WO2016088882A1 - Method for manufacturing metal oxide film, metal oxide film, thin-film transistor, method for manufacturing thin-film transistor, electronic device, and ultraviolet irradiation device - Google Patents

Method for manufacturing metal oxide film, metal oxide film, thin-film transistor, method for manufacturing thin-film transistor, electronic device, and ultraviolet irradiation device Download PDF

Info

Publication number
WO2016088882A1
WO2016088882A1 PCT/JP2015/084178 JP2015084178W WO2016088882A1 WO 2016088882 A1 WO2016088882 A1 WO 2016088882A1 JP 2015084178 W JP2015084178 W JP 2015084178W WO 2016088882 A1 WO2016088882 A1 WO 2016088882A1
Authority
WO
WIPO (PCT)
Prior art keywords
metal oxide
oxide film
film
substrate
solution
Prior art date
Application number
PCT/JP2015/084178
Other languages
French (fr)
Japanese (ja)
Inventor
文彦 望月
真宏 高田
Original Assignee
富士フイルム株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 富士フイルム株式会社 filed Critical 富士フイルム株式会社
Priority to KR1020177013093A priority Critical patent/KR101954551B1/en
Priority to JP2016562697A priority patent/JP6271760B2/en
Publication of WO2016088882A1 publication Critical patent/WO2016088882A1/en

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G15/00—Compounds of gallium, indium or thallium
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/02104—Forming layers
    • H01L21/02107—Forming insulating materials on a substrate
    • H01L21/02109—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates
    • H01L21/02112—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates characterised by the material of the layer
    • H01L21/02172—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates characterised by the material of the layer the material containing at least one metal element, e.g. metal oxides, metal nitrides, metal oxynitrides or metal carbides
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/136—Liquid crystal cells structurally associated with a semi-conducting layer or substrate, e.g. cells forming part of an integrated circuit
    • G02F1/1362—Active matrix addressed cells
    • G02F1/1368—Active matrix addressed cells in which the switching element is a three-electrode device
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/02104—Forming layers
    • H01L21/02107—Forming insulating materials on a substrate
    • H01L21/02109—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates
    • H01L21/02205—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates the layer being characterised by the precursor material for deposition
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/02104—Forming layers
    • H01L21/02107—Forming insulating materials on a substrate
    • H01L21/02296—Forming insulating materials on a substrate characterised by the treatment performed before or after the formation of the layer
    • H01L21/02318—Forming insulating materials on a substrate characterised by the treatment performed before or after the formation of the layer post-treatment
    • H01L21/02345—Forming insulating materials on a substrate characterised by the treatment performed before or after the formation of the layer post-treatment treatment by exposure to radiation, e.g. visible light
    • H01L21/02348—Forming insulating materials on a substrate characterised by the treatment performed before or after the formation of the layer post-treatment treatment by exposure to radiation, e.g. visible light treatment by exposure to UV light
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
    • H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic System or AIIIBV compounds with or without impurities, e.g. doping materials
    • H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
    • H01L21/324—Thermal treatment for modifying the properties of semiconductor bodies, e.g. annealing, sintering
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/70—Manufacture or treatment of devices consisting of a plurality of solid state components formed in or on a common substrate or of parts thereof; Manufacture of integrated circuit devices or of parts thereof
    • H01L21/77—Manufacture or treatment of devices consisting of a plurality of solid state components or integrated circuits formed in, or on, a common substrate
    • H01L21/78—Manufacture or treatment of devices consisting of a plurality of solid state components or integrated circuits formed in, or on, a common substrate with subsequent division of the substrate into plural individual devices
    • H01L21/82—Manufacture or treatment of devices consisting of a plurality of solid state components or integrated circuits formed in, or on, a common substrate with subsequent division of the substrate into plural individual devices to produce devices, e.g. integrated circuits, each consisting of a plurality of components
    • H01L21/822—Manufacture or treatment of devices consisting of a plurality of solid state components or integrated circuits formed in, or on, a common substrate with subsequent division of the substrate into plural individual devices to produce devices, e.g. integrated circuits, each consisting of a plurality of components the substrate being a semiconductor, using silicon technology
    • H01L21/8232—Field-effect technology
    • H01L21/8234—MIS technology, i.e. integration processes of field effect transistors of the conductor-insulator-semiconductor type
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
    • H01L27/02—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier
    • H01L27/04—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier the substrate being a semiconductor body
    • H01L27/06—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier the substrate being a semiconductor body including a plurality of individual components in a non-repetitive configuration
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
    • H01L27/02—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier
    • H01L27/04—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier the substrate being a semiconductor body
    • H01L27/08—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier the substrate being a semiconductor body including only semiconductor components of a single kind
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L29/00—Semiconductor devices adapted for rectifying, amplifying, oscillating or switching, or capacitors or resistors with at least one potential-jump barrier or surface barrier, e.g. PN junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof  ; Multistep manufacturing processes therefor
    • H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
    • H01L29/68—Types of semiconductor device ; Multistep manufacturing processes therefor controllable by only the electric current supplied, or only the electric potential applied, to an electrode which does not carry the current to be rectified, amplified or switched
    • H01L29/76—Unipolar devices, e.g. field effect transistors
    • H01L29/772—Field effect transistors
    • H01L29/78—Field effect transistors with field effect produced by an insulated gate
    • H01L29/786—Thin film transistors, i.e. transistors with a channel being at least partly a thin film

Definitions

  • the present invention relates to a method for producing a metal oxide film, a metal oxide film, a thin film transistor, a method for producing a thin film transistor, an electronic device, and an ultraviolet irradiation apparatus.
  • a metal oxide semiconductor film has been put into practical use in the production by a vacuum film forming method and is currently attracting attention.
  • research and development have been actively conducted on the production of metal oxide semiconductor films by a liquid phase process for the purpose of easily forming metal oxide semiconductor films having high semiconductor characteristics at low temperature and atmospheric pressure. ing.
  • Nature, Vol. 489 (2012) p. 128. In U.S. Pat. No. 5,637, it is reported that a thin film transistor having high transport properties is produced at a low temperature of 150 ° C. or lower by applying a solution on a substrate and performing ultraviolet irradiation.
  • a metal oxide semiconductor precursor film is formed using a solution of an inexpensive metal salt such as nitrate or acetate, and a semiconductor conversion process is performed by heat treatment or microwave irradiation.
  • a method for forming an oxide film is disclosed.
  • a metal oxide semiconductor precursor film is formed using a solution of nitrate, acetate or the like, and light is irradiated in the presence of oxygen to produce the metal oxide semiconductor film. A method is disclosed.
  • the present invention provides a method for producing a metal oxide film that can easily produce a metal oxide film with reduced unnecessary residual components that may impair the functions expected of the metal oxide film by a coating method, and is unnecessary.
  • An object is to provide a metal oxide film with reduced residual components.
  • Another object of the present invention is to provide a thin film transistor, a thin film transistor manufacturing method, and an electronic device that have high linear mobility and excellent operational stability. It is another object of the present invention to provide an ultraviolet irradiation device that can easily convert a precursor film into a metal oxide film.
  • ⁇ 3> The method for producing a metal oxide film according to ⁇ 1> or ⁇ 2>, wherein the content of indium contained in the solution is 50 atom% or more with respect to the total amount of metal components contained in the solution.
  • ⁇ 4> The method for producing a metal oxide film according to any one of ⁇ 1> to ⁇ 3>, wherein the temperature of the substrate during the ultraviolet irradiation is 150 ° C. or lower.
  • ⁇ 5> The method for producing a metal oxide film according to any one of ⁇ 1> to ⁇ 4>, wherein the solution is a solution of indium nitrate.
  • ⁇ 6> The method for producing a metal oxide film according to ⁇ 5>, wherein the solution of indium nitrate contains at least one of methanol and methoxyethanol as a solvent.
  • ⁇ 7> The method for producing a metal oxide film according to any one of ⁇ 1> to ⁇ 6>, wherein the solution further contains at least one selected from the group consisting of zinc, tin, gallium, and aluminum.
  • ⁇ 8> The method for producing a metal oxide film according to any one of ⁇ 1> to ⁇ 7>, wherein the concentration of the metal component in the solution is 0.01 mol / L or more and 0.5 mol / L or less.
  • ⁇ 9> The metal oxide according to any one of ⁇ 1> to ⁇ 8>, wherein the irradiation with ultraviolet rays irradiates the precursor film with ultraviolet rays containing light having a wavelength of 300 nm or less at an illuminance of 10 mW / cm 2 or more.
  • a method for producing a membrane In the precursor film forming step, the solution is applied onto the substrate by at least one coating method selected from an inkjet method, a dispenser method, a relief printing method, and an intaglio printing method.
  • ⁇ 1> to ⁇ 9> The manufacturing method of the metal oxide film as described in any one.
  • ⁇ 11> A metal oxide film produced by the method for producing a metal oxide film according to any one of ⁇ 1> to ⁇ 10>.
  • ⁇ 12> A metal oxide film containing indium and having a hydrogen content of 1.0 ⁇ 10 22 pieces / cm 3 or less.
  • ⁇ 13> The metal oxide film according to ⁇ 11> or ⁇ 12>, wherein the content of indium contained in the metal oxide film is 50 atom% or more with respect to the total amount of metal components contained in the metal oxide film.
  • a method for producing a thin film transistor comprising a step of forming a metal oxide film by the method for producing a metal oxide film according to any one of ⁇ 1> to ⁇ 10>.
  • a thin film transistor comprising the metal oxide film according to any one of ⁇ 11> to ⁇ 13>.
  • An electronic device having the thin film transistor according to ⁇ 15>.
  • a decompression chamber A support base for supporting and heating the substrate in the decompression chamber; A vacuum pump for reducing the pressure in the vacuum chamber to 10 Pa or less; A light source for irradiating the substrate supported by the support base with ultraviolet rays; Ultraviolet irradiation device with ⁇ 18>
  • the manufacturing method of the metal oxide film which can manufacture simply the metal oxide film with which the unnecessary residual component which may impair the function anticipated to a metal oxide film reduced by the apply
  • the present invention also provides a thin film transistor, a thin film transistor manufacturing method, and an electronic device that have high linear mobility and excellent operational stability.
  • the ultraviolet irradiation device which can convert easily from a precursor film
  • FIG. 1 is a schematic view showing a configuration of an example (bottom gate-bottom contact type) thin film transistor manufactured according to the present invention.
  • FIG. It is a schematic sectional drawing which shows a part of liquid crystal display device of embodiment. It is a schematic block diagram of the electrical wiring of the liquid crystal display device shown in FIG. It is a schematic sectional drawing which shows a part of organic EL display apparatus of embodiment.
  • FIG. It is a schematic block diagram of the electrical wiring of the organic electroluminescence display shown in FIG. It is a schematic sectional drawing which shows a part of X-ray sensor array of embodiment. It is a schematic block diagram of the electrical wiring of the X-ray sensor array shown in FIG. It is a schematic block diagram which shows an example of a structure of the ultraviolet irradiation device used at the conversion process in this indication.
  • a method of manufacturing a metal oxide film according to the present disclosure includes a precursor film forming step of forming a precursor film of a metal oxide film by applying a solution containing indium and a solvent on a substrate, and a precursor film in a heated state And a conversion step of converting the precursor film into a metal oxide film by irradiating with ultraviolet rays in an atmosphere of 10 Pa or less.
  • a metal oxide film precursor film formed by applying a solution containing indium is heated and irradiated with ultraviolet (UV) radiation in an atmosphere close to vacuum. It has been found that a hydrogen content in the oxide film is greatly reduced and a metal oxide film having good electrical characteristics can be obtained. The reason for this is not clear, but it is considered that if the precursor film is irradiated with UV while heating under a high degree of reduced pressure, unnecessary components in the film are decomposed and easily escape from the film.
  • UV ultraviolet
  • a solution containing indium and a solvent (hereinafter sometimes referred to as a “metal oxide precursor solution”) is applied onto a substrate and a precursor film of a metal oxide film (hereinafter referred to as “ May be referred to as a “metal oxide precursor film”.
  • a solution (metal oxide precursor solution) for forming a precursor film of a metal oxide film contains at least indium as a metal component.
  • the “metal component” means metal atoms (including ions) contained in the metal oxide precursor solution.
  • the metal oxide precursor solution is obtained by weighing a solute such as a metal salt as a raw material so that the solution has a desired concentration, and stirring and dissolving in a solvent. The stirring time is not particularly limited as long as the solute is sufficiently dissolved.
  • the indium content in the metal oxide precursor solution is preferably 50 atom% or more based on the total amount of metal components contained in the solution.
  • a metal oxide precursor solution containing indium in the above concentration range a metal oxide film in which 50 atom% or more of the total amount of metal components in the film becomes indium is obtained, and a metal oxide film having high electron transfer characteristics Can be obtained.
  • the metal component (metal element) other than indium include Ga, Zn, Mg, Al, Sn, Sb, Cd, and Ge, depending on applications.
  • a metal atom-containing compound such as a metal salt, a metal halide, or an organometallic compound
  • metal salts include nitrates, sulfates, phosphates, carbonates, acetates, oxalates, etc.
  • metal halides include chlorides, iodides, bromides and the like
  • organometallic compounds include Examples thereof include metal alkoxides, organic acid salts, metal ⁇ -diketonates and the like.
  • the metal oxide precursor solution is preferably a solution in which at least indium nitrate is dissolved in a solvent (indium nitrate solution).
  • indium nitrate solution indium nitrate solution
  • indium nitrate is efficiently decomposed by ultraviolet light in the conversion step, and easily converted into an indium-containing oxide film.
  • Indium nitrate may be a hydrate.
  • the metal oxide precursor solution preferably further contains at least one selected from the group consisting of zinc, tin, gallium, and aluminum as a metal element other than indium.
  • the metal oxide precursor solution contains an appropriate amount of the above metal element other than indium, the electrical stability of the obtained metal oxide film is improved.
  • the threshold voltage can be controlled to a desired value by including an appropriate amount of the above metal element other than indium.
  • metal oxides oxide semiconductors or oxide conductors containing indium and the above metal elements other than indium
  • In—Ga—Zn—O IGZO
  • In—Zn—O IZO
  • IGO In—Ga— O
  • ITO In—Sn—O
  • ITZO In—Sn—Zn—O
  • the solvent used for the metal oxide precursor solution containing indium nitrate is not particularly limited as long as the metal atom-containing compound to be used is dissolved.
  • Water, alcohol solvents methanol, ethanol, propanol, ethylene glycol, etc.
  • amide solvents N, N-dimethylformamide, etc.
  • ketone solvents acetone, N-methylpyrrolidone, sulfolane, N, N-dimethylimidazolidinone, etc.
  • ether solvents tetrahydrofuran, methoxyethanol, etc.
  • nitrile solvents acetonitrile, etc.
  • Other examples include hetero atom-containing solvents other than those described above. These solvents may be used individually by 1 type, and 2 or more types may be mixed and used for them. In particular, at least one of methanol and methoxyethanol can be suitably used from the viewpoints of solubility and paintability.
  • the concentration of the metal component in the metal oxide precursor solution (the sum of the mole fractions of each metal when multiple metals are included) is arbitrarily selected according to the viscosity of the solution and the target film thickness. However, from the viewpoint of the flatness and productivity of the metal oxide film, it is preferably 0.01 mol / L or more and 1.0 mol / L or less, and 0.01 mol / L or more and 0.5 mol / L or less. It is more preferable that
  • the shape, structure, size, and the like of the substrate on which the metal oxide film is formed are not particularly limited and can be appropriately selected according to the purpose.
  • the structure of the substrate may be a single layer structure or a laminated structure.
  • the material constituting the substrate is not particularly limited, and a substrate made of glass, an inorganic material such as YSZ (Yttria-Stabilized Zirconia), a resin, a resin composite material, or the like can be used.
  • a resin substrate or a substrate made of a resin composite material (resin composite material substrate) is preferable in terms of light weight and flexibility.
  • Inorganic materials contained in the composite material of inorganic material and resin include inorganic particles such as silicon oxide particles, metal nanoparticles, inorganic oxide nanoparticles, and inorganic nitride nanoparticles, carbon fibers such as carbon fibers and carbon nanotubes.
  • inorganic particles such as silicon oxide particles, metal nanoparticles, inorganic oxide nanoparticles, and inorganic nitride nanoparticles
  • carbon fibers such as carbon fibers and carbon nanotubes.
  • glass materials such as materials, glass flakes, glass fibers, and glass beads.
  • composite plastic material of resin and clay mineral composite plastic material of resin and particles having mica-derived crystal structure
  • laminated plastic material having at least one bonding interface between resin and thin glass, inorganic layer and organic Examples include a composite material having barrier performance having at least one bonding interface by alternately laminating layers.
  • a stainless steel substrate a metal multilayer substrate in which stainless and different metals are laminated, an aluminum substrate, or an aluminum substrate with an oxide film whose surface insulation is improved by subjecting the surface to oxidation treatment (for example, anodization treatment), an oxide film
  • oxidation treatment for example, anodization treatment
  • oxide film An attached silicon substrate or the like
  • the resin substrate or the resin composite material substrate is preferably excellent in heat resistance, dimensional stability, solvent resistance, electrical insulation, workability, low air permeability, low moisture absorption, and the like.
  • the resin substrate or the resin composite material substrate may include a gas barrier layer for preventing permeation of moisture, oxygen, and the like, an undercoat layer for improving the flatness of the substrate or the adhesion to the lower electrode, and the like.
  • the thickness of the substrate used in the present disclosure is not particularly limited, but is preferably 50 ⁇ m or more and 500 ⁇ m or less. When the thickness of the substrate is 50 ⁇ m or more, the flatness of the substrate itself is further improved. Further, when the thickness of the substrate is 500 ⁇ m or less, the flexibility of the substrate itself is further improved, and the use as a substrate for a flexible device becomes easier.
  • a lower electrode, an insulating film, or the like may be provided on the substrate.
  • a metal oxide film is formed on the lower electrode or the insulating film on the substrate.
  • a step of performing a surface treatment on the surface of the substrate on which the coating film (precursor film) is to be formed may be included.
  • a surface treatment for removing moisture and dirt on the substrate as a pretreatment for applying the metal oxide precursor solution to the substrate.
  • the substrate surface treatment include ultraviolet (UV) ozone treatment, argon plasma treatment, and nitrogen plasma treatment.
  • UV ozone treatment for example, a UV ozone treatment apparatus (Model 144AX-100 manufactured by Jelight-company-Inc) can be used and performed for about 1 to 3 minutes under the following conditions and wavelengths. -Conditions: atmospheric pressure, in air-Wavelength: 254 nm (30 mW / cm 2 ), 185 nm (3.3 mW / cm 2 )
  • Methods for applying the metal oxide precursor solution on the substrate include spray coating, spin coating, blade coating, dip coating, casting, roll coating, bar coating, die coating, mist, and inkjet.
  • the coating film is preferably dried by heat treatment to obtain a metal oxide precursor film.
  • the fluidity of the coating film can be reduced and the flatness of the finally obtained metal oxide film can be improved.
  • an appropriate drying temperature preferably 35 ° C. or more and 100 ° C. or less
  • the method for the heat treatment is not particularly limited, and can be selected from hot plate heating, electric furnace heating, infrared heating, microwave heating, and the like.
  • the start of drying is not particularly limited, it is preferably started within 5 minutes after coating from the viewpoint of keeping the flatness of the film uniform.
  • the precursor film is converted to a metal oxide film by irradiating the heated precursor film with ultraviolet rays in an atmosphere of 10 Pa or less.
  • the pressure at the time of conversion is preferably 1 Pa or less, and more preferably 0.1 Pa or less. If the pressure at which the precursor film is converted to a metal oxide film is 1 Pa or less, a metal oxide film having a hydrogen content of 1.0 ⁇ 10 22 pieces / cm 3 or less can be obtained.
  • the hydrogen content in the metal oxide film in the present disclosure is calculated from secondary ion mass spectrometry (SIMS: Secondary Ion Mass Spectrometry).
  • substrate at the time of performing ultraviolet irradiation is less than 200 degreeC. If the substrate temperature in the conversion step is less than 200 ° C., it can be easily applied to a resin substrate having low heat resistance, and the increase in thermal energy can be suppressed to reduce the manufacturing cost. From the viewpoint of being able to deal with a wider variety of resin substrates, the substrate temperature in the conversion step is more preferably 150 ° C. or lower. On the other hand, from the viewpoint of performing the conversion from the precursor film to the metal oxide film in a short time, the substrate temperature in the conversion process is preferably 120 ° C. or higher. The substrate temperature in the conversion process can be measured with a thermolabel. Although the conversion process to a metal oxide film depends on the illuminance of ultraviolet rays, it is preferably from 5 seconds to 120 minutes from the viewpoint of productivity.
  • the heating means for the substrate in the conversion step is not particularly limited, and may be selected from hot plate heating, electric furnace heating, infrared heating, microwave heating, and the like.
  • the substrate may be heated during the ultraviolet treatment using radiant heat from a light source such as an ultraviolet lamp used for ultraviolet irradiation, or the temperature of the substrate may be controlled by a heater or the like.
  • radiant heat from an ultraviolet lamp or the like it can be controlled by adjusting the lamp-substrate distance and / or the lamp output.
  • the film surface of the metal oxide precursor film is irradiated with ultraviolet light including light having a wavelength of 300 nm or less at an illuminance of 10 mW / cm 2 or more.
  • ultraviolet light including light having a wavelength of 300 nm or less at an illuminance of 10 mW / cm 2 or more.
  • Examples of the ultraviolet light source include a UV lamp and a laser, and a UV lamp is preferable from the viewpoint of performing ultraviolet irradiation with a uniform and inexpensive facility over a large area.
  • Examples of UV lamps include excimer lamps, deuterium lamps, low pressure mercury lamps, high pressure mercury lamps, ultra high pressure mercury lamps, metal halide lamps, helium lamps, carbon arc lamps, cadmium lamps, electrodeless discharge lamps, etc. It is preferable to use a mercury lamp because the metal oxide precursor film can be easily converted into the metal oxide film.
  • the apparatus used for the conversion step is not limited, but, for example, supported by a decompression chamber, a support base that supports and heats the substrate in the decompression chamber, a vacuum pump that decompresses the decompression chamber to 10 Pa or less, and a support base.
  • An ultraviolet irradiation apparatus including a light source that irradiates the substrate with ultraviolet rays can be suitably used.
  • the position adjustment means for adjusting the positional relationship between the light source and the support base is further provided, the UV irradiation power (illuminance) for irradiating the substrate by adjusting the distance between the light source and the substrate on the support base. Can be adjusted.
  • FIG. 11 schematically illustrates an example of the configuration of an apparatus used for the conversion process in the present disclosure.
  • An apparatus 400 shown in FIG. 11 includes a stage 412 having a heater function in a vacuum chamber (decompression chamber) 410, and can adjust the substrate temperature on the stage (support base) 412.
  • the stage 412 can be moved up and down by turning the handle (position adjusting means) 418.
  • Outside the vacuum chamber 410 are a turbo mechanical pump (vacuum pump) 414 for vacuum exhaust, an N 2 gas introduction port (MFC: mass flow controller) 424, a vacuum gauge 422, a UV irradiation unit (light source) 416, and a vent valve 426, respectively.
  • MFC mass flow controller
  • a pressure adjustment valve 420 is provided between the vacuum chamber 410 and the turbo mechanical pump 414, and the pressure in the chamber 410 can be adjusted to 10 Pa or less.
  • the UV irradiation unit 416 can irradiate the substrate on the stage 412 with ultraviolet light through the quartz glass 417, and the UV irradiation power (illuminance) for irradiating the substrate on the stage 412 by adjusting the height of the stage 412. Can be adjusted.
  • the UV irradiation power (illuminance) applied to the substrate on the stage 412 may be adjusted by moving the position of the UV irradiation unit 416, or the substrate may be irradiated by changing the output of the UV lamp of the UV irradiation unit 416. It is good also as a structure which adjusts UV irradiation power (illuminance) to perform.
  • the film thickness of the metal oxide film produced according to the present disclosure is not particularly limited and may be selected according to the application.
  • the film thickness is preferably 50 nm or less, and more preferably about 10 nm.
  • the metal oxide film manufacturing method of the present disclosure can easily obtain a metal oxide film in which unnecessary residual components are reduced by a liquid phase method even at a low temperature process of less than 200 ° C.
  • a flexible electronic device such as a flexible display can be manufactured at low cost.
  • a method for manufacturing a metal oxide film of the present disclosure includes, for example, oxidation of a thin film transistor (TFT). It can be suitably used to form a physical semiconductor layer (active layer) and an electrode. For example, by forming an oxide semiconductor layer as a semiconductor layer (active layer) by the method for manufacturing a metal oxide film of the present disclosure, a thin film transistor having high linear mobility and excellent operational stability can be obtained. it can.
  • TFT thin film transistor
  • the element structure of the TFT according to the present disclosure is not particularly limited, and may be any of a so-called reverse stagger structure (also referred to as a bottom gate type) and a stagger structure (also referred to as a top gate type) based on the position of the gate electrode. Also good. Further, based on the contact portion between the semiconductor layer and the source and drain electrodes (referred to as “source / drain electrodes” as appropriate), either a so-called top contact type or bottom contact type may be employed.
  • the “top gate type” is a mode in which a gate electrode is disposed on the upper side of the gate insulating film and a semiconductor layer is formed on the lower side of the gate insulating film when the substrate on which the TFT is formed is the lowest layer.
  • the “bottom gate type” is a form in which a gate electrode is disposed below the gate insulating film and a semiconductor layer is formed above the gate insulating film.
  • the “bottom contact type” is a form in which the source / drain electrodes are formed before the semiconductor layer and the lower surface of the semiconductor layer is in contact with the source / drain electrodes. Is formed before the source / drain electrodes, and the upper surface of the semiconductor layer is in contact with the source / drain electrodes.
  • FIG. 1 is a schematic diagram showing an example of a top contact type TFT according to the present disclosure having a top gate structure.
  • the above-described oxide semiconductor film is stacked as the semiconductor layer 14 on one main surface of the substrate 12.
  • a source electrode 16 and a drain electrode 18 are disposed on the semiconductor layer 14 so as to be separated from each other, and a gate insulating film 20 and a gate electrode 22 are sequentially stacked.
  • FIG. 2 is a schematic diagram illustrating an example of a TFT according to the present disclosure having a top gate structure and a bottom contact type.
  • the source electrode 16 and the drain electrode 18 are disposed on one main surface of the substrate 12 so as to be separated from each other. Then, the above-described oxide semiconductor film, the gate insulating film 20, and the gate electrode 22 are sequentially stacked as the semiconductor layer 14.
  • FIG. 3 is a schematic diagram illustrating an example of a top contact type TFT according to the present disclosure having a bottom gate structure.
  • the gate electrode 22, the gate insulating film 20, and the above-described oxide semiconductor film as the semiconductor layer 14 are sequentially stacked on one main surface of the substrate 12.
  • a source electrode 16 and a drain electrode 18 are disposed on the surface of the semiconductor layer 14 so as to be separated from each other.
  • FIG. 4 is a schematic diagram showing an example of a bottom contact type TFT according to the present disclosure with a bottom gate structure.
  • the gate electrode 22 and the gate insulating film 20 are sequentially stacked on one main surface of the substrate 12.
  • the source electrode 16 and the drain electrode 18 are provided on the surface of the gate insulating film 20 so as to be separated from each other, and the above-described oxide semiconductor film is stacked as the semiconductor layer 14.
  • the bottom gate type thin film transistor shown in FIG. 3 will be mainly described as a representative example.
  • the thin film transistor according to the present disclosure is not limited to the bottom gate type, and may be a top gate type thin film transistor. Good.
  • the shape, structure, size, etc. of the substrate 12 on which the TFT is formed are not particularly limited, and can be appropriately selected from the above-described substrates according to the purpose. Moreover, there is no restriction
  • the gate electrode 22 is formed on the substrate 12 that has been subjected to, for example, UV ozone treatment.
  • the gate electrode 22 is made of a material having high conductivity, for example, metal such as Al, Cu, Mo, Cr, Ta, Ti, Ag, Au, Al—Nd, Ag alloy, tin oxide, zinc oxide, indium oxide, indium oxide. It can be formed using a metal oxide conductive film such as tin (In—Sn—O), indium zinc oxide (In—Zn—O), or In—Ga—Zn—O.
  • these conductive films can be used as a single layer structure or a stacked structure of two or more layers.
  • the gate electrode 22 is made of a material used from a wet method such as a printing method or a coating method, a physical method such as a vacuum deposition method, a sputtering method or an ion plating method, or a chemical method such as a CVD or plasma CVD method.
  • the film is formed according to a method appropriately selected in consideration of the suitability of the above.
  • the film thickness of the metal film for forming the gate electrode 22 is preferably 10 nm or more and 1000 nm or less, preferably 50 nm or more and 200 nm or less in consideration of film forming property, patterning property by etching or lift-off method, conductivity, and the like. More preferably.
  • the gate electrode 22 may be formed by patterning into a predetermined shape by an etching or lift-off method, or the pattern may be formed directly by an inkjet method, a printing method, or the like. At this time, it is preferable to pattern the gate electrode 22 and the gate wiring (not shown) at the same time.
  • the gate insulating film 20 is preferably made of a material having high insulating properties.
  • an insulating film such as SiO 2 , SiN x , SiON, Al 2 O 3 , Y 2 O 3 , Ta 2 O 5 , HfO 2 , or a compound thereof is used.
  • the insulating film may include two or more types, and may have a single layer structure or a stacked structure.
  • the gate insulating film 20 can be formed from a printing method, a wet method such as a coating method, a physical method such as a vacuum deposition method, a sputtering method or an ion plating method, or a chemical method such as a CVD or plasma CVD method.
  • the film may be formed according to a method appropriately selected in consideration of suitability with the material to be used.
  • the gate insulating film 20 may be an organic insulating film or an inorganic insulating film as long as it has gate insulating characteristics. For example, as the inorganic insulating film by a wet method, a SiO 2 film, a SiON film, a SiN film, or the like using a polysilazane compound solution can be given.
  • the gate insulating film 20 needs to have a thickness for reducing leakage current and improving voltage resistance. On the other hand, if the gate insulating film 20 is too thick, the driving voltage is increased.
  • the thickness of the gate insulating film 20 is preferably 10 nm to 10 ⁇ m, more preferably 50 nm to 1000 nm, and particularly preferably 100 nm to 400 nm.
  • the semiconductor layer 14 is formed on the gate insulating film 20.
  • a solution containing indium is applied on the gate insulating film 20 and dried to form a precursor film of the metal oxide semiconductor film, and then the precursor film is heated. In this state, it is converted into a metal oxide semiconductor film by irradiating with ultraviolet rays under an atmosphere of 10 Pa or less.
  • the metal oxide semiconductor film is patterned into the shape of the semiconductor layer 14.
  • the semiconductor layer 14 may be patterned by forming the semiconductor layer 14 patterned by the ink jet method, the dispenser method, the relief printing method, and the intaglio printing method, and the metal oxide semiconductor film may be formed by photolithography and etching.
  • the semiconductor layer 14 may be patterned into the shape.
  • a resist pattern is formed by photolithography on the remaining portion of the metal oxide semiconductor film, and an acid such as hydrochloric acid, nitric acid, dilute sulfuric acid, or a mixed solution of phosphoric acid, nitric acid and acetic acid is used.
  • the pattern of the semiconductor layer 14 is formed by etching with a solution.
  • the thickness of the semiconductor layer 14 is preferably 5 nm or more and 50 nm or less from the viewpoint of flatness and time required for film formation.
  • a protective layer (not shown) for protecting the semiconductor layer 14 is preferably formed on the semiconductor layer 14 when the source / drain electrodes 16 and 18 are etched.
  • the protective layer may be formed after the metal oxide semiconductor film.
  • the protective layer may be formed before the patterning of the metal oxide semiconductor film or may be formed after the patterning.
  • the protective layer is preferably an insulator, and the material constituting the protective layer may be an inorganic material or an organic material such as a resin.
  • the protective layer may be removed after the source electrode 16 and the drain electrode 18 (source / drain electrodes 16 and 18) are formed.
  • Source / drain electrodes 16 and 18 are formed on a semiconductor layer 14 formed of a metal oxide semiconductor film.
  • the source / drain electrodes 16 and 18 each have a high conductivity functioning as an electrode, for example, a metal such as Al, Mo, Cr, Ta, Ti, Ag, Au, Al—Nd, an Ag alloy, tin oxide, oxidation It can be formed using a metal oxide conductive film such as zinc, indium oxide, indium tin oxide (In—Sn—O), indium zinc oxide (In—Zn—O), or In—Ga—Zn—O. .
  • a wet method such as a printing method or a coating method, a physical method such as a vacuum deposition method, a sputtering method, or an ion plating method, a CVD (chemical vapor deposition), or a plasma CVD method.
  • the film may be formed according to a method appropriately selected in consideration of suitability with a material to be used from among chemical methods such as the above.
  • the film thickness of the source / drain electrodes 16 and 18 is preferably 10 nm or more and 1000 nm or less, preferably 50 nm or more and 100 nm or less in consideration of film forming properties, patterning properties by etching or lift-off methods, conductivity, and the like. More preferred.
  • the source / drain electrodes 16 and 18 may be formed by patterning into a predetermined shape by, for example, etching or a lift-off method after forming a conductive film, or may be directly formed by an inkjet method or the like. At this time, it is preferable to pattern the source / drain electrodes 16 and 18 and wiring (not shown) connected to these electrodes simultaneously.
  • the application of the thin film transistor of the present embodiment described above is not particularly limited, but since a thin film transistor exhibiting high semiconductor characteristics and stability at a low temperature can be produced at a relatively low temperature, various electronic devices, particularly low heat resistance and low cost.
  • the present invention can also be applied to manufacture of a flexible electronic device using a resin substrate. Specifically, it is suitable for manufacturing a flexible display using a driving element in a display device such as a liquid crystal display device, an organic EL (Electro Luminescence) display device, and an inorganic EL display device, and a resin substrate having low heat resistance.
  • the thin film transistor manufactured according to the present disclosure is suitably used as a driving element (driving circuit) in various electronic devices such as various sensors such as an X-ray sensor and an image sensor, and a MEMS (Micro Electro Mechanical System).
  • driving element driving circuit
  • various electronic devices such as various sensors such as an X-ray sensor and an image sensor, and a MEMS (Micro Electro Mechanical System).
  • MEMS Micro Electro Mechanical System
  • FIG. 5 shows a partial schematic cross-sectional view of a liquid crystal display device according to an embodiment of the present disclosure
  • FIG. 6 shows a schematic configuration diagram of electrical wiring.
  • the liquid crystal display device 100 includes a top contact type TFT 10 having the top gate structure shown in FIG. 1 and a pixel lower electrode on the gate electrode 22 protected by the passivation layer 102 of the TFT 10. 104 and a liquid crystal layer 108 sandwiched between the counter upper electrode 106 and an R (red) G (green) B (blue) color filter 110 for developing different colors corresponding to each pixel.
  • polarizing plates 112a and 112b are provided on the substrate 12 side and the RGB color filter 110, respectively.
  • the liquid crystal display device 100 includes a plurality of gate lines 112 that are parallel to each other and data lines 114 that are parallel to each other and intersect the gate lines 112.
  • the gate wiring 112 and the data wiring 114 are electrically insulated.
  • the TFT 10 is provided in the vicinity of the intersection between the gate wiring 112 and the data wiring 114.
  • the gate electrode 22 of the TFT 10 is connected to the gate wiring 112, and the source electrode 16 of the TFT 10 is connected to the data wiring 114.
  • the drain electrode 18 of the TFT 10 is connected to the pixel lower electrode 104 through a contact hole 116 provided in the gate insulating film 20 (a conductor is embedded in the contact hole 116).
  • the pixel lower electrode 104 forms a capacitor 118 together with the grounded counter upper electrode 106.
  • FIG. 7 is a schematic sectional view of a part of an active matrix organic EL display device according to an embodiment of the present disclosure
  • FIG. 8 is a schematic configuration diagram of electrical wiring.
  • the active matrix organic EL display device 200 of the present embodiment includes the TFT 10 having the top gate structure shown in FIG. 1 as a driving TFT 10a and a switching TFT 10b on a substrate 12 having a passivation layer 202.
  • 10b is provided with an organic EL light emitting element 214 composed of an organic light emitting layer 212 sandwiched between a lower electrode 208 and an upper electrode 210, and the upper surface is also protected by a passivation layer 216.
  • the organic EL display device 200 of this embodiment includes a plurality of gate wirings 220 that are parallel to each other, and data wirings 222 and driving wirings 224 that are parallel to each other and intersect the gate wirings 220. ing.
  • the gate wiring 220, the data wiring 222, and the drive wiring 224 are electrically insulated.
  • the gate electrode 22 of the switching TFT 10 b is connected to the gate wiring 220, and the source electrode 16 of the switching TFT 10 b is connected to the data wiring 222.
  • the drain electrode 18 of the switching TFT 10b is connected to the gate electrode 22 of the driving TFT 10a, and the driving TFT 10a is kept on by using the capacitor 226.
  • the source electrode 16 of the driving TFT 10 a is connected to the driving wiring 224, and the drain electrode 18 is connected to the organic EL light emitting element 214.
  • the upper electrode 210 may be a top emission type using a transparent electrode, or the bottom electrode 208 and each TFT electrode may be a transparent electrode.
  • FIG. 9 shows a schematic sectional view of a part
  • FIG. 10 shows a schematic configuration diagram of electric wiring.
  • the X-ray sensor 300 of this embodiment includes the TFT 10 and the capacitor 310 formed on the substrate 12, the charge collection electrode 302 formed on the capacitor 310, the X-ray conversion layer 304, and the upper electrode 306. Composed.
  • a passivation film 308 is provided on the TFT 10.
  • the capacitor 310 has a structure in which an insulating film 316 is sandwiched between a capacitor lower electrode 312 and a capacitor upper electrode 314.
  • the capacitor upper electrode 314 is connected to one of the source electrode 16 and the drain electrode 18 (the drain electrode 18 in FIG. 9) of the TFT 10 through a contact hole 318 provided in the insulating film 316.
  • the charge collection electrode 302 is provided on the capacitor upper electrode 314 in the capacitor 310 and is in contact with the capacitor upper electrode 314.
  • the X-ray conversion layer 304 is a layer made of amorphous selenium, and is provided so as to cover the TFT 10 and the capacitor 310.
  • the upper electrode 306 is provided on the X-ray conversion layer 304 and is in contact with the X-ray conversion layer 304.
  • the X-ray sensor 300 of this embodiment includes a plurality of gate wirings 320 that are parallel to each other and a plurality of data wirings 322 that intersect with the gate wirings 320 and are parallel to each other.
  • the gate wiring 320 and the data wiring 322 are electrically insulated.
  • the TFT 10 is provided in the vicinity of the intersection between the gate wiring 320 and the data wiring 322.
  • the gate electrode 22 of the TFT 10 is connected to the gate wiring 320, and the source electrode 16 of the TFT 10 is connected to the data wiring 322.
  • the drain electrode 18 of the TFT 10 is electrically connected to the charge collection electrode 302, and the charge collection electrode 302 is connected to the capacitor 310.
  • X-rays enter from the upper electrode 306 side in FIG. 9 and generate electron-hole pairs in the X-ray conversion layer 304.
  • the generated charge is accumulated in the capacitor 310 and read out by sequentially scanning the TFT 10.
  • the liquid crystal display device 100, the organic EL display device 200, and the X-ray sensor 300 include the top gate structure TFT shown in FIG. 1, but the top gate structure TFT shown in FIG. There is no limitation, and the TFT having the structure shown in FIGS. 2 to 4 may be used.
  • TFT elements were produced as follows and electrical characteristics were evaluated. Indium nitrate (In (NO 3 ) 3 xH 2 O, purity: 4N, manufactured by Kojundo Chemical Laboratory Co., Ltd.) was dissolved in 2-methoxyethanol (special grade reagent, manufactured by Wako Pure Chemical Industries, Ltd.), 0.1 mol An indium nitrate solution for forming a semiconductor layer having a concentration of / L was prepared.
  • Indium nitrate In (NO 3 ) 3 xH 2 O, purity: 4N, manufactured by Kojundo Chemical Laboratory Co., Ltd.
  • 2-methoxyethanol special grade reagent, manufactured by Wako Pure Chemical Industries, Ltd.
  • a simple TFT using a p-type silicon substrate with a thermal oxide film as a substrate, the silicon substrate serving as a gate electrode, and the thermal oxide film as a gate insulating film was fabricated.
  • the prepared indium nitrate solution was spin-coated on a 1-inch square p-type silicon substrate with a thermal oxide film at a rotational speed of 1500 rpm for 30 seconds, and then dried on a hot plate heated to 60 ° C. for 1 minute. Thereby, an oxide semiconductor precursor film (thickness: 10 nm) was formed.
  • the precursor film is converted into a metal oxide film by irradiating ultraviolet rays in an atmosphere in which the pressure is adjusted in a heated state.
  • an ultraviolet irradiation apparatus having the schematic configuration shown in FIG. 11 was used.
  • a TMP (turbo mechanical pump manufactured by VARIAN) is provided as a pump 414 for evacuation, chamber pressure: air to 1 ⁇ 10 ⁇ 4 Pa, sample substrate temperature: room temperature to 600 ° C., UV irradiation power (illuminance): It can be set to 1 to 30 mW / cm 2 .
  • the irradiation power can be changed by adjusting the height of the sample stage (support stage) 412.
  • the ultraviolet illuminance at a wavelength of 254 nm is measured using an ultraviolet light meter (manufactured by Oak Manufacturing Co., Ltd., UV-M10, photoreceiver UV-25), and the stage position is adjusted to 10 mW / cm 2.
  • the oxide semiconductor precursor film was converted under the conditions shown in Table 1.
  • Condition 1 is conversion in the atmosphere
  • Condition 2 is evacuated from the atmosphere to 1 ⁇ 10 ⁇ 4 Pa, and after evacuation is stopped, N 2 gas is introduced and conversion is performed at atmospheric pressure.
  • Conditions 3 to 8 are in evacuation Then, after the pressure was adjusted to a certain degree of vacuum by the pressure adjusting valve 420, the conversion treatment was performed. In condition 9, the conversion treatment was performed while reducing the pressure from the atmosphere to 0.8 atm (about 0.081 MPa). Under any conditions, the substrate temperature in the conversion step was fixed at 150 ° C., and the UV treatment time was fixed at 30 minutes. The substrate temperature during the ultraviolet irradiation treatment was monitored with a thermo label.
  • source / drain electrodes were formed on the metal oxide semiconductor film by sputtering.
  • the source / drain electrodes were formed by pattern deposition using a metal mask, and Ti was deposited to a thickness of 50 nm.
  • the size of the source / drain electrodes was 1 mm ⁇ 1 mm, respectively, and the distance between the electrodes was 0.2 mm.
  • the fabrication of the simple TFT element is completed.
  • the measurement of the V g -I d characteristic is performed by fixing the drain voltage (V d ) to +1 V, changing the gate voltage (V g ) within a range of ⁇ 15 V to +15 V, and drain current (I d ) at each gate voltage. It was performed by measuring.
  • the measurement atmosphere is dry air and atmospheric pressure (flow for 60 minutes in advance), eliminating the influence of moisture during measurement, measuring 5 times repeatedly, linear mobility (initial mobility) and Vth shift (rising of TFT) Voltage shift).
  • Linear mobility was determined from the V g -I d characteristics in Table 1, were calculated from the 5 times repeated Vth shift after measurement ([Delta] Vth) and secondary ion mass spectrometry (SIMS), a hydrogen amount in the semiconductor film.
  • SIMS was performed using “PHI ADEPT1010” manufactured by Physical Electronics.
  • ⁇ Vth is less than 2.0 V, and particularly under conditions 6 to 8 where the pressure in the conversion process is 1 Pa or less, the amount of hydrogen in the semiconductor film decreases to 1.0 ⁇ 10 22 pieces / cm 3 or less.
  • ⁇ Vth and the amount of hydrogen were almost the same. From these results, the conversion to the semiconductor film eliminates the influence of oxygen and the like, and the amount of hydrogen in the semiconductor film depends on the pressure in the conversion process, and the smaller the amount of hydrogen in the film, the smaller ⁇ Vth and the stable operation It is thought that the property improves.
  • An oxide semiconductor precursor film is formed on a p-type silicon substrate with a thermal oxide film using the prepared indium nitrate / zinc nitrate mixed solution, and converted into an oxide semiconductor film in the same manner as in Condition 1 or Condition 4.
  • the source / drain electrodes were formed and evaluated.
  • the conversion process was performed in the same manner as condition 1, it did not operate as a TFT.
  • the initial mobility of the TFT is 5.4 cm 2 / Vs, ⁇ Vth is 1.7 V, and the amount of hydrogen in the film is 1.77 ⁇ 10 22 / cm 3. Met.

Abstract

A method for manufacturing a metal oxide film, application of the method, and an ultraviolet irradiation device provided with a pressure-reduction chamber, a support platform for supporting and heating a substrate inside the pressure-reduction chamber, a vacuum pump for reducing the pressure inside the pressure-reduction chamber to 10 Pa or less, and a light source for irradiating the substrate supported by the support platform with ultraviolet radiation; the method including: a precursor film formation step in which a solution containing indium and a solvent is applied on a substrate and a precursor film of a metal oxide film is formed; and a conversion step in which the precursor film in a heated state is irradiated with ultraviolet radiation in an atmosphere of 10 Pa or less, whereby the precursor film is converted to a metal oxide film.

Description

金属酸化物膜の製造方法、金属酸化物膜、薄膜トランジスタ、薄膜トランジスタの製造方法、電子デバイス、及び紫外線照射装置Metal oxide film manufacturing method, metal oxide film, thin film transistor, thin film transistor manufacturing method, electronic device, and ultraviolet irradiation apparatus
　本発明は、金属酸化物膜の製造方法、金属酸化物膜、薄膜トランジスタ、薄膜トランジスタの製造方法、電子デバイス、及び紫外線照射装置に関する。 The present invention relates to a method for producing a metal oxide film, a metal oxide film, a thin film transistor, a method for producing a thin film transistor, an electronic device, and an ultraviolet irradiation apparatus.
　金属酸化物半導体膜は真空成膜法による製造において実用化がなされ、現在注目を集めている。一方で、簡便に、低温及び大気圧下で高い半導体特性を有する金属酸化物半導体膜を形成することを目的とした、液相プロセスによる金属酸化物半導体膜の作製に関して研究開発が盛んに行われている。
　例えば、Ｎａｔｕｒｅ，Ｖｏｌ．４８９　（２０１２）　ｐ．１２８．において、溶液を基板上に塗布し、紫外線照射を行うことで、１５０℃以下の低温で高い輸送特性を有する薄膜トランジスタを作製することが報告されている。 A metal oxide semiconductor film has been put into practical use in the production by a vacuum film forming method and is currently attracting attention. On the other hand, research and development have been actively conducted on the production of metal oxide semiconductor films by a liquid phase process for the purpose of easily forming metal oxide semiconductor films having high semiconductor characteristics at low temperature and atmospheric pressure. ing.
For example, Nature, Vol. 489 (2012) p. 128. In U.S. Pat. No. 5,637, it is reported that a thin film transistor having high transport properties is produced at a low temperature of 150 ° C. or lower by applying a solution on a substrate and performing ultraviolet irradiation.
　一方、国際公開第２００９－８１８６２号では、安価な硝酸塩、酢酸塩等の金属塩の溶液を用いて金属酸化物半導体前駆体膜を形成し、熱処理又はマイクロ波照射による半導体変換処理を行って金属酸化物膜を形成する手法が開示されている。
　また、国際公開第２００９－１１２２４号では、硝酸塩、酢酸塩等の溶液を用いて金属酸化物半導体の前駆体膜を形成し、酸素存在下で光を照射することによって金属酸化物半導体膜を製造する方法が開示されている。 On the other hand, in International Publication No. 2009-81862, a metal oxide semiconductor precursor film is formed using a solution of an inexpensive metal salt such as nitrate or acetate, and a semiconductor conversion process is performed by heat treatment or microwave irradiation. A method for forming an oxide film is disclosed.
Also, in International Publication No. 2009-11224, a metal oxide semiconductor precursor film is formed using a solution of nitrate, acetate or the like, and light is irradiated in the presence of oxygen to produce the metal oxide semiconductor film. A method is disclosed.
　Ｎａｔｕｒｅ，Ｖｏｌ．４８９　（２０１２）　ｐ．１２８．に開示されている手法では、硝酸塩又は酢酸塩を溶媒中で７５℃、１２時間加熱攪拌を施して金属メトキシエトキシドを作製することが記載されており、溶液作製における手間とコストが増加する。また、アルコキシドを作製するため、大気中では加水分解を起こしやすく、安定性に問題がある。　
　一方、国際公開第２００９－８１８６２号又は国際公開第２００９－１１２２４号に開示されている方法では、２００℃未満の低温で高い電気伝達特性を有する金属酸化物膜を得ることが困難である。 Nature, Vol. 489 (2012) p. 128. In the method disclosed in JP-A No. 1993-110, it is described that a metal methoxyethoxide is produced by heating and stirring nitrate or acetate in a solvent at 75 ° C. for 12 hours, which increases the labor and cost in producing the solution. Further, since the alkoxide is produced, hydrolysis is likely to occur in the air, and there is a problem in stability.
On the other hand, according to the method disclosed in International Publication No. 2009-81862 or International Publication No. 2009-11224, it is difficult to obtain a metal oxide film having high electrical transfer characteristics at a low temperature of less than 200 ° C.
　本発明は、金属酸化物膜に期待される機能を損なうおそれがある不要な残留成分が低減した金属酸化物膜を塗布法によって簡便に製造することができる金属酸化物膜の製造方法及び不要な残留成分が低減した金属酸化物膜を提供することを目的とする。
　また、本発明は、線形移動度が高く、且つ、動作安定性に優れた薄膜トランジスタ、薄膜トランジスタの製造方法、及び電子デバイスを提供することを目的とする。
　また、本発明は、前駆体膜から金属酸化物膜への転化を容易に行うことができる紫外線照射装置を提供することを目的とする。 The present invention provides a method for producing a metal oxide film that can easily produce a metal oxide film with reduced unnecessary residual components that may impair the functions expected of the metal oxide film by a coating method, and is unnecessary. An object is to provide a metal oxide film with reduced residual components.
Another object of the present invention is to provide a thin film transistor, a thin film transistor manufacturing method, and an electronic device that have high linear mobility and excellent operational stability.
It is another object of the present invention to provide an ultraviolet irradiation device that can easily convert a precursor film into a metal oxide film.
　上記目的を達成するため、以下の発明が提供される。
＜１＞　インジウム及び溶媒を含む溶液を基板上に塗布して金属酸化物膜の前駆体膜を形成する前駆体膜形成工程と、
　加熱した状態の前駆体膜に対して１０Ｐａ以下の雰囲気下で紫外線照射を行うことにより前駆体膜を金属酸化物膜に転化させる転化工程と、
　を含む金属酸化物膜の製造方法。
＜２＞　紫外線照射を１Ｐａ以下の雰囲気下で行う＜１＞に記載の金属酸化物膜の製造方法。
＜３＞　溶液に含まれるインジウムの含有量が、溶液に含まれる金属成分の総量に対して５０ａｔｏｍ％以上である＜１＞又は＜２＞に記載の金属酸化物膜の製造方法。
＜４＞　紫外線照射を行う際の基板の温度が、１５０℃以下である＜１＞～＜３＞のいずれか１つに記載の金属酸化物膜の製造方法。
＜５＞　溶液が、硝酸インジウムの溶液である＜１＞～＜４＞のいずれか１つに記載の金属酸化物膜の製造方法。
＜６＞　硝酸インジウムの溶液が、溶媒としてメタノール及びメトキシエタノールの少なくとも一方を含む＜５＞に記載の金属酸化物膜の製造方法。
＜７＞　溶液が、亜鉛、錫、ガリウム及びアルミニウムからなる群より選ばれる少なくとも１種をさらに含有する＜１＞～＜６＞のいずれか１つに記載の金属酸化物膜の製造方法。
＜８＞　溶液中の金属成分の濃度が、０．０１ｍｏｌ／Ｌ以上０．５ｍｏｌ／Ｌ以下である＜１＞～＜７＞のいずれか１つに記載の金属酸化物膜の製造方法。
＜９＞　紫外線照射は、前駆体膜に対し、波長３００ｎｍ以下の光を含む紫外線を１０ｍＷ／ｃｍ２以上の照度で照射する＜１＞～＜８＞のいずれか１つに記載の金属酸化物膜の製造方法。
＜１０＞　前駆体膜形成工程において、溶液を、インクジェット法、ディスペンサー法、凸版印刷法、及び凹版印刷法から選択される少なくとも一種の塗布法により基板上に塗布する＜１＞～＜９＞のいずれか１つに記載の金属酸化物膜の製造方法。 In order to achieve the above object, the following invention is provided.
<1> A precursor film forming step of forming a precursor film of a metal oxide film by applying a solution containing indium and a solvent on a substrate;
A conversion step of converting the precursor film into a metal oxide film by irradiating the precursor film in a heated state with an ultraviolet ray under an atmosphere of 10 Pa or less;
The manufacturing method of the metal oxide film containing this.
<2> The method for producing a metal oxide film according to <1>, wherein the ultraviolet irradiation is performed in an atmosphere of 1 Pa or less.
<3> The method for producing a metal oxide film according to <1> or <2>, wherein the content of indium contained in the solution is 50 atom% or more with respect to the total amount of metal components contained in the solution.
<4> The method for producing a metal oxide film according to any one of <1> to <3>, wherein the temperature of the substrate during the ultraviolet irradiation is 150 ° C. or lower.
<5> The method for producing a metal oxide film according to any one of <1> to <4>, wherein the solution is a solution of indium nitrate.
<6> The method for producing a metal oxide film according to <5>, wherein the solution of indium nitrate contains at least one of methanol and methoxyethanol as a solvent.
<7> The method for producing a metal oxide film according to any one of <1> to <6>, wherein the solution further contains at least one selected from the group consisting of zinc, tin, gallium, and aluminum.
<8> The method for producing a metal oxide film according to any one of <1> to <7>, wherein the concentration of the metal component in the solution is 0.01 mol / L or more and 0.5 mol / L or less.
<9> The metal oxide according to any one of <1> to <8>, wherein the irradiation with ultraviolet rays irradiates the precursor film with ultraviolet rays containing light having a wavelength of 300 nm or less at an illuminance of 10 mW / cm 2 or more. A method for producing a membrane.
<10> In the precursor film forming step, the solution is applied onto the substrate by at least one coating method selected from an inkjet method, a dispenser method, a relief printing method, and an intaglio printing method. <1> to <9> The manufacturing method of the metal oxide film as described in any one.
＜１１＞　＜１＞～＜１０＞のいずれか１つに記載の金属酸化物膜の製造方法により製造された金属酸化物膜。
＜１２＞　インジウムを含み、水素含有量が１．０×１０２２個／ｃｍ３以下である金属酸化物膜。
＜１３＞　金属酸化物膜に含まれるインジウムの含有量が、金属酸化物膜に含まれる金属成分の総量に対して５０ａｔｏｍ％以上である＜１１＞又は＜１２＞に記載の金属酸化物膜。 <11> A metal oxide film produced by the method for producing a metal oxide film according to any one of <1> to <10>.
<12> A metal oxide film containing indium and having a hydrogen content of 1.0 × 10 22 pieces / cm 3 or less.
<13> The metal oxide film according to <11> or <12>, wherein the content of indium contained in the metal oxide film is 50 atom% or more with respect to the total amount of metal components contained in the metal oxide film.
＜１４＞　＜１＞～＜１０＞のいずれか１つに記載の金属酸化物膜の製造方法により金属酸化物膜を形成する工程を含む薄膜トランジスタの製造方法。 <14> A method for producing a thin film transistor, comprising a step of forming a metal oxide film by the method for producing a metal oxide film according to any one of <1> to <10>.
＜１５＞　＜１１＞～＜１３＞のいずれか１つに記載の金属酸化物膜を備えた薄膜トランジスタ。
＜１６＞　＜１５＞に記載の薄膜トランジスタを有する電子デバイス。 <15> A thin film transistor comprising the metal oxide film according to any one of <11> to <13>.
<16> An electronic device having the thin film transistor according to <15>.
＜１７＞　減圧室と、
　減圧室内で基板を支持し、且つ、加熱する支持台と、
　減圧室内を１０Ｐａ以下に減圧する真空ポンプと、
　支持台に支持された基板に対して紫外線を照射する光源と、
　を備えた紫外線照射装置。
＜１８＞　光源と支持台との位置関係を調整する位置調整手段を備えた＜１７＞に記載の紫外線照射装置。 <17> A decompression chamber;
A support base for supporting and heating the substrate in the decompression chamber;
A vacuum pump for reducing the pressure in the vacuum chamber to 10 Pa or less;
A light source for irradiating the substrate supported by the support base with ultraviolet rays;
Ultraviolet irradiation device with
<18> The ultraviolet irradiation device according to <17>, further including a position adjusting unit that adjusts a positional relationship between the light source and the support base.
　本発明によれば、金属酸化物膜に期待される機能を損なうおそれがある不要な残留成分が低減した金属酸化物膜を塗布法によって簡便に製造することができる金属酸化物膜の製造方法及び不要な残留成分が低減した金属酸化物膜が提供される。
　また、本発明によれば、線形移動度が高く、且つ、動作安定性に優れた薄膜トランジスタ、薄膜トランジスタの製造方法、及び電子デバイスが提供される。
　また、本発明によれば、前駆体膜から金属酸化物膜への転化を容易に行うことができる紫外線照射装置が提供される。 ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the metal oxide film which can manufacture simply the metal oxide film with which the unnecessary residual component which may impair the function anticipated to a metal oxide film reduced by the apply | coating method, and A metal oxide film in which unnecessary residual components are reduced is provided.
The present invention also provides a thin film transistor, a thin film transistor manufacturing method, and an electronic device that have high linear mobility and excellent operational stability.
Moreover, according to this invention, the ultraviolet irradiation device which can convert easily from a precursor film | membrane to a metal oxide film is provided.
本発明により製造される薄膜トランジスタの一例（トップゲート－トップコンタクト型）の構成を示す概略図である。It is the schematic which shows the structure of an example (top gate-top contact type) of the thin-film transistor manufactured by this invention. 本発明により製造される薄膜トランジスタの一例（トップゲート－ボトムコンタクト型）の構成を示す概略図である。It is the schematic which shows the structure of an example (top gate-bottom contact type) of the thin-film transistor manufactured by this invention. 本発明により製造される薄膜トランジスタの一例（ボトムゲート－トップコンタクト型）の構成を示す概略図である。It is the schematic which shows the structure of an example (bottom gate-top contact type) of the thin-film transistor manufactured by this invention. 本発明により製造される薄膜トランジスタの一例（ボトムゲート－ボトムコンタクト型）の構成を示す概略図である。1 is a schematic view showing a configuration of an example (bottom gate-bottom contact type) thin film transistor manufactured according to the present invention. FIG. 実施形態の液晶表示装置の一部分を示す概略断面図である。It is a schematic sectional drawing which shows a part of liquid crystal display device of embodiment. 図５に示す液晶表示装置の電気配線の概略構成図である。It is a schematic block diagram of the electrical wiring of the liquid crystal display device shown in FIG. 実施形態の有機ＥＬ表示装置の一部分を示す概略断面図である。It is a schematic sectional drawing which shows a part of organic EL display apparatus of embodiment. 図７に示す有機ＥＬ表示装置の電気配線の概略構成図である。It is a schematic block diagram of the electrical wiring of the organic electroluminescence display shown in FIG. 実施形態のＸ線センサアレイの一部分を示す概略断面図である。It is a schematic sectional drawing which shows a part of X-ray sensor array of embodiment. 図９に示すＸ線センサアレイの電気配線の概略構成図である。It is a schematic block diagram of the electrical wiring of the X-ray sensor array shown in FIG. 本開示における転化工程で使用する紫外線照射装置の構成の一例を示す概略構成図である。It is a schematic block diagram which shows an example of a structure of the ultraviolet irradiation device used at the conversion process in this indication.
　以下、添付の図面を参照しながら、本発明について具体的に説明する。
　なお、図中、同一又は対応する機能を有する部材（構成要素）には同じ符号を付して適宜説明を省略する。また、本明細書において「～」の記号により数値範囲を示す場合、下限値及び上限値として記載されている数値が含まれる。 Hereinafter, the present invention will be specifically described with reference to the accompanying drawings.
In the drawings, members (components) having the same or corresponding functions are denoted by the same reference numerals and description thereof is omitted as appropriate. In the present specification, when a numerical range is indicated by the symbol “˜”, numerical values described as the lower limit value and the upper limit value are included.
［金属酸化物膜の製造方法］
　本開示の金属酸化物膜の製造方法は、インジウム及び溶媒を含む溶液を基板上に塗布して金属酸化物膜の前駆体膜を形成する前駆体膜形成工程と、加熱した状態の前駆体膜に対して１０Ｐａ以下の雰囲気下で紫外線照射を行うことにより前駆体膜を金属酸化物膜に転化させる転化工程と、を含む。 [Production Method of Metal Oxide Film]
A method of manufacturing a metal oxide film according to the present disclosure includes a precursor film forming step of forming a precursor film of a metal oxide film by applying a solution containing indium and a solvent on a substrate, and a precursor film in a heated state And a conversion step of converting the precursor film into a metal oxide film by irradiating with ultraviolet rays in an atmosphere of 10 Pa or less.
　溶液を用いた液相法によって金属酸化物膜を形成する場合、気相法で使用するような大掛かりな真空成膜装置は不要であるが、金属酸化物膜の機能を損なうおそれのある不要な成分が残り易く、残留成分は膜の電気特性（例えば、抵抗率及び電気的安定性）への影響が大きい。
　本発明者らが研究を重ねたところ、インジウムを含む溶液を塗布して形成した金属酸化物膜の前駆体膜を加熱した状態で真空に近い雰囲気下で紫外線（ＵＶ）照射を行うことで金属酸化物膜中の水素含有量が大きく低減し、良好な電気特性を有する金属酸化物膜が得られることを見出した。その理由は定かでないが、前駆体膜に対し、高度な減圧下で加熱しながらＵＶ照射を行うと、膜中の不要な成分が分解して膜から抜け易くなるためと考えられる。 When forming a metal oxide film by a liquid phase method using a solution, a large-scale vacuum film forming apparatus used in a gas phase method is unnecessary, but an unnecessary function that may impair the function of the metal oxide film is unnecessary. The component tends to remain, and the residual component has a great influence on the electrical characteristics (for example, resistivity and electrical stability) of the film.
As a result of repeated research by the present inventors, a metal oxide film precursor film formed by applying a solution containing indium is heated and irradiated with ultraviolet (UV) radiation in an atmosphere close to vacuum. It has been found that a hydrogen content in the oxide film is greatly reduced and a metal oxide film having good electrical characteristics can be obtained. The reason for this is not clear, but it is considered that if the precursor film is irradiated with UV while heating under a high degree of reduced pressure, unnecessary components in the film are decomposed and easily escape from the film.
＜前駆体膜形成工程＞
　前駆体膜形成工程では、インジウム及び溶媒を含む溶液（以下、「金属酸化物前駆体溶液」と記す場合がある。）を基板上に塗布して金属酸化物膜の前駆体膜（以下、「金属酸化物前駆体膜」と記す場合がある。）を形成する。 <Precursor film forming step>
In the precursor film forming step, a solution containing indium and a solvent (hereinafter sometimes referred to as a “metal oxide precursor solution”) is applied onto a substrate and a precursor film of a metal oxide film (hereinafter referred to as “ May be referred to as a “metal oxide precursor film”.
（溶液）
　本開示において金属酸化物膜の前駆体膜を形成するための溶液（金属酸化物前駆体溶液）は、金属成分として少なくともインジウムを含有する。ここで「金属成分」とは、金属酸化物前駆体溶液に含まれる金属原子（イオンを含む）を意味する。
　金属酸化物前駆体溶液は、原料となる金属塩等の溶質を、溶液が所望の濃度となるように秤量し、溶媒中で攪拌して溶解させることで得られる。攪拌を行う時間は溶質が十分に溶解されれば特に制限はない。 (solution)
In the present disclosure, a solution (metal oxide precursor solution) for forming a precursor film of a metal oxide film contains at least indium as a metal component. Here, the “metal component” means metal atoms (including ions) contained in the metal oxide precursor solution.
The metal oxide precursor solution is obtained by weighing a solute such as a metal salt as a raw material so that the solution has a desired concentration, and stirring and dissolving in a solvent. The stirring time is not particularly limited as long as the solute is sufficiently dissolved.
　金属酸化物前駆体溶液中のインジウム含有量は、溶液中に含まれる金属成分の総量に対して５０ａｔｏｍ％以上であることが好ましい。上記濃度範囲のインジウムを含む金属酸化物前駆体溶液を用いることで、膜中の金属成分の総量の５０ａｔｏｍ％以上がインジウムとなる金属酸化物膜が得られ、電子伝達特性の高い金属酸化物膜を得ることができる。ここで、金属酸化物膜に含み得るインジウム以外の金属成分（金属元素）としては、用途にもよるが、Ｇａ、Ｚｎ、Ｍｇ、Ａｌ、Ｓｎ、Ｓｂ、Ｃｄ、Ｇｅ等が挙げられる。 The indium content in the metal oxide precursor solution is preferably 50 atom% or more based on the total amount of metal components contained in the solution. By using a metal oxide precursor solution containing indium in the above concentration range, a metal oxide film in which 50 atom% or more of the total amount of metal components in the film becomes indium is obtained, and a metal oxide film having high electron transfer characteristics Can be obtained. Here, examples of the metal component (metal element) other than indium that can be included in the metal oxide film include Ga, Zn, Mg, Al, Sn, Sb, Cd, and Ge, depending on applications.
　金属酸化物前駆体溶液に含まれる金属成分の由来となる化合物（原料）としては、金属塩、金属ハロゲン化物、有機金属化合物等の金属原子含有化合物を用いることができる。
　金属塩としては、硝酸塩、硫酸塩、燐酸塩、炭酸塩、酢酸塩、蓚酸塩等が挙げられ、金属ハロゲン化物としては、塩化物、ヨウ化物、臭化物等が挙げられ、有機金属化合物としては、金属アルコキシド、有機酸塩、金属β－ジケトネート等が挙げられる。 As the compound (raw material) from which the metal component contained in the metal oxide precursor solution is derived, a metal atom-containing compound such as a metal salt, a metal halide, or an organometallic compound can be used.
Examples of metal salts include nitrates, sulfates, phosphates, carbonates, acetates, oxalates, etc., metal halides include chlorides, iodides, bromides and the like, and organometallic compounds include Examples thereof include metal alkoxides, organic acid salts, metal β-diketonates and the like.
　金属酸化物前駆体溶液は、溶媒に少なくとも硝酸インジウムを溶解させた溶液（硝酸インジウム溶液）であることが好ましい。硝酸インジウムを溶解した金属酸化物前駆体溶液を塗布して得られた金属酸化物前駆体膜は、転化工程において、硝酸インジウムが紫外光によって効率よく分解され、インジウム含有酸化物膜に容易に転化させることができる。なお、硝酸インジウムは水和物であってもよい。 The metal oxide precursor solution is preferably a solution in which at least indium nitrate is dissolved in a solvent (indium nitrate solution). In the metal oxide precursor film obtained by applying a metal oxide precursor solution in which indium nitrate is dissolved, indium nitrate is efficiently decomposed by ultraviolet light in the conversion step, and easily converted into an indium-containing oxide film. Can be made. Indium nitrate may be a hydrate.
　金属酸化物前駆体溶液は、インジウム以外の金属元素として、亜鉛、錫、ガリウム、及びアルミニウムからなる群より選ばれる少なくとも１種をさらに含むことが好ましい。金属酸化物前駆体溶液が、インジウム以外の上記金属元素を適量含むことにより、得られる金属酸化物膜の電気的安定性が向上する。例えば、金属酸化物半導体膜においては、インジウム以外の上記金属元素を適量含むことにより、閾値電圧を所望の値に制御することも可能となる。
　インジウムとインジウム以外の上記金属元素を含む金属酸化物（酸化物半導体又は酸化物導電体）としては、Ｉｎ－Ｇａ－Ｚｎ－Ｏ（ＩＧＺＯ）、Ｉｎ－Ｚｎ－Ｏ（ＩＺＯ）、Ｉｎ－Ｇａ－Ｏ（ＩＧＯ）、Ｉｎ－Ｓｎ－Ｏ（ＩＴＯ）、Ｉｎ－Ｓｎ－Ｚｎ－Ｏ（ＩＴＺＯ）等が挙げられる。 The metal oxide precursor solution preferably further contains at least one selected from the group consisting of zinc, tin, gallium, and aluminum as a metal element other than indium. When the metal oxide precursor solution contains an appropriate amount of the above metal element other than indium, the electrical stability of the obtained metal oxide film is improved. For example, in the metal oxide semiconductor film, the threshold voltage can be controlled to a desired value by including an appropriate amount of the above metal element other than indium.
As metal oxides (oxide semiconductors or oxide conductors) containing indium and the above metal elements other than indium, In—Ga—Zn—O (IGZO), In—Zn—O (IZO), In—Ga— O (IGO), In—Sn—O (ITO), In—Sn—Zn—O (ITZO), and the like can be given.
　硝酸インジウムを含む金属酸化物前駆体溶液に用いる溶媒は、用いる金属原子含有化合物が溶解するものであれば特に制限されず、水、アルコール溶媒（メタノール、エタノール、プロパノール、エチレングリコール等）、アミド溶媒（Ｎ，Ｎ－ジメチルホルムアミド等）、ケトン溶媒（アセトン、Ｎ－メチルピロリドン、スルホラン、Ｎ，Ｎ－ジメチルイミダゾリジノン等）、エーテル溶媒（テトラヒドロフラン、メトキシエタノール等）、ニトリル溶媒（アセトニトリル等）、その他上記以外のヘテロ原子含有溶媒等が挙げられる。これらの溶媒は１種単独で用いてもよいし、２種以上を混合して用いてもよい。
　特に溶解性、塗れ性の観点からメタノール及びメトキシエタノールの少なくとも１種を好適に用いることができる。 The solvent used for the metal oxide precursor solution containing indium nitrate is not particularly limited as long as the metal atom-containing compound to be used is dissolved. Water, alcohol solvents (methanol, ethanol, propanol, ethylene glycol, etc.), amide solvents (N, N-dimethylformamide, etc.), ketone solvents (acetone, N-methylpyrrolidone, sulfolane, N, N-dimethylimidazolidinone, etc.), ether solvents (tetrahydrofuran, methoxyethanol, etc.), nitrile solvents (acetonitrile, etc.), Other examples include hetero atom-containing solvents other than those described above. These solvents may be used individually by 1 type, and 2 or more types may be mixed and used for them.
In particular, at least one of methanol and methoxyethanol can be suitably used from the viewpoints of solubility and paintability.
　また、金属酸化物前駆体溶液中の金属成分の濃度（複数の金属が含まれる場合は各金属の含有モル分率の総和）は、溶液の粘度及び目標とする膜厚に応じて任意に選択することができるが、金属酸化物膜の平坦性及び生産性の観点から、０．０１ｍｏｌ／Ｌ以上１．０ｍｏｌ／Ｌ以下であることが好ましく、０．０１ｍｏｌ／Ｌ以上０．５ｍｏｌ／Ｌ以下であることがより好ましい。 The concentration of the metal component in the metal oxide precursor solution (the sum of the mole fractions of each metal when multiple metals are included) is arbitrarily selected according to the viscosity of the solution and the target film thickness. However, from the viewpoint of the flatness and productivity of the metal oxide film, it is preferably 0.01 mol / L or more and 1.0 mol / L or less, and 0.01 mol / L or more and 0.5 mol / L or less. It is more preferable that
（基板）
　本開示において金属酸化物膜を形成する基板の形状、構造、大きさ等については特に制限はなく、目的に応じて適宜選択することができる。
　例えば基板の構造は単層構造であってもよいし、積層構造であってもよい。 (substrate)
In the present disclosure, the shape, structure, size, and the like of the substrate on which the metal oxide film is formed are not particularly limited and can be appropriately selected according to the purpose.
For example, the structure of the substrate may be a single layer structure or a laminated structure.
　基板を構成する材料としては特に限定はなく、ガラス、ＹＳＺ（Yttria－Stabilized Zirconia；イットリア安定化ジルコニア）等の無機材料、樹脂、樹脂複合材料等からなる基板を用いることができる。中でも軽量である点、可撓性を有する点から樹脂基板又は樹脂複合材料からなる基板（樹脂複合材料基板）が好ましい。 The material constituting the substrate is not particularly limited, and a substrate made of glass, an inorganic material such as YSZ (Yttria-Stabilized Zirconia), a resin, a resin composite material, or the like can be used. Of these, a resin substrate or a substrate made of a resin composite material (resin composite material substrate) is preferable in terms of light weight and flexibility.
　具体的には、ポリブチレンテレフタレート、ポリエチレンテレフタレート、ポリエチレンナフタレート、ポリブチレンナフタレート、ポリスチレン、ポリカーボネート、ポリスルホン、ポリエーテルスルホン、ポリアリレート、アリルジグリコールカーボネート、ポリアミド、ポリイミド、ポリアミドイミド、ポリエーテルイミド、ポリベンズアゾール、ポリフェニレンサルファイド、ポリシクロオレフィン、ノルボルネン樹脂、ポリクロロトリフルオロエチレン等のフッ素樹脂、液晶ポリマー、アクリル樹脂、エポキシ樹脂、シリコーン樹脂、アイオノマー樹脂、シアネート樹脂、架橋フマル酸ジエステル、環状ポリオレフィン、芳香族エーテル、マレイミド・オレフィン、セルロース、エピスルフィド化合物等の合成樹脂基板が挙げられる。 Specifically, polybutylene terephthalate, polyethylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polystyrene, polycarbonate, polysulfone, polyethersulfone, polyarylate, allyl diglycol carbonate, polyamide, polyimide, polyamideimide, polyetherimide, Fluorine resin such as polybenzazole, polyphenylene sulfide, polycycloolefin, norbornene resin, polychlorotrifluoroethylene, liquid crystal polymer, acrylic resin, epoxy resin, silicone resin, ionomer resin, cyanate resin, crosslinked fumaric acid diester, cyclic polyolefin, Examples include synthetic resin substrates such as aromatic ethers, maleimide / olefins, cellulose, and episulfide compounds. That.
　また、無機材料と樹脂との複合材料に含まれる無機材料としては、酸化珪素粒子、金属ナノ粒子、無機酸化物ナノ粒子、無機窒化物ナノ粒子等の無機粒子、カーボン繊維、カーボンナノチューブ等の炭素材料、ガラスフレーク、ガラスファイバー、ガラスビーズ等のガラス材料が挙げられる。 Inorganic materials contained in the composite material of inorganic material and resin include inorganic particles such as silicon oxide particles, metal nanoparticles, inorganic oxide nanoparticles, and inorganic nitride nanoparticles, carbon fibers such as carbon fibers and carbon nanotubes. Examples thereof include glass materials such as materials, glass flakes, glass fibers, and glass beads.
　また、樹脂と粘土鉱物との複合プラスチック材料、樹脂と雲母派生結晶構造を有する粒子との複合プラスチック材料、樹脂と薄いガラスとの間に少なくとも１つの接合界面を有する積層プラスチック材料、無機層と有機層を交互に積層することで少なくとも１つの接合界面を有するバリア性能を有する複合材料等が挙げられる。 Also, composite plastic material of resin and clay mineral, composite plastic material of resin and particles having mica-derived crystal structure, laminated plastic material having at least one bonding interface between resin and thin glass, inorganic layer and organic Examples include a composite material having barrier performance having at least one bonding interface by alternately laminating layers.
　また、ステンレス基板又はステンレスと異種金属を積層した金属多層基板、アルミニウム基板又は表面に酸化処理（例えば陽極酸化処理）を施すことで表面の絶縁性を向上させた酸化皮膜付きのアルミニウム基板、酸化膜付きシリコン基板等を用いることもできる。 In addition, a stainless steel substrate, a metal multilayer substrate in which stainless and different metals are laminated, an aluminum substrate, or an aluminum substrate with an oxide film whose surface insulation is improved by subjecting the surface to oxidation treatment (for example, anodization treatment), an oxide film An attached silicon substrate or the like can also be used.
　また、樹脂基板又は樹脂複合材料基板は、耐熱性、寸法安定性、耐溶剤性、電気絶縁性、加工性、低通気性、及び低吸湿性等に優れていることが好ましい。樹脂基板又は樹脂複合材料基板は、水分、酸素等の透過を防止するためのガスバリア層、基板の平坦性又は下部電極との密着性を向上するためのアンダーコート層等を備えていてもよい。 In addition, the resin substrate or the resin composite material substrate is preferably excellent in heat resistance, dimensional stability, solvent resistance, electrical insulation, workability, low air permeability, low moisture absorption, and the like. The resin substrate or the resin composite material substrate may include a gas barrier layer for preventing permeation of moisture, oxygen, and the like, an undercoat layer for improving the flatness of the substrate or the adhesion to the lower electrode, and the like.
　本開示で用いる基板の厚みに特に制限はないが、５０μｍ以上５００μｍ以下であることが好ましい。基板の厚みが５０μｍ以上であると、基板自体の平坦性がより向上する。また、基板の厚みが５００μｍ以下であると、基板自体の可撓性がより向上し、フレキシブルデバイス用基板としての使用がより容易となる。 The thickness of the substrate used in the present disclosure is not particularly limited, but is preferably 50 μm or more and 500 μm or less. When the thickness of the substrate is 50 μm or more, the flatness of the substrate itself is further improved. Further, when the thickness of the substrate is 500 μm or less, the flexibility of the substrate itself is further improved, and the use as a substrate for a flexible device becomes easier.
　また、基板上に、下部電極、絶縁膜等を備えていてもよく、その場合には基板上の下部電極又は絶縁膜上に金属酸化物膜が形成される。 Further, a lower electrode, an insulating film, or the like may be provided on the substrate. In that case, a metal oxide film is formed on the lower electrode or the insulating film on the substrate.
（表面処理）
　基板上に金属酸化物前駆体溶液を塗布する前に、基板の塗布膜（前駆体膜）を形成する側の面に対して表面処理を行う工程を含んでもよい。例えば、薄膜トランジスタを製造する場合、ゲート絶縁膜の形成後から室内環境下に長時間放置すると、絶縁膜の表面に水分、カーボン、有機成分等の異物が付着し、トランジスタ特性（動作安定性）に悪影響を与える可能性がある。そこで、金属酸化物前駆体溶液を基板に塗布する前処理として、基板に対して水分及び汚れを除去するための表面処理を行うことが好ましい。基板の表面処理としては、紫外線（ＵＶ）オゾン処理、アルゴンプラズマ処理、窒素プラズマ処理等が挙げられる。
　ＵＶオゾン処理としては、例えば、ＵＶオゾン処理装置（Jelight-company-Inc製　Model144AX-100）を用い、下記の条件及び波長にて１～３分程度行うことができる。
・条件：大気圧、空気中
・波長：２５４ｎｍ（３０ｍＷ／ｃｍ２）、１８５ｎｍ（３．３ｍＷ／ｃｍ２） (surface treatment)
Before applying the metal oxide precursor solution on the substrate, a step of performing a surface treatment on the surface of the substrate on which the coating film (precursor film) is to be formed may be included. For example, when a thin film transistor is manufactured, if it is left in an indoor environment for a long time after the formation of the gate insulating film, foreign matters such as moisture, carbon, and organic components adhere to the surface of the insulating film, and the transistor characteristics (operational stability) are improved. May have adverse effects. Therefore, it is preferable to perform a surface treatment for removing moisture and dirt on the substrate as a pretreatment for applying the metal oxide precursor solution to the substrate. Examples of the substrate surface treatment include ultraviolet (UV) ozone treatment, argon plasma treatment, and nitrogen plasma treatment.
As the UV ozone treatment, for example, a UV ozone treatment apparatus (Model 144AX-100 manufactured by Jelight-company-Inc) can be used and performed for about 1 to 3 minutes under the following conditions and wavelengths.
-Conditions: atmospheric pressure, in air-Wavelength: 254 nm (30 mW / cm 2 ), 185 nm (3.3 mW / cm 2 )
（塗布）
　金属酸化物前駆体溶液を基板上に塗布する方法としては、スプレーコート法、スピンコート法、ブレードコート法、ディップコート法、キャスト法、ロールコート法、バーコート法、ダイコート法、ミスト法、インクジェット法、ディスペンサー法、スクリーン印刷法、凸版印刷法、凹版印刷法等が挙げられる。特に、微細パターンを容易に形成する観点から、インクジェット法、ディスペンサー法、凸版印刷法、及び凹版印刷法から選択される少なくとも一種の塗布法を用いることが好ましい。 (Application)
Methods for applying the metal oxide precursor solution on the substrate include spray coating, spin coating, blade coating, dip coating, casting, roll coating, bar coating, die coating, mist, and inkjet. Method, dispenser method, screen printing method, relief printing method, intaglio printing method and the like. In particular, from the viewpoint of easily forming a fine pattern, it is preferable to use at least one coating method selected from an inkjet method, a dispenser method, a relief printing method, and an intaglio printing method.
（乾燥）
　金属酸化物前駆体溶液を基板上に塗布した後、好ましくは加熱処理によって塗布膜を乾燥させ、金属酸化物前駆体膜を得る。乾燥によって、塗布膜の流動性を低減させ、最終的に得られる金属酸化物膜の平坦性を向上させることができる。また、適切な乾燥温度（好ましくは３５℃以上１００℃以下）を選択することにより、最終的により緻密な金属酸化物膜を得ることができる。
　加熱処理の方法は特に限定されず、ホットプレート加熱、電気炉加熱、赤外線加熱、マイクロ波加熱等から選択することができる。
　乾燥の開始は特に限定されるものではないが、膜の平坦性を均一に保つ観点から、塗布後、５分以内に開始することが好ましい。 (Dry)
After coating the metal oxide precursor solution on the substrate, the coating film is preferably dried by heat treatment to obtain a metal oxide precursor film. By drying, the fluidity of the coating film can be reduced and the flatness of the finally obtained metal oxide film can be improved. Further, by selecting an appropriate drying temperature (preferably 35 ° C. or more and 100 ° C. or less), a final denser metal oxide film can be obtained.
The method for the heat treatment is not particularly limited, and can be selected from hot plate heating, electric furnace heating, infrared heating, microwave heating, and the like.
Although the start of drying is not particularly limited, it is preferably started within 5 minutes after coating from the viewpoint of keeping the flatness of the film uniform.
＜転化工程＞
　転化工程では、加熱した状態の前駆体膜に対して１０Ｐａ以下の雰囲気下で紫外線照射を行うことにより前駆体膜を金属酸化物膜に転化させる。
　金属酸化物膜中の水素成分をより減少させる観点から　転化させる際の圧力は１Ｐａ以下が好ましく、０．１Ｐａ以下がより好ましい。前駆体膜を金属酸化物膜に転化させる際の圧力を１Ｐａ以下にすれば、水素含有量が１．０×１０２２個／ｃｍ３以下の金属酸化物膜を得ることもできる。なお、本開示における金属酸化物膜中の水素含有量は、二次イオン質量分析（ＳＩＭＳ：Ｓｅｃｏｎｄａｒｙ　Ｉｏｎ　Ｍａｓｓ　Ｓｐｅｃｔｒｏｍｅｔｒｙ）から算出される。 <Conversion process>
In the conversion step, the precursor film is converted to a metal oxide film by irradiating the heated precursor film with ultraviolet rays in an atmosphere of 10 Pa or less.
From the viewpoint of further reducing the hydrogen component in the metal oxide film, the pressure at the time of conversion is preferably 1 Pa or less, and more preferably 0.1 Pa or less. If the pressure at which the precursor film is converted to a metal oxide film is 1 Pa or less, a metal oxide film having a hydrogen content of 1.0 × 10 22 pieces / cm 3 or less can be obtained. In addition, the hydrogen content in the metal oxide film in the present disclosure is calculated from secondary ion mass spectrometry (SIMS: Secondary Ion Mass Spectrometry).
　紫外線照射を行う際の基板の温度は２００℃未満であることが好ましい。転化工程における基板温度が２００℃未満であれば耐熱性の低い樹脂基板への適用が容易となり、また、熱エネルギーの増大を抑制して製造コストを低く抑えることができる。より多種の樹脂基板に対応が可能となる観点から、転化工程における基板温度は１５０℃以下であることがより好ましい。
　一方、前駆体膜から金属酸化物膜への転化を短時間で行う観点から、転化工程における基板温度は１２０℃以上であることが好ましい。転化工程における基板温度はサーモラベルによって測定することができる。
　金属酸化物膜への転化工程は、紫外線の照度にもよるが、生産性の観点から、５秒以上１２０分以下であることが好ましい。 It is preferable that the temperature of the board | substrate at the time of performing ultraviolet irradiation is less than 200 degreeC. If the substrate temperature in the conversion step is less than 200 ° C., it can be easily applied to a resin substrate having low heat resistance, and the increase in thermal energy can be suppressed to reduce the manufacturing cost. From the viewpoint of being able to deal with a wider variety of resin substrates, the substrate temperature in the conversion step is more preferably 150 ° C. or lower.
On the other hand, from the viewpoint of performing the conversion from the precursor film to the metal oxide film in a short time, the substrate temperature in the conversion process is preferably 120 ° C. or higher. The substrate temperature in the conversion process can be measured with a thermolabel.
Although the conversion process to a metal oxide film depends on the illuminance of ultraviolet rays, it is preferably from 5 seconds to 120 minutes from the viewpoint of productivity.
　転化工程における基板に対する加熱手段は特に限定されず、ホットプレート加熱、電気炉加熱、赤外線加熱、マイクロ波加熱等から選択すればよい。
　紫外線処理時の基板の加熱は、紫外線照射に用いる紫外線ランプ等の光源からの輻射熱を利用してもよく、ヒーター等によって基板の温度を制御してもよい。紫外線ランプ等からの輻射熱を用いる際には、ランプ－基板間距離及び／又はランプ出力を調整することで制御することができる。 The heating means for the substrate in the conversion step is not particularly limited, and may be selected from hot plate heating, electric furnace heating, infrared heating, microwave heating, and the like.
The substrate may be heated during the ultraviolet treatment using radiant heat from a light source such as an ultraviolet lamp used for ultraviolet irradiation, or the temperature of the substrate may be controlled by a heater or the like. When radiant heat from an ultraviolet lamp or the like is used, it can be controlled by adjusting the lamp-substrate distance and / or the lamp output.
　転化工程において、金属酸化物前駆体膜の膜面には波長３００ｎｍ以下の光を含む紫外光を１０ｍＷ／ｃｍ２以上の照度で照射することが好ましい。３００ｎｍ以下の波長範囲の紫外光を１０ｍＷ／ｃｍ２以上の照度で照射することで、より短い時間で金属酸化物前駆体膜から金属酸化物膜への転化を行うことができる。 In the conversion step, it is preferable that the film surface of the metal oxide precursor film is irradiated with ultraviolet light including light having a wavelength of 300 nm or less at an illuminance of 10 mW / cm 2 or more. By irradiating ultraviolet light in a wavelength range of 300 nm or less with an illuminance of 10 mW / cm 2 or more, conversion from the metal oxide precursor film to the metal oxide film can be performed in a shorter time.
　紫外線の光源としては、ＵＶランプ及びレーザーが挙げられ、大面積に均一に且つ安価な設備で紫外線照射を行う観点からＵＶランプが好ましい。
　ＵＶランプとしては、例えばエキシマランプ、重水素ランプ、低圧水銀ランプ、高圧水銀ランプ、超高圧水銀ランプ、メタルハライドランプ、ヘリウムランプ、カーボンアークランプ、カドミウムランプ、無電極放電ランプ等が挙げられ、特に低圧水銀ランプを用いると容易に金属酸化物前駆体膜から金属酸化物膜への転化が行えることから好ましい。 Examples of the ultraviolet light source include a UV lamp and a laser, and a UV lamp is preferable from the viewpoint of performing ultraviolet irradiation with a uniform and inexpensive facility over a large area.
Examples of UV lamps include excimer lamps, deuterium lamps, low pressure mercury lamps, high pressure mercury lamps, ultra high pressure mercury lamps, metal halide lamps, helium lamps, carbon arc lamps, cadmium lamps, electrodeless discharge lamps, etc. It is preferable to use a mercury lamp because the metal oxide precursor film can be easily converted into the metal oxide film.
（紫外線照射装置）
　ここで、本開示における転化工程に用いる装置について説明する。
　転化工程に用いる装置は限定されないが、例えば、減圧室と、減圧室内で基板を支持し、且つ、加熱する支持台と、減圧室内を１０Ｐａ以下に減圧する真空ポンプと、支持台に支持された基板に対して紫外線を照射する光源と、を備えた紫外線照射装置を好適に用いることができる。
　また、光源と支持台との位置関係を調整する位置調整手段をさらに備えた構成とすれば、光源と支持台上の基板との距離を調整することで基板に照射するＵＶ照射パワー（照度）を調整することができる。 (UV irradiation device)
Here, the apparatus used for the conversion process in this indication is explained.
The apparatus used for the conversion step is not limited, but, for example, supported by a decompression chamber, a support base that supports and heats the substrate in the decompression chamber, a vacuum pump that decompresses the decompression chamber to 10 Pa or less, and a support base. An ultraviolet irradiation apparatus including a light source that irradiates the substrate with ultraviolet rays can be suitably used.
Further, if the position adjustment means for adjusting the positional relationship between the light source and the support base is further provided, the UV irradiation power (illuminance) for irradiating the substrate by adjusting the distance between the light source and the substrate on the support base. Can be adjusted.
　図１１は、本開示における転化工程に用いられる装置の構成の一例を概略的に示している。図１１に示す装置４００は、真空チャンバ（減圧室）４１０内にヒーター機能を備えたステージ４１２が設けられ、ステージ（支持台）４１２上の基板温度を調整することができ、また、大気側からハンドル（位置調整手段）４１８を回すことによりステージ４１２を上下動させることができる。真空チャンバ４１０の外側には真空排気用のターボメカニカルポンプ（真空ポンプ）４１４、Ｎ２ガス導入ポート（ＭＦＣ：マスフローコントローラ）４２４、真空計４２２、ＵＶ照射ユニット（光源）４１６、ベントバルブ４２６がそれぞれ配置されている。真空チャンバ４１０とターボメカニカルポンプ４１４との間には圧力調整バルブ４２０が設けられており、チャンバ４１０内の圧力を１０Ｐａ以下に調整することができる。 FIG. 11 schematically illustrates an example of the configuration of an apparatus used for the conversion process in the present disclosure. An apparatus 400 shown in FIG. 11 includes a stage 412 having a heater function in a vacuum chamber (decompression chamber) 410, and can adjust the substrate temperature on the stage (support base) 412. The stage 412 can be moved up and down by turning the handle (position adjusting means) 418. Outside the vacuum chamber 410 are a turbo mechanical pump (vacuum pump) 414 for vacuum exhaust, an N 2 gas introduction port (MFC: mass flow controller) 424, a vacuum gauge 422, a UV irradiation unit (light source) 416, and a vent valve 426, respectively. Has been placed. A pressure adjustment valve 420 is provided between the vacuum chamber 410 and the turbo mechanical pump 414, and the pressure in the chamber 410 can be adjusted to 10 Pa or less.
　ＵＶ照射ユニット４１６は石英ガラス４１７を通じてステージ４１２上の基板に対して紫外光を照射することができ、ステージ４１２の高さを調整することでステージ４１２上の基板に照射するＵＶ照射パワー（照度）を調整することができる。なお、ＵＶ照射ユニット４１６の位置を移動させてステージ４１２上の基板に照射するＵＶ照射パワー（照度）を調整する構成としてもよいし、ＵＶ照射ユニット４１６の紫外線ランプの出力を変えて基板に照射するＵＶ照射パワー（照度）を調整する構成としてもよい。 The UV irradiation unit 416 can irradiate the substrate on the stage 412 with ultraviolet light through the quartz glass 417, and the UV irradiation power (illuminance) for irradiating the substrate on the stage 412 by adjusting the height of the stage 412. Can be adjusted. The UV irradiation power (illuminance) applied to the substrate on the stage 412 may be adjusted by moving the position of the UV irradiation unit 416, or the substrate may be irradiated by changing the output of the UV lamp of the UV irradiation unit 416. It is good also as a structure which adjusts UV irradiation power (illuminance) to perform.
　本開示によって製造される金属酸化物膜の膜厚は特に限定されず用途に応じて選択すればよい。例えば、本開示により薄膜トランジスタの半導体層を形成する場合、膜厚は５０ｎｍ以下が好ましく、より好ましくは１０ｎｍ程度である。 The film thickness of the metal oxide film produced according to the present disclosure is not particularly limited and may be selected according to the application. For example, when forming a semiconductor layer of a thin film transistor according to the present disclosure, the film thickness is preferably 50 nm or less, and more preferably about 10 nm.
　本開示の金属酸化物膜の製造方法は、液相法により２００℃未満の低温プロセスでも不要な残留成分が低減した金属酸化物膜を簡便に得ることができる。また、大掛かりな真空装置を用いる必要がない点、耐熱性の低い安価な樹脂基板を用いることができる点、安価な原料を用いることができる点等からデバイスの作製コストを大幅に低減可能となる。
　また、耐熱性の低い樹脂基板にも適用できることからフレキシブルディスプレイ等のフレキシブル電子デバイスを安価に作製することが可能となる。 The metal oxide film manufacturing method of the present disclosure can easily obtain a metal oxide film in which unnecessary residual components are reduced by a liquid phase method even at a low temperature process of less than 200 ° C. In addition, it is possible to significantly reduce the device manufacturing cost from the point that it is not necessary to use a large vacuum device, the point that an inexpensive resin substrate with low heat resistance can be used, and the point that inexpensive raw materials can be used. .
Further, since it can be applied to a resin substrate having low heat resistance, a flexible electronic device such as a flexible display can be manufactured at low cost.
［薄膜トランジスタ］
　本開示では、不要な残留成分が低減し、良好な電気特性を有する金属酸化物膜を製造することができることから、本開示の金属酸化物膜の製造方法は、例えば、薄膜トランジスタ（ＴＦＴ）の酸化物半導体層（活性層）及び電極の形成に好適に用いることができる。例えば、半導体層（活性層）として、本開示の金属酸化物膜の製造方法によって酸化物半導体層を形成することで、線形移動度が高く、且つ、動作安定性に優れた薄膜トランジスタを得ることができる。 [Thin film transistor]
In the present disclosure, unnecessary residual components are reduced, and a metal oxide film having good electrical characteristics can be manufactured. Therefore, a method for manufacturing a metal oxide film of the present disclosure includes, for example, oxidation of a thin film transistor (TFT). It can be suitably used to form a physical semiconductor layer (active layer) and an electrode. For example, by forming an oxide semiconductor layer as a semiconductor layer (active layer) by the method for manufacturing a metal oxide film of the present disclosure, a thin film transistor having high linear mobility and excellent operational stability can be obtained. it can.
　以下、本開示の金属酸化物膜の製造方法をＴＦＴの半導体層（酸化物半導体膜）の形成に適用する形態について主に説明するが、本発明はＴＦＴの半導体層の形成に限定されるものではない。 Hereinafter, although the form which applies the manufacturing method of the metal oxide film of this indication to formation of the semiconductor layer (oxide semiconductor film) of TFT is mainly demonstrated, this invention is limited to formation of the semiconductor layer of TFT. is not.
　本開示に係るＴＦＴの素子構造は特に限定されず、ゲート電極の位置に基づいた、いわゆる逆スタガ構造（ボトムゲート型とも呼ばれる）及びスタガ構造（トップゲート型とも呼ばれる）のいずれの態様であってもよい。また、半導体層とソース電極及びドレイン電極（適宜、「ソース・ドレイン電極」という。）との接触部分に基づき、いわゆるトップコンタクト型、ボトムコンタクト型のいずれの態様であってもよい。
　「トップゲート型」とは、ＴＦＴが形成されている基板を最下層としたときに、ゲート絶縁膜の上側にゲート電極が配置され、ゲート絶縁膜の下側に半導体層が形成された形態であり、「ボトムゲート型」とは、ゲート絶縁膜の下側にゲート電極が配置され、ゲート絶縁膜の上側に半導体層が形成された形態である。また、「ボトムコンタクト型」とは、ソース・ドレイン電極が半導体層よりも先に形成されて半導体層の下面がソース・ドレイン電極に接触する形態であり、「トップコンタクト型」とは、半導体層がソース・ドレイン電極よりも先に形成されて半導体層の上面がソース・ドレイン電極に接触する形態である。 The element structure of the TFT according to the present disclosure is not particularly limited, and may be any of a so-called reverse stagger structure (also referred to as a bottom gate type) and a stagger structure (also referred to as a top gate type) based on the position of the gate electrode. Also good. Further, based on the contact portion between the semiconductor layer and the source and drain electrodes (referred to as “source / drain electrodes” as appropriate), either a so-called top contact type or bottom contact type may be employed.
The “top gate type” is a mode in which a gate electrode is disposed on the upper side of the gate insulating film and a semiconductor layer is formed on the lower side of the gate insulating film when the substrate on which the TFT is formed is the lowest layer. The “bottom gate type” is a form in which a gate electrode is disposed below the gate insulating film and a semiconductor layer is formed above the gate insulating film. The “bottom contact type” is a form in which the source / drain electrodes are formed before the semiconductor layer and the lower surface of the semiconductor layer is in contact with the source / drain electrodes. Is formed before the source / drain electrodes, and the upper surface of the semiconductor layer is in contact with the source / drain electrodes.
　図１は、トップゲート構造でトップコンタクト型の本開示に係るＴＦＴの一例を示す模式図である。図１に示すＴＦＴ１０では、基板１２の一方の主面上に半導体層１４として上述の酸化物半導体膜が積層されている。そして、半導体層１４上にソース電極１６及びドレイン電極１８が互いに離間して設置され、更にゲート絶縁膜２０と、ゲート電極２２とが順に積層されている。 FIG. 1 is a schematic diagram showing an example of a top contact type TFT according to the present disclosure having a top gate structure. In the TFT 10 shown in FIG. 1, the above-described oxide semiconductor film is stacked as the semiconductor layer 14 on one main surface of the substrate 12. A source electrode 16 and a drain electrode 18 are disposed on the semiconductor layer 14 so as to be separated from each other, and a gate insulating film 20 and a gate electrode 22 are sequentially stacked.
　図２は、トップゲート構造でボトムコンタクト型の本開示に係るＴＦＴの一例を示す模式図である。図２に示すＴＦＴ３０では、基板１２の一方の主面上にソース電極１６及びドレイン電極１８が互いに離間して設置されている。そして、半導体層１４として上述の酸化物半導体膜と、ゲート絶縁膜２０と、ゲート電極２２と、が順に積層されている。 FIG. 2 is a schematic diagram illustrating an example of a TFT according to the present disclosure having a top gate structure and a bottom contact type. In the TFT 30 shown in FIG. 2, the source electrode 16 and the drain electrode 18 are disposed on one main surface of the substrate 12 so as to be separated from each other. Then, the above-described oxide semiconductor film, the gate insulating film 20, and the gate electrode 22 are sequentially stacked as the semiconductor layer 14.
　図３は、ボトムゲート構造でトップコンタクト型の本開示に係るＴＦＴの一例を示す模式図である。図３に示すＴＦＴ４０では、基板１２の一方の主面上にゲート電極２２と、ゲート絶縁膜２０と、半導体層１４として上述の酸化物半導体膜と、が順に積層されている。そして、半導体層１４の表面上にソース電極１６及びドレイン電極１８が互いに離間して設置されている。 FIG. 3 is a schematic diagram illustrating an example of a top contact type TFT according to the present disclosure having a bottom gate structure. In the TFT 40 shown in FIG. 3, the gate electrode 22, the gate insulating film 20, and the above-described oxide semiconductor film as the semiconductor layer 14 are sequentially stacked on one main surface of the substrate 12. A source electrode 16 and a drain electrode 18 are disposed on the surface of the semiconductor layer 14 so as to be separated from each other.
　図４は、ボトムゲート構造でボトムコンタクト型の本開示に係るＴＦＴの一例を示す模式図である。図４に示すＴＦＴ５０では、基板１２の一方の主面上にゲート電極２２と、ゲート絶縁膜２０と、が順に積層されている。そして、ゲート絶縁膜２０の表面上にソース電極１６及びドレイン電極１８が互いに離間して設置され、更に、半導体層１４として上述の酸化物半導体膜が積層されている。 FIG. 4 is a schematic diagram showing an example of a bottom contact type TFT according to the present disclosure with a bottom gate structure. In the TFT 50 shown in FIG. 4, the gate electrode 22 and the gate insulating film 20 are sequentially stacked on one main surface of the substrate 12. Then, the source electrode 16 and the drain electrode 18 are provided on the surface of the gate insulating film 20 so as to be separated from each other, and the above-described oxide semiconductor film is stacked as the semiconductor layer 14.
　以下の実施形態では、代表例として図３に示すボトムゲート型の薄膜トランジスタについて主に説明するが、本開示に係る薄膜トランジスタはボトムゲート型に限定されることなく、トップゲート型の薄膜トランジスタであってもよい。 In the following embodiments, the bottom gate type thin film transistor shown in FIG. 3 will be mainly described as a representative example. However, the thin film transistor according to the present disclosure is not limited to the bottom gate type, and may be a top gate type thin film transistor. Good.
（基板）
　ＴＦＴを形成する基板１２の形状、構造、大きさ等については特に制限はなく、例えば、前述した基板から目的に応じて適宜選択することができる。
　また、本開示で用いる基板の厚みに特に制限はないが、５０μｍ以上５００μｍ以下であることが好ましい。
　基板の厚みが５０μｍ以上であると、基板自体の平坦性がより向上する。また、基板の厚みが５００μｍ以下であると、基板自体の可撓性がより向上し、可撓性デバイス用基板としての使用がより容易になる。また、例えば、可撓性デバイスの作製プロセスにおいて、ガラス基板に仮固着したフレキシブル基板上に薄膜トランジスタを形成した後、ガラス基板からフレキシブル基板を剥離する形態であってもよい。 (substrate)
The shape, structure, size, etc. of the substrate 12 on which the TFT is formed are not particularly limited, and can be appropriately selected from the above-described substrates according to the purpose.
Moreover, there is no restriction | limiting in particular in the thickness of the board | substrate used by this indication, However, It is preferable that they are 50 micrometers or more and 500 micrometers or less.
When the thickness of the substrate is 50 μm or more, the flatness of the substrate itself is further improved. Further, when the thickness of the substrate is 500 μm or less, the flexibility of the substrate itself is further improved, and the use as a flexible device substrate becomes easier. For example, in the manufacturing process of a flexible device, after forming a thin-film transistor on the flexible substrate temporarily fixed to the glass substrate, the form which peels a flexible substrate from a glass substrate may be sufficient.
（ゲート電極）
　基板１２の洗浄後、例えばＵＶオゾン処理を行った基板１２にゲート電極２２を形成する。ゲート電極２２は高い導電性を有する材料、例えば、Ａｌ，Ｃｕ，Ｍｏ，Ｃｒ，Ｔａ，Ｔｉ，Ａｇ，Ａｕ等の金属、Ａｌ－Ｎｄ、Ａｇ合金、酸化錫、酸化亜鉛、酸化インジウム、酸化インジウム錫（Ｉｎ－Ｓｎ－Ｏ）、酸化亜鉛インジウム（Ｉｎ－Ｚｎ－Ｏ）、Ｉｎ－Ｇａ－Ｚｎ－Ｏ等の金属酸化物導電膜等を用いて形成することができる。ゲート電極２２としてはこれらの導電膜を単層構造又は２層以上の積層構造として用いることができる。 (Gate electrode)
After cleaning the substrate 12, the gate electrode 22 is formed on the substrate 12 that has been subjected to, for example, UV ozone treatment. The gate electrode 22 is made of a material having high conductivity, for example, metal such as Al, Cu, Mo, Cr, Ta, Ti, Ag, Au, Al—Nd, Ag alloy, tin oxide, zinc oxide, indium oxide, indium oxide. It can be formed using a metal oxide conductive film such as tin (In—Sn—O), indium zinc oxide (In—Zn—O), or In—Ga—Zn—O. As the gate electrode 22, these conductive films can be used as a single layer structure or a stacked structure of two or more layers.
　ゲート電極２２は、印刷方式、コーティング方式等の湿式方式、真空蒸着法、スパッタリング法、イオンプレーティング法等の物理的方式、ＣＶＤ、プラズマＣＶＤ法等の化学的方式等の中から使用する材料との適性を考慮して適宜選択した方法に従って成膜する。
　ゲート電極２２を形成するための金属膜の膜厚は、成膜性、エッチング又はリフトオフ法によるパターンニング性、導電性等を考慮すると、１０ｎｍ以上１０００ｎｍ以下とすることが好ましく、５０ｎｍ以上２００ｎｍ以下とすることがより好ましい。
　成膜後、エッチング又はリフトオフ法により所定の形状にパターンニングすることにより、ゲート電極２２を形成してもよく、インクジェット法、印刷法等により直接パターン形成してもよい。この際、ゲート電極２２及びゲート配線（図示しない）を同時にパターンニングすることが好ましい。 The gate electrode 22 is made of a material used from a wet method such as a printing method or a coating method, a physical method such as a vacuum deposition method, a sputtering method or an ion plating method, or a chemical method such as a CVD or plasma CVD method. The film is formed according to a method appropriately selected in consideration of the suitability of the above.
The film thickness of the metal film for forming the gate electrode 22 is preferably 10 nm or more and 1000 nm or less, preferably 50 nm or more and 200 nm or less in consideration of film forming property, patterning property by etching or lift-off method, conductivity, and the like. More preferably.
After the film formation, the gate electrode 22 may be formed by patterning into a predetermined shape by an etching or lift-off method, or the pattern may be formed directly by an inkjet method, a printing method, or the like. At this time, it is preferable to pattern the gate electrode 22 and the gate wiring (not shown) at the same time.
（ゲート絶縁膜）
　ゲート電極２２及び配線（図示しない）を形成した後、ゲート絶縁膜２０を形成する。ゲート絶縁膜２０は高い絶縁性を有する材料が好ましく、例えばＳｉＯ２、ＳｉＮｘ、ＳｉＯＮ、Ａｌ２Ｏ３、Ｙ２Ｏ３、Ｔａ２Ｏ５、ＨｆＯ２等の絶縁膜、又はこれらの化合物を２種以上含む絶縁膜としてもよく、単層構造であっても積層構造であってもよい。
　ゲート絶縁膜２０の形成は、印刷方式、コーティング方式等の湿式方式、真空蒸着法、スパッタリング法、イオンプレーティング法等の物理的方式、ＣＶＤ、プラズマＣＶＤ法等の化学的方式等の中から使用する材料との適性を考慮して適宜選択した方法に従って成膜すればよい。ゲート絶縁膜２０は、ゲート絶縁特性を有していれば、有機絶縁膜でも無機絶縁膜でもよい。例えば、湿式方式による無機絶縁膜としては、ポリシラザン化合物溶液を用いたＳｉＯ２膜、ＳｉＯＮ膜、ＳｉＮ膜などが挙げられる。 (Gate insulation film)
After forming the gate electrode 22 and wiring (not shown), the gate insulating film 20 is formed. The gate insulating film 20 is preferably made of a material having high insulating properties. For example, an insulating film such as SiO 2 , SiN x , SiON, Al 2 O 3 , Y 2 O 3 , Ta 2 O 5 , HfO 2 , or a compound thereof is used. The insulating film may include two or more types, and may have a single layer structure or a stacked structure.
The gate insulating film 20 can be formed from a printing method, a wet method such as a coating method, a physical method such as a vacuum deposition method, a sputtering method or an ion plating method, or a chemical method such as a CVD or plasma CVD method. The film may be formed according to a method appropriately selected in consideration of suitability with the material to be used. The gate insulating film 20 may be an organic insulating film or an inorganic insulating film as long as it has gate insulating characteristics. For example, as the inorganic insulating film by a wet method, a SiO 2 film, a SiON film, a SiN film, or the like using a polysilazane compound solution can be given.
　なお、ゲート絶縁膜２０はリーク電流の低下及び電圧耐性の向上のための厚みを有する必要がある一方、ゲート絶縁膜２０の厚みが大きすぎると駆動電圧の上昇を招いてしまう。ゲート絶縁膜２０の材質にもよるが、ゲート絶縁膜２０の厚みは１０ｎｍ以上１０μｍ以下が好ましく、５０ｎｍ以上１０００ｎｍ以下がより好ましく、１００ｎｍ以上４００ｎｍ以下が特に好ましい。 Note that the gate insulating film 20 needs to have a thickness for reducing leakage current and improving voltage resistance. On the other hand, if the gate insulating film 20 is too thick, the driving voltage is increased. Although depending on the material of the gate insulating film 20, the thickness of the gate insulating film 20 is preferably 10 nm to 10 μm, more preferably 50 nm to 1000 nm, and particularly preferably 100 nm to 400 nm.
（半導体層）
　ゲート絶縁膜２０を形成した後、ゲート絶縁膜２０上に半導体層１４を形成する。前述した本開示の金属酸化物膜の製造方法に従い、ゲート絶縁膜２０上にインジウムを含む溶液を塗布して乾燥させて金属酸化物半導体膜の前駆体膜を形成した後、前駆体膜を加熱した状態で１０Ｐａ以下の雰囲気下で紫外線照射を行うことにより金属酸化物半導体膜に転化させる。 (Semiconductor layer)
After forming the gate insulating film 20, the semiconductor layer 14 is formed on the gate insulating film 20. In accordance with the method for manufacturing a metal oxide film of the present disclosure described above, a solution containing indium is applied on the gate insulating film 20 and dried to form a precursor film of the metal oxide semiconductor film, and then the precursor film is heated. In this state, it is converted into a metal oxide semiconductor film by irradiating with ultraviolet rays under an atmosphere of 10 Pa or less.
　金属酸化物半導体膜を半導体層１４の形状にパターンニングする。半導体層１４のパターンニングは前述したインクジェット法、ディスペンサー法、凸版印刷法、及び凹版印刷法によってパターンニングされた半導体層１４を形成してもよいし、金属酸化物半導体膜をフォトリソグラフィー及びエッチングによって半導体層１４の形状にパターンニングしてもよい。
　フォトリソグラフィー及びエッチングによりパターン形成を行うには、金属酸化物半導体膜の残存させる部分にフォトリソグラフィーによりレジストパターンを形成し、塩酸、硝酸、希硫酸、又は燐酸、硝酸及び酢酸の混合液等の酸溶液によりエッチングすることにより半導体層１４のパターンを形成する。 The metal oxide semiconductor film is patterned into the shape of the semiconductor layer 14. The semiconductor layer 14 may be patterned by forming the semiconductor layer 14 patterned by the ink jet method, the dispenser method, the relief printing method, and the intaglio printing method, and the metal oxide semiconductor film may be formed by photolithography and etching. The semiconductor layer 14 may be patterned into the shape.
In order to form a pattern by photolithography and etching, a resist pattern is formed by photolithography on the remaining portion of the metal oxide semiconductor film, and an acid such as hydrochloric acid, nitric acid, dilute sulfuric acid, or a mixed solution of phosphoric acid, nitric acid and acetic acid is used. The pattern of the semiconductor layer 14 is formed by etching with a solution.
　半導体層１４の厚みは、平坦性及び膜形成に要する時間の観点から５ｎｍ以上５０ｎｍ以下であることが好ましい。 The thickness of the semiconductor layer 14 is preferably 5 nm or more and 50 nm or less from the viewpoint of flatness and time required for film formation.
（保護層）
　半導体層１４上にはソース・ドレイン電極１６，１８のエッチング時に半導体層１４を保護するための保護層（不図示）を形成することが好ましい。保護層の成膜方法に特に限定はなく、金属酸化物半導体膜に続けて成膜すればよい。保護層は、金属酸化物半導体膜のパターンニングの前に形成してもよいし、パターンニングの後に形成してもよい。
　保護層としては絶縁体が好ましく、保護層を構成する材料は無機材料であってもよく、樹脂のような有機材料であってもよい。なお、保護層はソース電極１６及びドレイン電極１８（ソース・ドレイン電極１６，１８）の形成後に除去しても構わない。 (Protective layer)
A protective layer (not shown) for protecting the semiconductor layer 14 is preferably formed on the semiconductor layer 14 when the source / drain electrodes 16 and 18 are etched. There is no particular limitation on the method for forming the protective layer, and the protective layer may be formed after the metal oxide semiconductor film. The protective layer may be formed before the patterning of the metal oxide semiconductor film or may be formed after the patterning.
The protective layer is preferably an insulator, and the material constituting the protective layer may be an inorganic material or an organic material such as a resin. The protective layer may be removed after the source electrode 16 and the drain electrode 18 (source / drain electrodes 16 and 18) are formed.
（ソース・ドレイン電極）
　金属酸化物半導体膜で形成された半導体層１４上にソース・ドレイン電極１６，１８を形成する。ソース・ドレイン電極１６，１８はそれぞれ電極として機能する高い導電性を有する材料、例えば、Ａｌ，Ｍｏ，Ｃｒ，Ｔａ，Ｔｉ，Ａｇ，Ａｕ等の金属、Ａｌ－Ｎｄ、Ａｇ合金、酸化錫、酸化亜鉛、酸化インジウム、酸化インジウム錫（Ｉｎ－Ｓｎ－Ｏ）、酸化亜鉛インジウム（Ｉｎ－Ｚｎ－Ｏ）、Ｉｎ－Ｇａ－Ｚｎ－Ｏ等の金属酸化物導電膜等を用いて形成することができる。 (Source / drain electrodes)
Source / drain electrodes 16 and 18 are formed on a semiconductor layer 14 formed of a metal oxide semiconductor film. The source / drain electrodes 16 and 18 each have a high conductivity functioning as an electrode, for example, a metal such as Al, Mo, Cr, Ta, Ti, Ag, Au, Al—Nd, an Ag alloy, tin oxide, oxidation It can be formed using a metal oxide conductive film such as zinc, indium oxide, indium tin oxide (In—Sn—O), indium zinc oxide (In—Zn—O), or In—Ga—Zn—O. .
　ソース・ドレイン電極１６，１８を形成する場合、印刷方式、コーティング方式等の湿式方式、真空蒸着法、スパッタリング法、イオンプレーティング法等の物理的方式、ＣＶＤ（化学気相蒸着）、プラズマＣＶＤ法等の化学的方式等の中から使用する材料との適性を考慮して適宜選択した方法に従って成膜すればよい。 When the source / drain electrodes 16 and 18 are formed, a wet method such as a printing method or a coating method, a physical method such as a vacuum deposition method, a sputtering method, or an ion plating method, a CVD (chemical vapor deposition), or a plasma CVD method. The film may be formed according to a method appropriately selected in consideration of suitability with a material to be used from among chemical methods such as the above.
　ソース・ドレイン電極１６，１８の膜厚は、成膜性、エッチング又はリフトオフ法によるパターンニング性、導電性等を考慮すると、１０ｎｍ以上１０００ｎｍ以下とすることが好ましく、５０ｎｍ以上１００ｎｍ以下とすることがより好ましい。 The film thickness of the source / drain electrodes 16 and 18 is preferably 10 nm or more and 1000 nm or less, preferably 50 nm or more and 100 nm or less in consideration of film forming properties, patterning properties by etching or lift-off methods, conductivity, and the like. More preferred.
　ソース・ドレイン電極１６，１８は、導電膜を形成した後、例えば、エッチング又はリフトオフ法により所定の形状にパターンニングして形成してもよく、インクジェット法等により直接パターン形成してもよい。この際、ソース・ドレイン電極１６，１８及びこれらの電極に接続する配線（図示しない）を同時にパターンニングすることが好ましい。 The source / drain electrodes 16 and 18 may be formed by patterning into a predetermined shape by, for example, etching or a lift-off method after forming a conductive film, or may be directly formed by an inkjet method or the like. At this time, it is preferable to pattern the source / drain electrodes 16 and 18 and wiring (not shown) connected to these electrodes simultaneously.
　以上で説明した本実施形態の薄膜トランジスタの用途には特に限定はないが、低温で高い半導体特性と安定性を示す薄膜トランジスタを比較的低温で作製できることから、各種電子デバイス、特に耐熱性の低い安価な樹脂基板を用いたフレキシブルな電子デバイスの作製にも適用することができる。具体的には、液晶表示装置、有機ＥＬ（Ｅｌｅｃｔｒｏ　Ｌｕｍｉｎｅｓｃｅｎｃｅ）表示装置、無機ＥＬ表示装置等の表示装置における駆動素子、耐熱性の低い樹脂基板を用いたフレキシブルディスプレイの作製に好適である。 The application of the thin film transistor of the present embodiment described above is not particularly limited, but since a thin film transistor exhibiting high semiconductor characteristics and stability at a low temperature can be produced at a relatively low temperature, various electronic devices, particularly low heat resistance and low cost. The present invention can also be applied to manufacture of a flexible electronic device using a resin substrate. Specifically, it is suitable for manufacturing a flexible display using a driving element in a display device such as a liquid crystal display device, an organic EL (Electro Luminescence) display device, and an inorganic EL display device, and a resin substrate having low heat resistance.
　更に本開示により製造される薄膜トランジスタは、Ｘ線センサ、イメージセンサ等の各種センサ、ＭＥＭＳ（Ｍｉｃｒｏ　Ｅｌｅｃｔｒｏ　Ｍｅｃｈａｎｉｃａｌ　Ｓｙｓｔｅｍ）等、種々の電子デバイスにおける駆動素子（駆動回路）として好適に用いられる。
　以下、本開示により製造される薄膜トランジスタを適用した電子デバイスの一例について説明する。 Furthermore, the thin film transistor manufactured according to the present disclosure is suitably used as a driving element (driving circuit) in various electronic devices such as various sensors such as an X-ray sensor and an image sensor, and a MEMS (Micro Electro Mechanical System).
Hereinafter, an example of an electronic device to which the thin film transistor manufactured according to the present disclosure is applied will be described.
＜液晶表示装置＞
　本開示の一実施形態である液晶表示装置について、図５に一部分の概略断面図を示し、図６に電気配線の概略構成図を示す。 <Liquid crystal display device>
FIG. 5 shows a partial schematic cross-sectional view of a liquid crystal display device according to an embodiment of the present disclosure, and FIG. 6 shows a schematic configuration diagram of electrical wiring.
　図５に示すように、本実施形態の液晶表示装置１００は、図１に示したトップゲート構造でトップコンタクト型のＴＦＴ１０と、ＴＦＴ１０のパッシベーション層１０２で保護されたゲート電極２２上に画素下部電極１０４および対向上部電極１０６で挟まれた液晶層１０８と、各画素に対応させて異なる色を発色させるためのＲ（赤）Ｇ（緑）Ｂ（青）のカラーフィルタ１１０とを備え、ＴＦＴ１０の基板１２側およびＲＧＢカラーフィルタ１１０上にそれぞれ偏光板１１２ａ、１１２ｂを備えた構成である。 As shown in FIG. 5, the liquid crystal display device 100 according to the present embodiment includes a top contact type TFT 10 having the top gate structure shown in FIG. 1 and a pixel lower electrode on the gate electrode 22 protected by the passivation layer 102 of the TFT 10. 104 and a liquid crystal layer 108 sandwiched between the counter upper electrode 106 and an R (red) G (green) B (blue) color filter 110 for developing different colors corresponding to each pixel. In this configuration, polarizing plates 112a and 112b are provided on the substrate 12 side and the RGB color filter 110, respectively.
　また、図６に示すように、本実施形態の液晶表示装置１００は、互いに平行な複数のゲート配線１１２と、ゲート配線１１２と交差する、互いに平行なデータ配線１１４とを備えている。ここでゲート配線１１２とデータ配線１１４は電気的に絶縁されている。ゲート配線１１２とデータ配線１１４との交差部付近に、ＴＦＴ１０が備えられている。 As shown in FIG. 6, the liquid crystal display device 100 according to the present embodiment includes a plurality of gate lines 112 that are parallel to each other and data lines 114 that are parallel to each other and intersect the gate lines 112. Here, the gate wiring 112 and the data wiring 114 are electrically insulated. The TFT 10 is provided in the vicinity of the intersection between the gate wiring 112 and the data wiring 114.
　ＴＦＴ１０のゲート電極２２は、ゲート配線１１２に接続されており、ＴＦＴ１０のソース電極１６はデータ配線１１４に接続されている。また、ＴＦＴ１０のドレイン電極１８はゲート絶縁膜２０に設けられたコンタクトホール１１６を介して（コンタクトホール１１６に導電体が埋め込まれて）画素下部電極１０４に接続されている。画素下部電極１０４は、接地された対向上部電極１０６とともにキャパシタ１１８を構成している。 The gate electrode 22 of the TFT 10 is connected to the gate wiring 112, and the source electrode 16 of the TFT 10 is connected to the data wiring 114. The drain electrode 18 of the TFT 10 is connected to the pixel lower electrode 104 through a contact hole 116 provided in the gate insulating film 20 (a conductor is embedded in the contact hole 116). The pixel lower electrode 104 forms a capacitor 118 together with the grounded counter upper electrode 106.
＜有機ＥＬ表示装置＞
　本開示の一実施形態に係るアクティブマトリックス方式の有機ＥＬ表示装置について、図７に一部分の概略断面図を示し、図８に電気配線の概略構成図を示す。 <Organic EL display device>
FIG. 7 is a schematic sectional view of a part of an active matrix organic EL display device according to an embodiment of the present disclosure, and FIG. 8 is a schematic configuration diagram of electrical wiring.
　本実施形態のアクティブマトリックス方式の有機ＥＬ表示装置２００は、図１に示したトップゲート構造のＴＦＴ１０が、パッシベーション層２０２を備えた基板１２上に、駆動用ＴＦＴ１０ａおよびスイッチング用ＴＦＴ１０ｂとして備えられ、ＴＦＴ１０ａ，１０ｂ上に下部電極２０８および上部電極２１０に挟まれた有機発光層２１２からなる有機ＥＬ発光素子２１４を備え、上面もパッシベーション層２１６により保護された構成となっている。 The active matrix organic EL display device 200 of the present embodiment includes the TFT 10 having the top gate structure shown in FIG. 1 as a driving TFT 10a and a switching TFT 10b on a substrate 12 having a passivation layer 202. , 10b is provided with an organic EL light emitting element 214 composed of an organic light emitting layer 212 sandwiched between a lower electrode 208 and an upper electrode 210, and the upper surface is also protected by a passivation layer 216.
　また、図８に示すように、本実施形態の有機ＥＬ表示装置２００は、互いに平行な複数のゲート配線２２０と、ゲート配線２２０と交差する、互いに平行なデータ配線２２２および駆動配線２２４とを備えている。ここで、ゲート配線２２０とデータ配線２２２、駆動配線２２４とは電気的に絶縁されている。スイッチング用ＴＦＴ１０ｂのゲート電極２２は、ゲート配線２２０に接続されており、スイッチング用ＴＦＴ１０ｂのソース電極１６はデータ配線２２２に接続されている。また、スイッチング用ＴＦＴ１０ｂのドレイン電極１８は駆動用ＴＦＴ１０ａのゲート電極２２に接続されるとともに、キャパシタ２２６を用いることで駆動用ＴＦＴ１０ａをオン状態に保つ。駆動用ＴＦＴ１０ａのソース電極１６は駆動配線２２４に接続され、ドレイン電極１８は有機ＥＬ発光素子２１４に接続される。 As shown in FIG. 8, the organic EL display device 200 of this embodiment includes a plurality of gate wirings 220 that are parallel to each other, and data wirings 222 and driving wirings 224 that are parallel to each other and intersect the gate wirings 220. ing. Here, the gate wiring 220, the data wiring 222, and the drive wiring 224 are electrically insulated. The gate electrode 22 of the switching TFT 10 b is connected to the gate wiring 220, and the source electrode 16 of the switching TFT 10 b is connected to the data wiring 222. The drain electrode 18 of the switching TFT 10b is connected to the gate electrode 22 of the driving TFT 10a, and the driving TFT 10a is kept on by using the capacitor 226. The source electrode 16 of the driving TFT 10 a is connected to the driving wiring 224, and the drain electrode 18 is connected to the organic EL light emitting element 214.
　なお、図７に示した有機ＥＬ表示装置において、上部電極２１０を透明電極としてトップエミッション型としてもよいし、下部電極２０８およびＴＦＴの各電極を透明電極とすることによりボトムエミッション型としてもよい。 In the organic EL display device shown in FIG. 7, the upper electrode 210 may be a top emission type using a transparent electrode, or the bottom electrode 208 and each TFT electrode may be a transparent electrode.
＜Ｘ線センサ＞
　本開示の一実施形態であるＸ線センサについて、図９に一部分の概略断面図を示し、図１０に電気配線の概略構成図を示す。 <X-ray sensor>
As for an X-ray sensor according to an embodiment of the present disclosure, FIG. 9 shows a schematic sectional view of a part, and FIG. 10 shows a schematic configuration diagram of electric wiring.
　本実施形態のＸ線センサ３００は基板１２上に形成されたＴＦＴ１０およびキャパシタ３１０と、キャパシタ３１０上に形成された電荷収集用電極３０２と、Ｘ線変換層３０４と、上部電極３０６とを備えて構成される。ＴＦＴ１０上にはパッシベーション膜３０８が設けられている。 The X-ray sensor 300 of this embodiment includes the TFT 10 and the capacitor 310 formed on the substrate 12, the charge collection electrode 302 formed on the capacitor 310, the X-ray conversion layer 304, and the upper electrode 306. Composed. A passivation film 308 is provided on the TFT 10.
　キャパシタ３１０は、キャパシタ用下部電極３１２とキャパシタ用上部電極３１４とで絶縁膜３１６を挟んだ構造となっている。キャパシタ用上部電極３１４は絶縁膜３１６に設けられたコンタクトホール３１８を介し、ＴＦＴ１０のソース電極１６およびドレイン電極１８のいずれか一方（図９においてはドレイン電極１８）と接続されている。 The capacitor 310 has a structure in which an insulating film 316 is sandwiched between a capacitor lower electrode 312 and a capacitor upper electrode 314. The capacitor upper electrode 314 is connected to one of the source electrode 16 and the drain electrode 18 (the drain electrode 18 in FIG. 9) of the TFT 10 through a contact hole 318 provided in the insulating film 316.
　電荷収集用電極３０２は、キャパシタ３１０におけるキャパシタ用上部電極３１４上に設けられており、キャパシタ用上部電極３１４に接している。
　Ｘ線変換層３０４はアモルファスセレンからなる層であり、ＴＦＴ１０およびキャパシタ３１０を覆って設けられている。
　上部電極３０６はＸ線変換層３０４上に設けられており、Ｘ線変換層３０４に接している。 The charge collection electrode 302 is provided on the capacitor upper electrode 314 in the capacitor 310 and is in contact with the capacitor upper electrode 314.
The X-ray conversion layer 304 is a layer made of amorphous selenium, and is provided so as to cover the TFT 10 and the capacitor 310.
The upper electrode 306 is provided on the X-ray conversion layer 304 and is in contact with the X-ray conversion layer 304.
　図１０に示すように、本実施形態のＸ線センサ３００は、互いに平行な複数のゲート配線３２０と、ゲート配線３２０と交差する、互いに平行な複数のデータ配線３２２とを備えている。ここでゲート配線３２０とデータ配線３２２は電気的に絶縁されている。ゲート配線３２０とデータ配線３２２との交差部付近に、ＴＦＴ１０が備えられている。 As shown in FIG. 10, the X-ray sensor 300 of this embodiment includes a plurality of gate wirings 320 that are parallel to each other and a plurality of data wirings 322 that intersect with the gate wirings 320 and are parallel to each other. Here, the gate wiring 320 and the data wiring 322 are electrically insulated. The TFT 10 is provided in the vicinity of the intersection between the gate wiring 320 and the data wiring 322.
　ＴＦＴ１０のゲート電極２２は、ゲート配線３２０に接続されており、ＴＦＴ１０のソース電極１６はデータ配線３２２に接続されている。また、ＴＦＴ１０のドレイン電極１８は電荷収集用電極３０２に電気的に接続されており、さらに電荷収集用電極３０２は、キャパシタ３１０に接続されている。 The gate electrode 22 of the TFT 10 is connected to the gate wiring 320, and the source electrode 16 of the TFT 10 is connected to the data wiring 322. The drain electrode 18 of the TFT 10 is electrically connected to the charge collection electrode 302, and the charge collection electrode 302 is connected to the capacitor 310.
　本実施形態のＸ線センサ３００において、Ｘ線は図９中、上部電極３０６側から入射してＸ線変換層３０４で電子－正孔対を生成する。Ｘ線変換層３０４に上部電極３０６によって高電界を印加しておくことにより、生成した電荷はキャパシタ３１０に蓄積され、ＴＦＴ１０を順次走査することによって読み出される。 In the X-ray sensor 300 of this embodiment, X-rays enter from the upper electrode 306 side in FIG. 9 and generate electron-hole pairs in the X-ray conversion layer 304. By applying a high electric field to the X-ray conversion layer 304 by the upper electrode 306, the generated charge is accumulated in the capacitor 310 and read out by sequentially scanning the TFT 10.
　なお、上記実施形態の液晶表示装置１００、有機ＥＬ表示装置２００、及びＸ線センサ３００においては、図１に示すトップゲート構造のＴＦＴを備えているが、図１に示すトップゲート構造のＴＦＴに限定されず、図２～図４に示す構造のＴＦＴであってもよい。 Note that the liquid crystal display device 100, the organic EL display device 200, and the X-ray sensor 300 according to the above embodiment include the top gate structure TFT shown in FIG. 1, but the top gate structure TFT shown in FIG. There is no limitation, and the TFT having the structure shown in FIGS. 2 to 4 may be used.
　以下に実施例を説明するが、本発明は以下の実施例により何ら限定されない。 Examples will be described below, but the present invention is not limited to the following examples.
＜Ｉｎを含む金属酸化物膜を形成した実施例及び比較例＞
　本発明の効果をより簡便に説明するために、以下のようにＴＦＴ素子を作製し電気特性を評価した。
　硝酸インジウム（Ｉｎ（ＮＯ３）３・ｘＨ２Ｏ、純度：４Ｎ，高純度化学研究所社製）を２－メトキシエタノール（試薬特級、和光純薬工業社製）中に溶解させ、０．１ｍｏｌ／Ｌの濃度の半導体層形成用硝酸インジウム溶液を作製した。 <Examples and comparative examples in which a metal oxide film containing In was formed>
In order to explain the effects of the present invention more simply, TFT elements were produced as follows and electrical characteristics were evaluated.
Indium nitrate (In (NO 3 ) 3 xH 2 O, purity: 4N, manufactured by Kojundo Chemical Laboratory Co., Ltd.) was dissolved in 2-methoxyethanol (special grade reagent, manufactured by Wako Pure Chemical Industries, Ltd.), 0.1 mol An indium nitrate solution for forming a semiconductor layer having a concentration of / L was prepared.
　基板として熱酸化膜付ｐ型シリコン基板を用い、シリコン基板がゲート電極となり、熱酸化膜をゲート絶縁膜として用いる簡易型のＴＦＴを作製した。１インチ四方の熱酸化膜付ｐ型シリコン基板上に、作製した硝酸インジウム溶液を１５００ｒｐｍの回転速度で３０秒間スピンコートした後、６０℃に加熱されたホットプレート上で１分間乾燥を行った。これにより、酸化物半導体前駆体膜（厚さ：１０ｎｍ）を形成した。 A simple TFT using a p-type silicon substrate with a thermal oxide film as a substrate, the silicon substrate serving as a gate electrode, and the thermal oxide film as a gate insulating film was fabricated. The prepared indium nitrate solution was spin-coated on a 1-inch square p-type silicon substrate with a thermal oxide film at a rotational speed of 1500 rpm for 30 seconds, and then dried on a hot plate heated to 60 ° C. for 1 minute. Thereby, an oxide semiconductor precursor film (thickness: 10 nm) was formed.
　次に、前駆体膜を加熱した状態で圧力を調整した雰囲気下で紫外線照射を行うことにより金属酸化物膜に転化させる。
　転化工程では、前述した図１１に示す概略構成を有する紫外線照射装置を用いた。真空排気用のポンプ４１４としてＴＭＰ（ターボメカニカルポンプ　ＶＡＲＩＡＮ社製）を備えており、チャンバ内圧力：大気～１×１０－４Ｐａ、サンプル基板温度：室温～６００℃、ＵＶ照射パワー（照度）：１～３０ｍＷ／ｃｍ２に設定することができる。サンプルステージ（支持台）４１２の高さ調整により照射パワーを変えることができる。 Next, the precursor film is converted into a metal oxide film by irradiating ultraviolet rays in an atmosphere in which the pressure is adjusted in a heated state.
In the conversion step, an ultraviolet irradiation apparatus having the schematic configuration shown in FIG. 11 was used. A TMP (turbo mechanical pump manufactured by VARIAN) is provided as a pump 414 for evacuation, chamber pressure: air to 1 × 10 −4 Pa, sample substrate temperature: room temperature to 600 ° C., UV irradiation power (illuminance): It can be set to 1 to 30 mW / cm 2 . The irradiation power can be changed by adjusting the height of the sample stage (support stage) 412.
　図１１に示す装置において、波長２５４ｎｍの紫外線照度を紫外線光量計（オーク製作所社製、ＵＶ－Ｍ１０、受光器ＵＶ－２５）を用いて測定し、１０ｍＷ／ｃｍ２になるようにステージ位置の調整を行い、酸化物半導体前駆体膜の転化を表１に示す条件で行った。 In the apparatus shown in FIG. 11, the ultraviolet illuminance at a wavelength of 254 nm is measured using an ultraviolet light meter (manufactured by Oak Manufacturing Co., Ltd., UV-M10, photoreceiver UV-25), and the stage position is adjusted to 10 mW / cm 2. The oxide semiconductor precursor film was converted under the conditions shown in Table 1.
　条件１は大気中で転化処理、条件２は大気から１×１０－４Ｐａまで真空排気し、真空排気停止後にＮ２ガスを導入して大気圧で転化処理、条件３～８は真空排気中で圧力調整バルブ４２０によりそれぞれ一定の真空度に調整した後、転化処理を行った。また、条件９は大気から０．８気圧（約０．０８１ＭＰａ）まで減圧しながら転化処理を行った。
　なお、いずれの条件でも転化工程における基板温度は１５０℃、ＵＶ処理時間は３０分にそれぞれ固定した。なお、紫外線照射処理時の基板温度はサーモラベルでモニターした。 Condition 1 is conversion in the atmosphere, Condition 2 is evacuated from the atmosphere to 1 × 10 −4 Pa, and after evacuation is stopped, N 2 gas is introduced and conversion is performed at atmospheric pressure. Conditions 3 to 8 are in evacuation Then, after the pressure was adjusted to a certain degree of vacuum by the pressure adjusting valve 420, the conversion treatment was performed. In condition 9, the conversion treatment was performed while reducing the pressure from the atmosphere to 0.8 atm (about 0.081 MPa).
Under any conditions, the substrate temperature in the conversion step was fixed at 150 ° C., and the UV treatment time was fixed at 30 minutes. The substrate temperature during the ultraviolet irradiation treatment was monitored with a thermo label.
　転化処理後に金属酸化物半導体膜上にソース・ドレイン電極をスパッタ成膜により形成した。ソース・ドレイン電極はメタルマスクを用いたパターン成膜にて作製し、Ｔｉを厚さ５０ｎｍに成膜した。ソース・ドレイン電極のサイズは各々１ｍｍ×１ｍｍとし、電極間距離は０．２ｍｍとした。
　ここで簡易型ＴＦＴ素子の作製が完了となる。 After the conversion treatment, source / drain electrodes were formed on the metal oxide semiconductor film by sputtering. The source / drain electrodes were formed by pattern deposition using a metal mask, and Ti was deposited to a thickness of 50 nm. The size of the source / drain electrodes was 1 mm × 1 mm, respectively, and the distance between the electrodes was 0.2 mm.
Here, the fabrication of the simple TFT element is completed.
　得られた簡易型ＴＦＴについて、半導体パラメータ・アナライザー４１５６Ｃ（アジレントテクノロジー社製）を用い、トランジスタ特性Ｖｇ－Ｉｄの測定を行った。 The resulting simplified type TFT, and using a semiconductor parameter analyzer 4156C (manufactured by Agilent Technologies), were measured transistor characteristics V g -I d.
　Ｖｇ－Ｉｄ特性の測定は、ドレイン電圧（Ｖｄ）を＋１Ｖに固定し、ゲート電圧（Ｖｇ）を－１５Ｖ～＋１５Ｖの範囲内で変化させ、各ゲート電圧におけるドレイン電流（Ｉｄ）を測定することにより行った。測定の雰囲気はドライエアー雰囲気で大気圧（事前に６０分間フロー）とし、測定時の水分の影響を排除し、５回繰り返し計測し、線形移動度（初期移動度）とＶｔｈシフト（ＴＦＴの立ち上がり電圧シフト）を求めた。 The measurement of the V g -I d characteristic is performed by fixing the drain voltage (V d ) to +1 V, changing the gate voltage (V g ) within a range of −15 V to +15 V, and drain current (I d ) at each gate voltage. It was performed by measuring. The measurement atmosphere is dry air and atmospheric pressure (flow for 60 minutes in advance), eliminating the influence of moisture during measurement, measuring 5 times repeatedly, linear mobility (initial mobility) and Vth shift (rising of TFT) Voltage shift).
　表１にＶｇ－Ｉｄ特性から求めた線形移動度、５回繰り返し計測後のＶｔｈシフト（ΔＶｔｈ）及び二次イオン質量分析（ＳＩＭＳ）から算出した、半導体膜中の水素量を示す。ＳＩＭＳは、Ｐｙｓｉｃａｌ　Ｅｌｅｃｔｒｏｎｉｃｓ社の「ＰＨＩ　ＡＤＥＰＴ１０１０」を用いて行った。 Linear mobility was determined from the V g -I d characteristics in Table 1, were calculated from the 5 times repeated Vth shift after measurement ([Delta] Vth) and secondary ion mass spectrometry (SIMS), a hydrogen amount in the semiconductor film. The SIMS was performed using “PHI ADEPT1010” manufactured by Physical Electronics.
Figure JPOXMLDOC01-appb-T000001
 
Figure JPOXMLDOC01-appb-T000001
 
　条件１、９ではＴＦＴとして動作しなかった。要因としては転化工程時の残存酸素にて半導体層の酸素欠損がターミネートされ、キャリアが消失し、半導体膜として機能しなかったと考えられる。
　条件２、３ではトランジスタ特性は確認できたが、ΔＶｔｈが２．０Ｖを超え、動作安定性に問題がある。条件２では初期移動度が一番大きいが、残留水素量も一番大きいため、水素が余剰キャリアとして動作し、動作安定性を悪くしていると考えられる。 Under conditions 1 and 9, it did not operate as a TFT. The cause is considered to be that oxygen deficiency in the semiconductor layer was terminated by residual oxygen in the conversion process, carriers disappeared, and the semiconductor film did not function.
Although the transistor characteristics were confirmed under conditions 2 and 3, ΔVth exceeded 2.0 V, and there was a problem in operation stability. In condition 2, the initial mobility is the largest, but the amount of residual hydrogen is also the largest. Therefore, it is considered that hydrogen operates as a surplus carrier and deteriorates the operational stability.
　条件４～８ではΔＶｔｈが２．０Ｖ未満となり、特に転化工程での圧力が１Ｐａ以下の条件６～８の場合には半導体膜の水素量が１．０×１０２２個／ｃｍ３以下に低下し、ΔＶｔｈ及び水素量が概ね同じであった。これらの結果から、半導体膜への転化には酸素等の影響を排除し、且つ半導体膜中の水素量は転化工程における圧力に依存し、膜中の水素量が少ないほどΔＶｔｈが小さく、動作安定性が向上すると考えられる。 Under conditions 4 to 8, ΔVth is less than 2.0 V, and particularly under conditions 6 to 8 where the pressure in the conversion process is 1 Pa or less, the amount of hydrogen in the semiconductor film decreases to 1.0 × 10 22 pieces / cm 3 or less. However, ΔVth and the amount of hydrogen were almost the same. From these results, the conversion to the semiconductor film eliminates the influence of oxygen and the like, and the amount of hydrogen in the semiconductor film depends on the pressure in the conversion process, and the smaller the amount of hydrogen in the film, the smaller ΔVth and the stable operation It is thought that the property improves.
＜ＩｎとＺｎを含む金属酸化物膜を形成した比較例及び実施例＞
　以下のような試料を作製し、評価を行った。
　硝酸インジウム（Ｉｎ（ＮＯ３）３・ｘＨ２Ｏ、純度：４Ｎ，高純度化学研究所社製）、硝酸亜鉛（Ｚｎ（ＮＯ３）２・６Ｈ２Ｏ、純度：３Ｎ，高純度化学研究所社製）を２－メトキシエタノール（試薬特級、和光純薬工業社製）中に溶解させ、硝酸インジウム濃度０．０９５ｍｏｌ／Ｌ、硝酸亜鉛濃度０．００５ｍｏｌ／Ｌの濃度の硝酸インジウム・硝酸亜鉛混合溶液を作製した。
　作製した硝酸インジウム・硝酸亜鉛混合溶液を用いて熱酸化膜付ｐ型シリコン基板上に酸化物半導体前駆体膜を形成し、条件１又は条件４と同様にして酸化物半導体膜に転化させた後、ソース・ドレイン電極を形成し、評価を行った。
　条件１と同様にして転化工程を行なった場合は、ＴＦＴとして動作しなかった。
　条件４と同様にして転化工程を行なった場合のＴＦＴは、初期移動度は５．４ｃｍ２／Ｖｓ、ΔＶｔｈは１．７Ｖであり、膜中水素量は１．７７×１０２２個／ｃｍ３であった。 <Comparative Examples and Examples Forming Metal Oxide Films Containing In and Zn>
The following samples were prepared and evaluated.
Indium nitrate (In (NO 3) 3 · xH 2 O, purity: 4N, manufactured by Kojundo Chemical Laboratory Co., Ltd.), zinc nitrate (Zn (NO 3) 2 · 6H 2 O, purity: 3N, Kojundo Chemical Laboratory Is dissolved in 2-methoxyethanol (special grade reagent, manufactured by Wako Pure Chemical Industries, Ltd.) and mixed with indium nitrate and zinc nitrate with indium nitrate concentration of 0.095 mol / L and zinc nitrate concentration of 0.005 mol / L. A solution was made.
An oxide semiconductor precursor film is formed on a p-type silicon substrate with a thermal oxide film using the prepared indium nitrate / zinc nitrate mixed solution, and converted into an oxide semiconductor film in the same manner as in Condition 1 or Condition 4. The source / drain electrodes were formed and evaluated.
When the conversion process was performed in the same manner as condition 1, it did not operate as a TFT.
When the conversion process is performed in the same manner as in condition 4, the initial mobility of the TFT is 5.4 cm 2 / Vs, ΔVth is 1.7 V, and the amount of hydrogen in the film is 1.77 × 10 22 / cm 3. Met.
　２０１４年１２月５日に出願された日本特許出願２０１４－２４７０７４号の開示はその全体が参照により本明細書に取り込まれる。
　本明細書に記載された全ての文献、特許、特許出願、および技術規格は、個々の文献、特許、特許出願、および技術規格が参照により取り込まれることが具体的かつ個々に記された場合と同程度に、本明細書中に参照により取り込まれる。 The disclosure of Japanese Patent Application No. 2014-247074 filed on December 5, 2014 is incorporated herein by reference in its entirety.
All documents, patents, patent applications, and technical standards mentioned in this specification are specifically and individually described as individual documents, patents, patent applications, and technical standards are incorporated by reference. To the same extent, it is incorporated herein by reference.

Claims (18)

  1. 　インジウム及び溶媒を含む溶液を基板上に塗布して金属酸化物膜の前駆体膜を形成する前駆体膜形成工程と、
    　加熱した状態の前記前駆体膜に対して１０Ｐａ以下の雰囲気下で紫外線照射を行うことにより前記前駆体膜を金属酸化物膜に転化させる転化工程と、
    　を含む金属酸化物膜の製造方法。     A precursor film forming step of forming a precursor film of a metal oxide film by applying a solution containing indium and a solvent on a substrate;
    A conversion step of converting the precursor film into a metal oxide film by irradiating the precursor film in a heated state with an ultraviolet ray under an atmosphere of 10 Pa or less;
    The manufacturing method of the metal oxide film containing this.
  2. 　前記紫外線照射を１Ｐａ以下の雰囲気下で行う請求項１に記載の金属酸化物膜の製造方法。 The method for producing a metal oxide film according to claim 1, wherein the ultraviolet irradiation is performed in an atmosphere of 1 Pa or less.
  3. 　前記溶液に含まれるインジウムの含有量が、前記溶液に含まれる金属成分の総量に対して５０ａｔｏｍ％以上である請求項１又は請求項２に記載の金属酸化物膜の製造方法。 The method for producing a metal oxide film according to claim 1 or 2, wherein the content of indium contained in the solution is 50 atom% or more based on the total amount of metal components contained in the solution.
  4. 　前記紫外線照射を行う際の前記基板の温度が、１５０℃以下である請求項１～請求項３のいずれか１項に記載の金属酸化物膜の製造方法。 The method for producing a metal oxide film according to any one of claims 1 to 3, wherein a temperature of the substrate when the ultraviolet irradiation is performed is 150 ° C or lower.
  5. 　前記溶液が、硝酸インジウムの溶液である請求項１～請求項４のいずれか１項に記載の金属酸化物膜の製造方法。 The method for producing a metal oxide film according to any one of claims 1 to 4, wherein the solution is a solution of indium nitrate.
  6. 　前記硝酸インジウムの溶液が、前記溶媒としてメタノール及びメトキシエタノールの少なくとも一方を含む請求項５に記載の金属酸化物膜の製造方法。 6. The method for producing a metal oxide film according to claim 5, wherein the solution of indium nitrate contains at least one of methanol and methoxyethanol as the solvent.
  7. 　前記溶液が、亜鉛、錫、ガリウム及びアルミニウムからなる群より選ばれる少なくとも１種をさらに含有する請求項１～請求項６のいずれか１項に記載の金属酸化物膜の製造方法。 7. The method for producing a metal oxide film according to claim 1, wherein the solution further contains at least one selected from the group consisting of zinc, tin, gallium, and aluminum.
  8. 　前記溶液中の金属成分の濃度が、０．０１ｍｏｌ／Ｌ以上０．５ｍｏｌ／Ｌ以下である請求項１～請求項７のいずれか１項に記載の金属酸化物膜の製造方法。 The method for producing a metal oxide film according to any one of claims 1 to 7, wherein the concentration of the metal component in the solution is 0.01 mol / L or more and 0.5 mol / L or less.
  9. 　前記紫外線照射は、前記前駆体膜に対し、波長３００ｎｍ以下の光を含む紫外線を１０ｍＷ／ｃｍ２以上の照度で照射する請求項１～請求項８のいずれか１項に記載の金属酸化物膜の製造方法。 The metal oxide film according to any one of claims 1 to 8, wherein in the ultraviolet irradiation, the precursor film is irradiated with ultraviolet rays including light having a wavelength of 300 nm or less at an illuminance of 10 mW / cm 2 or more. Manufacturing method.
  10. 　前記前駆体膜形成工程において、前記溶液を、インクジェット法、ディスペンサー法、凸版印刷法、及び凹版印刷法から選択される少なくとも一種の塗布法により前記基板上に塗布する請求項１～請求項９のいずれか１項に記載の金属酸化物膜の製造方法。 In the precursor film forming step, the solution is applied onto the substrate by at least one application method selected from an inkjet method, a dispenser method, a relief printing method, and an intaglio printing method. The manufacturing method of the metal oxide film of any one of Claims 1.
  11. 　請求項１～請求項１０のいずれか１項に記載の金属酸化物膜の製造方法により製造された金属酸化物膜。 A metal oxide film produced by the method for producing a metal oxide film according to any one of claims 1 to 10.
  12. 　インジウムを含み、水素含有量が１．０×１０２２個／ｃｍ３以下である金属酸化物膜。 A metal oxide film containing indium and having a hydrogen content of 1.0 × 10 22 pieces / cm 3 or less.
  13. 　前記金属酸化物膜に含まれるインジウムの含有量が、前記金属酸化物膜に含まれる金属成分の総量に対して５０ａｔｏｍ％以上である請求項１１又は請求項１２に記載の金属酸化物膜。 The metal oxide film according to claim 11 or 12, wherein a content of indium contained in the metal oxide film is 50 atom% or more based on a total amount of metal components contained in the metal oxide film.
  14. 　請求項１～請求項１０のいずれか１項に記載の金属酸化物膜の製造方法により金属酸化物膜を形成する工程を含む薄膜トランジスタの製造方法。 A method for producing a thin film transistor, comprising a step of forming a metal oxide film by the method for producing a metal oxide film according to any one of claims 1 to 10.
  15. 　請求項１１～請求項１３のいずれか１項に記載の金属酸化物膜を備えた薄膜トランジスタ。 A thin film transistor comprising the metal oxide film according to any one of claims 11 to 13.
  16. 　請求項１５に記載の薄膜トランジスタを有する電子デバイス。 An electronic device having the thin film transistor according to claim 15.
  17. 　減圧室と、
    　前記減圧室内で基板を支持し、且つ、加熱する支持台と、
    　前記減圧室内を１０Ｐａ以下に減圧する真空ポンプと、
    　前記支持台に支持された前記基板に対して紫外線を照射する光源と、
    　を備えた紫外線照射装置。     A decompression chamber;
    A support base for supporting and heating the substrate in the decompression chamber;
    A vacuum pump for reducing the pressure in the vacuum chamber to 10 Pa or less;
    A light source for irradiating the substrate supported by the support base with ultraviolet rays;
    Ultraviolet irradiation device with
  18. 　前記光源と前記支持台との位置関係を調整する位置調整手段を備えた請求項１７に記載の紫外線照射装置。 The ultraviolet irradiation device according to claim 17, further comprising a position adjusting unit that adjusts a positional relationship between the light source and the support base.
PCT/JP2015/084178 2014-12-05 2015-12-04 Method for manufacturing metal oxide film, metal oxide film, thin-film transistor, method for manufacturing thin-film transistor, electronic device, and ultraviolet irradiation device WO2016088882A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
KR1020177013093A KR101954551B1 (en) 2014-12-05 2015-12-04 Method for manufacturing metal oxide film, metal oxide film, thin-film transistor, method for manufacturing thin-film transistor, electronic device, and ultraviolet irradiation device
JP2016562697A JP6271760B2 (en) 2014-12-05 2015-12-04 Method for producing metal oxide film and method for producing thin film transistor

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2014-247074 2014-12-05
JP2014247074 2014-12-05

Publications (1)

Publication Number Publication Date
WO2016088882A1 true WO2016088882A1 (en) 2016-06-09

Family

ID=56091817

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2015/084178 WO2016088882A1 (en) 2014-12-05 2015-12-04 Method for manufacturing metal oxide film, metal oxide film, thin-film transistor, method for manufacturing thin-film transistor, electronic device, and ultraviolet irradiation device

Country Status (4)

Country Link
JP (1) JP6271760B2 (en)
KR (1) KR101954551B1 (en)
TW (1) TWI689622B (en)
WO (1) WO2016088882A1 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10861731B2 (en) * 2017-01-19 2020-12-08 Axcelis Technologies, Inc. Radiant heating presoak
JP6881120B2 (en) * 2017-07-19 2021-06-02 東京エレクトロン株式会社 Substrate processing equipment, substrate processing method and storage medium

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001106567A (en) * 1999-10-07 2001-04-17 Hitachi Cable Ltd Substrate for forming transparent electrically conductive film and formation method of the same conductive film
JP2005169267A (en) * 2003-12-11 2005-06-30 Dainippon Printing Co Ltd Film forming apparatus and film forming method
JP2005243249A (en) * 2004-02-24 2005-09-08 Ulvac Japan Ltd Liquid dispersion for forming transparent conductive membrane, method for forming the transparent conductive membrane, and transparent electrodes
JP2009018224A (en) * 2007-07-10 2009-01-29 Tokyo Ohka Kogyo Co Ltd Film forming method and film forming device
JP2011142311A (en) * 2009-12-11 2011-07-21 Semiconductor Energy Lab Co Ltd Semiconductor device and method of manufacturing the same
JP2014207431A (en) * 2013-03-19 2014-10-30 富士フイルム株式会社 Metal oxide film, manufacturing method thereof, thin-film transistor, display device, image sensor and x-ray sensor

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10644163B2 (en) * 2008-08-27 2020-05-05 Idemitsu Kosan Co., Ltd. Semiconductor film comprising an oxide containing in atoms, Sn atoms and Zn atoms

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001106567A (en) * 1999-10-07 2001-04-17 Hitachi Cable Ltd Substrate for forming transparent electrically conductive film and formation method of the same conductive film
JP2005169267A (en) * 2003-12-11 2005-06-30 Dainippon Printing Co Ltd Film forming apparatus and film forming method
JP2005243249A (en) * 2004-02-24 2005-09-08 Ulvac Japan Ltd Liquid dispersion for forming transparent conductive membrane, method for forming the transparent conductive membrane, and transparent electrodes
JP2009018224A (en) * 2007-07-10 2009-01-29 Tokyo Ohka Kogyo Co Ltd Film forming method and film forming device
JP2011142311A (en) * 2009-12-11 2011-07-21 Semiconductor Energy Lab Co Ltd Semiconductor device and method of manufacturing the same
JP2014207431A (en) * 2013-03-19 2014-10-30 富士フイルム株式会社 Metal oxide film, manufacturing method thereof, thin-film transistor, display device, image sensor and x-ray sensor

Also Published As

Publication number Publication date
KR20170070179A (en) 2017-06-21
TW201627529A (en) 2016-08-01
JPWO2016088882A1 (en) 2017-09-07
TWI689622B (en) 2020-04-01
KR101954551B1 (en) 2019-03-05
JP6271760B2 (en) 2018-01-31

Similar Documents

Publication Publication Date Title
JP6180908B2 (en) Metal oxide semiconductor film, thin film transistor, display device, image sensor and X-ray sensor
WO2014148206A1 (en) Metal oxide film, method for manufacturing same, thin film transistor, display apparatus, image sensor, and x-ray sensor
JP6181306B2 (en) Method for producing metal oxide film
US9779938B2 (en) Metal oxide thin film, method of producing same, and coating solution for forming metal oxide thin film used in said method
JP6096102B2 (en) Method for producing metal oxide semiconductor film
JP6271760B2 (en) Method for producing metal oxide film and method for producing thin film transistor
JP6061831B2 (en) Method for producing metal oxide film and method for producing thin film transistor
JP6177711B2 (en) Metal oxide film manufacturing method, metal oxide film, thin film transistor, and electronic device
JP6195986B2 (en) Method for manufacturing metal oxide semiconductor film and method for manufacturing thin film transistor
JP6257799B2 (en) Metal oxide semiconductor film, thin film transistor, and electronic device
JP6086854B2 (en) Metal oxide film manufacturing method, metal oxide film, thin film transistor, display device, image sensor, and X-ray sensor

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 15866178

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2016562697

Country of ref document: JP

Kind code of ref document: A

ENP Entry into the national phase

Ref document number: 20177013093

Country of ref document: KR

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 15866178

Country of ref document: EP

Kind code of ref document: A1