TWI626511B - Method for manufacturing thin film transistor substrate with protective film - Google Patents

Abstract

The invention provides a thin-film transistor substrate, which is a thin-film transistor substrate provided with a protective film, which can impart high driving stability.

The invention relates to a thin-film transistor substrate, which is a thin-film transistor substrate including a thin-film transistor and a protective film covering the thin-film transistor. The protective film is composed of a cured product of a photosensitive siloxane composition. The crystal substrate is characterized in that the thin film transistor has a semiconductor layer composed of an oxide semiconductor; the photosensitive siloxane composition contains: at least two polysiloxanes having different alkali dissolution rates; a sensitizer; and a solvent.

Description

Method for manufacturing thin film transistor substrate with protective film

The invention relates to a thin film transistor substrate with a protective film and a method for manufacturing the same.

In recent years, for high-resolution displays, thin-film transistors using oxide semiconductors typified by amorphous thin-film transistors (InGaZnO) are being actively developed. Compared with amorphous silicon thin film transistors used in liquid crystal displays, oxide semiconductors have a larger electron mobility and exhibit superior electrical characteristics such as a larger ON / OFF ratio. Therefore, they are expected to be used as driving elements for organic EL display devices. And power-saving components. In the development of displays, it is a particularly important issue to maintain the stability of device operation as a transistor and the uniformity on a large-area substrate. The insulating film that protects the oxide semiconductor layer from the external gas is an extremely important factor in the stability of the device operation. However, as such an insulating film, a protective insulating film (Patent Documents 1 and 2) which is "applied to a conventional thin film transistor using amorphous silicon" is mainly used, and it has essentially no use of an oxide semiconductor. Concerns of possession. Moreover, this is considered to be one of the main reasons for limiting the performance of "thin film transistors using oxide semiconductors".

The protective film of the oxide semiconductor must be able to suppress the intrusion of moisture, hydrogen, and oxygen. The invasion of these impurities significantly changes the conductivity of the oxide semiconductor, changes the threshold value, and the like, thereby hindering the operation stability. From this point of view, the conventional protective insulating film is mainly formed in a single-layer or multi-layer state by applying a physical vapor deposition method (PVD) such as chemical vapor deposition (CVD) or sputtering. SiOx, SiNx, SiONx, etc. Processes such as CVD for forming such highly barrier inorganic films have a concern of damaging the underlying layer of thin film transistors using oxide semiconductors, that is, oxide semiconductors. Specifically, SiO ₂ films and SiN films are used as conventional protective films formed using a vacuum evaporation device. However, these films are formed by decomposing a raw material gas with a plasma or the like. Therefore, in this process, The ion species generated from the plasma may damage the surface of the oxide semiconductor and deteriorate the characteristics of the thin film. In addition, when manufacturing an oxide semiconductor device, there is a concern that the oxide semiconductor is further deteriorated in processes such as various chemical solutions and dry etching. Therefore, as protection from the manufacturing process, a protective film such as an etching barrier film may be used in combination (Patent Document 3).

When a film-forming method using such a gas is used, it is difficult to form a uniform protective film when a large-screen display is produced. Therefore, in order to solve this problem, a method of forming a protective film by a coating method has been proposed.

[Prior technical literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2013-211410

[Patent Document 2] Japanese Patent Laid-Open No. 2013-207247

[Patent Document 3] Japanese Patent Laid-Open No. 2012-235105

[Patent Document 4] Japanese Patent Laid-Open No. 2013-89971

[Non-patent literature]

[Non-Patent Document 1] Juan Paolo Bermundo, Yasuaki Ishikawa, Haruka Yamazaki, Toshiaki Nonaka, Yukiharu Uraoka, "Effect of polysilsesquioxane passivation layer on the dark and illuminated negative bias stress of amorphous InGaZnO thin-film transistors", 60th Applied Physics Proceedings of the Society's Spring Academic Lecture, March 29, 2013, 29p-F1-5

[Non-Patent Document 2] Juan Paolo Bermundo, Yasuaki Ishikawa, Haruka Yamazaki, Toshiaki Nonaka, Yukiharu Uraoka, "Effect of reactive ion etching and post-annealing conditions on the characteristics and reliability of a-InGaZnO thin-film transistors with polysilsesquioxane based passivation layer ", Proceedings of The 13th International Meeting on Information Display (IMID), August 26, 2013, 431 pages (P2-30)

However, the solutions for forming a protective film used so far in this coating method mainly include polyimide resins and acrylic resins, and the films formed using the solutions cannot be annealed at high temperatures, and therefore most of them fail to exhibit sufficient performance. There is room for improvement. Also, it was also mentioned A coating type protective film using a siloxane resin is disclosed (Patent Document 4). Although this document shows the initial transistor characteristics of a semiconductor device provided with the protective film, it does not fully disclose driving stability and is considered to have room for improvement. In addition, a method has been proposed in which a siloxane resin is used as a coating-type protective film, and when the protective film is processed by dry etching, a deteriorated oxide semiconductor device is subjected to an oxygen environment at 300 ° C for 2 hours. Annealing is performed to restore the characteristics of the semiconductor element, thereby producing highly reliable elements (Non-Patent Documents 1 and 2). However, the method of processing the protective film by dry etching and the long-term annealing of the semiconductor element at a high temperature has a high cost, and from the viewpoint of production efficiency, there is room for further improvement.

The inventors of the present case have studied a method for solving the above-mentioned problems, and have obtained the following insight. From a photosensitive silicone composition containing at least two kinds of polysiloxane, a photosensitizer, and a solvent having different alkali dissolution rates, it is possible to easily and conveniently A method for forming a thin film transistor substrate with a protective film. It was further found that the thin film transistor substrate provided with such a protective film can suppress the degradation of the thin film transistor, and can impart relatively high driving stability to the thin film transistor substrate by relatively gentle annealing. The present invention has been completed based on the above findings.

Therefore, an object of the present invention is to provide a thin-film transistor substrate, which is a thin-film transistor substrate having a protective film, which can provide high driving stability.

In addition, another object of the present invention is to provide a manufacturing method, which is a method for manufacturing a thin-film transistor substrate having a protective film. The protective film can be processed by exposure and development, and the thin-film transistor substrate can be annealed. Gives thin film transistors high driving stability.

According to an aspect of the present invention, there is provided a thin film transistor substrate including a thin film transistor and a protective film covering the thin film transistor. The protective film is made of a cured product of a photosensitive silicone composition. The transistor substrate is characterized in that the thin film transistor has a semiconductor layer composed of an oxide semiconductor; the photosensitive siloxane composition contains: at least two polysiloxanes having different alkali dissolution rates; a sensitizer; and a solvent.

In addition, according to a preferred aspect of the present invention, there is provided a thin film transistor substrate as described above, which is formed of a photosensitive silicone composition containing the following polysiloxanes (I) and (II): Polysiloxane (I) is a polymer obtained by subjecting a silane compound represented by the following formula (1) and a silane compound represented by the following formula (2) to hydrolysis and condensation in the presence of a basic catalyst. 2. Siloxane, the pre-baked film can be dissolved in a 5% by weight aqueous solution of tetramethylammonium hydroxide, and the dissolution rate is below 1000 Å / s; RSi (OR ¹ ) ₃ . ． ． (1)

Si (OR ¹ ) ₄ . ． ． (2)

(In the formula, R represents a linear, branched, or cyclic alkyl group having 1 to 20 carbon atoms, or a linear, branched, or branched carbon group having 1 to 20 carbon atoms in which at least one methylene group can be replaced by oxygen. A cyclic alkyl group, or an aryl group having 6 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms in which at least one hydrogen can be replaced by fluorine; R ¹ represents an alkyl group having 1 to 5 carbon atoms; and Polysiloxane (II), which is a polysiloxane obtained by subjecting at least the silane compound of the general formula (1) to hydrolysis and condensation in the presence of an acidic or basic catalyst, after pre-baking The film can be dissolved in a 2.38% by weight aqueous solution of tetramethylammonium hydroxide, and the dissolution rate is above 100 Å / s.

According to another aspect of the present invention, there is provided a manufacturing method, which is the method for manufacturing a thin-film transistor substrate as described above, and is characterized by including the following steps: a step of preparing a photosensitive silicone composition, the photosensitive silicon The oxyalkane composition contains at least two polysiloxanes, photosensitizers, and solvents having different alkali dissolution rates; the photosensitive siloxane composition is coated on a thin film transistor, and the solvent is dried to form a protective film precursor layer. A step of exposing the protective film precursor layer; a step of developing the exposed protective film precursor layer; a step of heating and curing the developed protective film precursor layer to form a protective film; and The thin film transistor provided with the protective film hardened by heating is a step of annealing at least once.

According to the present invention, a thin film transistor substrate with a protective film can be provided, which is resistant to voltage stress, light stress, and light. Voltage stress exhibits high stability. Conventional coating-type protective films have made it extremely difficult to provide a thin film transistor with high stability against stress. In addition, according to the present invention, a thin-film transistor that operates stably can be more easily realized. In addition, since a vacuum device is not required, productivity is greatly improved.

1‧‧‧Thin-film transistor substrate with protective film

2‧‧‧ Gate layer

3‧‧‧Gate insulation

4‧‧‧ metal oxide semiconductor layer

5‧‧‧Source electrode

6‧‧‧ Drain electrode

7‧‧‧ protective film

8‧‧‧ pixel electrode

9‧‧‧ contact hole

FIG. 1 is a schematic diagram showing an aspect (Example 1) of a thin film transistor substrate with a protective film according to the present invention.

FIG. 2 is a schematic diagram showing another aspect of a thin film transistor substrate with a protective film according to the present invention.

FIG. 3 is a schematic diagram showing another aspect of a thin film transistor substrate with a protective film according to the present invention.

FIG. 4 is a graph showing transmission characteristics of a thin film transistor substrate according to the present invention.

FIG. 5 is a graph showing the performance recovery by annealing of the thin-film transistor substrate according to Comparative Example 2. FIG.

FIG. 6 is a graph showing transmission characteristics of a thin film transistor substrate according to Comparative Example 2. FIG.

FIG. 7 is a graph showing the performance recovery by annealing of the thin-film transistor substrate according to Reference Example 1. FIG.

FIG. 8 is a graph showing transmission characteristics of a thin film transistor substrate according to Reference Example 1. FIG.

FIG. 9 is a graph showing the performance recovery by annealing of the thin-film transistor substrate according to Reference Example 2. FIG.

[Forms for Implementing Invention]

Embodiments of the present invention will be described in detail with reference to the attached drawings as follows.

First, FIG. 1 shows an aspect of a thin film transistor substrate 1 having a protective film formed by the manufacturing method of the present invention. In FIG. 1, a gate insulating layer 3 is formed on the gate layer 2, and a metal oxide semiconductor layer 4 is formed above the gate insulating layer 3. Furthermore, at both ends of the metal oxide semiconductor layer 4, the source electrode 5 and the drain electrode 6 are respectively in contact with the gate insulating layer 3. Although not shown in the figure, an etching stopper film may be formed on the metal oxide semiconductor layer 4. The protective film 7 covers the metal oxide semiconductor layer 4, the source electrode 5, and the drain electrode 6. As another aspect, for example, a thin-film transistor substrate having a structure in which a source electrode 5 and a drain electrode 6 that are in contact with the oxide semiconductor layer 4 through a contact hole 9 in the protective film 7 is formed (FIG. 2) Or, it is also applicable to a thin film transistor substrate with a top gate structure. In addition, the structure shown here is merely an example, and a thin film transistor substrate having a structure other than that shown here can also be manufactured by the manufacturing method of the present invention.

FIG. 3 shows an aspect of a thin film transistor substrate in which a pixel electrode 8 is formed on a protective film 7. The pixel electrode 8 is in contact with the drain electrode 6 through a contact hole 9 formed in the protective film.

[Thin film transistor substrate with protective film]

The thin-film transistor substrate of the present invention includes a thin-film transistor and a protective film covering the thin-film transistor. The protective film is composed of a cured product of a siloxane composition. The thin-film transistor substrate of the present invention may be provided with a plurality of protective films, or may have a second protective film on the protective film covering the thin-film transistor. In this specification, a thin film transistor refers to, for example, a substrate including an electrode, an electric circuit, a semiconductor layer, an insulating layer, and the like on its surface, and all elements constituting the thin film transistor substrate. Also, it is arranged on a substrate Examples of the wiring include gate wiring, data wiring, and through-hole wiring for connecting two or more wiring layers. Generally, an amorphous silicon semiconductor, a polycrystalline silicon semiconductor, and an oxide semiconductor are used as a semiconductor layer. The thin film transistor substrate with a protective film of the present invention can obtain high protection characteristics through an oxide semiconductor and an annealing process, which is particularly preferable from this viewpoint. Conventionally, an inorganic film such as a silicon oxide film and a silicon nitride film formed by a PE-CVD method has been used as a protective film in order to perform high-temperature annealing. However, in order to form contact holes in these inorganic films, reactive ions are required Etching etc. However, the reactive ion etching significantly promotes the deterioration of the oxide semiconductor. Therefore, in order to restore the performance of the semiconductor after processing, it is necessary to increase the annealing temperature described later. In the present invention, the protective film can suppress the deterioration of the semiconductor, and can impart relatively high driving stability to the thin film transistor by relatively gentle annealing.

The protective film of the thin-film transistor substrate of the present invention is formed of a photosensitive silicone composition containing at least two kinds of polysiloxane, a photosensitizer, and a solvent having different alkali dissolution rates. By using such a photosensitive siloxane composition, it has the following advantages: processing of the protective film can be performed by exposure and development; pattern processing by dry etching or the like is not required, so the damage to the performance of the thin film transistor is small, And the annealing time is short. The photosensitive silicone composition will be described in detail below.

[Photosensitive Silane Composition]

The photosensitive silicone composition is classified into a positive photosensitive silicone composition and a negative photosensitive silicone composition by the type of the photosensitive agent. A preferred positive-type photosensitive siloxane composition for forming a protective film of a thin-film transistor substrate of the present invention contains at least two polysiloxanes (I) and (II) having different alkali dissolution speeds as a photosensitive material. Diazonaphthoquinone derivatives As well as solvents. This positive-type photosensitive siloxane composition forms a positive-type photosensitive layer, which is formed because the exposed portion is soluble in an alkali developing solution and the exposed portion is removed by development. On the other hand, a preferred negative-type photosensitive silicone composition for forming a protective film of a thin-film transistor substrate of the present invention is characterized by including at least two polysiloxanes (I) having different alkali dissolution rates. And (II), a curing aid and a solvent which generate an acid or an alkali by light. This negative-type photosensitive silicone composition forms a negative-type photosensitive layer, which is formed because the exposed portion is insoluble in the alkali developing solution and remains after development.

<Polysiloxane>

Polysiloxane refers to a polymer having a Si-O-Si bond (siloxane bond) as a main chain. In addition, in this specification, the silsesquioxane polymer represented by the general formula (RSiO _1.5 ) _n is also contained in a polysiloxane.

In the present invention, as the polysiloxane contained in the photosensitive siloxane composition for forming a protective film, it is preferable to use at least two kinds of polysiloxanes having different alkali dissolution rates. As such polysiloxanes having different alkali dissolution rates, the following polysiloxanes (I) and (II) are preferably used. Polysiloxane (I) is a polysiloxane obtained by hydrolyzing and condensing a silane compound represented by the following formula (1) and a silane compound represented by the following formula (2) in the presence of a basic catalyst. . The pre-baked polysiloxane (I) film can be dissolved in a 5% by weight TMAH solution, and its dissolution rate is 1000 Å / sec or less, preferably 10 to 700 Å / sec. When the solubility is 10 Å / sec or more, the possibility of remaining insoluble matter after development becomes extremely low, and disconnection can be prevented, which is preferable.

RSi (OR ¹ ) ₃ (1)

Si (OR ¹ ) ₄ ... (2)

(In the formula, R represents a linear, branched, or cyclic alkyl group having 1 to 20 carbon atoms, or a linear, branched, or branched carbon group having 1 to 20 carbon atoms in which at least one methylene group can be replaced by oxygen. A cyclic alkyl group is either an aryl group having 6 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms in which at least one hydrogen can be replaced by fluorine; R ¹ represents an alkyl group having 1 to 5 carbon atoms.

Polysiloxane (II) is a polysiloxane obtained by subjecting at least a silane compound of the general formula (1) to hydrolysis and condensation in the presence of an acidic or basic catalyst. The pre-baked polysiloxane (II) film is soluble in a 2.38% by weight TMAH aqueous solution, and has a dissolution rate of 100 Å / s or more, preferably 100 to 15,000 Å / s. The dissolution rate of polysiloxane (II) can be selected from 100 Å / sec to 15,000 Å / sec according to the thickness of the target protective film. Even more preferred is 100 Å / s to 10,000 Å / s. By setting it to 15,000 Å / sec or less, it is possible to avoid a large difference in the dissolution rate from polysiloxane (I), and to perform development uniformly.

Polysiloxane (I) is difficult to cause "pattern" dripping when the developed pattern is heated and hardened. However, it cannot be used alone because of its extremely low alkali solubility. In addition, even if the alkali solubility is adjusted for the purpose of using polysiloxane (I) or polysiloxane (II) alone, the present invention does not provide the photosensitive silicone composition used to form a protective film. For pattern stability, polysiloxanes (I) and (II) are preferably used in combination. In addition, when there is a large difference in the dissolution rate, it is preferable to use a plurality of polysiloxanes (II) having different dissolution rates.

The content of the silane compound of the general formula (2) in the above-mentioned polysiloxane (I) and polysiloxane (II) can be appropriately set according to the application, but it is preferably in the polysiloxane compound 3 mole% to 40 mole%, From the viewpoint of controlling the hardness of the film and the thermal stability of the pattern, it is more preferably 5 mol% to 30 mol%. When the content is 3 mol% or more, the pattern stability at high temperature becomes better, and when it is 40 mol or less, the reactivity can be suppressed, and the stability during storage becomes more stable. good.

<Measurement and calculation method of alkali dissolution rate (ADR)>

The dissolution rates of the polysiloxanes (I) and (II) with respect to the TMAH aqueous solution were measured and calculated in the following manner.

First, polysiloxane was dissolved in propylene glycol monomethyl ether acetate (PGMEA) so as to be about 35% by weight. This solution was spin-coated on a silicon wafer so that the dry film thickness was about 2 μm, and then the solvent was further removed by heating on a hot plate at 100 ° C. for 60 seconds. The film thickness of the coating film was measured with an elliptical spectrum polarimeter (Woollam). Next, the silicon wafer having the film was immersed in a polysiloxane (I) (5% TMAH aqueous solution) and a polysiloxane (II) (2.38% TMAH aqueous solution) at room temperature (25 ° C) and measured. The time until the film disappears. The dissolution rate is calculated by dividing the initial film thickness by the time until the film disappears. When the dissolution rate is significantly slow, the film thickness is measured after a certain period of immersion, and the amount of change in film thickness before and after immersion is divided by the immersion time to calculate the dissolution rate.

In any of the polysiloxanes (I) and (II), the weight average molecular weight in terms of polystyrene is generally 700 to 10,000, and preferably 1,000 to 4,000. When the molecular weight is within the above range, it is possible to prevent development residues and obtain sufficient resolution, and the sensitivity also becomes good. Therefore, it is preferable to adjust the molecular weight within the above range.

The mixing ratio of the polysiloxanes (I) and (II) can be adjusted at any ratio according to the film thickness of the interlayer insulating film and the sensitivity and resolution of the photosensitive composition. Polysiloxane (I) is preferred because it prevents the "pattern" from collapsing during heat curing. The "pattern" collapse here refers to the deformation of the pattern when the pattern is heated. For example, a pattern with a rectangular cross section and clear ridgelines becomes a circle after heating, or the side of a rectangular shape close to vertical is inclined.

<Photosensitizer>

In the present invention, the photosensitive siloxane composition that is patterned by light contains various kinds of photosensitizers as its components. Examples of the photosensitizer used in the positive-type photosensitive siloxane composition include diazonaphthoquinone derivatives. Examples of the photosensitizer used in the negative-type photosensitive siloxane composition include photodecomposition to promote silane. Alcohol-based condensation curing aid. Hereinafter, each of the photosensitizers will be described.

<Diazonaphthoquinone derivatives>

The diazonaphthoquinone derivative of the present invention is a compound in which the naphthoquinonediazidesulfonic acid is ester-bonded with a compound having a phenolic hydroxyl group, and the structure is not particularly limited, but it is preferably one having more than one phenolic hydroxyl group Esters of compounds. As the naphthoquinonediazidesulfonic acid, 4-naphthoquinonediazidesulfonic acid or 5-naphthoquinonediazidesulfonic acid can be used. 4-naphthoquinonediazide sulfonate has absorption capacity in the i-line (wavelength 365 nm) region, so it is suitable for i-line exposure. In addition, 5-naphthoquinonediazide sulfonate has an absorption capacity in a wide range of wavelengths, so it is suitable for exposure over a wide range of wavelengths. It is preferable to select 4-naphthoquinonediazidesulfonate and 5-naphthoquinonediazidesulfonate according to the wavelength of exposure. 4-naphthoquinonediazide sulfonate and 5-naphthoquinonediazide sulfonate may be used in combination.

The compound having a phenolic hydroxyl group is not particularly limited, and examples thereof include the following compounds (trade names, manufactured by Honshu Chemical Industry Co., Ltd.).

The addition amount of the diazonaphthoquinone derivative is optimal according to the esterification rate of the naphthoquinonediazidesulfonic acid, the physical properties of the polysiloxane used, the required sensitivity, and the dissolution ratio of the exposed and unexposed parts. The addition amount is different, but as the interlayer insulating film of the present invention, it is preferably 3 to 20 parts by weight, and even more preferably 5 to 15 parts by weight, relative to 100 parts by weight of the polysiloxane compound. When the addition amount of the diazonaphthoquinone derivative is 3 parts by weight or more, the dissolution ratio between the exposed portion and the unexposed portion becomes high, and the photosensitivity is good. In order to obtain a good dissolution ratio, it is more preferably 5 parts by weight or more. The other side On the other hand, when the addition amount of the diazonaphthoquinone derivative is 20 parts by weight or less, the colorless transparency of the cured film is improved.

<Hardening aid>

As a hardening adjuvant used by this invention, there is a thing which decomposes by light irradiation, and promotes the condensation of a silanol group. Examples thereof include a photoacid generator that releases an active material that hardens the composition, that is, an acid, a photobase generator that releases an alkali, and the like. Here, examples of the light include visible light, ultraviolet rays, and infrared rays. Particularly preferred are those which generate an acid or an alkali by ultraviolet rays used for manufacturing a thin film transistor.

The addition amount of the hardening adjuvant differs depending on the type, amount of production, required sensitivity, and dissolution ratio of the exposed part and the unexposed part of the active material produced by the decomposition of the hardening adjuvant. 100 parts by weight of the polysiloxane mixture is preferably 0.001 to 10 parts by weight, and still more preferably 0.01 to 5 parts by weight. When the addition amount is 0.001 parts by weight or more, the dissolution ratio between the exposed portion and the unexposed portion becomes high, and the addition effect becomes good. On the other hand, if the addition amount of the curing aid is 10 parts by weight or less, cracks in the formed film can be suppressed, and coloring due to decomposition of the curing aid can be suppressed, so the colorless transparency of the film is improved.

Examples of the photoacid generator include a diazomethane compound, a diphenyliodonium salt, a triphenylsulfonium salt, a sulfonium salt, an ammonium salt, a sulfonium salt, a sulfonium imine compound, and the like. The structure of these photoacid generators can be represented by the general formula (A).

R ⁺ X ^- (A)

Here, R ⁺ represents hydrogen, a carbon atom, or an organic ion selected from the group consisting of an alkyl group, an aryl group, an alkenyl group, a fluorenyl group, and an alkoxy group modified with other heteroatoms, such as a diphenyliodonium ion, Triphenylphosphonium ion.

And, X ^- is preferably represented by the following formula according to any one kind of relative ion (counter ion).

_{^{SbY 6 - AsY 6 - R a}} p PY 6-p - R a q BY 4-q - R a q GaY 4-q - R a SO 3 - (R a SO 2) 3 C - (R a SO 2) _{^{2 N - R b COO - SCN}} -

(Where Y is a halogen atom; R ^a is an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms substituted with a substituent selected from fluorine, nitro and cyano; R ^b is hydrogen Or an alkyl group having 1 to 8 carbons; p is a value of 0 to 6; q is a value of 0 to 4).

As a specific ion relative to include the group comprising ^{_{BF 4 -, (C 6 F}} 5) 4 B -, ((CF 3) 2 C 6 H 3) 4 B -, PF 6 -, (CF 3 CF 2) ^{_{3 PF 3 -, SbF 6 -}} , (C 6 F 5) 4 Ga -, ((CF 3) 2 C 6 H 3) 4 Ga -, SCN -, (CF 3 SO 2) 3 C -, (CF 3 SO _{2) 2} N ^-, formate ion, acetate ion, trifluoromethanesulfonate ion, a nonafluorobutanesulfonate ion, a methanesulfonic acid ion, a butanesulfonic acid ion, a benzenesulfonate ion, toluenesulfonate ion and Group of sulfonic ion.

Among the photoacid generators used in the present invention, particularly preferred are those that generate sulfonic acids or boric acids. Examples include tolyl cumene sulfonium (pentafluorophenyl) boric acid (PHOTOINITIATOR 2074 (trade name) manufactured by Rhodia) ); Diphenyliodonium tetra (perfluorophenyl) boric acid; those in which the cation part is composed of a sulfonium ion and the anion part is composed of a pentafluoroborate ion.

In addition, triphenylsulfonium trifluoromethanesulfonic acid, triphenylsulfonium camphorsulfonic acid, triphenylsulfonium tetra (perfluorophenyl) boronic acid, 4-ethoxyfluorenyldimethylsulfonium hexafluoroarsenic acid, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothienium trifluoromethanesulfonic acid, 1- (4,7-dibutoxy-1-naphthalene) tetrahydrothienium trifluoromethanesulfonic acid , Diphenyliodonium trifluoromethanesulfonic acid, diphenyliodonium hexafluoroarsenic acid, and the like. Furthermore, a photoacid generator represented by the following formula may be used.

In the formula, A is independently selected from an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylcarbonyl group having 1 to 20 carbon atoms, and 6 carbon atoms. ~ 20 aryl carbonyl, hydroxyl and amine substituents; p is independently an integer of 0 ~ 5; B ^-can be listed: fluorinated alkylsulfonate, fluorinated arylsulfonate, fluorinated Alkyl borate, alkyl sulfonate, aryl sulfonate and the like. It is also possible to use a compound that exchanges the cations and anions represented by these chemical formulas with each other, or a photoacid generator that combines the cations or anions represented by these chemical formulas with the aforementioned various cations or anions. For example, a combination of any of the phosphonium ions represented by the chemical formula and a tetra (perfluorophenyl) borate ion, and any of the phosphonium ions represented by the chemical formula and a tetra (perfluorophenyl) borate ion can be used. The combination acts as a photoacid generator.

Examples of the photobase generator include a polysubstituted amidine compound having a fluorenyl group, a lactam, a fluorenimine compound, or a compound containing this structure.

Examples of the hot alkali generator include N- (2-nitrobenzyloxycarbonyl) imidazole, N- (3-nitrobenzyloxycarbonyl) imidazole, and N- (4-nitrobenzyloxycarbonyl) imidazole. , Imidazole derivatives such as N- (5-methyl-2-nitrobenzyloxycarbonyl) imidazole, N- (4-chloro-2-nitrobenzyloxycarbonyl) imidazole, 1,8-diazine bicyclic (5 , 4,0) Undecene-7, tertiary amines, quaternary ammonium salts, mixtures of these compounds. These alkali generators can be used singly or in combination with the same acid generators.

<Solvent>

Examples of the solvent include glycol monoalkane such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, and ethylene glycol monobutyl ether. Ethers; Diethylene glycol dialkyl ethers such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, etc .; methylcellulose acetate, Ethylene glycol alkyl ether acetates such as ethelacetate; propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, and other propylene glycol alkyl ether acetates; Aromatic hydrocarbons such as benzene, toluene, and xylene; ketones such as methyl ethyl ketone, acetone, methylpentyl ketone, methyl isobutyl ketone, and cyclohexanone. These solvents can be used alone or in combination of two or more kinds. The blending ratio of the solvents varies depending on the coating method or film thickness requirements after coating. For example, in the case of spray coating, it is 90% by weight or more based on the total weight of polysiloxane and an arbitrary component. However, it is generally 50% by weight in slit coating of a large glass substrate used for manufacturing a display. Above, preferably 60% by weight or more; generally 90% by weight or less, preferably 85% by weight or less.

<Optional component>

In addition, the photosensitive siloxane composition of the present invention may contain other optional components as required. Examples of such a component include a surfactant.

Among these components, a surfactant is preferably used in order to improve coating properties. Examples of the surfactant that can be used in the photosensitive silicone composition of the present invention include nonionic surfactants, anionic surfactants, and amphoteric surfactants.

Examples of the non-ionic surfactant include polyoxyethylene alkyl ethers such as polyoxyethylene dodecyl ether, polyoxyethylene oleyl ether, and polyoxyethylene cetyl ether. Ethers; and polyoxyethylene fatty acid diesters, polyoxy fatty acid monoesters, polyoxyethylene polyoxylates Acetylene glycol derivatives such as propylene block polymers, alkynols, acetylene glycols, polyethoxy alcohols of alkyne alcohols, and polyethoxy alcohols of acetylene glycols; fluorine-containing surfactants such as FLUORAD (trade name , Manufactured by Sumitomo 3M Co., Ltd.), MEGAFAC (trade name, manufactured by DIC Co., Ltd.), SULFURON (trade name, manufactured by Asahi Glass Co., Ltd.); or an organosiloxane surfactant such as KP341 (trade name, Shin-Etsu Chemical Co., Ltd.) Industry Co., Ltd.) and so on. Examples of the acetylene glycol include 3-methyl-1-butyne-3-ol, 3-methyl-1-pentyne-3-ol, and 3,6-dimethyl-4-octyne- 3,6-diol, 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,5-dimethyl-1-hexyne-3-ol, 2,5-dimethyl-3-hexyne-2,5-diol, 2,5-dimethyl-2,5-hexanediol, and the like.

Examples of the anionic surfactant include ammonium or organic amine salts of alkyl diphenyl ether disulfonic acid, ammonium or organic amine salts of alkyl diphenyl ether sulfonic acid, and alkyl benzene sulfonic acid. Ammonium salt or organic amine salt, polyoxyethylene alkyl ether sulfuric acid ammonium salt or organic amine salt, alkyl sulfuric acid ammonium salt or organic amine salt, and the like.

Examples of the amphoteric surfactant include 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolium trimethylammonium betaine (2-alkyl-N-carboxymethyl-N-hydroxyethylimidazoliumbetaine), Laurylamine propyl hydroxy hydroxytrimethylammonium betaine and the like.

These surfactants can be used singly or in combination of two or more. The blending ratio is generally 50 to 10,000 ppm, preferably 100 to 5,000 ppm, relative to the total weight of the photosensitive siloxane composition.

[Manufacturing method of thin film transistor with protective film]

A thin film transistor having a protective film (cured film) is obtained by applying a photosensitive silicone composition to a thin film transistor and heating it. At this time, a pattern such as a contact hole can be formed by performing exposure and development through a desired mask.

As a method for manufacturing a thin-film transistor substrate having an oxide semiconductor layer, a bottom-gate thin-film transistor (TFT) shown in FIG. 1 will be described as an example. The gate electrode 2 is patterned on a substrate made of glass or the like. The gate electrode material may be composed of a single layer or a laminate of two or more materials such as molybdenum, aluminum and aluminum alloys, copper and copper alloys, and titanium. A gate insulating film 3 is formed on the gate electrode. Generally, a silicon oxide film, a silicon nitride film, a silicon nitride oxide film, and the like can be formed as a gate insulating film by a PE-CVD method. The thickness of the gate insulating film is generally 100 to 300 nm. The oxide semiconductor layer 4 on the gate insulating film can be formed by a sputtering method in which a sputtering target having the same composition as an oxide semiconductor is formed by DC sputtering or RF sputtering, and by a sputtering method A liquid phase method in which a precursor solution such as a metal alkoxide, a metal organic acid salt, and a chloride, and a dispersion liquid of oxide semiconductor nano particles are applied and fired to form an oxide semiconductor layer. After patterning the oxide semiconductor layer 4, a source is performed. The drain electrodes 5 and 6 are patterned. As the source. The drain electrode material may be composed of a single layer or a laminated film of two or more materials such as molybdenum, aluminum and aluminum alloy, copper and copper alloy, and titanium.

A method for manufacturing a thin-film transistor substrate with a protective film is to apply a photosensitive siloxane composition to a thin-film transistor having the above-mentioned oxide semiconductor layer, dry it by pre-baking, and then expose it. After developing with a tetramethylammonium hydroxide aqueous solution (usually a 2.38% aqueous solution) to form a pattern such as a contact hole, the coated photosensitive siloxane composition (protective film precursor layer) is cured to form a protective film 7. In addition, for example, an indium tin oxide (ITO) film is formed on the protective film by a sputtering method, and the element shown in FIG. 3 is formed by patterning the film. In addition, an inorganic film may be formed on the protective film by CVD or PVD, or an organic material may be provided on the protective film by a coating method for the purpose of protective film or planarization.

Hereinafter, each step of the manufacturing method of this invention is demonstrated.

<Procedure for Preparing Photosensitive Silane Composition>

In the method for manufacturing a thin film transistor substrate provided with a protective film of the present invention, a photosensitive silicone composition containing at least two polysiloxanes, a photosensitizer, and a solvent having different alkali dissolution rates is prepared. The detailed description of each component of a photosensitive silicone composition is as follows.

<Coating step>

The coating step of the present invention is performed by coating the photosensitive siloxane composition on the surface of a thin film transistor. Any conventionally known method can be used as a conventional photosensitive composition, such as dip coating, roll coating, bar coating, bristle coating, spray coating, doctor blade coating, shower coating, spin coating, slit coating, and the like. Coating method to perform the coating step. The coating can be repeated one or more times as required to make the protective film precursor layer into a desired film thickness.

<Pre-baking step>

After the protective film precursor layer is formed, in order to further dry the layer and reduce the residual amount of the solvent, it is preferable to pre-bake the layer (plus Heat treatment). The pre-baking step is generally at a temperature of 70 to 150 ° C, preferably 90 to 130 ° C, in the case of a heating plate, 10 to 180 seconds, preferably 30 to 90 seconds, and in the case of a clean oven Can be implemented for 1 to 5 minutes. It is preferable to include a solvent removing step of performing spin and vacuum before the pre-baking.

<Exposure Step>

After the protective film precursor layer is formed, light is irradiated on the surface. As a light source used for light irradiation, any light source used in a conventional patterning method can be used. Examples of such a light source include high-pressure mercury lamps, low-pressure mercury lamps, lamps such as metal halides, xenon, laser diodes, and LEDs. As the irradiation light, ultraviolet rays such as g rays, h rays, and i rays are generally used. In addition to semiconductor-based microfabrication, 360 to 430 nm light (high-pressure mercury lamp) is generally used for patterning from several micrometers to tens of micrometers. Among them, in the case of a liquid crystal display device, 430 nm light is often used. Although the irradiation light by the energy source and the film thickness of the protective film precursor layer varies, but the diazonaphthoquinone derivative is positive type, it is generally 20 ~ 2000mJ / cm ^2, preferably 50 ~ 1000mJ / cm ² . If the irradiation light energy is less than 20 mJ / cm ² , sufficient resolution may not be obtained. Conversely, if the irradiation light energy is higher than 2000 mJ / cm ² , it may become overexposed and may cause halation. Moreover, in the case of a negative type, it is 1 to 500 mJ / cm ² , and preferably 10 to 100 mJ / cm ² . When the irradiation light energy is less than 1mJ / cm ^2, the film becomes too thin, and conversely, if higher than 500mJ / cm ^2, it becomes too much exposure, the resolution can not be obtained with the case.

In order to irradiate light into a pattern shape, a general photomask can be used. Such a mask may be selected from any known person. The environment during exposure is not special It is not limited as long as it is a general ambient gas environment (in the atmosphere) or a nitrogen environment. In the case where a thin film is formed on the entire surface of the substrate, light irradiation may be performed on the entire surface of the substrate. In the present invention, the term "pattern film" also includes a case where a thin film is formed on the entire surface of such a substrate.

<Post-exposure heating step>

After the exposure, in order to promote the reaction between the polymers in the film due to the reaction initiator that occurs at the exposed portion, post exposure curing (Post Exposure Baking) may be performed as required. This heat treatment is performed not to completely harden the protective film precursor layer, but to leave only a desired pattern on the substrate after development, and to remove other portions by development.

<Developing step>

After the exposure, after the post-exposure heating as required, the protective film precursor layer is developed. As a developing solution used for development, any conventionally known developing solution for developing a photosensitive siloxane composition can be used. In the present invention, a tetramethylammonium hydroxide (TMAH) aqueous solution is used in order to specify the dissolution rate of polysiloxane, but the developing solution used when forming a cured film is not limited to this. Examples of the preferred developer include tetraalkylammonium hydroxide, choline, alkali metal hydroxide, alkali metal metasilicate (hydrate), alkali metal phosphate (hydrate), ammonia, and alkyl groups. Aqueous solutions of alkaline compounds such as amines, alkanolamines, and heterocyclic amines, that is, alkaline developing solutions, and particularly preferred alkaline developing solutions are TMAH aqueous solutions. The alkali developing solution may further include a water-soluble organic solvent such as methanol, ethanol, or a surfactant, as required. The development method can also be known from the past Arbitrary choice in method. Specific examples include methods such as dipping in a developing solution, paddle, showering, slit coating, dip coating, spray coating, and the like. By this development, a pattern can be obtained. It is preferable to wash with water after developing with a developing solution. In addition, in the manufacturing method of the present invention, as shown in FIG. 3, a transparent electrode (pixel electrode 8) formed on the drain electrode 6 and the protective film 7 may be formed through the contact hole 9 formed by development. ) Conduction.

<Irradiation step after development>

When a positive-type composition is used and the formed protective film is used as a transparent film, it is preferable to perform light irradiation called bleaching exposure. By performing bleach exposure, the unreacted diazonaphthoquinone derivative remaining in the film undergoes photodecomposition, and the light transparency of the film is further improved. As a method of bleaching exposure, based high pressure mercury lamp, low pressure mercury lamp, etc., based on the thickness, (in terms of the amount of exposure wavelength of 365nm) is blanket exposure to 100 ~ 2,000mJ / cm ² or so. Moreover, in the case of a negative type, the hardening adjuvant in the residual film after development is activated by light irradiation, and the subsequent heat hardening can be performed more easily. According to the film thickness, full exposure is performed at about 100 to 2,000 mJ / cm ² (equivalent to 365 nm wavelength exposure).

<Heat-curing (firing) step>

The firing temperature when the protective film precursor layer is hardened may be arbitrarily selected as long as it is a temperature at which the protective film can be hardened. However, if the firing temperature is too low, the reaction may not proceed sufficiently and the curing may not be performed sufficiently. Therefore, the firing temperature is preferably 200 ° C or higher, and more preferably 250 ° C or higher.

If the temperature is too high, the manufacturing cost may increase, and the polymer may be decomposed. From this viewpoint, the temperature is preferably 500 ° C or lower. It is more preferably 400 ° C or lower. The firing time is not particularly limited, but it is generally 10 minutes or more, and preferably 20 minutes or more. It can be fired in an inert gas or the atmosphere.

<Annealing step>

After forming a thin film transistor having a protective film, annealing of the thin film transistor is performed. In particular, an element using an oxide semiconductor degrades the performance of a thin-film transistor because it is formed by PVD or CVD, pattern processing of dry etching and wet etching, and a step of peeling off a photoresist. Therefore, annealing is desired. To restore performance. After the protective film in the present invention is formed, annealing is performed at 250 ° C. or higher, thereby recovering the performance of the thin-film transistor that was once reduced during processing. In the present invention, it is particularly characterized in that a greatly deteriorated thin film transistor having an oxide semiconductor layer has a large performance recovery by annealing in the presence of oxygen. According to the deterioration degree of the oxide semiconductor, the annealing temperature is increased, or the annealing time is extended, thereby recovering the performance of the thin film transistor and improving the reliability of the device. The annealing temperature is from 250 ° C to 450 ° C, preferably from 300 ° C to 400 ° C. The annealing time is 30 minutes or more, preferably 60 minutes or more, but from the viewpoint of cost and production efficiency, it is more preferably 60 minutes or more and less than 120 minutes. The annealing is preferably performed in the presence of oxygen. In the case of a thin-film transistor substrate having a protective film formed of a conventional organic coating film, annealing at such a high temperature cannot be performed, so that the effect of substantially recovering performance by annealing cannot be achieved. However, the oxidation of the electrode and the coloration caused by the oxidation of the protective film of the present invention are considered. The effect is preferably annealing at 400 ° C or lower in the presence of oxygen. In addition, the protective film formed with the photosensitive siloxane composition of the present invention has photosensitivity, so that pattern processing such as dry etching is not required. Therefore, it has less damage to the performance of the thin film transistor and shortens the annealing time advantage.

[Example]

The present invention will be described in more detail with examples, as follows.

Synthesis example 1 (synthesis of polysiloxane (I))

In a 2 L flask equipped with a stirrer, thermometer, and cooling tube, 36.5 g of a 25% by weight aqueous solution of tetramethylammonium hydroxide (TMAH), 300 ml of isopropyl alcohol (IPA), and 1.5 g of water were placed, and then a dropping funnel was placed. In this step, a mixed solution of 44.6 g of phenyltrimethoxysilane, 34.1 g of methyltrimethoxysilane, and 3.8 g of tetramethoxysilane was mixed. This mixed solution was dropped at 60 ° C. and stirred at the same temperature for 3 hours, and then a 10% aqueous HCl solution was added for neutralization. 200 ml of toluene and 300 ml of water were added to the neutralization solution, and the mixture was separated into two layers. The obtained organic layer was concentrated under reduced pressure to remove the solvent, so that the propylene glycol had a solid concentration of 40% by weight. Methyl ether acetate (PGMEA) was added to the concentrate for mixing. The molecular weight (in terms of polystyrene) of the obtained polysiloxane (I) was a weight average molecular weight (Mw) = 1,420. The obtained resin solution was coated on a silicon wafer so that the film thickness after pre-baking was 2 μm, and the dissolution rate with respect to the 5% TMAH aqueous solution was measured to be 950 Å / sec.

Synthesis example 2 (synthesis of polysiloxane (II))

In a 2 L flask equipped with a stirrer, a thermometer, and a cooling tube, 36.5 g of a 25% by weight TMAH aqueous solution, 800 ml of IPA, 2.0 g of water, and then a mixed solution of 39.7 g of phenyltrimethoxysilane, 34.1 g of methyltrimethoxysilane, and 7.6 g of tetramethoxysilane was mixed in a dropping funnel. After the mixed solution was dropped at 10 ° C and stirred at the same temperature for 24 hours, a 10% aqueous HCl solution was added to neutralize. 400 ml of toluene and 100 ml of water were added to the neutralization solution, and the mixture was separated into two layers. The solvent was removed by concentrating the obtained organic layer under reduced pressure, so that the solid content concentration was 40% by weight. Add to the concentrate and mix. The molecular weight (in terms of polystyrene) of the obtained polysiloxane (II) was Mw = 2,200. The obtained resin solution was coated on a silicon wafer so that the film thickness after pre-baking was 2 μm, and the dissolution rate with respect to a 2.38% TMAH aqueous solution was measured to be 490 Å / sec.

Positive photosensitive siloxane composition A

After mixing at a ratio of polysiloxane (I): (II) = (80% by weight): (20% by weight), the polysiloxane mixture was adjusted to a 35% PGMEA solution so that Add 2.0 mol of 4-4 '-(1- (4- (1- (4-hydroxyphenol) -1-methylethyl) phenyl) ethylene) bisphenol to 12% by weight Naphthoquinone Modified Product (hereinafter referred to as "PAC"). In addition, KF-53 manufactured by Shin-Etsu Chemical Industry Co., Ltd. was added as a surfactant so as to be 0.3% by weight based on polysiloxane, and a photosensitive silicone composition A was obtained.

Example 1 (thin film transistor substrate with protective film of the present invention)

On the n-type doped silicon wafer, a 100 nm silicon oxide film is provided as a gate insulating film. A film (70 nm) of amorphous InGaZnO was formed on the gate insulating film by RF sputtering. After the pattern of the amorphous InGaZnO film is formed, the source electrode will be formed. The drain electrode is patterned. Use molybdenum as the source. Drain electrode material. Thereafter, the thin film transistor was annealed at 300 ° C for 1 hour. Next, a positive-type photosensitive silicone composition A was applied as a protective film by a spin coating method. After pre-baking at 100 ° C for 90 seconds, contact holes were formed by exposure and development.

Then, it was cured in a nitrogen atmosphere at 250 ° C. for 60 minutes to form a protective film. The thin film transistor provided with a protective film is annealed. Annealing was performed at 250 ° C for 1 hour in an oxygen environment. The protective film thickness was 400 nm. Figure 4 shows the transmission characteristics of the thin film transistor with a protective film after annealing. When stress is applied to a positive voltage, there is almost no change in characteristics, and good transmission characteristics of a thin film transistor can be obtained.

Comparative Example i (thin-film transistor substrate provided with a protective film containing a photosensitizer and one polysiloxane)

Polysiloxane (II) was adjusted to a 35% PGMEA solution, and 2.0 mol 4-4 '-(1- (4- (1- (4-hydroxyphenol) -1-methylethyl) phenyl) ethylene) bisphenol diazonaphthoquinone modified product (hereinafter referred to as "PAC"). In addition, KF-53 manufactured by Shin-Etsu Chemical Industry Co., Ltd. was added as a surfactant in an amount of 0.3% by weight based on polysiloxane to obtain a photosensitive silicone composition B. As in Example 1, a photosensitive siloxane composition B was applied as a protective film by a spin coating method. After pre-baking at 100 ° C for 90 seconds, contact holes were formed by exposure and development. Then, when it was hardened in a nitrogen environment at 250 ° C. for 60 minutes, the contact holes formed by development disappeared due to heat flow, and the transistor characteristics could not be measured.

Comparative example 2 (thin film transistor substrate without protective film)

On the gate electrode, a 100 nm silicon oxide film is provided as a gate insulating film. An amorphous InGaZnO was formed on the gate insulating film by an RF sputtering method. After the amorphous InGaZnO film is patterned, the source is performed. Patterning of the drain electrode. Use molybdenum as the source. Drain electrode material. Without a protective film, a thin film transistor without the protective film is annealed. Annealing was performed at 300 ° C for 2 hours. As shown in Fig. 5, the recovery performance by annealing is insufficient. Figure 6 shows the transmission characteristics of a thin film transistor. The change in the characteristics to the stress applied by the positive voltage is large, and the transmission characteristics of the unstable thin film transistor are obtained.

Reference example 1 (thin film transistor substrate provided with a protective film containing one type of polysiloxane)

Methylphenylsilsesquioxane (methyl: phenyl = 60 mol: 40 mol) was synthesized in the presence of a basic catalyst. The molecular weight (in terms of polystyrene) was Mw = 1,800. It is almost insoluble with respect to 5% TMAH aqueous solution, and the dissolution rate is about 0 Å / sec. The obtained polymer was adjusted to a 35% PGMEA solution, and KF-53 manufactured by Shin-Etsu Chemical Industry Co., Ltd. was added as a surfactant in an amount of 0.3% by weight based on polysiloxane to obtain a silicone composition C. In the same manner as in Example 1, the prepared silicone InGaZnO was spin-coated on the prepared amorphous InGaZnO, and then pre-baked at 100 ° C for 90 seconds and hardened (300 ° C, 1 hour). , Nitrogen) to form a protective film. After the contact hole is formed by dry etching, the thin film transistor is annealed in an oxygen environment at 300 ° C. for 1 hour. Figure 7 shows the transmission characteristics of a thin film transistor. Deterioration in characteristics occurs due to dry etching after the protective film is applied. Also, because It exhibits characteristics close to the initial characteristics for annealing. The change in characteristics caused by the applied stress was verified, and a large change in characteristics as shown in FIG. 8 was confirmed.

Reference example 2 (thin film transistor substrate provided with a protective film including an acrylic material)

For "acrylic resin containing 2-hydroxyethyl methacrylate and polymer containing vinyl silane polymer (Shinyue Chemicals KBM-5103)" and "methylphenylsilsesquioxane synthesized in Comparative Example 3" The composition is adjusted. 30% by weight of acrylic resin was added to 100% by weight of methylphenylsilsesquioxane. As in the examples, a surfactant was added and adjusted to a 35% solution. As in Comparative Example 3, a protective film was formed on the amorphous InGaZnO and contact holes were formed by dry etching. Then, the thin film transistor was annealed in an oxygen atmosphere at 300 ° C. for 1 hour. Figure 9 shows the transmission characteristics of thin film transistors before and after annealing. After annealing, good transistor characteristics such as high current flowing in the negative voltage region cannot be obtained.

Claims (4)

A manufacturing method is a method for manufacturing a thin-film transistor substrate. The thin-film transistor substrate includes a thin-film transistor having a semiconductor layer composed of an oxide semiconductor, and a photosensitive silicon oxide composition covering the thin-film transistor. A protective film made of a cured product. The manufacturing method includes the steps of preparing a photosensitive silicone composition containing at least two polysiloxanes and photosensitizers having different alkali dissolution rates. And a solvent, the at least two polysiloxanes having different alkali dissolution rates include polysiloxane (I), which is a combination of a silane compound represented by the following formula (1) and a silane compound represented by the following formula (2) Polysiloxane obtained by hydrolysis and condensation in the presence of an alkaline catalyst. The pre-baked film can be dissolved in a 5% by weight aqueous solution of tetramethylammonium hydroxide, and the dissolution rate is below 1000 Å / s. RSi (OR ¹ ) ₃ . ． ． (1) Si (OR ¹ ) ₄ . ． ． (2) (In the formula, R represents a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, or a linear chain having 1 to 20 carbon atoms in which at least one methylene group can be replaced by oxygen, A branched or cyclic alkyl group, or an aryl group having 6 to 20 carbon atoms, or at least one aryl group having 6 to 20 carbon atoms whose hydrogen can be replaced by fluorine; R ¹ represents an alkyl group having 1 to 5 carbon atoms ); And polysiloxane (II), which is a polysiloxane obtained by subjecting at least the silane compound of the general formula (1) to hydrolysis and condensation in the presence of an acidic or basic catalyst, and its pre-baking The latter film can be dissolved in a 2.38% by weight aqueous solution of tetramethylammonium hydroxide, and the dissolution rate is 100Å / sec or more; the photosensitive siloxane composition is coated on a thin film transistor, and the solvent is dried to form a protective film precursor A step of exposing the protective film precursor layer; a step of developing the exposed protective film precursor layer; a step of developing the protective film precursor layer at 200 ° C to 500 ° C A step of forming a protective film by heating and hardening at a temperature of more than 10 minutes at a temperature; and The step of annealing at least once at a temperature of 0 ° C to 450 ° C for a period of 30 minutes or more and less than 120 minutes. The method according to claim 1, wherein the annealing is performed in an oxygen environment at a temperature of 250 ° C to 400 ° C. The manufacturing method of claim 1 or 2, wherein the annealing is performed at a temperature of 300 ° C or higher and 400 ° C or lower. The manufacturing method as claimed in claim 1 or 2, comprising the step of forming a second protective film on the protective film.