TWI689622B - Method for manufacturing metal oxide film, metal oxide film, thin film transistor, thin film transistor manufacturing method, electronic component and ultraviolet irradiation device - Google Patents

Abstract

A method for manufacturing a metal oxide film and its application and an ultraviolet irradiation device, the method for manufacturing a metal oxide film includes the following steps: a precursor film forming step, a solution containing indium and a solvent is applied on a substrate to form a metal A precursor film of an oxide film; a conversion step of irradiating the heated precursor film with ultraviolet rays under an environment of 10 Pa or less to thereby convert the precursor film into a metal oxide film; the ultraviolet irradiation device includes: A pressure chamber; a support table that supports the substrate in the decompression chamber and heats it; a vacuum pump that decompresses the pressure reduction chamber to 10 Pa or less; and a light source that irradiates the substrate supported by the support table with ultraviolet rays.

Description

Method for manufacturing metal oxide film, metal oxide film, thin film transistor, thin film transistor manufacturing method, electronic component and ultraviolet irradiation device

The invention relates to a method for manufacturing a metal oxide film, a metal oxide film, a thin film transistor, a thin film transistor manufacturing method, an electronic component and an ultraviolet irradiation device.

The metal oxide semiconductor film has been put into practical use in the manufacturing by the vacuum film forming method, and it has attracted much attention at present. On the other hand, in order to easily form a metal oxide semiconductor film having high semiconductor characteristics at low temperature and atmospheric pressure, research and development on the production of a metal oxide semiconductor film using a liquid-phase process are being conducted. For example, in Nature, Volume 489 (2012), page 128, it is reported that a thin film transistor having high transmission characteristics at a low temperature of 150°C or less is produced by applying a solution to a substrate and irradiating ultraviolet rays.

On the other hand, International Publication No. 2009-81862 discloses a method of forming a metal oxide semiconductor precursor film using a solution of a metal salt such as an inexpensive nitrate or acetate, and conducting a semiconductor using heat treatment or microwave irradiation The conversion process forms a metal oxide film. Furthermore, International Publication No. 2009-11224 discloses a method of forming a precursor film of a metal oxide semiconductor using a solution of nitrate, acetate, etc., and manufacturing a metal oxide by irradiating light in the presence of oxygen Semiconductor film.

[Problems to be solved by the invention]

The method disclosed in Nature, Volume 489 (2012), page 128 describes the preparation of metal methoxyethanol by heating and stirring nitrate or acetate in a solvent at 75°C for 12 hours The time and cost of salt and solution production increase. Moreover, since the alkoxide is produced, hydrolysis is likely to occur in the atmosphere, and there is a problem in stability. On the other hand, in 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 transmission characteristics at a low temperature of less than 200°C.

An object of the present invention is to provide a method for producing a metal oxide film which can easily produce a metal oxide film with a reduced residual component by a coating method and a metal oxide film with a reduced residual component The undesired residual components may impair the expected function of the metal oxide film. Furthermore, an object of the present invention is to provide a thin film transistor with high linear mobility and excellent operation stability, a method for manufacturing the thin film transistor, and an electronic component. Furthermore, an object of the present invention is to provide an ultraviolet irradiation device that can easily perform conversion from a precursor film to a metal oxide film. [Means to solve the problem]

In order to achieve the above object, the following invention is provided. <1> A method for manufacturing a metal oxide film, including the following steps: a precursor film forming step, a solution containing indium and a solvent is applied on a substrate to form a metal oxide film precursor film; a conversion step, in The precursor film in the heated state is irradiated with ultraviolet rays in an environment of 10 Pa or less, thereby converting the precursor film into a metal oxide film. <2> The method for producing a metal oxide film according to <1>, wherein ultraviolet irradiation is performed in an environment 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 relative to the total amount of metal components contained in the solution %the above. <4> The method for producing a metal oxide film according to any one of <1> to <3>, wherein the temperature of the substrate during 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 method for producing a metal oxide film according to any one of <1> to <8>, wherein the ultraviolet irradiation irradiates the precursor film with an illuminance of 10 mW/cm ² or more, including a wavelength of 300 nm or less Ultraviolet light. <10> The method for producing a metal oxide film according to any one of <1> to <9>, wherein in the precursor film forming step, a method selected from the group consisting of an inkjet method, a dispenser method, and relief printing At least one of the coating method and the gravure printing method applies the solution to the substrate.

<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 relative to the total amount of metal components contained in the metal oxide film It is more than 50 atom%.

<14> A method of manufacturing a thin-film transistor, including the step of forming a metal oxide film by the method of manufacturing a metal oxide film according to any one of <1> to <10>.

<15> A thin film transistor including the metal oxide film according to any one of <11> to <13>. <16> An electronic component comprising the thin film transistor described in <15>.

<17> An ultraviolet irradiation device, including: a decompression chamber; a supporting table that supports the substrate in the decompression chamber and heating; a vacuum pump that decompresses the decompression chamber to 10 Pa or less; a light source, the substrate supported by the supporting table Irradiation of ultraviolet rays. <18> The ultraviolet irradiation device according to <17>, which includes a position adjustment unit that adjusts the positional relationship between the light source and the support table. [Effect of invention]

The present invention provides a method for manufacturing a metal oxide film that can easily produce a metal oxide film with a reduced residual component by a coating method and a metal oxide film with a reduced residual component, The unnecessary residual components may impair the expected function of the metal oxide film. Furthermore, the present invention provides a thin film transistor with high linear mobility and excellent operation stability, a method for manufacturing the thin film transistor, and an electronic device. Furthermore, the present invention provides an ultraviolet irradiation device that can easily perform conversion from a precursor film to a metal oxide film.

Hereinafter, the present invention will be described in detail while referring to the accompanying drawings. In addition, in the drawings, members (constituting elements) having the same or corresponding functions are denoted by the same symbols, and descriptions are appropriately omitted. In addition, in this specification, when the range of numerical values is indicated by the symbol of "-", the numerical value described is included as the lower limit value and the upper limit value.

[Method of Manufacturing Metal Oxide Film] The method of manufacturing a metal oxide film of the present disclosure includes the steps of forming a precursor film, applying a solution containing indium and a solvent on a substrate to form a precursor of a metal oxide film Film; conversion step, the precursor film in the heated state is irradiated with ultraviolet light under an environment of 10 Pa or less, thereby converting the precursor film into a metal oxide film.

In the case of 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 not necessary, but it is easy to remain and may damage the function of the metal oxide film. The required components and the residual components have a large influence on the electrical characteristics of the film (such as resistivity and electrical stability). The inventors of the present invention conducted repeated investigations and found that ultraviolet light (ultraviolet, UV) irradiation was performed in a near-vacuum environment while heating the precursor film of a metal oxide film formed by applying a solution containing indium. In this way, the hydrogen content in the metal oxide film can be reduced to a large extent, thereby obtaining a metal oxide film having good electrical characteristics. The reason is unclear, but the reason is considered to be that if the precursor film is irradiated with UV while being heated under a high degree of reduced pressure, unnecessary components in the film are easily decomposed and escape from the film.

<Precursor film forming step> In the precursor film forming step, a solution containing indium and a solvent (hereinafter sometimes referred to as "metal oxide precursor solution") is applied on the substrate to form a precursor of the metal oxide film Object film (hereinafter sometimes referred to as "metal oxide precursor film").

(Solution) In the present disclosure, a solution for forming a precursor film of a metal oxide film (metal oxide precursor solution) 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 can be obtained by weighing a solute such as a metal salt as a raw material so that the solution becomes a desired concentration, and stirring and dissolving it in a solvent. The time for stirring is not particularly limited if it can sufficiently dissolve the solute.

The indium content in the metal oxide precursor solution is preferably 50 atom% or more relative to 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 is indium can be obtained, and a metal oxide with high electron transfer characteristics can be obtained membrane. Here, metal components (metal elements) other than indium that can be contained in the metal oxide film also depend on the application, and examples include Ga, Zn, Mg, Al, Sn, Sb, Cd, and Ge.

As the compound (raw material) included in the metal oxide precursor solution as a source of the metal component, a metal atom-containing compound such as a metal salt, a metal halide, and an organometallic compound can be used. The metal salt includes nitrate, sulfate, phosphate, carbonate, acetate, oxalate, etc., the metal halide includes chloride, iodide, bromide, etc., and the organic metal compound includes metal alkoxide, organic acid. Salt, metal β-diketonate, etc.

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 the metal oxide precursor solution in which indium nitrate is dissolved, in the conversion step, indium nitrate is efficiently decomposed by ultraviolet light, and can be easily converted into an oxide film containing indium. In addition, indium nitrate may also be a hydrate.

It is preferable that the metal oxide precursor solution 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 the metal elements other than indium in an appropriate amount, the electrical stability of the obtained metal oxide film is improved. For example, by appropriately containing the metal elements other than indium in the metal oxide semiconductor film, the critical voltage can be controlled to a desired value. Examples of metal oxides (oxide semiconductors or oxide conductors) containing the metal elements other than indium and indium include In-Ga-Zn-O (IGZO), In-Zn-O (IZO), and In-Ga- O (IGO), In-Sn-O (ITO), In-Sn-Zn-O (ITZO), etc.

The solvent used in the metal oxide precursor solution containing indium nitrate is not particularly limited if it is a solvent that dissolves the metal atom-containing compound used, and examples include water and alcohol solvents (methanol, ethanol, propanol, ethylene glycol) Alcohols, etc.), amide solvents (N,N-dimethylformamide, etc.), ketone solvents (acetone, N-methylpyrrolidone, cyclobutane, N,N-dimethylimidazolidinone, etc.) , Ether solvents (tetrahydrofuran, methoxyethanol, etc.), nitrile solvents (acetonitrile, etc.), other solvents containing heteroatoms other than those mentioned above, etc. These solvents may be used alone or in combination of two or more. In particular, from the viewpoint of solubility and coatability, at least one of methanol and methoxyethanol can be suitably used.

Moreover, the concentration of the metal component in the metal oxide precursor solution (in the case of multiple metals is the sum of the molar fractions of each metal) can be arbitrarily selected according to the viscosity of the solution and the target film thickness, but it is selected from the metal From the viewpoint of the flatness and productivity of the oxide film, it is preferably 0.01 mol/L or more and 1.0 mol/L or less, and more preferably 0.01 mol/L or more and 0.5 mol/L or less.

(Substrate) In the present disclosure, the shape, structure, size, etc. 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.

The material constituting the substrate is not particularly limited, and substrates including inorganic materials such as glass, Yttria-Stabilized Zirconia (YSZ), resins, and resin composite materials can be used. Among them, a resin substrate or a substrate containing a resin composite material (resin composite substrate) is preferable from the viewpoint of light weight and flexibility.

Specific examples include polybutylene terephthalate, polyethylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polystyrene, polycarbonate, and polystyrene , Polyether ash, polyarylate, diethylene glycol carbonate, allyl alcohol ester, polyamide, polyimide, polyimide amide imide, polyether amide imide, poly indene, poly benzene Fluororesins such as sulfides, polycycloolefins, norbornene resins, polychlorotrifluoroethylene, liquid crystal polymers, acrylic resins, epoxy resins, silicone resins, ionic polymer resins, cyanate resins, crosslinked Fumar Synthetic resin substrates such as acid diesters, cyclic polyolefins, aromatic ethers, maleimide·olefins, cellulose, and episulfide compounds.

In addition, examples of the inorganic material contained in the composite material of the inorganic material and the resin include inorganic particles such as silicon oxide particles, metal nanoparticles, inorganic oxide nanoparticles, and inorganic nitride nanoparticles, carbon fibers, and carbon nanoparticles Carbon materials such as tubes, glass flakes, glass fibers, glass beads and other glass materials.

Moreover, a composite plastic material of resin and clay mineral, a composite plastic material of resin and particles having a mica-derived crystal structure, a laminated plastic material having at least one bonding interface between the resin and thin glass, by using an inorganic layer and A composite material having barrier properties, etc., in which the organic layers are alternately laminated to have at least one bonding interface.

Furthermore, it is also possible to use a stainless steel substrate or a metal multilayer substrate laminated with a different metal from stainless steel, an aluminum substrate, or an aluminum oxide film with an oxide film to improve the insulation of the surface by performing an oxidation treatment (eg, anodizing treatment) on the surface Substrates, silicon substrates with oxide films, etc.

Furthermore, the resin substrate or the resin composite material substrate is preferably excellent in heat resistance, dimensional stability, solvent resistance, electrical insulation, processability, low air permeability, and low moisture absorption. The resin substrate or the resin composite material substrate may include a gas barrier layer for preventing the transmission of moisture, oxygen, etc., and an undercoat layer for improving the flatness of the substrate or the adhesion with the lower electrode.

The thickness of the substrate used in the present disclosure is not particularly limited, and it is preferably 50 μm or more and 500 μm or less. If the thickness of the substrate is 50 μm or more, the flatness of the substrate itself is further improved. Moreover, if the thickness of the substrate is 500 μm or less, the flexibility of the substrate itself is further improved, and it becomes easier to use it as a substrate for a flexible element.

Furthermore, a lower electrode, an insulating film, and the like may be included on the substrate. In this case, a metal oxide film is formed on the lower electrode or the insulating film on the substrate.

(Surface treatment) Before applying the metal oxide precursor solution on the substrate, a step of surface-treating the surface of the substrate on which the coating film (precursor film) is formed may be included. For example, in the case of manufacturing thin film transistors, if the gate insulating film is formed and left for a long time in an indoor environment, foreign substances such as moisture, carbon, and organic components adhere to the surface of the insulating film, and there is Stability) the possibility of adverse effects. Therefore, as a pretreatment for applying the metal oxide precursor solution to the substrate, it is preferable to perform surface treatment to remove moisture and dirt on the substrate. Examples of the surface treatment of the substrate include ultraviolet (UV) ozone treatment, argon plasma treatment, and nitrogen plasma treatment. For the UV ozone treatment, for example, a UV ozone treatment device (Model 144AX-100 manufactured by Jelight-company-Inc) can be used 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 )

(Coating) The method of applying the metal oxide precursor solution on the substrate includes spray coating, spin coating, blade coating, dip coating, casting, roll coating, bar coating, die coating, Mist method, inkjet method, dispenser method, screen printing method, relief printing method, gravure printing method, etc. In particular, from the viewpoint of easy formation of 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 a gravure printing method.

(Drying) After the metal oxide precursor solution is applied 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 metal oxide film finally obtained can be improved. Moreover, by selecting a suitable drying temperature (preferably 35°C or higher and 100°C or lower), a denser metal oxide film can be finally obtained. The method of 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, but from the viewpoint of uniformly maintaining the flatness of the film, it is preferable to start within 5 minutes after coating.

<Conversion Step> In the conversion step, the precursor film in the heated state is irradiated with ultraviolet rays in an environment of 10 Pa or less, thereby converting the precursor film into a metal oxide film. From the viewpoint of further reducing the hydrogen content in the metal oxide film, the pressure during conversion is preferably 1 Pa or less, and more preferably 0.1 Pa or less. If the pressure at the time of converting the precursor film into the metal oxide film is 1 Pa or less, a metal oxide film having a hydrogen content of 1.0×10 ²² cells/cm ³ or less can also be obtained. In addition, the hydrogen content in the metal oxide film in the present disclosure is calculated by Secondary Ion Mass Spectrometry (SIMS).

The temperature of the substrate at the time of ultraviolet irradiation is preferably less than 200°C. If the substrate temperature in the conversion step is less than 200°C, it becomes easy to apply to a resin substrate with low heat resistance, and the increase in thermal energy can be suppressed and the manufacturing cost can be kept relatively low. From the viewpoint of being compatible with more types 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 conversion from the precursor film to the metal oxide film in a short time, the substrate temperature in the conversion step is preferably 120° C. or higher. The temperature of the substrate in the conversion step can be measured by a thermo label. The step of conversion to a metal oxide film also depends on the illuminance of ultraviolet rays, but from the viewpoint of productivity, it is preferably 5 seconds or more and 120 minutes or less.

The method of heating the substrate in the conversion step is not particularly limited, and can be selected from hot plate heating, electric furnace heating, infrared heating, microwave heating, and the like. In the ultraviolet treatment, the heating of the substrate may use 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 using radiant heat from an ultraviolet lamp or the like, it can be controlled by adjusting the lamp-substrate distance and/or lamp output power.

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 the wavelength range of 300 nm or less with an illuminance of 10 mW/cm ² or more, the conversion from the metal oxide precursor film to the metal oxide film can be performed in a shorter time.

Examples of the light source of ultraviolet rays include UV lamps and lasers. From the viewpoint of large area, uniformity, and ultraviolet irradiation with inexpensive equipment, UV lamps are preferred. Examples of UV lamps include excimer lamps, deuterium lamps, low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halogen lamps, helium lamps, carbon arc lamps, cadmium lamps, electrodeless discharge lamps, etc. In particular, if low-pressure mercury lamps are used, Since the conversion from the metal oxide precursor film to the metal oxide film can be easily performed, it is preferable.

(Ultraviolet irradiation device) Here, the device used for the conversion process in this disclosure is demonstrated. The device used in the conversion step is not limited, and for example, an ultraviolet irradiation device including: a decompression chamber; a supporting table that supports the substrate in the press chamber and heating; a vacuum pump to decompress the decompression chamber to 10 can be suitably used. Pa or less; the light source irradiates ultraviolet rays to the substrate supported by the support table. In addition, if the configuration further includes a position adjustment unit that adjusts the positional relationship between the light source and the support table, the UV irradiation power (illuminance) irradiated to the substrate can be adjusted by adjusting the distance between the light source and the substrate on the support table.

FIG. 11 schematically shows an example of the configuration of the device used in the conversion step in the present disclosure. The device 400 shown in FIG. 11 is provided with a platform 412 having a heater function in a vacuum chamber (decompression chamber) 410, which can adjust the temperature of the substrate on the platform (supporting table) 412, and by rotating the handle from the atmospheric side ( Position adjustment unit) 418 to move the platform 412 up and down. A vacuum mechanical exhaust pump (vacuum pump) 414, an N ₂ gas introduction port (mass flow controller: mass flow controller, MFC) 424, a vacuum gauge 422, and a UV irradiation unit (light source) are arranged outside the vacuum chamber 410, respectively 416、气气阀426. A pressure adjustment valve 420 is provided between the vacuum chamber 410 and the turbo mechanical pump 414 to adjust the pressure in the chamber 410 to 10 Pa or less.

The UV irradiation unit 416 can irradiate ultraviolet light to the substrate on the platform 412 through the quartz glass 417, and the UV irradiation power (illuminance) irradiated to the substrate on the platform 412 can be adjusted by adjusting the height of the platform 412. In addition, it may be configured to move the position of the UV irradiation unit 416 to adjust the UV irradiation power (illuminance) irradiated to the substrate on the stage 412, or it may be configured to change the output power of the UV lamp of the UV irradiation unit 416. Adjust the configuration of the UV irradiation power (illuminance) irradiated to the substrate.

The thickness of the metal oxide film manufactured by the present disclosure is not particularly limited, and can be selected according to the application. For example, in the case of forming a semiconductor layer of a thin film transistor by the present disclosure, the film thickness is preferably 50 nm or less, and more preferably about 10 nm.

The method for manufacturing a metal oxide film of the present disclosure can easily obtain a metal oxide film that can reduce unnecessary residual components even by a low-temperature process of less than 200°C by a liquid phase method. In addition, since it is not necessary to use a large-scale vacuum apparatus, an inexpensive resin substrate with low heat resistance can be used, and an inexpensive raw material can be used, it becomes possible to significantly reduce the manufacturing cost of the device. Furthermore, it can also be applied to a resin substrate with low heat resistance, so that flexible electronic components such as flexible displays can be manufactured at low cost.

[Thin Film Transistor] In the present disclosure, a metal oxide film with unnecessary residual components reduced and having good electrical characteristics can be manufactured. Therefore, the manufacturing method of the metal oxide film of the present disclosure can be applied to a thin film transistor ( Thin Film Transistor (TFT) is suitably used for the formation of the oxide semiconductor layer (active layer) and electrodes. For example, by forming the oxide semiconductor layer as a semiconductor layer (active layer) by the method of manufacturing a metal oxide film of the present disclosure, a thin film transistor with high linear mobility and excellent operation stability can be obtained.

In the following, the method of manufacturing the metal oxide film of the present disclosure is mainly described in the form of applying the method of forming a semiconductor layer (oxide semiconductor film) of a TFT, but the present invention is not limited to the formation of a semiconductor layer of a TFT.

The device structure of the TFT of the present disclosure is not particularly limited, and based on the position of the gate electrode, it may be a so-called reverse staggered structure (also called "bottom gate type") and a staggered structure (also called "top gate type") In any form. In addition, the contact portion of the semiconductor layer with the source electrode and the drain electrode (appropriately referred to as "source/drain electrode") may be in any form of a so-called top contact type or bottom contact type. The "top gate type" refers to a state in which a gate electrode is arranged on the upper side of the gate insulating film when the substrate on which the TFT is formed is the lowermost layer, and a semiconductor layer is formed on the lower side of the gate insulating film. "Pole type" refers to a configuration in which a gate electrode is arranged below the gate insulating film, and a semiconductor layer is formed on the upper side of the gate insulating film. Moreover, the so-called "bottom contact type" is a form in which the source and drain electrodes are formed before the semiconductor layer, and the lower surface of the semiconductor layer is in contact with the source and drain electrodes. The electrode electrode first forms a semiconductor layer, and the top surface of the semiconductor layer is in contact with the source and drain electrodes.

FIG. 1 is a schematic diagram showing an example of a TFT of the present disclosure having a top gate structure and a top contact type. In the TFT 10 shown in FIG. 1, the oxide semiconductor film as the semiconductor layer 14 is laminated on one of the main surfaces of the substrate 12. Furthermore, the source electrode 16 and the drain electrode 18 are provided on the semiconductor layer 14 spaced apart from each other, and a gate insulating film 20 and a gate electrode 22 are further deposited in this order.

2 is a schematic diagram showing an example of a TFT of 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 provided on one of the main surfaces of the substrate 12 spaced apart from each other. Furthermore, the oxide semiconductor film as the semiconductor layer 14, the gate insulating film 20, and the gate electrode 22 are sequentially stacked.

FIG. 3 is a schematic diagram showing an example of a TFT of the present disclosure having a bottom gate structure and a top contact type. In the TFT 40 shown in FIG. 3, the gate electrode 22, the gate insulating film 20, and the oxide semiconductor film as the semiconductor layer 14 are sequentially stacked on one of the main surfaces of the substrate 12. Furthermore, the source electrode 16 and the drain electrode 18 are provided on the surface of the semiconductor layer 14 spaced apart from each other.

4 is a schematic diagram showing an example of the bottom gate structure of the TFT of the present disclosure of the bottom contact type. In the TFT 50 shown in FIG. 4, a gate electrode 22 and a gate insulating film 20 are sequentially deposited on one of the main surfaces of the substrate 12. Further, the source electrode 16 and the drain electrode 18 are provided on the surface of the gate insulating film 20 spaced apart from each other, and the oxide semiconductor film as the semiconductor layer 14 is further laminated.

In the following embodiments, the bottom gate thin film transistor shown in FIG. 3 as a representative example will be mainly described, but the thin film transistor of the present disclosure is not limited to the bottom gate type, and may be a top gate Polar thin film transistor.

(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 substrates according to the purpose, for example. In addition, 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. If the thickness of the substrate is 50 μm or more, the flatness of the substrate itself is further improved. Moreover, if the thickness of the substrate is 500 μm or less, the flexibility of the substrate itself is further improved, and it becomes easier to use it as a substrate for a flexible element. Further, for example, in the manufacturing process of the flexible element, after forming the thin film transistor on the flexible substrate temporarily fixed on the glass substrate, the flexible substrate may be peeled off from the glass substrate.

(Gate electrode) After the substrate 12 is cleaned, for example, the gate electrode 22 is formed on the substrate 12 that has been subjected to UV ozone treatment. For the gate electrode 22, a material with high conductivity, such as metals such as Al, Cu, Mo, Cr, Ta, Ti, Ag, Au, Al-Nd, Ag alloy, tin oxide, zinc oxide, indium oxide, oxide Metal oxide conductive films such as indium tin (In-Sn-O), zinc indium oxide (In-Zn-O), and In-Ga-Zn-O are formed. As the gate electrode 22, these conductive films can be used in a single-layer structure or a laminated structure of two or more layers.

The gate electrode 22 may be formed into a film according to the following method, which includes wet methods such as a printing method and a coating method, a vacuum evaporation method, a sputtering method, an ion plating method, etc. in consideration of suitability with materials used The physical method is appropriately selected from among chemical methods such as chemical vapor deposition (CVD) and plasma CVD. The film thickness of the metal film for forming the gate electrode 22 is preferably 10 nm or more in consideration of film formability, patternability by etching or lift-off method, conductivity, and the like. , 1000 nm or less, more preferably 50 nm or more and 200 nm or less. After the film formation, the gate electrode 22 can be formed by patterning into a predetermined shape by etching or lift-off method; or the pattern can be directly formed by inkjet method, 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.

(Gate insulating 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 a material with high insulation, 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 the like, or The insulating film containing two or more of these compounds may have a single-layer structure or a laminated structure. The formation of the gate insulating film 20 may be performed by forming a film according to the following method, which considers suitability with the material to be used, such as a wet method such as a printing method and a coating method, a vacuum evaporation method, a sputtering method, The physical methods such as the ion plating method and the chemical methods such as the CVD and plasma CVD methods are appropriately selected. If the gate insulating film 20 has gate insulating properties, it may be an organic insulating film or an inorganic insulating film. For example, an inorganic insulating film using a wet method includes a SiO ₂ film, a SiON film, and a SiN film using a polysilazane compound solution.

In addition, the gate insulating film 20 needs to have a thickness for reducing leakage current and improving voltage resistance. On the other hand, if the thickness of the gate insulating film 20 is too large, the driving voltage will increase. Depending on the material of the gate insulating film 20, the thickness of the gate insulating film 20 is preferably 10 nm or more and 10 μm or less, more preferably 50 nm or more and 1000 nm or less, and particularly preferably 100 nm or more , Below 400 nm.

(Semiconductor layer) After the gate insulating film 20 is formed, the semiconductor layer 14 is formed on the gate insulating film 20. According to the method for manufacturing a metal oxide film of the present disclosure, after applying a solution containing indium on the gate insulating film 20 and drying it to form a precursor film of a metal oxide semiconductor film, the precursor film In a heated state, ultraviolet radiation is performed in an environment of 10 Pa or less, thereby converting into a metal oxide semiconductor film.

The metal oxide semiconductor film is patterned into the shape of the semiconductor layer 14. The patterning of the semiconductor layer 14 can form the patterned semiconductor layer 14 by the inkjet method, dispenser method, relief printing method, and gravure printing method, or the metal can be formed by photolithography and etching The oxide semiconductor film is patterned into the shape of the semiconductor layer 14. When patterning is performed by photolithography and etching, a resist pattern is formed by photolithography on the remaining portion of the metal oxide semiconductor film, by hydrochloric acid, nitric acid, dilute sulfuric acid, or phosphoric acid, nitric acid and An acid solution such as a mixed solution of acetic acid is etched to form a pattern of the semiconductor layer 14.

From the viewpoint of flatness and time required for film formation, the thickness of the semiconductor layer 14 is preferably 5 nm or more and 50 nm or less.

(Protective layer) Preferably, a protective layer (not shown) for protecting the semiconductor layer 14 during the etching of the source/drain electrodes 16 and 18 is preferably formed on the semiconductor layer 14. The method for forming the protective layer is not particularly limited, as long as the film is formed after the metal oxide semiconductor film. The protective layer may be formed before the patterning of the metal oxide semiconductor film, or 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. In addition, the protective layer may be removed after forming the source electrode 16 and the drain electrode 18 (source and drain electrodes 16, 18).

(Source and Drain Electrodes) Source and drain electrodes 16 and 18 are formed on the semiconductor layer 14 formed by the metal oxide semiconductor film. For the source and drain electrodes 16, 18, highly conductive materials that function as electrodes, such as metals such as Al, Mo, Cr, Ta, Ti, Ag, Au, Al-Nd, Ag alloy, tin oxide, are used , Zinc oxide, indium oxide, indium tin oxide (In-Sn-O), zinc indium oxide (In-Zn-O), In-Ga-Zn-O and other metal oxide conductive films are formed.

In the case of forming the source/drain electrodes 16, 18, it is sufficient to form a film in accordance with the following method, which considers suitability with the materials used and uses a wet method such as a printing method or a coating method, vacuum The physical methods such as the vapor deposition method, the sputtering method, and the ion plating method, and the chemical methods such as the CVD (chemical vapor deposition) and the plasma CVD method are appropriately selected.

In consideration of film-forming property, patterning property by etching or lift-off method, conductivity, etc., the film thickness of the source/drain electrodes 16, 18 is preferably 10 nm or more and 1000 nm or less, more preferably It is set to 50 nm or more and 100 nm or less.

After forming the conductive film, the source/drain electrodes 16 and 18 may be patterned into a predetermined shape by, for example, etching or a peeling method, or may be directly patterned by an inkjet method or the like. At this time, it is preferable to simultaneously pattern the source/drain electrodes 16, 18 and the wiring (not shown) connected to these electrodes.

The application of the thin film transistor of the present embodiment described above is not particularly limited, and it can also be applied from the viewpoint that a thin film transistor exhibiting high semiconductor characteristics and stability at a low temperature can be produced at a relatively low temperature. It is used in the production of various electronic components, especially flexible electronic components using an inexpensive resin substrate with low heat resistance. Specifically, it is suitable for the production of a driving element in a display device such as a liquid crystal display device, an organic electroluminescence (EL) display device, an inorganic EL display device, and a flexible display using a resin substrate with low heat resistance in.

In addition, the thin film transistors manufactured by the present disclosure can be used as various types of sensors such as X-ray sensors and image sensors, and driving elements (driving elements) in various electronic components such as microelectromechanical systems (MEMS) Circuit) and suitable for use. Hereinafter, an example of an electronic device to which the thin film transistor manufactured by the present disclosure is applied will be described.

<Liquid crystal display device> About the liquid crystal display device of one embodiment of the present disclosure, a schematic cross-sectional view of a part is shown in FIG. 5, and a schematic configuration diagram of electrical wiring is shown in FIG. 6.

As shown in FIG. 5, the liquid crystal display device 100 of the present embodiment has the following structure: the top contact type TFT 10 including the top gate structure shown in FIG. 1, and the TFT 10 is protected by the passivation layer 102 The liquid crystal layer 108 sandwiched between the lower pixel electrode 104 and the upper electrode 106 on the gate electrode 22 of the gate electrode 22 is used to emit different colors of R (red) G (green) B ( (Blue) color filter 110, and includes a polarizing plate 112a and a polarizing plate 112b on the substrate 12 side of the TFT 10 and on the RGB color filter 110, respectively.

Further, as shown in FIG. 6, the liquid crystal display device 100 of the present embodiment includes a plurality of gate wirings 112 parallel to each other, and parallel data wirings 114 crossing the gate wiring 112. Here, the gate wiring 112 and the data wiring 114 are electrically insulated. The TFT 10 is included near the intersection of 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. Furthermore, the drain electrode 18 of the TFT 10 is connected to the pixel lower electrode 104 via a contact hole 116 (a conductor is buried in the contact hole 116) provided in the gate insulating film 20. The pixel lower electrode 104 and the grounded upper electrode 106 together form a capacitor 118.

<Organic EL Display Device> An active matrix organic EL display device according to an embodiment of the present disclosure shows a partial schematic cross-sectional view in FIG. 7 and a schematic configuration diagram of electrical wiring in FIG. 8.

The active matrix organic EL display device 200 of the present embodiment is configured as follows: the top gate structure TFT 10 shown in FIG. 1 is on the substrate 12 including the passivation layer 202 as the driving TFT 10a and the switching TFT 10b TFT 10a, TFT 10b includes an organic EL light-emitting element 214, the organic EL light-emitting element 214 includes an organic light-emitting layer 212 sandwiched between the lower electrode 208 and the upper electrode 210, the upper surface is also through the passivation layer 216 Be protected.

Further, as shown in FIG. 8, the organic EL display device 200 of the present embodiment includes a plurality of gate wirings 220 parallel to each other, and data wirings 222 and drive wirings 224 parallel to each other crossing the gate wirings 220. Here, the gate wiring 220 is electrically insulated from the data wiring 222 and the driving wiring 224. The gate electrode 22 of the switching TFT 10b is connected to the gate wiring 220, and the source electrode 16 of the switching TFT 10b is connected to the data wiring 222. Furthermore, 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 maintained in a via state by using a capacitor 226. The source electrode 16 of the driving TFT 10a is connected to the driving wiring 224, and the drain electrode 18 is connected to the organic EL light emitting element 214.

In addition, in the organic EL display device shown in FIG. 7, the upper electrode 210 may be a transparent electrode to be a top emission type, or the bottom electrode 208 and each electrode of the TFT may be a transparent electrode to be a bottom emission. type.

<X-ray sensor> The X-ray sensor according to an embodiment of the present disclosure shows a schematic cross-sectional view of a part in FIG. 9 and a schematic configuration diagram of electrical wiring in FIG. 10.

The X-ray sensor 300 of the present embodiment includes a TFT 10 formed on the substrate 12 and a capacitor 310, a charge collection electrode 302 formed on the capacitor 310, an X-ray conversion layer 304, and an upper electrode 306. A passivation film 308 is provided on the TFT 10.

The capacitor 310 has a structure in which the insulating film 316 is sandwiched between the capacitor lower electrode 312 and the capacitor upper electrode 314. The upper electrode 314 for the capacitor is connected to any one of the source electrode 16 and the drain electrode 18 of the TFT 10 (the drain electrode 18 in FIG. 9) through a contact hole 318 provided in the insulating film 316.

The charge collection electrode 302 is provided on the capacitor upper electrode 314 of the capacitor 310 and is in contact with the capacitor upper electrode 314. The X-ray conversion layer 304 is a layer containing amorphous selenium, and is provided 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.

As shown in FIG. 10, the X-ray sensor 300 of this embodiment includes a plurality of gate wirings 320 parallel to each other, and a plurality of data wirings 322 parallel to each other crossing the gate wiring 320. Here, the gate wiring 320 and the data wiring 322 are electrically insulated. The TFT 10 is included near the intersection of 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. Furthermore, the drain electrode 18 of the TFT 10 is electrically connected to the charge collection electrode 302, and furthermore, the charge collection electrode 302 is connected to the capacitor 310.

In the X-ray sensor 300 of the present embodiment, X-rays are incident from the upper electrode 306 side in FIG. 9, and electron-hole pairs are generated by the X-ray conversion layer 304. By applying a high electric field to the X-ray conversion layer 304 in advance through the upper electrode 306, the generated charges are stored in the capacitor 310 and read out by sequentially scanning the TFT 10.

In addition, the liquid crystal display device 100, the organic EL display device 200, and the X-ray sensor 300 of the above-described embodiment include the top gate structure TFT shown in FIG. 1, but it is not limited to that shown in FIG. The TFT with the top gate structure may also be the TFT with the structure shown in FIG. 2 to FIG. 4. [Example]

The following describes the examples, but the present invention is not limited by the following examples.

<Examples and Comparative Examples in which a Metal Oxide Film Containing In was Formed> In order to explain the effect of the present invention more simply, a TFT element was produced as follows and the electrical characteristics were evaluated. Indium nitrate (In(NO ₃ ) ₃ ·xH ₂ O, purity 4 N, manufactured by High Purity Chemical Research Institute Co., Ltd.) was dissolved in 2-methoxyethanol (reagent special grade, manufactured by Wako Pure Chemical Industries, Ltd.) to produce An indium nitrate solution for forming a semiconductor layer with a concentration of 0.1 mol/L.

A p-type silicon substrate with a thermal oxide film is used as the substrate, and a simple TFT in which the silicon substrate becomes the gate electrode and the thermal oxide film is used as the gate insulating film is fabricated. On a 1-inch square p-type silicon substrate with a thermal oxide film, the prepared indium nitrate solution was spin-coated at a rotation speed of 1500 rpm for 30 seconds, and then dried on a hot plate heated at 60°C for 1 minute. This forms an oxide semiconductor precursor film (thickness 10 nm).

Next, it is converted into a metal oxide film by irradiating ultraviolet rays in an environment where the pressure is adjusted while the precursor film is heated. In the conversion step, an ultraviolet irradiation device having the schematic configuration shown in FIG. 11 is used. The vacuum exhaust pump 414 can be set to have TMP (turbo mechanical pump, manufactured by VARIAN), the pressure in the chamber is atmospheric to 1×10 ^-4 Pa, and the temperature of the sample substrate is room temperature to 600°C. The UV irradiation power (illuminance) is 1 mW/cm ² to 30 mW/cm ² . The irradiation power can be changed by adjusting the height of the sample platform (support table) 412.

In the apparatus shown in FIG. 11, the ultraviolet illuminance at a wavelength of 254 nm was measured using an ultraviolet photometer (manufactured by ORC, UV-M10, light receiver UV-25) to become 10 mW/cm ² . The position of the stage is adjusted in a manner that converts the oxide semiconductor precursor film under the conditions shown in Table 1.

Condition 1 is to perform conversion treatment in the atmosphere, Condition 2 is to evacuate from the atmosphere to 1×10 ^-4 Pa in vacuum, introduce N ₂ gas after vacuum evacuation is stopped, and perform conversion treatment at atmospheric pressure, Conditions 3 to 8 are In the vacuum exhaust, each pressure is adjusted to a certain degree of vacuum by the pressure adjustment valve 420, and then the conversion process is performed. In addition, condition 9 is to perform the conversion treatment while reducing the pressure from the atmosphere to 0.8 atm (about 0.081 MPa). In addition, under any conditions, the substrate temperature in the conversion step was fixed to 150° C., and the UV treatment time was fixed to 30 minutes. In addition, the temperature of the substrate during the ultraviolet irradiation treatment can be monitored by a thermal label.

After the conversion process, a source electrode and a drain electrode are formed on the metal oxide semiconductor film by sputtering. The source and drain electrodes can be produced by patterning using a metal mask, and Ti is formed to a thickness of 50 nm. The dimensions of the source and drain electrodes are set to 1 mm×1 mm, and the distance between the electrodes is set to 0.2 mm. This completes the fabrication of simple TFT elements.

Regarding the obtained simple type TFT, a semiconductor parameter analyzer 4156C (manufactured by Agilent Technologies) was used to measure the transistor characteristics V _g -I _d .

The V _g -I _d characteristic is measured by fixing the drain voltage (V _d ) to +1 V and changing the gate voltage (V _g ) within the range of -15 V to +15 V, Measure the drain current (I _d ) at each gate voltage. The measurement environment is set to atmospheric pressure in a dry air environment (pre-flow for 60 minutes) to eliminate the influence of moisture during measurement. Repeat the measurement 5 times to obtain the linear mobility (initial mobility) and threshold voltage (Threshold Voltage, Vth ) Offset (the rising voltage offset of TFT).

Table 1 shows the linear mobility calculated from the V _g -I _d characteristic, the Vth shift (ΔVth) after 5 repeated measurements, and the hydrogen in the semiconductor film calculated by secondary ion mass spectrometry (SIMS) the amount. SIMS was performed using "PHI ADEPT1010" from Pysical Electronics.

[Table 1]

Under Condition 1 and Condition 9, it does not operate as a TFT. As the main reason, it is considered that the residual oxygen in the conversion step terminates the oxygen defect of the semiconductor layer, the carrier disappears, and it cannot function as a semiconductor film.

Under condition 2 and condition 3, although the transistor characteristics can be confirmed, ΔVth exceeds 2.0V, and there is a problem in terms of operation stability. Under Condition 2, although the initial mobility is the largest, the amount of residual hydrogen is also the largest. Therefore, hydrogen operates as a residual carrier, deteriorating the stability of the operation.

Under Condition 4 to Condition 8, ΔVth becomes less than 2.0V, and especially under Condition 6 to Condition 8 where the pressure in the conversion step is 1 Pa or less, the amount of hydrogen in the semiconductor film is reduced to 1.0×10 ²² pieces/cm ³ or less, ΔVth and the amount of hydrogen are almost the same. From these results, it can be seen that the influence of oxygen and the like is excluded from the conversion to the semiconductor film, and the amount of hydrogen in the semiconductor film depends on the pressure in the conversion step. The smaller the amount of hydrogen in the film, the smaller the ΔVth, and the improved operational stability .

<Comparative Examples and Examples of Metal Oxide Films Containing In and Zn>

The samples shown below were prepared and evaluated.

Indium nitrate _{(In (NO 3) 3 .xH} 2 O, having a purity of 4N, manufactured by Kojundo Chemical Co.), 3N, high purity chemical research zinc nitrate _{(Zn (NO 3) 2 .6H} 2 O, purity Manufactured by our company) dissolved in 2-methoxyethanol (reagent grade, manufactured by Wako Pure Chemical Industries, Ltd.) to produce indium nitrate with an indium nitrate concentration of 0.095 mol/L and a zinc nitrate concentration of 0.005 mol/L. Zinc nitrate mixed solution.

Use the produced indium nitrate. A mixed solution of zinc nitrate is used to form an oxide semiconductor precursor film on a p-type silicon substrate with a thermal oxide film, which is converted into an oxide semiconductor film in the same manner as in condition 1 or condition 4 to form source and drain electrodes And evaluate it. When the conversion step is performed in the same manner as in Condition 1, it does not operate as a TFT. When the conversion step was performed in the same manner as in Condition 4, the initial mobility of the TFT was 5.4 cm ² /Vs, ΔVth was 1.7 V, and the amount of hydrogen in the film was 1.77×10 ²² pieces/cm ³ .

As a disclosure of Japanese Patent Application No. 2014-247074 filed on December 5, 2014, the entirety of this is incorporated into this specification by reference. All documents, patents, patent applications, and technical specifications described in this specification are equivalent to the case where each document, patent, patent application, and technical specifications are specifically and individually described and incorporated by reference. It is incorporated into this specification by reference.

10, 30, 40, 50‧‧‧‧TFT 10a‧‧‧Drive TFT 10b‧‧‧Exchange TFT 12‧‧‧Substrate 14‧‧‧Semiconductor layer 16‧‧‧Source electrode 18‧‧‧Drain electrode 20‧‧‧Gate insulating film 22‧‧‧Gate electrode 100‧‧‧Liquid crystal display device 102, 202, 216‧‧‧ Passivation layer 104‧‧‧ Pixel lower electrode 106‧‧‧ Pair upper electrode 108‧ ‧‧Liquid crystal layer 110‧‧‧RGB color filter 112, 220, 320 ‧‧‧ gate wiring 112a, 112b ‧‧‧ polarizer 114, 222, 322‧‧‧ data wiring 116, 318‧‧‧ contact hole 118, 226, 310 ‧ ‧ ‧ capacitor 200 ‧ ‧ ‧ organic EL display device 208 ‧ ‧ ‧ lower electrode 210, 306 ‧ ‧ ‧ upper electrode 212 ‧ ‧ ‧ organic light-emitting layer 214 ‧ ‧ ‧ organic EL light-emitting element 224 ‧ ‧ ‧ Drive wiring 300 ‧‧‧X-ray sensor 302 ‧‧‧ charge collection electrode 304 ‧‧‧ X-ray conversion layer 308 ‧‧‧ passivation film 312 ‧‧‧ capacitor lower electrode 314 ‧‧‧ capacitor upper electrode 316 ‧‧‧Insulation film 400‧‧‧Device 410‧‧‧Vacuum chamber/decompression chamber/chamber 412‧‧‧‧Platform/support table 414‧‧‧Turbo mechanical pump/vacuum pump 416‧‧‧UV irradiation unit/light source 417 ‧‧‧Quartz glass 418‧‧‧handle/position adjustment unit 420‧‧‧pressure adjustment valve 422‧‧‧vacuum gauge 424‧‧‧N ₂ gas introduction port/MFC 426‧‧‧vent valve

FIG. 1 is a schematic diagram showing an example (top gate-top contact type) of a thin film transistor manufactured by the present invention. FIG. 2 is a schematic diagram showing an example of a configuration of a thin film transistor (top gate-bottom contact type) manufactured by the present invention. FIG. 3 is a schematic diagram showing an example of a configuration of a thin film transistor (bottom gate-top contact type) manufactured by the present invention. FIG. 4 is a schematic diagram showing an example of a configuration of a thin film transistor (bottom gate-bottom contact type) manufactured by the present invention. 5 is a schematic cross-sectional view showing a part of the liquid crystal display device of the embodiment. 6 is a schematic configuration diagram of electrical wiring of the liquid crystal display device shown in FIG. 5. 7 is a schematic cross-sectional view showing a part of an organic electroluminescence (Electro Luminescence, EL) display device of an embodiment. 8 is a schematic configuration diagram of electrical wiring of the organic EL display device shown in FIG. 7. 9 is a schematic cross-sectional view showing a part of the X-ray sensor array of the embodiment. 10 is a schematic configuration diagram of electrical wiring of the X-ray sensor array shown in FIG. 9. 11 is a schematic configuration diagram showing an example of the configuration of an ultraviolet irradiation device used in the conversion step in the present disclosure.

400‧‧‧device

410‧‧‧Vacuum chamber/decompression chamber/chamber

412‧‧‧Platform/support table

414‧‧‧Turbo mechanical pump/vacuum pump

416‧‧‧UV irradiation unit/light source

417‧‧‧Quartz glass

418‧‧‧handle/position adjustment unit

420‧‧‧pressure regulating valve

422‧‧‧Vacuum gauge

424‧‧‧N ₂ gas inlet port/MFC

426‧‧‧Vent valve

Claims (10)

A method of manufacturing a metal oxide film, comprising: a precursor film forming step, applying a solution of indium nitrate containing indium and a solvent on a substrate to form a metal oxide film precursor film; a conversion step by using When the temperature of the substrate is less than 200°C, the precursor film in the heated state is irradiated with ultraviolet rays in an environment of 10 Pa or less, thereby converting the precursor film into a metal oxide film. The method for manufacturing a metal oxide film according to item 1 of the patent application scope, wherein the ultraviolet irradiation is performed in an environment of 1 Pa or less. The method for manufacturing a metal oxide film according to item 1 or 2 of the patent application scope, wherein the content of indium contained in the solution is relative to the total amount of metal components contained in the solution It is said to be above 50 atom%. The method for manufacturing a metal oxide film according to the first or second patent application, wherein the temperature of the substrate when the ultraviolet ray is irradiated is 150° C. or lower. The method for manufacturing a metal oxide film according to item 1 of the patent application range, wherein the solution of indium nitrate contains at least one of methanol and methoxyethanol as the solvent. The method for manufacturing a metal oxide film according to claim 1 or claim 2, wherein the solution further contains at least one selected from the group consisting of zinc, tin, gallium, and aluminum. Metal oxide film as described in item 1 or 2 of patent application The method of manufacturing wherein the concentration of the metal component in the solution is 0.01 mol/L or more and 0.5 mol/L or less. The method for manufacturing a metal oxide film according to item 1 or item 2 of the patent application range, wherein the ultraviolet irradiation irradiates the precursor film with light having a wavelength of 300 nm or less at an illuminance of 10 mW/cm ² or more Of ultraviolet light. The method of manufacturing a metal oxide film according to the first or second patent application, wherein in the precursor film forming step, a method selected from an inkjet method, a dispenser method, a relief printing method, And at least one coating method of gravure printing method to apply the solution to the substrate. A method for manufacturing a thin-film transistor, which includes the step of forming a metal oxide film by the method for manufacturing a metal oxide film according to any one of claims 1 to 9.

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