Thin-film transistor having an inorganic semiconductor channel layer and method for manufacturing the same

Abstract

This invention provides a thin-film transistor that utilizes an inorganic semiconductor layer as a channel layer, and a method for manufacturing the same. [Solution] In an inorganic semiconductor layer, a channel layer is patterned, and an inorganic photosensitive layer is coated for patterning. The inorganic photosensitive layer is formed on the patterned inorganic photosensitive layer by irradiation with extreme ultraviolet light or an electron beam. When heat treatment is performed on the inorganic photosensitive layer pattern, the inorganic photosensitive layer pattern is modified into the patterned inorganic semiconductor layer 120. Therefore, since no separate photoresist is required for the formation of the channel layer and no etching process is required via the formed photoresist pattern, the efficiency of the process is improved.

Description

[Technical Field]

[0001] The present invention relates to an electronic device having an inorganic semiconductor channel, and more particularly to a thin-film transistor and a method for manufacturing the same, which utilizes an inorganic semiconductor that is patterned by extreme ultraviolet light or an electron beam without using a photoresist and acts as a channel. [Background technology]

[0002] Semiconductor technology utilizing silicon wafers is steadily developing. At the heart of this development lies the increasing number of transistors contained within a chip, which requires finer manufacturing processes. As the size of transistor elements decreases, the distance electrons travel decreases, improving the response speed to electrical changes. Furthermore, the reduction in size enables lower voltage operation, resulting in improved power efficiency.

[0003] A crucial step in reducing or miniaturizing element size is the photolithography process. Photolithography is a type of printing that utilizes light. When light is shone onto the top of a mask, the shape formed on the mask is transferred onto the photoresist by the transmitted light. The photoresist is characterized by the fact that chemical changes occur in areas exposed to ultraviolet light, extreme ultraviolet light, or electron beams. Typically, the patterning process utilizes a differential development speed between exposed and unexposed areas. Patterning consists of a step of exposing the photoresist to an energy source through the mask to record an image, and a development step of removing selected areas from the photoresist through development. Positive tone resist is characterized by the fact that areas exposed to ultraviolet light, etc., are deformed and selectively removed, while negative tone resist is characterized by the removal of areas not exposed to ultraviolet light, etc.

[0004] Furthermore, photoresists are classified into chemically amplified resists (CAR) and non-chemically amplified resists based on their operating principle. Chemically amplified resists contain a photoacid generator that generates acid in response to light, causing an acid-catalyzed reaction within the resist. While this has the advantage of amplifying the reaction even with small amounts of light, it has poor thermal stability and the stochastic effect makes it difficult to achieve accuracy and consistency in pattern formation.

[0005] To overcome the shortcomings of the aforementioned chemically amplified resists, research is being conducted on inorganic photosensitive compositions. Inorganic photoresists have excellent corrosion resistance and high mechanical strength, which allows for the formation of ultrafine patterns at very thin thicknesses, thus preventing the problem of pattern destruction.

[0006] However, the inorganic photosensitive compositions mentioned above are used only as photoresists and must be removed in subsequent processes. In other words, the inorganic photosensitive materials discussed in this industry are limited to use as photoresists and must be removed in the manufacturing process of electronic devices.

[0007] If an inorganic photosensitive composition is disclosed that can be used as both a photoresist and a semiconductor material simultaneously, subsequent separate lamination processes, etching processes, and etching processes for removing the resist would become unnecessary, dramatically improving process convenience and device stability. [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] The first technical problem that the present invention aims to solve is to provide a thin-film transistor that uses an inorganic semiconductor layer modified with a photosensitive inorganic photosensitive layer instead of a photoresist.

[0009] Furthermore, a second technical problem that the present invention aims to solve is to provide a method for manufacturing a thin-film transistor to achieve the first technical problem. [Means for solving the problem]

[0010] To achieve the first technical problem described above, the present invention provides a thin-film transistor comprising a gate electrode; a gate dielectric film formed on the gate electrode; an inorganic semiconductor layer formed on the gate dielectric film; and a source electrode and a drain electrode formed on the inorganic semiconductor layer, wherein the inorganic semiconductor layer is made of acetate-stabilized tin dioxide modified by heat treatment.

[0011] To achieve the second technical problem described above, the present invention provides a method for manufacturing a thin-film transistor, comprising the steps of: forming a gate electrode; forming a gate dielectric film on the gate electrode; forming an inorganic semiconductor layer on the gate dielectric film in which an inorganic photosensitive layer pattern having acetate-stabilized tin oxide has been modified; and forming a source electrode and a drain electrode on the inorganic semiconductor layer, wherein the inorganic semiconductor layer is formed by heat treatment of the inorganic photosensitive layer pattern. [Effects of the Invention]

[0012] According to the present invention described above, the inorganic photosensitive layer composed of acetic acid-stabilized tin dioxide can be patterned by irradiation with extreme ultraviolet light or an electron beam. That is, no separate photoresist is required on top for pattern formation. The patterned inorganic photosensitive layer is modified into an inorganic semiconductor layer by heat treatment. Therefore, the steps of applying a photoresist to form the inorganic semiconductor layer, forming a photoresist pattern through a lithography process, and using the photoresist pattern as an etching mask to form a pattern are omitted.

[0013] Therefore, the process for patterning the channel layer is drastically reduced, ensuring productivity. [Brief explanation of the drawing]

[0014] [Figure 1] A cross-sectional view for explaining a method for manufacturing an inorganic semiconductor layer according to a preferred embodiment of the present invention. [Figure 2] A cross-sectional view for explaining a method for manufacturing an inorganic semiconductor layer according to a preferred embodiment of the present invention. [Figure 3] A cross-sectional view for explaining a method for manufacturing an inorganic semiconductor layer according to a preferred embodiment of the present invention. [Figure 4] A schematic diagram of a molecular structure when an electron beam or extreme ultraviolet ray is irradiated to the inorganic photosensitive layer of FIG. 2 and a baking process is performed according to a preferred embodiment of the present invention. [Figure 5] A schematic diagram of a molecular structure for explaining the modification of an inorganic semiconductor layer by heat treatment of FIG. 3 according to a preferred embodiment of the present invention. [Figure 6] A cross-sectional view illustrating a thin film transistor using an inorganic semiconductor according to a preferred embodiment of the present invention. [Figure 7] A graph showing the molecular structure and atomic configuration of an inorganic photoreceptor according to Production Example 1 of the present invention. [Figure 8] An image illustrating an inorganic photosensitive layer pattern formed according to Production Example 2 of the present invention. [Figure 9] A graph measuring the sensitivity of the inorganic photosensitive layer according to Production Example 2 of the present invention. [Figure 10] A graph showing the transfer characteristics in a common source configuration of a thin film transistor according to Production Example 3 of the present invention. [Figure 11] A graph for confirming the operation of a thin film transistor in a saturation region according to Production Example 3 of the present invention.

Mode for Carrying Out the Invention

[0015] Because the present invention can be modified in various ways and may take on various forms, specific embodiments are illustrated in the drawings and described in detail herein. However, this should not be understood as limiting the present invention to specific embodiments, but rather as including all modifications, equivalents, or substitutions that fall within the spirit and technical scope of the present invention. In the description of each drawing, similar components are given the same reference numerals. Unless otherwise specifically defined, all terms used herein, including technical or scientific terms, have the same meaning as that generally understood by a person of ordinary skill in the art to which the present invention pertains. Terms as defined in commonly used dictionaries should be interpreted as having the meaning consistent with their meaning in the context of the relevant art, and not as ideal or overly formal unless explicitly defined herein.

[0016] Preferred embodiments of the present invention will be described in more detail below with reference to the attached drawings.

[0017] (Example: Thin-film transistor utilizing an inorganic semiconductor layer with magnetic patterning properties) In this embodiment, a thin-film transistor utilizing an inorganic semiconductor layer is provided. The inorganic semiconductor layer is derived from acetate-stabilized tin dioxide SnO2(CH3COOH)2 and has a tin oxide network structure with repeating Sn-O-Sn bonds, and electrons are non-uniformly distributed throughout the entire network.

[0018] The inorganic semiconductor layer is formed by forming an inorganic photosensitive layer, patterning the inorganic photosensitive layer, and curing.

[0019] Figures 1 to 3 are cross-sectional views illustrating a method for manufacturing an inorganic semiconductor layer according to a preferred embodiment of the present invention.

[0020] Figure 1 shows that an inorganic photosensitive layer 110 is formed on a substrate 100. The substrate 100 can be made of silicon material and can be the underlying film material on which the inorganic semiconductor layer is formed.

[0021] An inorganic photosensitive layer 110 is formed on the substrate 100 through a spin coating process. The inorganic photosensitive layer 110 contains acetate-stabilized tin dioxide.

[0022] The inorganic photosensitive layer 110 has a molecular solid state. A molecular solid is a state in which, although it appears to be a solid state externally, microscopically no chemical bonds are formed between molecules, and the molecules are aggregated together by van der Waals interactions. In this molecular solid, electron movement occurs mainly by electron hopping between adjacent molecules. Therefore, the electron mobility is 0.1 cm². 2 It has a very low value, less than or equal to / (V·s).

[0023] Referring to Figure 2, the inorganic photosensitive layer is irradiated with extreme ultraviolet light or an electron beam. Then, it is baked at 200°C to 250°C for 1 minute, at which point the irradiated area becomes insoluble, and the unirradiated area is dissolved and removed in the development process.

[0024] This is because, as shown in Figure 2, most of the ligands bound to the molecules forming the inorganic photosensitive layer are dissociated by electron beam irradiation, intermolecular bonding occurs during the baking process, and inorganic polymers are formed in the electron beam-irradiated area. However, since ligands are easily dissociated by heat, if the inorganic photosensitive layer is heated at a higher temperature, ligands will gradually dissociate even in the areas not irradiated by the electron beam, causing intermolecular bonding to occur. This leads to a problem where the chemical contrast between the exposed and unexposed areas decreases during the subsequent development process, and this must be avoided.

[0025] The inventors of this invention investigated the baking process for the inorganic photosensitive layer, focusing on temperature, and confirmed that if the baking temperature is below 200°C, intermolecular crosslinking is insufficient, causing the thin film to dissolve completely in the developer, making pattern formation impossible. Furthermore, if the baking temperature exceeds 250°C, the entire film, including the unirradiated areas, becomes thermally crosslinked, preventing the developer from dissolving the thin film. The irradiated areas are insoluble in TMAH (tetramethylammonium hydroxide). The inorganic photosensitive layer pattern 111 is formed by the development process.

[0026] When an inorganic polymer pattern is formed by irradiating it with an electron beam and going through a baking process, most of the ligands are removed. However, the unit size of the polymer is too small to be used as an inorganic semiconductor layer. Since electron mobility is inversely proportional to the number of empty spaces through which electrons can travel when they move in the semiconductor layer, it is necessary to increase the unit size of the inorganic polymer by heat treatment after pattern formation.

[0027] Referring to Figure 3, heat treatment is performed on the inorganic photosensitive layer pattern. Through heat treatment at 300°C to 450°C, the inorganic photosensitive layer is modified into an inorganic semiconductor layer 120. The number of intermolecular crosslinks required for the inorganic photosensitive layer to be modified into an inorganic semiconductor layer must be greater than the number of intermolecular crosslinks required for photosensitivity. If the heat treatment temperature for the inorganic photosensitive layer pattern is below 300°C, the intermolecular crosslinking is insufficient, and modification into an inorganic semiconductor layer does not occur. Furthermore, if the heat treatment temperature exceeds 450°C, the lower layer undergoes thermal deformation, making it impossible to manufacture a semiconductor.

[0028] During heat treatment, neutral acetic acid molecules that form coordination bonds within the acetic acid-stabilized tin dioxide are dissociated and removed. During this removal process, a core structure of tin dioxide is formed, which is thermodynamically very unstable. Therefore, chemical bonds are formed between the tin dioxide core molecules, which corresponds to an addition polymerization reaction. Consequently, a network structure of tin oxide with repeated Sn-O-Sn bonds is formed, and electrons are de-unequalized within the network, forming the inorganic semiconductor layer 120. In the inorganic semiconductor layer 120 where electron de-unequalization has occurred, electron transfer occurs due to an externally applied voltage, and the electron mobility is 0.1 to 50 cm⁻¹. 2 It can reach / (V·s). During the heat treatment process, neutral acetic acid molecules can remain in the inorganic semiconductor layer 120, and the higher the concentration of residual acetic acid molecules, the lower the electron mobility in the inorganic semiconductor layer.

[0029] Figure 4 is a schematic diagram of the molecular structure when the inorganic photosensitive layer shown in Figure 2 is irradiated with an electron beam or extreme ultraviolet light and a baking process is performed, according to a preferred embodiment of the present invention.

[0030] Referring to Figure 4, when a spin-coated inorganic photosensitive layer is irradiated with an electron beam or the like, the molecular structure of the inorganic photosensitive layer does not fundamentally change, but electrons are supplied to the irradiated region. In the spin-coated state, SnO2(CH3COOH)2 is formed at the molecular level, and CH3COOH acts as a ligand in the unit molecule. Furthermore, the cationic ligand L (=CH3COOH) forms a weak van der Waals bond with the oxygen atom of SnO2. When irradiated with an electron beam or the like, electrons or light energy are supplied to the irradiated region. Therefore, the unit molecule enters an excited state due to irradiation with electrons or light energy.

[0031] When thermal energy is supplied to the electrons supplied to the irradiated region through baking, the double bonds of SnO are converted to single bonds, forming a polymer with Sn-O-Sn single bonds. For example, the polymer has the following molecular structure formula. [Molecular structure] [ka]

[0032] In the above molecular structural formula, L is the ligand, which is CH3COOH.

[0033] The ends of the polymer can be terminated by double-bonded oxygen atoms and single-bonded CH3COOH atoms. In particular, the terminal ligand L (=CH3COOH) forms van der Waals bonds with the oxygen atoms that form the double bonds at the ends of other polymers, and thus retains its shape during the development process.

[0034] Figure 5 is a schematic diagram of the molecular structure illustrating the modification of the inorganic semiconductor layer by heat treatment shown in Figure 3 according to a preferred embodiment of the present invention.

[0035] Referring to Figure 5, the energy supplied by heat treatment removes the ligand L at the end of the primary polymer, and the double-bonded oxygen forms a single bond with the tin atom at the adjacent end of the primary polymer, forming a Sn-O-Sn network structure. The process described above should be understood as the removal of the ligand CH3COOH and a secondary polymerization step.

[0036] Figure 6 is a cross-sectional view showing a thin-film transistor using an inorganic semiconductor according to a preferred embodiment of the present invention.

[0037] Referring to Figure 6, a gate electrode 210 is formed on the substrate 200. The gate electrode 210 is not particularly limited as long as it has a conductive material. Therefore, a highly doped silicon or metallic material can be used as the gate electrode 210.

[0038] A gate dielectric film 220 is formed on the gate electrode 210. The gate dielectric film 220 is made of a material having polarization properties, and any material used in normal semiconductor processes is suitable.

[0039] An inorganic semiconductor layer 230 acting as a channel layer is formed on the gate dielectric film 220. The inorganic semiconductor layer 230 is a patterned inorganic semiconductor, and no other photoresist is used to form the pattern. As explained in Figures 1 to 5, the inorganic semiconductor layer 230 is derived from acetate-stabilized tin dioxide SnO2(CH3COOH)2.

[0040] First, an inorganic photosensitive layer is formed on the gate dielectric film 220. The inorganic photosensitive layer contains acetic acid-stabilized tin dioxide. The substance is dissolved in ethyl lactate to form a coating solution. The inorganic photosensitive layer is formed on the gate dielectric film 220 by spin coating with the coating solution.

[0041] Next, the inorganic photosensitive layer is irradiated with an electron beam or extreme ultraviolet light to perform a patterning process on the inorganic photosensitive layer. This forms an inorganic photosensitive layer pattern. The inorganic photosensitive layer pattern contains acetic acid-stabilized tin dioxide.

[0042] Next, a vacuum heat treatment is performed at a temperature of 300°C to 450°C. This vacuum heat treatment is a process in which a vacuum pump is used to discharge the gas generated during the heat treatment from the inorganic photosensitive layer pattern. Through this heat treatment, the inorganic photosensitive layer pattern is modified into an inorganic semiconductor layer 230. The inorganic semiconductor layer 230 acts as a channel in a thin-film transistor.

[0043] A source electrode 240 and a drain electrode 245 are formed on the inorganic semiconductor layer 230. The source electrode 240 and the drain electrode 245 are required to be made of a normal metal material, but there are no special limitations.

[0044] The following describes the production of a coating solution for forming an inorganic semiconductor layer and the formation of an inorganic semiconductor pattern, which are the core concepts of this invention, through examples of production.

[0045] (Manufacturing Example 1: Manufacturing of Inorganic Photoreceptors) The inorganic photoreceptor in this manufacturing example can be mixed with a solvent to form an inorganic photosensitive solution, and an inorganic photosensitive layer is formed by spin-coating the inorganic photosensitive solution.

[0046] 0.304 g of tin oxide powder purchased from QURES Corporation was placed in a round-bottom flask, 16 ml of methanol was added, and then 24 ml of acetic acid was added. After adding the acetic acid, the mixture was stirred at room temperature for 30 minutes to ensure uniform dispersion, and then heated at 70°C for 15 hours, stirring to induce the reaction.

[0047] Finally, the solvent is removed using a vacuum pump to obtain a yellow solid phase. The solid phase is acetic acid-stabilized tin dioxide, with the composition SnO2(CH3COOH)2.

[0048] Figure 7 is a graph showing the molecular structure and atomic composition of the inorganic photoreceptor produced by Manufacturing Example 1 of the present invention.

[0049] Referring to Figure 7, MALDI-TOF (matrix-assisted laser desorption / ionization time-of-flight) analysis is used in the 100-1,000 m / z range to confirm the atomic and molecular structure of the inorganic photoreceptor synthesized in Manufacturing Example 1.

[0050] Methanol was used as the solvent, and graph (a) shows [SnO2(CH3COOH)2+H] + The analysis results are shown, and graph (b) shows [SnO2(CH3COOH)2+Na] + The analysis results are shown below. The peak in the 272.929 Da region of graph (a) is [SnO2(CH3COOH)2+H] + The peak in the 294.944 Da region is [SnO2(CH3COOH)2+Na]+ This demonstrates the molecular structure of the inorganic photoreceptor.

[0051] (Manufacturing Example 2: Manufacturing of Inorganic Photosensitive Layer Patterns) The acetate-stabilized tin dioxide synthesized according to Production Example 1 is dissolved in 2 wt% ethyl lactate to form a coating solution. This coating solution corresponds to an inorganic photosensitive solution, which is applied to a silicon wafer and spin-coated at 3,000 rpm to form an inorganic photosensitive layer.

[0052] Next, a 5kV electron beam is irradiated to form a pattern and confirm that it acts as a negative-tonnage photoresist. The inorganic photosensitive layer, selectively irradiated with the electron beam, is heated at 230°C for 1 minute to switch the irradiated area to insoluble.

[0053] Next, 2.38% TMAH is introduced to remove the inorganic photosensitive layer other than the pattern.

[0054] Figure 8 is an image showing the inorganic photosensitive layer pattern formed by Manufacturing Example 2 of the present invention.

[0055] Referring to Figure 8, it can be confirmed that the inorganic photosensitive layer pattern formed with acetic acid-stabilized tin dioxide is regularly formed. Furthermore, it can be confirmed that the areas in the developer containing TMAH that were not irradiated with the electron beam have been accurately removed.

[0056] Figure 9 is a graph showing the sensitivity of the inorganic photosensitive layer measured according to Manufacturing Example 2 of the present invention.

[0057] Referring to Figure 9, sensitivity to the electron beam is measured using the difference in exposure under 5kV electron beam conditions. Contrast is calculated on a logarithmic scale, and sensitivity is measured while increasing the exposure of the pattern area by a factor of 1.1.

[0058] Measurement result D 50 = 22.88 μC / cm2 The sensitivity and contrast γ = 2.3 were shown.

[0059] In addition to the above Production Example 2, the inventor of the present invention confirmed the performance of the inorganic photosensitive agent of the present invention under extreme ultraviolet irradiation conditions. As a result of the confirmation, a line pattern with a size of several tens of nm was formed.

[0060] As confirmed in the above Production Example, the inorganic photoreceptor of the present invention does not require another photoresist for pattern formation and exhibits negative-type photosensitive characteristics by itself. Hereinafter, the application to a transistor is disclosed through other production examples.

[0061] (Production Example 3: Production of a thin film transistor using an inorganic semiconductor) p ++ A wafer having SiO2 with a thickness of 100 nm formed on a silicon wafer is provided. The coating solution of Production Example 1 is prepared on the provided wafer. The coating solution is one in which stannic oxide stabilized with acetic acid is dissolved in ethyl lactate at 2 wt%. The coating solution is coated on the provided wafer at a speed of 500 rpm for 5 seconds, and then spin-coated at a speed of 3,000 rpm for 30 seconds. Further, irradiation of an electron beam or extreme ultraviolet light to the channel region is performed using an electron beam or extreme ultraviolet light.

[0062] Subsequently, it is heated at a temperature of 150 ° C for 1 minute, and patterning with respect to the channel region is performed through a development process.

[0063] After patterning, it is cured at 350 ° C for 3 hours in a vacuum atmosphere to modify the inorganic photosensitive layer pattern into an inorganic semiconductor pattern.

[0064] Al is vapor-deposited on the inorganic semiconductor pattern having semiconductor characteristics in physical properties, and source electrodes and drain electrodes are formed.

[0065] p ++The doped silicon wafer acts as a gate electrode, SiO2 acts as a gate dielectric film, and the inorganic semiconductor pattern acts as a channel layer.

[0066] Figure 10 is a graph showing the transfer characteristics of a thin-film transistor in a common-source configuration according to Manufacturing Example 3 of the present invention.

[0067] Referring to Figure 10, the source electrode is grounded and a voltage of 40V is applied to the drain electrode. That is, V ds The voltage is fixed at 40V, and the gate voltage V gs While increasing the voltage from -40V to 40V in 1V increments, ds Measure V gs As I increase, ds An increasing phenomenon has also been observed. In particular, I ds The increase exhibits exponential characteristics. This means that an inversion phenomenon occurs in the channel layer, where the conductivity of the channel increases with increasing gate voltage. In other words, through the confirmation of the transfer characteristics in Figure 10, it is confirmed that the inorganic semiconductor of the present invention has semiconducting properties.

[0068] Figure 11 is a graph showing the operation of the thin-film transistor in the saturation region according to Manufacturing Example 3 of the present invention.

[0069] Referring to Figure 11, the source electrode is grounded, and the gate electrode has a gate voltage V gs A drain voltage V is applied. ds As the current I flowing through the drain-source increases ds This is measured.

[0070] Gate voltage V gs As V increases, the inorganic semiconductor layer forming the channel layer turns on and operates in the linear region. That is, V ds As I increase, ds A region that increases linearly also appears. However, V dsAs the voltage increases further, pinch-off occurs from the channel layer adjacent to the drain electrode, and the inorganic semiconductor layer, which is the channel layer, operates in the saturation region. When a thin-film transistor operates in the saturation region, it can be used as a current source or amplifier.

[0071] In the present invention described above, the inorganic photosensitive layer composed of acetic acid-stabilized tin dioxide can be patterned by irradiation with extreme ultraviolet light or an electron beam. That is, no additional photoresist is required on top for pattern formation. The patterned inorganic photosensitive layer is modified into an inorganic semiconductor layer by heat treatment. Therefore, the steps of applying a photoresist to form the inorganic semiconductor layer, forming a photoresist pattern through a lithography process, and using the photoresist pattern as an etching mask to form a pattern are omitted.

[0072] Therefore, the process for patterning the channel layer is significantly reduced, ensuring productivity. [Explanation of Symbols]

[0073] 100, 200 circuit boards 110 Inorganic photosensitive layer 111 Inorganic photosensitive layer pattern 120, 230 Inorganic semiconductor layer 210 Guard Station 220 Gate Dielectric Film 240 source electrodes 245 Drain electrode

Claims

1. Steps to form a gate electrode; A step of forming a gate dielectric film on the gate electrode; The steps of forming an inorganic semiconductor layer on the gate dielectric film having an inorganic photosensitive layer pattern with acetate-stabilized tin oxide; and The step includes forming a source electrode and a drain electrode on the inorganic semiconductor layer, A method for manufacturing a thin-film transistor, characterized in that the inorganic semiconductor layer is formed by heat treatment of the inorganic photosensitive layer pattern.

2. The acetic acid-stabilized tin oxide is SnO ２ (CH ３ COOH) ２ A method for manufacturing a thin-film transistor according to claim 1, characterized by having the following composition.

3. The method for manufacturing a thin-film transistor according to claim 2, characterized in that acetic acid is removed from the inorganic photosensitive layer pattern by the heat treatment.

4. The method for manufacturing a thin-film transistor according to claim 2, characterized in that the inorganic photosensitive layer pattern is modified by the heat treatment to an inorganic semiconductor layer which is a tin oxide network having repeated Sn-O-Sn bonds.

5. The step of forming the inorganic semiconductor layer is, A step of applying the coating solution having the acetate-stabilized tin oxide onto the gate dielectric film to form an inorganic photosensitive layer; The steps of irradiating the inorganic photosensitive layer with an electron beam or extreme ultraviolet light to form the inorganic photosensitive layer pattern; and A method for manufacturing a thin-film transistor according to claim 1, characterized by including the step of heat-treating the inorganic photosensitive layer pattern under conditions of 300°C to 450°C to modify the inorganic photosensitive layer pattern into the inorganic semiconductor layer.

6. The step of forming the inorganic photosensitive layer pattern is, A step of irradiating the inorganic photosensitive layer with the electron beam or extreme ultraviolet light; A step of baking at 200°C to 250°C to make the irradiated area insoluble; and The method for manufacturing a thin-film transistor according to claim 5, characterized by comprising the step of removing the unirradiated region using TMAH (tetramethylammonium hydroxyl) after baking to form an insoluble pattern of the irradiated region.

7. The coating solution is SnO ２ (CH ３ COOH) ２ A method for producing a thin-film transistor according to claim 5, characterized in that an inorganic photoreceptor of acetate-stabilized tin dioxide having the composition is dissolved in ethyl lactate to form the transistor.

8. The inorganic photoreceptor is, The steps of mixing tin oxide powder with methanol to form a mixed solution; and The method for manufacturing a thin-film transistor according to claim 7, characterized by comprising the step of adding acetic acid to the mixed solution and inducing a reaction to obtain acetic acid-stabilized tin dioxide.

9. The method for manufacturing a thin-film transistor according to claim 8, characterized in that, after adding the acetic acid, the reaction is induced at 60°C to 90°C.

10. The method for manufacturing a thin-film transistor according to claim 5, characterized in that the inorganic photosensitive layer pattern has the following molecular structural formula. [Molecular structural formula] 【Chemistry 1】 In the above molecular structural formula, L is a ligand, CH ３ It is COOH.

11. The method for manufacturing a thin-film transistor according to claim 10, characterized in that the inorganic photosensitive layer pattern has shape-retaining ability by forming van der Waals bonds between the double-bonded oxygen at the end of the molecular structural formula and ligand L of another molecular structural formula.

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