Oxide semiconductor, its manufacturing method and semiconductor device including the same

Abstract

An Al-Sb-O based oxide semiconductor containing aluminum (Al) and antimony (Sb) has excellent electrical conductivity and band gap, and such a semiconductor can be applied to thin film transistors and the like.

Description

[Technical Field]

[0001] The present invention relates to an oxide semiconductor, a method for producing the same, and a semiconductor device including the same. [Background technology]

[0002] Oxide semiconductors are semiconductor materials whose conductivity and bandgap are controlled by doping with oxides such as zinc oxide, cadmium oxide, and indium oxide. They are generally transparent semiconductor materials with wide bandgaps.

[0003] Oxide semiconductors have a wide band gap and cannot absorb low-energy visible or infrared light, allowing them to transmit light in the visible light range (360-800 nm). In recent years, oxide semiconductors have become extremely important materials in the field of transparent semiconductors due to their excellent optical and electrical properties. They are semiconductor materials with high potential applications in various industrial fields, such as transparent displays, transparent sensors, and transparent solar cells.

[0004] For example, oxide semiconductors such as zinc oxide are semiconductor materials whose conductivity can be controlled by doping or whose band gap can be controlled by alloying. The key feature of such oxide semiconductors is their wide band gap, which allows them to have extremely high optical transparency in the visible light range, making them transparent.

[0005] Professor Hideo Hosono of the Tokyo Institute of Technology (Japan) disclosed in Korean Patent No. 0939998 indium gallium zinc oxide (IGZO), a transparent semiconductor with high charge mobility, and thin-film transistors using it. IGZO is an oxide material composed of indium, gallium, zinc, and oxygen. It is a semiconductor material with a wide bandgap of more than 3 eV. IGZO, as an oxide semiconductor, can be used to fabricate thin-film transistors, and is therefore already used as backplane panel devices in the display field. Thin-film transistors fabricated using IGZO have better charge mobility than amorphous silicon thin-film transistors, and therefore are used as backplane circuits and switching devices in the display field. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Korean Patent No. 0939998 (January 26, 2010) Summary of the Invention [Problem to be solved by the invention]

[0007] To find a new material to replace IGZO, which is currently used as an oxide semiconductor, the inventors identified researchable areas through data mining from big data on oxides, analyzed physical properties such as conductivity and band gap related to thin-film transistors (TFTs), and filtered candidates through data screening, thereby obtaining potential combinations of elements.

[0008] The inventors also created a database of these structures and secured a list of materials with a high probability of crystallization from their phase equilibrium diagrams (see Figure 1). After analyzing physical properties such as conductivity and band gap using machine learning techniques, oxides containing aluminum (Al) and antimony (Sb) were ultimately selected as the materials to replace IGZO.

[0009] Therefore, an object of the present invention is to provide a new oxide semiconductor having excellent conductivity and band gap that can be applied to thin film transistors, and a method for producing the same. In addition, another object of the present invention is to provide a semiconductor device, a thin film transistor, and a display device that use such an oxide semiconductor. [Means for solving the problem]

[0010] The present invention provides an oxide semiconductor including an oxide containing aluminum (Al) and antimony (Sb).

[0011] Additionally, the present invention provides a method for producing an oxide semiconductor, the method comprising mixing a first precursor solution containing an aluminum precursor and a second precursor solution containing an antimony precursor to prepare a sol-gel solution, and coating the sol-gel solution onto a substrate to form an oxide semiconductor thin film.

[0012] Additionally, the present invention provides a method for producing an oxide semiconductor, which comprises sputter-depositing an aluminum precursor and an antimony precursor onto a substrate to form an oxide semiconductor thin film containing aluminum and antimony.

[0013] Additionally, the present invention provides a semiconductor device including a substrate, a dielectric layer formed on the substrate, a semiconductor layer including an oxide semiconductor formed on the dielectric layer, and an electrode formed on the semiconductor layer.

[0014] Additionally, the present invention provides a thin film transistor comprising a semiconductor device.

[0015] Additionally, the present invention provides a display device comprising a thin film transistor. [Effects of the Invention]

[0016] The Al-Sb-O-based oxide semiconductor according to the present invention has excellent electrical conductivity and band gap, and is therefore applicable to semiconductor devices such as thin film transistors, etc. Such Al-Sb-O-based oxide semiconductor devices can be incorporated into display devices to improve their performance. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a phase equilibrium diagram of an Al—Sb—O-based oxide semiconductor according to one embodiment. [Figure 2] FIG. 2 is a cross-sectional view of a device including an oxide semiconductor according to one embodiment (100: substrate, 200: dielectric layer, 300: semiconductor layer, 400: electrode). [Figure 3] FIG. 3 shows an example of an AFM image of the surface of an oxide semiconductor thin film. [Figure 4] 4a-4c show the test results of oxide semiconductor devices fabricated by solution processing with various Al:Sb molar ratios. [Figure 5] 5a-5c show the test results of oxide semiconductor devices fabricated by solution processing with various Al:Sb molar ratios. [Figure 6] 6a to 6d show the test results of oxide semiconductor devices that were subjected to heat treatment under various conditions after solution deposition. [Figure 7] 7a to 7d show the test results of oxide semiconductor devices that were solution processed and then heat-treated under various conditions. [Figure 8] 8a-8d show the test results of oxide semiconductor devices fabricated by solution processing with various thin film thicknesses. [Figure 9] 9a and 9b show the test results of oxide semiconductor devices fabricated by solution processing with various additives. [Figure 10] FIG. 10 shows the results of TG-DTA analysis of an oxide semiconductor according to one embodiment. [Figure 11] FIG. 11 shows the results of an XRD analysis of an oxide semiconductor according to one embodiment. [Figure 12] FIG. 12 shows the results of an XPS analysis of an oxide semiconductor according to one embodiment. [Figure 13] 13a-13e show test results of oxide semiconductor devices fabricated by deposition methods with various Al:Sb molar ratios. [Figure 14] 14a-14c show test results of oxide semiconductor devices fabricated by deposition methods with various partial pressure ratios of Ar:O2. [Figure 15] 15a-15d show test results of oxide semiconductor devices that were heat treated at various temperatures after deposition. [Figure 16] 16a-16c show test results of oxide semiconductor devices fabricated by deposition methods with various thin film thicknesses. DETAILED DESCRIPTION OF THE INVENTION

[0018] Various embodiments and examples of the present invention will be described in detail below with reference to the drawings.

[0019] In the description of the present invention, if it is recognized that detailed descriptions of related known structures or functions would obscure the essence of the present invention, such detailed descriptions will be omitted. In addition, for the purpose of explanation, the dimensions of individual elements in the accompanying drawings may be exaggerated or omitted, and may differ from the actual dimensions.

[0020] In this specification, when an element is described as being formed on, connected to, or combined with another element, this means that one element is formed on, connected to, or combined with the other element directly or indirectly through the other element. In addition, it should be understood that the references to the terms above and below each component may differ depending on the direction from which the object is viewed.

[0021] In this specification, the terms used to refer to components (or components) are used to distinguish them from one another and are not intended to limit the scope of the present invention. In addition, in this specification, the singular expressions "a," "an," and "the" are to be construed as covering the plural unless otherwise specified in the context.

[0022] As used herein, the term "comprising" is intended to identify certain features, regions, steps, methods, elements, and / or components (or components). This does not exclude the presence or addition of any other features, regions, steps, methods, elements, and / or components, unless specifically stated to the contrary.

[0023] In this specification, the terms "first," "second," etc. are used to describe various components. However, the components should not be limited by these terms. These terms are used only to distinguish one element from another.

[0024] oxide semiconductor The oxide semiconductor according to the present invention includes an oxide containing aluminum (Al) and antimony (Sb).

[0025] In one embodiment, the oxide semiconductor according to the present invention may be composed of an oxide containing aluminum (Al) and antimony (Sb), i.e., the oxide semiconductor according to the present invention may be composed only of aluminum (Al), antimony (Sb), and oxygen (O).

[0026] The content of the oxide containing aluminum (Al) and antimony (Sb) can be 50% by weight or more, 70% by weight or more, 80% by weight or more, 90% by weight or more, 95% by weight or more, 97% by weight or more, 99% by weight or more, 99.5% by weight or more, 99.9% by weight or more, or 100% by weight based on the total weight of the oxide semiconductor of the present invention.

[0027] In the oxide semiconductor according to the present invention, the molar ratio between aluminum (Al) and antimony (Sb) is preferably adjusted to a predetermined range.

[0028] In one embodiment, the molar ratio of aluminum (Al) and antimony (Sb) in the oxide may be 10:1 to 1:10.

[0029] For example, the molar ratio of aluminum (Al) and antimony (Sb) in the oxide can be 10:1 to 1:10, 10:1 to 1:8, 10:1 to 1:6, 10:1 to 1:4, 10:1 to 1:2, 10:1 to 1:1, 8:1 to 1:10, 6:1 to 1:10, 4:1 to 1:10, 2:1 to 1:10, 1:1 to 1:10, 8:1 to 1:8, 6:1 to 1:6, 4:1 to 1:4, 3:1 to 1:3, 2:1 to 1:2, 1.5:1 to 1:1.5, or about 1:1.

[0030] In addition, the molar ratio of aluminum (Al), antimony (Sb) and oxygen (O) in the oxide can be adjusted within a predetermined range.

[0031] In one embodiment, the oxide is represented by Formula 1: [Formula 1] Al x Sb y O z (wherein 1≦x≦8, 1≦y≦8, and 1≦z≦15)

[0032] In Formula 1, x can be, for example, 1 or more, 2 or more, 3 or more, or 4 or more, and 8 or less, 7 or less, 6 or less, 5 or less, 4 or less, 3 or less, or 2 or less, and particularly 1 to 8, 1 to 6, 1 to 4, 1 to 3, 1 to 2, 2 to 8, 3 to 8, 4 to 8, or 2 to 6.

[0033] In Formula 1, y can be, for example, 1 or more, 2 or more, 3 or more, or 4 or more, and 8 or less, 7 or less, 6 or less, 5 or less, 4 or less, 3 or less, or 2 or less, and particularly 1 to 8, 1 to 6, 1 to 4, 1 to 3, 1 to 2, 2 to 8, 3 to 8, 4 to 8, or 2 to 6.

[0034] In Formula 1, z may be, for example, 1 or more, 2 or more, 3 or more, 4 or more, 5 or more, 6 or more, 7 or more, or 8 or more, and may be 15 or less, 14 or less, 13 or less, 12 or less, 11 or less, 10 or less, 9 or less, or 8 or less, and may be 1 to 15, 1 to 13, 1 to 11, 1 to 10, 1 to 9, 1 to 8, 1 to 6, 1 to 5, 3 to 15, 5 to 15, 7 to 15, 8 to 15, 10 to 15, or 12 to 15.

[0035] In addition, x, y, and z can be integers within the ranges exemplified above.

[0036] In particular, in Formula 1, x can be 1 or 2, y can be 1 or 2, and z can be an integer from 3 to 5. More specifically, in Formula 1, x can be 1, y can be 1, and z can be 4.

[0037] Additionally, in Formula 1, x, y, and z can be determined within a range that satisfies the balance in terms of the oxidation number or valence of the metal elements (Al, Sb) and the oxygen element (O). In particular, since Al is +3, Sb is +3 or +5, and oxygen is -2, the values ​​of x, y, and z can be limited to satisfy the valence balance of the chemical formula combining these elements. For example, in Formula 1, when Sb is +5, the chemical formula satisfying the valence balance can include AlSbO4, and when Sb is +3, the chemical formula satisfying the valence balance can include AlSbO3. However, in addition to this, various chemical formulas are possible depending on the molar ratio of the constituent elements (Al, Sb, and O) as long as the valence balance is satisfied.

[0038] In particular, the oxides of formula 1 are AlSbO4, AlSbO3, Al4Sb2O9, Al2Sb4O 13 , Al4Sb2O 11 and Al2Sb4O9, but is not limited to these.

[0039] In addition, the oxide semiconductor according to the present invention may further contain additional components other than the oxide containing aluminum (Al) and antimony (Sb), such as aluminum oxide, antimony oxide, or other oxides.

[0040] In some embodiments, the oxide semiconductor may be crystalline. In particular, it may have one or more crystalline peaks in its X-ray diffraction (XRD) spectrum. In other embodiments, the oxide semiconductor may be amorphous. In particular, it may have no crystalline peaks in its X-ray diffraction (XRD) spectrum.

[0041] The oxide semiconductor, when fabricated as a thin film, may have a surface roughness within a predetermined range (see FIG. 3). For example, the RMS roughness (Rq) may be 0.5 nm or more, 0.7 nm or more, 1 nm or more, 1.2 nm or more, or 1.4 nm or more, and may be 3 nm or less, 2.5 nm or less, 2 nm or less, 1.7 nm or less, or 1.5 nm or less, and as a specific example, 1 nm to 2 nm.

[0042] The oxide semiconductor according to the present invention has conductivity and a band gap that are applicable to thin film transistors and the like.

[0043] For example, the oxide semiconductor according to the present invention may have n-type properties.

[0044] The n-type conductivity of oxide semiconductors is 50 1 / ( f Ωms) That's it, 70 1 / ( f Ωms) That's it, 80 1 / ( f Ωms ) or more, 90 1 / ( f Ωms ) or more, 95 1 / ( f Ωms) That's all, 97 1 / ( f Ωms ) or more, 98 1 / ( f Ωms) or more, or 99 1 / ( f Ωms) In addition, the n-type conductivity of the oxide semiconductor can be 300 1 / ( f Ωm / s) Below, 200 1 / ( f Ωms) or less, or 120 1 / ( f Ωms) As a specific example, n-type conductivity of an oxide semiconductor can be 80 1 / ( f Ωms) ~120 1 / ( f Ωms) It could be.

[0045] In addition, the oxide semiconductor according to the present invention can have p-type properties depending on the composition.

[0046] The p-type conductivity of oxide semiconductors is 5 1 / ( f Ωms) That's it, 10 1 / ( f Ωms) That's all, 15 1 / ( f Ωms) or more, or 20 1 / ( f Ωms) In addition, the p-type conductivity of the oxide semiconductor can be 100 1 / ( f Ωm / s) Below, 70 1 / ( f Ωms) Below, 50 1 / ( f Ωms) or less, or 30 1 / ( f Ωm / s) As a specific example, the p-type conductivity of an oxide semiconductor can be 10 1 / ( f Ωms) ~50 1 / ( f Ωms) It could be.

[0047] The conductivity can be calculated using first-principles calculations and the Boltzmann transport equation as well as Hall effect measurements.

[0048] The band gap of the oxide semiconductor can be 1 eV or more, 1.2 eV or more, 1.3 eV or more, 1.4 eV or more, 1.5 eV or more, or 1.6 eV or more. In addition, the band gap of the oxide semiconductor can be 3 eV or less, 2.5 eV or less, 2 eV or less, or 1.8 eV or less. As a specific example, the band gap of the oxide semiconductor can be 1.5 eV to 2 eV. The band gap can be measured, for example, by measuring the absorbance of a sample with a UV-visible spectrometer and plotting a Tauc plot to calculate the optical band gap.

[0049] In one embodiment, the oxide semiconductor is 80 1 / ( f Ωms) The material may have n-type conductivity of 1.5 eV or greater and a measured bandgap of 1.5 eV or greater.

[0050] Therefore, a semiconductor device, such as a thin film transistor (TFT), including the oxide semiconductor according to the present invention can have excellent performance.

[0051] Field-effect mobility (μ FE ) is, for example, 0.001 cm 2 / Vs or more, 0.01cm 2 / Vs or more, 0.1cm 2 / Vs or more, 0.2cm 2 / Vs or more, 0.3cm 2 / Vs or more, 0.4cm 2 / Vs or more, or 0.5 cm 2 / Vs or more, and 10 cm 2 / Vs or less, 7cm 2 / Vs or less, 5cm 2 / Vs or less, 3cm 2 / Vs or less, 2cm 2 / Vs or less, 1cm 2 / Vs or less, 0.9cm 2 / Vs or less, 0.8cm 2 / Vs or less, 0.7cm 2 / Vs or less, or 0.6cm 2 As a specific example, the field-effect mobility (μ FE ) is 0.01cm 2 / Vs~10cm 2 / Vs, 0.1cm 2 / Vs~10cm 2 / Vs, 0.01cm 2 / Vs~1cm 2 / Vs, or 0.1 cm 2 / Vs~5cm 2 / Vs.

[0052] The on / off ratio of an Al-Sb-O-based oxide semiconductor device is, for example, 1.0×10 2 That's it, 1.0 x 10 3 That's it, 1.0 x 10 4 That's it, 3.0 x 10 4 That's it, 5.0 x 10 4 That's it, 7.0 x 10 4 or more, or 9.0 x 104 or more, and 1.0×10 7 Below, 5.0 x 10 6 Below, 3.0 x 10 6 Below, 1.0 x 10 6 Below, 5.0 x 10 5 Below, 3.0 x 10 5 or less, or 1.0×10 5 As a specific example, the on / off ratio of an Al—Sb—O-based oxide semiconductor device can be 1.0×10 2 ~1.0×10 7 , 1.0×10 2 ~1.0×10 5 , 1.0×10 3 ~1.0×10 7 , or 1.0 × 10 3 ~1.0×10 5 It could be.

[0053] Threshold voltage (V th ) can be, for example, −40 V or more, −30 V or more, −20 V or more, −10 V or more, 0 V or more, +3 V or more, +5 V or more, or +7 V or more, and +40 V or less, +30 V or less, +20 V or less, or +10 V or less. As a specific example, the threshold voltage (V th ) can be -40V to +40V, -10V to +30V, or 0V to 20V.

[0054] The subthreshold swing (SS) of an Al—Sb—O-based oxide semiconductor device can be, for example, 0.1 V / decade or more, 0.5 V / decade or more, 1 V / decade or more, 1.5 V / decade or more, or 2 V / decade or more, and 30 V / decade or less, 10 V / decade or less, 5 V / decade or less, or 3 V / decade or less. As a specific example, the subthreshold swing (SS) of an Al—Sb—O-based oxide semiconductor device can be 0.1 V / decade to 30 V / decade, 0.1 V / decade to 10 V / decade, 0.1 V / decade to 3 V / decade, or 1 V / decade to 30 V / decade.

[0055] In one embodiment, the Al—Sb—O-based oxide semiconductor device has n-type characteristics and a surface area of ​​0.1 cm 2 / Vs~10cm 2 / Vs field-effect mobility (μ FE ), 1.0×10 3 ~1.0×10 7 On / Off ratio of -40V to +40V threshold voltage (V th ), and may have a subthreshold swing (SS) of 0.1 V / decade to 10 V / decade.

[0056] In another embodiment, the Al—Sb—O based oxide semiconductor device has p-type characteristics, 2 / Vs~1cm 2 / Vs field-effect mobility (μ FE ), 1.0×10 2 ~1.0×10 5 On / Off ratio of -40V to +40V threshold voltage (V th ), and may have a subthreshold swing (SS) of 0.1V / decade to 3V / decade.

[0057] Oxide semiconductor manufacturing method (solution method) According to the present invention, the oxide semiconductor can be produced by a solution process or a deposition process.

[0058] According to certain embodiments, the oxide semiconductor may be produced by a solution process, such as a sol-gel process.

[0059] For example, a method for producing an oxide semiconductor includes mixing a first precursor solution containing an aluminum precursor and a second precursor solution containing an antimony precursor to prepare a sol-gel solution, and coating the sol-gel solution onto a substrate to form an oxide semiconductor thin film.

[0060] The types of aluminum precursor and antimony precursor used to produce the oxide semiconductor are not particularly limited.

[0061] For example, the aluminum precursor can be at least one selected from the group consisting of aluminum chloride, aluminum chloride hexahydrate, aluminum acetate, aluminum diacetate, aluminum acetylacetonate, aluminum sulfate hydrate, aluminum hydroxide hydrate, and aluminum isopropoxide.

[0062] Additionally, the antimony precursor can be at least one selected from the group consisting of antimony(III) chloride, antimony(V) chloride, antimony(III) acetate, antimony(III) sulfide, antimony(V) sulfide, antimony(III) fluoride, antimony(V) fluoride, and antimony ethoxide.

[0063] The first precursor solution may include a first solvent, and the second precursor solution may include a second solvent.

[0064] The first solvent and the second solvent are not particularly limited as long as they are solvents capable of dissolving or dispersing the aluminum precursor and the antimony precursor.

[0065] In particular, the first solvent and the second solvent may each be at least one selected from the group consisting of acetonitrile, ethylene glycol, 2-methoxyethanol, ethanol, methanol, dimethylformamide, dimethylsulfoxide, and deionized water.

[0066] Thus, the sol-gel solution may contain at least one solvent selected from the group consisting of acetonitrile, ethylene glycol, 2-methoxyethanol, ethanol, methanol, dimethylformamide, dimethyl sulfoxide, and deionized water. The sol-gel solution may contain a mixture of one or two solvents. For example, it may contain a mixture of acetonitrile and ethylene glycol.

[0067] In certain examples, the aluminum precursor includes aluminum acetate, aluminum diacetate, or the like, the antimony precursor includes antimony acetate, or the like, and the sol-gel solution includes 2-methoxyethanol, methanol, ethanol, or other alcoholic solvents.

[0068] In another example, the aluminum precursor includes aluminum acetate or the like, the antimony precursor includes antimony chloride or the like, and the sol-gel solution includes dimethylformamide, dimethylsulfoxide, or other aprotic polar solvent.

[0069] In another example, the aluminum precursor includes aluminum chloride, the antimony precursor includes antimony chloride, and the sol-gel solution includes a mixed solvent of acetonitrile and ethylene glycol, where the weight ratio of acetonitrile to ethylene glycol in the mixed solvent can be 10:1 to 1:10.

[0070] The concentration of the sol-gel solution (i.e., the concentration of the precursor) can be 0.01 M or more, 0.05 M or more, 0.1 M or more, or 0.5 M or more, and can be 10 M or less, 5 M or less, 3 M or less, 2 M or less, 1.5 M or less, or 1 M or less. As a specific example, the concentration of the sol-gel solution can be in the range of 0.05 M to 3 M.

[0071] The first precursor solution and the second precursor solution may further contain one or more additives. The additives may be selected from the group consisting of deionized water, hydrogen peroxide, monoethanolamine (MEA), and acetylacetone. Thus, the sol-gel solution may further contain one or more additives selected from the group consisting of deionized water, hydrogen peroxide, monoethanolamine, and acetylacetone. The content of the additive may be 0.01 wt % or more, 0.1 wt % or more, or 0.5 wt % or more, and 20 wt % or less, 10 wt % or less, 5 wt % or less, or 1 wt % or less, based on the total weight of the sol-gel solution. In a specific example, the sol-gel solution may further contain 1 wt % to 20 wt % deionized water based on the total weight of the sol-gel solution. In another specific example, the sol-gel solution may further contain 0.1 wt % to 5 wt % monoethanolamine based on the total weight of the sol-gel solution.

[0072] The first precursor solution and the second precursor solution are stirred under constant temperature conditions using a heating device such as a hot plate to prepare a sol-gel solution. The temperature during the preparation of the sol-gel solution (sol-gel reaction temperature) can be 20°C or higher, 40°C or higher, 60°C or higher, or 80°C or higher, and can be 200°C or lower, 150°C or lower, or 120°C or lower. The time required to prepare the sol-gel solution can be 1 hour or higher, 2 hours or higher, or 3 hours or higher, and can be 10 hours or lower, 8 hours or lower, or 6 hours or lower. As a specific example, the preparation of the sol-gel solution can be carried out at 25°C to 140°C for 1 hour to 72 hours.

[0073] The coating can be performed using spin coating, dip coating, bar coating, or doctor blade. The spin coating speed can be, for example, 500 rpm or more, 1000 rpm or more, or 1500 rpm or more, and 6000 rpm or less, 4000 rpm or less, or 3000 rpm or less.

[0074] The coating layer obtained after coating may be subjected to a heat treatment.

[0075] The heat treatment can be carried out in an air or nitrogen atmosphere.

[0076] The heat treatment temperature may be 60°C or higher, 90°C or higher, 100°C or higher, 120°C or higher, or 150°C or higher, and may be 1000°C or lower, 900°C or lower, 700°C or lower, 500°C or lower, 300°C or lower, or 200°C or lower. The heat treatment time may be 10 seconds or higher, 30 seconds or higher, 1 minute or higher, 5 minutes or higher, 10 minutes or higher, or 30 minutes or higher, and may be 7 hours or lower, 5 hours or lower, 3 hours or lower, 2 hours or lower, or 1 hour or lower. As a specific example, the heat treatment may be performed at a temperature of 150°C to 1000°C for 30 minutes to 5 hours. More specifically, the heat treatment may be performed for 1 hour, 3 hours, or 5 hours.

[0077] The heat treatment may be carried out once or twice or more times. For example, at least one selected from heat treatment at a temperature of 90°C to 200°C for 30 seconds to 1 hour, heat treatment at a temperature of 90°C to 200°C for 1 minute to 1 hour, heat treatment at a temperature of 150°C to 900°C for 30 minutes to 5 hours, and heat treatment at a temperature of 80°C to 300°C for 10 minutes to 3 hours may be carried out. Alternatively, two or more of these may be carried out consecutively.

[0078] The heat treatment may be carried out through a heating device such as an oven or an electric furnace.

[0079] In addition, a heat treatment step for drying and gelling the coating layer may be carried out prior to the heat treatment. The heat treatment for drying and gelling may be a common heat treatment using a hot plate or the like. For example, the heat treatment temperature for drying and gelling may be 100°C or higher, 110°C or higher, 120°C or higher, or 130°C or higher, and 200°C or lower, 180°C or lower, 160°C or lower, 150°C or lower, or 140°C or lower. In addition, the heat treatment time for drying and gelling may be 30 seconds or longer, 1 minute or longer, 3 minutes or longer, 5 minutes or longer, or 10 minutes or longer, and 2 hours or shorter, 1 hour or shorter, 30 minutes or shorter, or 20 minutes or shorter.

[0080] Oxide semiconductor manufacturing method (deposition method) According to another embodiment, the oxide semiconductor may be produced by a deposition method, in particular by vacuum deposition, more particularly by sputtering deposition.

[0081] For example, a method for producing an oxide semiconductor includes sputtering-depositing an aluminum precursor and an antimony precursor onto a substrate to form an oxide semiconductor thin film containing aluminum and antimony.

[0082] The aluminum precursor may include aluminum oxide, and the antimony precursor may include antimony oxide.

[0083] The aluminum oxide may include, for example, Al2O3, and the antimony precursor may include, for example, Sb2O3.

[0084] Thus, an oxide semiconductor produced by sputtering deposition may have a composition, for example, as shown in Formula 2 below. [Formula 2] (Al2O3) 1-a (Sb2O3) a (In the formula, 0 <a<1)

[0085] Sputter deposition can be carried out using, for example, DC sputtering, RF sputtering, magnetron sputtering, bias sputtering, reactive sputtering, and the like.

[0086] Sputtering deposition may use a discharge gas, such as an inert gas, such as argon gas, helium gas, neon gas, xenon gas, etc. In addition, sputtering deposition may use a reactive gas, such as oxygen gas.

[0087] Specifically, sputtering deposition can be performed by injecting argon gas and oxygen gas, for example, the partial pressure of oxygen gas can be 0% or more, 0.5% or more, 1% or more, 2% or more, or 5% or more, and 20% or less, 15% or less, or 10% or less, based on the partial pressure of argon gas.

[0088] Specifically, the partial pressure ratio of argon gas to oxygen gas may be in the range of 20:0.1 to 20:2. More specifically, the partial pressure ratio of argon gas to oxygen gas may be 20:0.1 to 20:1.5, 20:0.1 to 20:0.7, 20:0.1 to 20:0.3, 20:0.3 to 20:2, 20:0.7 to 20:2, or 20:0.3 to 20:0.7.

[0089] The RF power applied during sputtering deposition can be 20 W or more, 25 W or more, 30 W or more, or 50 W or more, and can be 500 W or less, 300 W or less, 200 W or less, 150 W or less, or 100 W or less, and as a specific example, can be 25 W to 200 W.

[0090] The operating pressure during sputtering deposition can be 0.1 mTorr or more, 0.2 mTorr or more, 0.5 mTorr or more, or 1 mTorr or more, and can be 10 mTorr or less, 5 mTorr or less, 3 mTorr or less, or 2 mTorr or less, with 0.2 mTorr to 3 mTorr being a specific example.

[0091] The method for manufacturing an oxide semiconductor according to the above embodiment may further include a heat treatment after the sputtering deposition.

[0092] The heat treatment can be carried out in an air or nitrogen atmosphere.

[0093] The heat treatment temperature may be 60°C or higher, 90°C or higher, 100°C or higher, 120°C or higher, or 150°C or higher, and may be 1000°C or lower, 900°C or lower, 700°C or lower, 500°C or lower, 300°C or lower, or 200°C or lower. The heat treatment time may be 10 seconds or higher, 30 seconds or higher, 1 minute or higher, 5 minutes or higher, 10 minutes or higher, or 30 minutes or higher, and may be 7 hours or lower, 5 hours or lower, 3 hours or lower, 2 hours or lower, or 1 hour or lower. As a specific example, the heat treatment may be performed at a temperature of 150°C to 1000°C for 30 minutes to 5 hours. More specifically, the heat treatment may be performed for 1 hour, 3 hours, or 5 hours.

[0094] The heat treatment may be carried out through a heating device such as an oven or an electric furnace.

[0095] Alternatively, the heat treatment can be carried out through electron beam treatment.

[0096] For example, a target to be heated is placed inside the chamber of an electron beam accelerator and filled with discharge gas. RF power is then applied to form a plasma state, separating the discharge gas into electrons and ions. When DC voltage is applied, the electrons are accelerated in the form of an electron beam as they pass through the acceleration tube, quickly reaching and colliding with the surface of the target. Such electron beam treatment has the same effect as heat treatment, but it also has the advantage of improving the composition, crystallinity, and electrical properties after electron beam treatment.

[0097] Argon gas, helium gas, neon gas, or xenon gas can be used as a discharge gas during electron beam processing. The flow rate of the discharge gas can be, for example, 1 sccm or more, 5 sccm or more, or 10 sccm or more, and 50 sccm or less, 30 sccm or less, or 15 sccm or less.

[0098] In addition, during electron beam processing, the density of the plasma can be controlled by adjusting the radio frequency (RF) power, and the degree of acceleration of the electron beam can be controlled by adjusting the direct current (DC) voltage, which allows for the production of metal oxide layers with various properties.

[0099] For example, the RF power for controlling the plasma density during electron beam treatment can be adjusted to 100 W or more, 150 W or more, 200 W or more, 250 W or more, or 300 W or more, and 700 W or less, 500 W or less, 450 W or less, 400 W or less, or 350 W or less. In addition, the DC voltage for accelerating the electron beam during electron beam treatment can be adjusted to 100 V or more, 200 V or more, 300 V or more, 400 V or more, or 500 V or more, and 1500 V or less, 1300 V or less, 1100 V or less, 900 V or less, 800 V or less, 700 V or less, or 600 V or less. In addition, the electron beam treatment time can be 10 seconds or more, 30 seconds or more, 1 minute or more, 2 minutes or more, or 3 minutes or more, and 30 minutes or less, 20 minutes or less, 10 minutes or less, 7 minutes or less, or 5 minutes or less. As a specific example, the electron beam treatment may be carried out at an RF power of 150 W to 500 W and a DC voltage of 200 V to 1000 V for 30 seconds to 10 minutes.

[0100] The oxide semiconductor thin film prepared in this manner may have a thickness of 1 nm or more, 5 nm or more, 10 nm or more, 20 nm or more, or 30 nm or more, and may be 500 nm or less, 300 nm or less, 200 nm or less, 100 nm or less, or 50 nm or less. For example, the thickness of the oxide semiconductor thin film may be 5 nm to 50 nm. As a specific example, the thickness of the oxide semiconductor thin film may be 10 nm to 100 nm. More specifically, the thickness of the oxide semiconductor thin film may be 10 nm to 50 nm, 10 nm to 40 nm, 10 nm to 25 nm, 20 nm to 100 nm, 20 nm to 50 nm, 20 nm to 40 nm, 40 nm to 100 nm, or 20 nm to 40 nm.

[0101] semiconductor devices The oxide semiconductor according to the present invention has excellent conductivity and band gap, and therefore can be applied to semiconductor devices. Accordingly, the present invention provides a semiconductor device comprising the above-mentioned oxide semiconductor.

[0102] A semiconductor device according to the present invention includes a substrate and a semiconductor layer formed on the substrate, the semiconductor layer including the oxide semiconductor. In addition, the semiconductor device may further include a dielectric layer between the substrate and the semiconductor layer. In addition, the semiconductor device may further include an electrode on the semiconductor layer.

[0103] 2 is a cross-sectional view of a semiconductor device including an oxide semiconductor according to an embodiment. Referring to FIG. 2, the semiconductor device according to an embodiment includes a substrate (100), a dielectric layer (200) formed on the substrate (100), a semiconductor layer (300) including an oxide semiconductor and formed on the dielectric layer (200), and an electrode (400) formed on the semiconductor layer (300). Here, the oxide semiconductor includes an oxide containing aluminum (Al) and antimony (Sb) as described above.

[0104] The substrate is a base for forming a semiconductor device and is not particularly limited in terms of material. It may be, for example, silicon, glass, plastic, or metal foil. The substrate may be plate-shaped, or may be formed to have a predetermined pattern by depositing and patterning a metal material such as molybdenum (Mo) or aluminum (Al) on the substrate. Alternatively, the substrate may contain a metal or metal oxide as a conductive material used as a gate electrode. Specifically, it may contain at least one of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), and silver (Ag). The thickness of the substrate is not particularly limited, but may be, for example, 0.01 mm or more, 0.1 mm or more, 0.5 mm or more, or 1 mm or more, and 10 mm or less, 5 mm or less, 3 mm or less, or 2 mm or less.

[0105] The dielectric layer is formed on the substrate and functions to insulate the substrate, semiconductor layer, and electrodes. The dielectric layer may include an insulating material used in common semiconductor processes. For example, the dielectric layer may include at least one dielectric selected from the group consisting of silicon oxide (SiO2), hafnium oxide (HfO2), aluminum oxide (Al2O3), zirconium oxide (ZrO2), and silicon nitride (Si3N4). The dielectric layer may be formed using methods such as vacuum deposition, chemical vapor deposition, physical vapor deposition, atomic layer deposition, metalorganic chemical vapor deposition, plasma-enhanced chemical vapor deposition, molecular beam epitaxy, hydride vapor phase epitaxy, sputtering, spin coating, and dip coating. The dielectric layer may have a thickness of 10 nm or more, 20 nm or more, 30 nm or more, or 50 nm or more, and may be 500 nm or less, 300 nm or less, 200 nm or less, or 100 nm or less. By way of example, the thickness of the dielectric layer may be between 50 nm and 200 nm.

[0106] The semiconductor layer is made of the oxide semiconductor described above, i.e., it includes an oxide containing aluminum (Al) and antimony (Sb). The semiconductor layer can be formed by the solution method or deposition method described above. The semiconductor layer can further include an additional oxide semiconductor other than the oxide semiconductor of the present invention. The additional oxide semiconductor can be, for example, at least one selected from indium gallium zinc oxide (IGZO), indium tin zinc oxide (ITZO), zinc oxide (ZnO), indium zinc oxide (IZO), indium oxide (InO), indium tin oxide (ITO), indium gallium oxide (IGO), zinc tin oxide (ZTO), silicon indium zinc oxide (SIZO), gallium zinc oxide (GZO), hafnium indium zinc oxide (HIZO), and aluminum zinc tin oxide (AZTO). The semiconductor layer may have a thickness of 1 nm or more, 5 nm or more, 10 nm or more, 20 nm or more, or 30 nm or more, and may be 500 nm or less, 300 nm or less, 200 nm or less, 100 nm or less, or 50 nm or less. For example, the thickness of the semiconductor layer may be 5 nm to 50 nm. As a specific example, the thickness of the semiconductor layer may be 10 nm to 100 nm. More specifically, the thickness of the semiconductor layer may be 10 nm to 50 nm, 10 nm to 40 nm, 10 nm to 25 nm, 20 nm to 100 nm, 20 nm to 50 nm, 20 nm to 40 nm, 40 nm to 100 nm, or 20 nm to 40 nm.

[0107] The electrodes may include a source electrode and a drain electrode, which may be spaced apart from each other and electrically connected to the semiconductor layer. The electrodes may be formed from a metal material. For example, the electrodes may include, but are not limited to, at least one selected from the group consisting of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), copper (Cu), indium tin oxide (ITO), indium zinc oxide (IZO), and indium tin zinc oxide (ITZO). The electrodes may be obtained by depositing a conductive film on the semiconductor layer, forming a photoresist pattern thereon, and patterning the conductive film using the photoresist pattern as a mask. Conductive films can be formed using methods such as vacuum deposition (or vacuum evaporation), chemical vapor deposition (or chemical vapor deposition), physical vapor deposition (or physical vapor deposition), atomic layer deposition, metalorganic chemical vapor deposition, plasma-enhanced chemical vapor deposition, molecular beam epitaxy, hydride vapor phase epitaxy, sputtering, spin coating, and dip coating.

[0108] The electrode may have a thickness of 5 nm or more, 10 nm or more, 30 nm or more, or 50 nm or more, and may be 500 nm or less, 300 nm or less, 200 nm or less, or 100 nm or less. For example, the thickness of the electrode may be 10 nm to 200 nm.

[0109] The semiconductor device of the present invention can be used as a field effect transistor (FET) and in particular as a thin film transistor (TFT) applied to display devices.

[0110] Accordingly, the present invention provides field effect transistors and thin film transistors that include the above semiconductor devices.

[0111] In particular, the semiconductor device of the present invention may be used as a transistor, such as a pixel driving device, used in a liquid crystal display (LCD) or organic light emitting display (OLED) device.

[0112] The semiconductor device according to the present invention has a field effect mobility (μ FE ), on / off ratio, threshold voltage (V th ) and subthreshold swing (SS), and therefore can be used in display devices and the like by replacing conventional oxide semiconductors (e.g., IGZO).

[0113] Thus, the present invention also provides a display device comprising a thin film transistor.

[0114] As an example, the display device is a liquid crystal display (LCD) device, which may include a polarizer (or polarizing plate), a liquid crystal display panel, a backlight unit, and other optical sheets. In particular, the liquid crystal display panel may include a color filter, a liquid crystal cell, and a driving substrate, and the driving substrate may include a thin film transistor.

[0115] As another example, the display device may be an organic light-emitting display (OLED) device, and the organic light-emitting display device may include a polarizer and an organic light-emitting display panel. In particular, the organic light-emitting display panel may include an organic light-emitting substrate and a driving substrate, and the driving substrate may include thin-film transistors.

[0116] A display device using a thin film transistor containing the Al—Sb—O-based oxide semiconductor of the present invention as described above can exhibit excellent performance. [Example]

[0117] Examples are provided below to aid in understanding the present invention, but the present invention is not limited to these examples.

[0118] Example A: Preparation of Al-Sb-O-based oxide semiconductor by solution method Step 1: Preparation of the sol-gel solution 0.1 M aluminum acetylacetonate and 0.1 M antimony acetate were added to 5 mL of 2-methoxyethanol as a solvent, and 120 μL of monoethanolamine as a catalyst was added to it, followed by stirring in a stirrer at 80 °C and 700 RPM for 2 hours to prepare an Al-Sb-O sol-gel solution.

[0119] Step 2: Preparation of the sol-gel coating layer The sol-gel solution prepared above was filtered through a 1 μm syringe filter. To enhance (or modify) the surface properties of a Si substrate on which a 100 nm SiO2 dielectric layer had been deposited, UV / ozone (UVO) treatment was performed for 10 minutes. Then, 150 μL of the filtered Al-Sb-O sol-gel solution was applied (or coated) onto the substrate, followed by spin coating at 3000 rpm for 20 seconds using a spin coater. After coating, the substrate was heat-treated on a hot plate at 150 °C for 10 minutes to form a coating layer (thin film).

[0120] Process 3: Heat treatment To oxidize the formed thin film and enhance its physical properties, heat treatment was carried out using an electric furnace at various temperatures ranging from 200 to 800°C for 1 to 5 hours.

[0121] Then, a 100 nm thick ITO electrode was deposited on the oxide semiconductor thin film to fabricate a thin film transistor (TFT), and its characteristics were tested.

[0122] A variety of oxide semiconductors were prepared by solution processing according to the method of Example A using the solvents, precursors and process conditions shown in Tables 1 and 2 below.

[0123] [Table 1]

[0124] [Table 2]

[0125] Table 3 below shows the band gap and conductivity of the Al-Sb-O-based oxide semiconductors according to the examples, which are confirmed to be at a level suitable for thin film transistors. Here, the band gap was calculated by measuring the absorbance of the sample with a UV-visible spectrometer and plotting a Tauc plot, and the conductivity was calculated using first-principles calculations and the Boltzmann transport equation.

[0126] [Table 3]

[0127] Example A1: Change in the composition ratio of Al and Sb The same procedure as in Example A was repeated, except that a sol-gel solution containing an aluminum precursor and an antimony precursor was prepared using 2-methoxyethanol or acetonitrile / ethylene glycol as a solvent, followed by spin-coating to obtain a 27 nm-thick oxide semiconductor thin film and heat-treating at 400°C. The precursor molar ratio was changed to adjust the Al:Sb element molar ratio in the Al-Sb-O-based oxide semiconductor to 5:1, 3:1, 1:1, 1:3, or 1:5. An ITO electrode was then deposited on the oxide semiconductor thin film to fabricate a thin-film transistor (TFT), and its electrical properties were tested.

[0128] Figures 4a-5c show the test results of oxide semiconductor devices fabricated by solution processing using various Al:Sb molar ratios and solvents. The field-effect mobility (μ FE ), on / off ratio, V th The values ​​of μ and SS varied depending on the molar ratio of Al:Sb and the solvent. The highest μ was observed when the molar ratio of Al:Sb was about 1:1. FE showed.

[0129] Example A2: Changes in heat treatment conditions The same procedure as in Example A was repeated, except that a 0.8 M sol-gel solution containing 0.4 M aluminum acetylacetonate and 0.4 M antimony chloride as precursors was prepared using 5 mL of 2-methoxyethanol as a solvent, and then spin-coated to obtain a 27 nm-thick oxide semiconductor thin film. The resulting oxide semiconductor thin film was then heat-treated at temperatures of 200°C, 400°C, 600°C, or 800°C in an air or nitrogen atmosphere. An ITO electrode was then deposited on the oxide semiconductor thin film to fabricate a thin-film transistor (TFT), and its electrical properties were tested.

[0130] 6a to 7d show the test results of oxide semiconductor devices that were heat-treated under various conditions after the solution method. FE ), on / off ratio, V th The values ​​of μ and SS varied depending on the atmosphere (oxygen or nitrogen) during the heat treatment and the heat treatment temperature. The highest μ was observed when the heat treatment temperature was about 400-600°C. FE showed.

[0131] Example A3: Variation in film thickness The same procedure as in Example A was repeated, except that a 0.8 M sol-gel solution containing 0.4 M aluminum acetylacetonate and 0.4 M antimony chloride as precursors was prepared using 5 mL of 2-methoxyethanol as a solvent, and then spin-coated to obtain an oxide semiconductor thin film, which was then heat-treated at 400 °C. The spin-coating rpm was changed to adjust the thickness of the oxide semiconductor thin film to 45 nm, 35 nm, 27 nm, or 15 nm. An ITO electrode was then deposited on the oxide semiconductor thin film to fabricate a thin-film transistor (TFT), and its electrical properties were tested.

[0132] Figures 8a to 8d show the test results of oxide semiconductor devices fabricated with various thin film thicknesses after solution deposition. FE ), on / off ratio, V thThe values ​​of μ and SS varied depending on the thickness of the oxide semiconductor thin film. The highest μ was observed when the thickness of the oxide semiconductor thin film was approximately 20 to 30 nm. FE showed.

[0133] Example A4: Use of additives The same procedure as in Example A was repeated, except that a 0.8 M sol-gel solution containing 0.4 M aluminum acetylacetonate and 0.4 M antimony chloride as precursors was prepared using 5 mL of 2-methoxyethanol as a solvent, followed by spin-coating to obtain an oxide semiconductor thin film, which was then heat-treated at 400 °C. In this case, 0.2 mL of deionized water or 0.120 mL of monoethanolamine was added to the sol-gel solution, and the procedure was repeated. An ITO electrode was then deposited on the oxide semiconductor thin film to fabricate a thin-film transistor (TFT), and its electrical properties were tested.

[0134] Figures 9a and 9b show the test results of oxide semiconductor devices fabricated by solution processing using various additives. The test results showed that the field-effect mobility (μ FE ), on / off ratio, V th , and SS varied depending on the additive. FE showed.

[0135] Test Example 1: Electrical Properties of Oxide Semiconductor Devices The electrical characteristics of the thin film transistors (TFTs) fabricated in the examples were tested. The electrical characteristics of the TFTs were determined by measuring both the transfer curve and the output curve. In the transfer curve, V G is applied to a total of 161 points in 0.5V increments in the range of -40V to 40V, and V D was measured by applying various values ​​between 0.1V and 20.1V. In the output curve, V D was measured at a total of 81 points in 0.5V increments in the range of 0 to 40V, and V Gwas measured in 5 V increments in the range of 0 to 25 V. The measurements were performed using a Hewlett Packard 4145B semiconductor parameter analyzer.

[0136] Test Example 2: TG-DTA The synthesis state of the Al-Sb-O-based oxide semiconductor was confirmed using a thermogravimetric-differential thermal analyzer (TG-DTA).

[0137] The same procedure as in Example A was repeated, except that a 0.8 M sol-gel solution containing 0.4 M aluminum acetylacetonate and 0.4 M antimony chloride as precursors was prepared using 5 mL of 2-methoxyethanol as a solvent, and then spin-coated to obtain an oxide semiconductor. The oxide semiconductor thus obtained was analyzed by TG-DTA while being subjected to heat treatment at temperatures varying from 0°C to 1200°C.

[0138] Figure 10 shows the TG-DTA analysis results of the Al-Sb-O-based oxide semiconductor, which indicates that the most stable state is around 500°C, and that sufficient synthesis has been achieved.

[0139] Test Example 3: XRD The crystallinity and crystallization temperature of the Al-Sb-O-based oxide semiconductor were measured by X-ray diffraction (XRD) analysis.

[0140] The same procedure as in Example A was repeated, except that a 0.8 M sol-gel solution containing 0.4 M aluminum acetylacetonate and 0.4 M antimony chloride as precursors was prepared using 5 mL of 2-methoxyethanol as a solvent, and then spin-coated to obtain a 100 nm-thick oxide semiconductor thin film. The oxide semiconductor thus obtained was heat-treated in air at temperatures of 200°C, 400°C, 600°C, 800°C, and 1000°C, and XRD analysis was performed.

[0141] Figure 11 shows the results of XRD analysis of the Al-Sb-O-based oxide semiconductor. No characteristic peaks were observed at 200°C, 400°C, and 600°C, indicating that the material was amorphous. However, characteristic peaks were observed at 800°C and 100°C, indicating that the material was crystalline.

[0142] Test Example 4: XPS The composition ratio of the Al-Sb-O-based oxide semiconductor was analyzed by X-ray photoelectron spectroscopy (XPS).

[0143] The same procedure as in Example A was repeated, except that a 0.8 M sol-gel solution containing 0.4 M aluminum acetylacetonate and 0.4 M antimony chloride as precursors was prepared using 5 mL of 2-methoxyethanol as a solvent, and then spin-coated to obtain a 27 nm-thick oxide semiconductor thin film, followed by heat treatment at 400°C.

[0144] Figure 12 shows the results of XPS analysis of an Al-Sb-O-based oxide semiconductor. The content of each element contained in the oxide was calculated from these results and is shown in the table below. The oxide semiconductor analyzed in Figure 12 was confirmed to have an element molar ratio of Al and Sb of approximately 1:1.

[0145] [Table 4]

[0146] Example B: Preparation of Al-Sb-O-based oxide semiconductor by sputtering deposition Step 1: Preparing the precursor A 99.99% pure Al2O3 target and a 99.99% pure Sb2O3 target were prepared with a thickness of 4 mm and a length of 2 inches, respectively. A 2 mm thick copper (Cu) backplate was used to smoothly transfer current to the targets and maintain the temperature of the bonding surface.

[0147] Step 2: Sputtering deposition Al-Sb-O thin films were deposited on Si / SiO2 substrates using a co-sputtering method by applying RF power to Al2O3 and Sb2O3 targets, respectively. RF power was supplied in various combinations in the range of 25-150 W for Al2O3 and 15-70 W for Sb2O3.

[0148] Process 3: Heat treatment To synthesize the formed thin films and enhance their physical properties, heat treatment was carried out using an electric furnace at various temperatures ranging from 200 to 800°C for 1 to 5 hours.

[0149] A 100 nm thick ITO electrode was deposited on the oxide semiconductor thin film thus obtained to fabricate a thin film transistor (TFT), and its characteristics were tested.

[0150] Example B1: Variation in Al:Sb molar ratio The same procedure as in Example B was repeated to obtain an Al-Sb-O-based oxide semiconductor thin film, which was then heat-treated at 40°C. At this time, the RF power applied to the Al precursor and the Sb precursor was changed so that the Al:Sb molar ratio in the Al-Sb-O-based oxide semiconductor was adjusted to 5:1, 3:1, 1:1, 1:3, or 1:5. Then, an ITO electrode was deposited on the oxide semiconductor thin film, and a thin-film transistor (TFT) was fabricated and its electrical properties were tested.

[0151] 13a-13e show the test results of oxide semiconductor devices fabricated by deposition methods with various Al:Sb molar ratios. FE ), on / off ratio, V th The values ​​of μ and SS varied depending on the molar ratio of Al:Sb. The highest μ was observed when the molar ratio of Al:Sb was about 1:1. FE showed.

[0152] Example B2: Change in Argon:Oxygen Partial Pressure Ratio The same procedure as in Example B was repeated to obtain an Al-Sb-O-based oxide semiconductor thin film, which was then heat-treated at 40°C. Sputtering was performed while adjusting the Ar:O2 partial pressure ratio to 20:0.1, 20:0.5, and 20:1.0. An ITO electrode was then deposited on the oxide semiconductor thin film to fabricate a thin-film transistor (TFT), and its electrical properties were tested.

[0153] 14a to 14c show the test results of oxide semiconductor devices fabricated by deposition at various Ar:O2 partial pressure ratios. FE ), on / off ratio, V th The values ​​of μ and SS varied depending on the partial pressure ratio of Al:O2. The highest μ was observed when the partial pressure ratio of Al:O2 was about 20:1. FE showed.

[0154] Example B3: Variation in heat treatment temperature The same procedure as in Example B was repeated, except that sputtering deposition was performed for 1000 seconds with an Ar:O2 partial pressure ratio of 20:0.1 and RF powers of 150 W for Al and 30 W for Sb, to obtain an Al-Sb-O-based oxide semiconductor thin film with a thickness of 30 nm. The resulting oxide semiconductor thin film was then heat-treated in an air atmosphere at temperatures of 200°C, 400°C, 600°C, or 800°C. An ITO electrode was then deposited on the oxide semiconductor thin film to fabricate a thin-film transistor (TFT), and its electrical properties were tested.

[0155] 15a to 15d show the test results of oxide semiconductor devices that were heat-treated at various temperatures after deposition. The test results showed that the field-effect mobility (μ FE ), on / off ratio, V th The values ​​of μ and SS varied depending on the heat treatment temperature. The highest μ was observed when the heat treatment temperature was about 400°C. FE showed.

[0156] Example B4: Variation in film thickness An Al-Sb-O-based oxide semiconductor thin film was obtained by repeating the same procedure as in Example B, except that the sputtering deposition was performed while setting the partial pressure ratio of Ar:O2 to 20:0.1 and the RF power to 150 W for Al and 30 W for Sb.

[0157] At this time, the thickness of the sputter-deposited oxide semiconductor thin film was adjusted to 15 nm, 30 nm, or 45 nm.

[0158] Then, an ITO electrode was deposited on the oxide semiconductor thin film to fabricate a thin film transistor (TFT), and its electrical properties were tested.

[0159] 16a to 16c show the test results of oxide semiconductor devices fabricated with various thin film thicknesses through deposition methods. As a result of the tests, the field-effect mobility (μ FE ), on / off ratio, V th , and SS varied depending on the thickness of the oxide semiconductor thin film. The highest μ was observed when the thickness of the oxide semiconductor thin film was about 30 nm. FE showed. The present disclosure includes the following aspects. (Aspect 1) Oxide semiconductors, including oxides containing aluminum (Al) and antimony (Sb). (Aspect 2) 2. The oxide semiconductor according to embodiment 1, wherein the molar ratio of aluminum (Al) to antimony (Sb) in the oxide is 10:1 to 1:10. (Aspect 3) The oxide is represented by the following formula 1 [Formula 1] Al x Sb y O z wherein 1≦x≦8, 1≦y≦8, and 1≦z≦15. (Aspect 4) The oxide is AlSbO 4 , AlSbO 3 、Al 4 Sb 2 O 9 、Al 2 Sb 4 O13 、Al 4 Sb 2 O 11 , and Al 2 Sb 4 O 9 2. The oxide semiconductor according to embodiment 1, wherein the oxide semiconductor is at least one selected from the group consisting of: (Aspect 5) 2. The oxide semiconductor of embodiment 1, wherein the oxide semiconductor has n-type conductivity of 80 1 / (fΩms) or greater and a band gap of 1.5 eV or greater. (Aspect 6) A method for producing an oxide semiconductor according to aspect 1, comprising: mixing a first precursor solution containing an aluminum precursor and a second precursor solution containing an antimony precursor to prepare a sol-gel solution; and Coating a sol-gel solution onto a substrate to form an oxide semiconductor thin film A method comprising: (Aspect 7) the aluminum precursor is at least one selected from the group consisting of aluminum chloride, aluminum chloride hexahydrate, aluminum acetate, aluminum diacetate, aluminum acetylacetonate, aluminum sulfate hydrate, aluminum hydroxide hydrate, and aluminum isopropoxide; 7. The method for producing an oxide semiconductor according to claim 6, wherein the antimony precursor is at least one selected from the group consisting of antimony(III) chloride, antimony(V) chloride, antimony(III) acetate, antimony(III) sulfide, antimony(V) sulfide, antimony(III) fluoride, antimony(V) fluoride, and antimony ethoxide. (Aspect 8) 7. The method for producing an oxide semiconductor according to claim 6, wherein the sol-gel solution contains at least one selected from the group consisting of acetonitrile, ethylene glycol, 2-methoxyethanol, ethanol, methanol, dimethylformamide, dimethyl sulfoxide, and deionized water. (Aspect 9) 7. The method for producing an oxide semiconductor according to embodiment 6, wherein the concentration of the sol-gel solution is in the range of 0.05M to 3M. (Aspect 10) 7. The method for producing an oxide semiconductor according to embodiment 6, wherein the sol-gel solution further comprises one or more additives selected from the group consisting of deionized water, hydrogen peroxide, monoethanolamine, and acetylacetone. (Aspect 11) 7. The method for producing an oxide semiconductor according to embodiment 6, wherein the sol-gel solution is prepared at 25° C. to 140° C. for 1 hour to 72 hours. (Aspect 12) 7. The method for producing an oxide semiconductor according to embodiment 6, further comprising a heat treatment after coating, wherein the heat treatment is carried out at a temperature of 150° C. to 1000° C. for 30 minutes to 5 hours in an air or nitrogen atmosphere. (Aspect 13) A method for producing an oxide semiconductor according to aspect 1, comprising: A method comprising sputter-depositing an aluminum precursor and an antimony precursor onto a substrate to form an oxide semiconductor thin film containing aluminum and antimony. (Aspect 14) 14. The method for producing an oxide semiconductor according to embodiment 13, wherein the aluminum precursor comprises aluminum oxide and the antimony precursor comprises antimony oxide. (Aspect 15) 14. The method for producing an oxide semiconductor according to embodiment 13, wherein the sputtering deposition is carried out by injecting argon gas and oxygen gas, and the partial pressure ratio of the argon gas to the oxygen gas is in the range of 20:0.1 to 20:2. (Aspect 16) 14. The method for producing an oxide semiconductor according to embodiment 13, further comprising a heat treatment after the sputtering deposition, wherein the heat treatment is carried out at a temperature of 150° C. to 1000° C. for 30 minutes to 5 hours in an air or nitrogen atmosphere. (Aspect 17) A semiconductor device comprising: a substrate; a dielectric layer formed on the substrate; a semiconductor layer formed on the dielectric layer and including the oxide semiconductor of embodiment 1; and an electrode formed on the semiconductor layer. (Aspect 18) 18. The semiconductor device according to embodiment 17, wherein the semiconductor layer has a thickness of 5 nm to 50 nm. (Aspect 19) A thin film transistor comprising the semiconductor device of embodiment 17. (Aspect 20) A display device comprising the thin film transistor of embodiment 19.

Claims

1. An oxide semiconductor comprising an oxide containing aluminum (Al) and antimony (Sb), and having n-type conductivity of 80 1 / (fΩms) or more and a band gap of 1.5 eV or more.

2. 2. The oxide semiconductor according to claim 1, wherein the molar ratio of aluminum (Al) to antimony (Sb) in the oxide is 10:1 to 1:

10.

3. The oxide is represented by the following formula 1 [Formula 1] Al ｘ Sb ｙ O ｚ The oxide semiconductor according to claim 1 , wherein 1≦x≦8, 1≦y≦8, and 1≦z≦15.

4. The oxide is AlSbO ４ , AlSbO ３ , Al ４ Sb ２ O ９ , Al ２ Sb ４ O １３ , Al ４ Sb ２ O １１ , and Al ２ Sb ４ O ９ The oxide semiconductor according to claim 1 , wherein the oxide semiconductor is at least one selected from the group consisting of:

5. 2. The method for producing an oxide semiconductor according to claim 1, mixing a first precursor solution containing an aluminum precursor and a second precursor solution containing an antimony precursor to prepare a sol-gel solution; and Coating a sol-gel solution onto a substrate to form an oxide semiconductor thin film. A method comprising:

6. the aluminum precursor is at least one selected from the group consisting of aluminum chloride, aluminum chloride hexahydrate, aluminum acetate, aluminum diacetate, aluminum acetylacetonate, aluminum sulfate hydrate, aluminum hydroxide hydrate, and aluminum isopropoxide; 6. The method for producing an oxide semiconductor according to claim 5, wherein the antimony precursor is at least one selected from the group consisting of antimony(III) chloride, antimony(V) chloride, antimony(III) acetate, antimony(III) sulfide, antimony(V) sulfide, antimony(III) fluoride, antimony(V) fluoride, and antimony ethoxide.

7. 6. The method for producing an oxide semiconductor according to claim 5, wherein the sol-gel solution contains at least one selected from the group consisting of acetonitrile, ethylene glycol, 2-methoxyethanol, ethanol, methanol, dimethylformamide, dimethyl sulfoxide, and deionized water.

8. 6. The method for producing an oxide semiconductor according to claim 5, wherein the concentration of the sol-gel solution is in the range of 0.05M to 3M.

9. 6. The method for producing an oxide semiconductor according to claim 5, wherein the sol-gel solution further contains one or more additives selected from the group consisting of deionized water, hydrogen peroxide, monoethanolamine, and acetylacetone.

10. 6. The method for producing an oxide semiconductor according to claim 5, wherein the preparation of the sol-gel solution is carried out at 25° C. to 140° C. for 1 hour to 72 hours.

11. 6. The method for producing an oxide semiconductor according to claim 5, further comprising a heat treatment after coating, wherein the heat treatment is carried out at a temperature of 150° C. to 1000° C. for 30 minutes to 5 hours in an air or nitrogen atmosphere.

12. 2. The method for producing an oxide semiconductor according to claim 1, A method comprising sputter-depositing an aluminum precursor and an antimony precursor onto a substrate to form an oxide semiconductor thin film containing aluminum and antimony.

13. The method for producing an oxide semiconductor according to claim 12 , wherein the aluminum precursor comprises aluminum oxide and the antimony precursor comprises antimony oxide.

14. 13. The method for producing an oxide semiconductor according to claim 12, wherein the sputtering deposition is carried out by injecting argon gas and oxygen gas, and the partial pressure ratio of the argon gas and the oxygen gas is in the range of 20:0.1 to 20:

2.

15. 13. The method for producing an oxide semiconductor according to claim 12, further comprising a heat treatment after the sputtering deposition, wherein the heat treatment is carried out at a temperature of 150° C. to 1000° C. for 30 minutes to 5 hours in an air or nitrogen atmosphere.

16. A semiconductor device comprising: a substrate; a dielectric layer formed on the substrate; a semiconductor layer formed on the dielectric layer and comprising the oxide semiconductor of claim 1; and an electrode formed on the semiconductor layer.

17. 17. The semiconductor device of claim 16, wherein the semiconductor layer has a thickness of 5 nm to 50 nm.

18. A thin film transistor comprising the semiconductor device of claim 16.

19. 20. A display device comprising the thin film transistor of claim 18.

Images