mass of the entire dispersion. Yes, the content of the organic compound is 0.1% by mass or more and 20% by mass or less, the content of the solvent is 20% by mass or more and 99.98% by mass or less, and after the dispersion is dried The ratio (S2 / S1) between the area S1 of the peak attributed to the O ²⁻ ion of zinc oxide and the area S2 of the peak attributed to the O ²⁻ ion of oxygen deficiency in the O1s spectrum in XPS measurement of Dispersion characterized by being 0.25 or more and 0.60 or less.

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