KR20080030454A - Composition for dielectric thin film, metal oxide dielectric thin film using the same and preparation method thereof - Google Patents

Abstract

A composition for a dielectric thin film is provided to allow application of a low-temperature process, to realize a high dielectric constant, and to impart a low driving voltage and high charge transportability to electronic devices. A composition for a dielectric thin film comprises: a metal halide represented by the formula of MaXb (wherein M is a metal element selected from Group 1-14 metals, X is a halogen atom, a is an integer of 1-3, and b is an integer of 1-10), as a metal oxide precursor; at least one of metal alkoxide and ether compound; and an organic solvent. The composition preferably comprises 0.1-50 wt% of a metal halide, 0.1-50 wt% of at least one of metal alkoxide and ether compound, and the balance amount of an organic solvent.

Description

Composition for Dielectric Thin Film, Metal Oxide Dielectric Thin Film Using the Same and Preparation Method Thereof}

1 is a schematic cross-sectional view of a thin film transistor having a top contact structure according to an embodiment of the present invention;

2 is a schematic cross-sectional view of a thin film transistor having a bottom contact structure according to an embodiment of the present invention;

3 is a schematic cross-sectional view of a thin film transistor having a top contact structure according to Example 7;

4 is a schematic cross-sectional view of a thin film transistor having a top contact structure according to Example 8;

5 is a graph showing the results of analyzing the composition of the dielectric thin film prepared in Examples 3 to 6,

6 is a schematic cross-sectional view of a device for measuring electrical properties of a dielectric thin film prepared according to Example 1,

7 is a graph showing the results of measuring electrical characteristics of the device of FIG. 6;

8A and 8B are graphs showing the results of measuring electrical characteristics of the thin film transistors fabricated in Example 6 and Comparative Example 1, respectively;

9A and 9B are graphs showing the results of measuring electrical characteristics of the thin film transistors manufactured in Example 8, respectively.

<Explanation of symbols for the main parts of the drawings>

1: substrate 2: gate electrode 3: gate insulating layer

4 source electrode 5 drain electrode 6 semiconductor layer

The present invention relates to a dielectric thin film composition, a metal oxide dielectric thin film using the same, and a method for manufacturing the same. More specifically, a low temperature process is possible, and a dielectric thin film composition having a high dielectric constant (high-k) property. The present invention relates to a metal oxide dielectric thin film formed by using the same, a method of manufacturing the same, a transistor device including the dielectric thin film, and an electronic device having excellent electrical characteristics such as low driving voltage and high charge mobility, including the transistor device.

A thin film transistor (TFT) is a switching element that controls the operation of each pixel and a driving element of each pixel in a flat panel display device such as a liquid crystal display device (LCD) or an electroluminescence display device (ELD). It is used. In addition, thin film transistors are expected to be used in plastic chips for smart cards or inventory tags.

A high-k dielectric material is used as a gate insulating film of the thin film transistor, and a method of manufacturing the high-k dielectric thin film includes vacuum deposition processes such as chemical vapor deposition (CVD) and atomic layer deposition (ALD). vacuum deposition process and solution process using hydrolytic sol-gel method. Since the vacuum deposition method requires expensive equipment and is carried out under conditions of high temperature and high vacuum, the hydrolytic sol-gel method, which is a solution process that can be carried out at low cost, has recently attracted attention.

The hydrolysis sol-gel method is a technique using a process in which a sol generated by hydrolysis of a metal alkoxide or metal salt in a solution is gelled by a polycondensation reaction. The sol-gel process is carried out through three stages of reaction: hydrolysis, alcohol producing condensation, and water producing condensation. In the water condensation step, an oxide having a hydroxyl group is converted into a final oxide form. This conversion process does not proceed at low temperature, but only at a high temperature of 400 to 500 ° C. or higher. The high temperature process that proceeds at a high temperature of 400 ℃ or more has a problem that causes deformation and damage of a conventional substrate.

The present invention is to solve the problems of the prior art as described above, it is an object of the present invention to provide a dielectric film composition having a characteristic of high dielectric constant as well as a low temperature process is possible.

Another object of the present invention is to provide a metal oxide dielectric thin film formed using the composition and a method of manufacturing the same.

It is still another object of the present invention to provide a transistor device including the metal oxide dielectric thin film and an electronic device including the transistor device having excellent electrical characteristics such as low driving voltage and high charge mobility.

One aspect of the present invention for achieving the above object is a metal halide represented by the formula (1) which is a metal oxide precursor; A dielectric thin film composition comprising at least one of metal alkoxides and ether compounds and an organic solvent.

M _a X _b

Where

M is a metal of Groups 1 to 14,

X is a halogen element,

a is an integer of 1 to 3,

b is an integer from 1 to 10.

Another aspect of the present invention for achieving the above object is

(a) a metal halide represented by Formula 1 as a metal oxide precursor: and dissolving at least one of a metal alkoxide and an ether compound in an organic solvent to prepare a metal oxide precursor solution;

(b) coating the metal oxide precursor solution prepared in the previous step onto the substrate; And

(C) a method of manufacturing a metal oxide dielectric thin film comprising the step of obtaining a thin film by heat-treating the coated substrate.

[Formula 1]

M _a X _b

Where

 M is a metal of Groups 1 to 14,

       X is a halogen element,

a is an integer of 1 to 3,

b is an integer from 1 to 10.

Another aspect of the present invention for achieving the above object relates to a metal oxide dielectric thin film prepared by thinning the composition.

Another aspect of the present invention for achieving the above object relates to a transistor device comprising the metal oxide dielectric thin film.

Another aspect of the present invention for achieving the above object relates to an electronic device comprising the transistor device.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

In one embodiment, a dielectric thin film composition may include a metal halide represented by Chemical Formula 1 as a metal oxide precursor; At least one of metal alkoxides and ether compounds and an organic solvent.

[Formula 1]

M _a X _b

Where

M is a metal of Groups 1 to 14,

X is a halogen element,

a is an integer of 1 to 3,

b is an integer from 1 to 10.

When the dielectric thin film composition of the present invention is coated on a substrate and then heat treated, a dielectric thin film having a high dielectric constant may be manufactured. Since the dielectric thin film composition of the present invention forms a thin film by a non-hydrolyzed sol-gel method, a low temperature process is possible. The dielectric thin film manufactured using the composition of the present invention can be applied to a next generation high capacity memory material, a transistor gate insulating material, and the like, which replaces silicon oxide.

In the present invention, the metal of the metal precursor belongs to Groups 1 to 14, and may be used without limitation as long as the metal oxide is an insulator. Preferred examples of such metals include, but are not limited to, titanium (Ti), zirconium (Zr), hafnium (Hf), aluminum (Al), tantalum (Ta), silicon (Si), and the like.

The metal alkoxide of the dielectric thin film composition of the present invention may be represented by the following Chemical Formula 2.

M _a (OR ₁ ) _n

Where

M _a is a metal of Groups 1 to 14,

a is an integer of 1 to 3,

R ₁ is a hydrogen atom, a C1-C10 alkyl group, a C3-C10 cycloalkyl group or a C6-C15 aryl group, a C2-C30 acryloyl group, a C1-C10 acryloyloxy group, C1-C10 Alkyl group or cycloalkyl group substituted by epoxy group, C1-C10 vinyl group, C1-C10 allyl group, C1-C10 epoxy group, or C1-C10 alkoxy group,

n is an integer of 1-6.

In the present invention, the ether compound may be represented by the following formula (3).

R ₂ OR ₁

Where

R ₁ and R ₂ are each independently a hydrogen atom, an alkyl group of 1 to 10 carbon atoms, a cycloalkyl group of 3 to 10 carbon atoms or an aryl group of 6 to 15 carbon atoms, an acryloyl group of 2 to 30 carbon atoms, or an acryloyl jade of 1 to 10 carbon atoms. It is an alkyl group or a cycloalkyl group by which the C1-C10 epoxy group was substituted, a C1-C10 vinyl group, a C1-C10 allyl group, a C1-C10 epoxy group, or a C1-C10 alkoxy group.

As the organic solvent in the present invention, a conventional organic solvent may be used without particular limitation. Preferably, a hydrocarbon solvent such as hexane; Aromatic hydrocarbon solvents such as anisol, mesitylene or xylene; Ketone-based solvents such as methyl isobutyl ketone, 1-methyl-2-pyrrolidinone, and acetone; Ether-based solvents such as di (propylene glycol) methyl ether, cyclohexanone, tetrahydrofuran and isopropyl ether; Acetate-based solvents such as ethyl acetate, butyl acetate, and propylene glycol methyl ether acetate; Alcohol-based solvents such as alkoxy alcohol and butyl alcohol; Amide solvents such as dimethylacetamide and dimethylformamide; Silicon-based solvents; And it is preferable to use at least 1 sort (s) chosen from the group which consists of these mixtures. More preferred organic solvents include alkoxy alcohols such as 2-methoxy ethanol and ether solvents such as di (propylene glycol) methyl ether.

The composition ratio of the dielectric thin film composition of the present invention can be appropriately selected by those skilled in the art in some cases, but in terms of solubility of the dielectric thin film composition, 0.1 to 50% by weight of the metal halide; It is preferred to include 0.1 to 50% by weight of the metal alkoxide or ether compound and the balance of the solvent. More preferably, 1 to 20% by weight of the metal halide; It is preferred to include 1 to 20% by weight of the metal alkoxide or ether compound and the balance of the solvent.

In addition, in order to increase the solubility and shelf life of the dielectric thin film composition, those skilled in the art can appropriately determine organic binders, photosensitive monomers, photoinitiators, viscosity modifiers, storage stabilizers, wetting agents, etc. within the scope of not impairing the object of the present invention. One or more other additives of may be further added. Other additives, such as the organic binder, can be used without limitation, known materials known in the art of conventional electronic devices, respectively.

Another aspect of the invention relates to a method for producing a metal oxide dielectric thin film using the composition. When preparing a dielectric thin film by the method of the present invention, first, at least one of a metal halide, a metal alkoxide, and an ether compound represented by the following Chemical Formula 1 is dissolved in an organic solvent to prepare a metal oxide precursor solution.

[Formula 1]

M _a X _b

Where

M is a metal of Groups 1 to 14,

X is a halogen element,

a is an integer of 1 to 3,

b is an integer from 1 to 10.

The metal oxide precursor solution is then coated onto the substrate. Finally, the substrate coated for the sol-gel process is heat-treated to obtain a metal oxide thin film. In such a sol-gel process, a metal oxide thin film is formed by a non-hydrolytic sol-gel method.

In the present invention, the non-hydrolyzed sol-gel process may be performed by the reaction of a metal halide and a metal alkoxide represented by Scheme 1 (alkoxide route).

M _a X _b + M _a (OR ₁ ) _b → 2M _a O _{b / 2} + bR ₁ X

Wherein M _a is a metal of Groups 1 to 14,

X _b is a halogen element, a is an integer from 1 to 3,

b is an integer from 1 to 10,

R ₁ is a hydrogen atom, a C1-C10 alkyl group, a C3-C10 cycloalkyl group or a C6-C15 aryl group, a C2-C30 acryloyl group, a C1-C10 acryloyloxy group, An alkyl group or a cycloalkyl group substituted with a C 1-10 epoxy group, a C 1-10 vinyl group, a C 1-10 allyl group, a C 1-10 epoxy group, or a C 1-10 alkoxy group,

n is an integer of 1-6.

However, although the metal components of the metal halide and the metal alkoxide are represented by the same formula, it may be different from the above scheme, and the metal of the metal halide may be composed of two or more metal elements.

In Reaction Scheme 1, as a metal belonging to Groups 1 to 14, if the metal oxide represented by Formula 1 is an insulator, it may be used without limitation, titanium (Ti), zirconium (Zr), hafnium (Hf) Preferred is any one metal selected from the group consisting of aluminum (Al), tantalum (Ta) and silicon (Si).

Further, the halogen element may be used without limitation as long as it is a halogen element such as fluorine (F), chlorine (Cl), bromine (Br), and iodine (I), but fluorine, chlorine or bromine is preferable.

In the present invention, the non-hydrolyzed sol-gel method may also be carried out by the reaction of the metal halide and the ether compound represented by the following Scheme 2 (ether route). In this reaction, metal halides and ether compounds react to form metal alkoxides, and the metal alkoxides formed may react with metal halides to form metal oxides.

M _a X _b + b / 2R ₂ OR ₁ → 1/2 Ma (OR ₁ ) _b + b / 2R ₂ X _a (+ 1 / 2M _a X _b )

1 / 2M _a X _b + 1 / 2M _a (OR ₁ ) _b → M _a O _{b / 2} + R ₁ X _b

In the above scheme,

M _a is a metal of Groups 1 to 14,

X _b is a halogen element,

a is an integer of 1 to 3,

b is an integer from 1 to 10,

R ₁ and R ₂ are each independently a hydrogen atom, an alkyl group of 1 to 10 carbon atoms, a cycloalkyl group of 3 to 10 carbon atoms or an aryl group of 6 to 15 carbon atoms, an acryloyl group of 2 to 30 carbon atoms, or an acryloyl jade of 1 to 10 carbon atoms. Alkyl group or cycloalkyl group by which the C1-C10 epoxy group was substituted, C1-C10 vinyl group, C1-C10 allyl group, C1-C10

An epoxy group or an alkoxy group having 1 to 10 carbon atoms,

n is an integer of 1-6.

In Reaction Scheme 2, any metal belonging to Groups 1 to 14 can be used. Examples of preferred metals may include titanium (Ti), zirconium (Zr), hafnium (Hf), aluminum (Al), tantalum (Ta), silicon (Si), and the like. Therefore, an insulating thin film of TiO ₂ , SiO ₂ , ZrO ₂ , HfO ₂ , Al ₂ O ₃ , Ta ₂ O _3, or the like may be obtained by the non-hydrolytic sol-gel method.

In the above description, the method for reacting a metal halide with either one of the metal alkoxide and the ether compound has been described, but it is also possible to simultaneously react the metal halide with the metal alkoxide and the ether compound.

In the case of the hydrolysis sol-gel method, an oxide having a hydroxyl group (-OH) cannot be converted into a final oxide at a low temperature, and thus a high temperature process of 400 to 500 ° C or higher is required. On the other hand, according to the non-hydrolytic sol-gel method used in the present invention, since the hydroxyl group can be excluded in the reaction process, a low temperature process becomes possible.

Each step of the present invention will be described in more detail as follows.

In the metal precursor solution preparation step, one or more of the metal halide and the metal alkoxide and the ether compound represented by Chemical Formula 1 are prepared by dissolving in an organic solvent.

The composition ratio of the metal precursor solution of the present invention is not particularly limited and may be appropriately determined and selected by those skilled in the art in some cases. For example, the metal precursor solution may include 0.1 to 50 wt% of a metal halide; It may be prepared by mixing in a conventional manner at a ratio of 0.1 to 50% by weight of the metal alkoxide or ether compound and the residual solvent.

As the organic solvent, a conventional organic solvent may be used without particular limitation. Preferably hydrocarbon solvent, such as hexane; Aromatic hydrocarbon solvents such as anisole, methylene or xylene; Ketone solvents such as methyl isobutyl ketone, 1-methyl-2-pyrrolidinone and acetone; Ether solvents such as di (propylene glycol) methyl ether, cyclohexanone, tetrahydrofuran and isopropyl ether; Acetate solvents such as ethyl acetate, butyl acetate and propylene glycol methyl ether acetate; Alcohol solvents such as alkoxy alcohol and butyl alcohol; Amide solvents such as dimethylacetamide and dimethylformamide; Silicone solvents; And one or more selected from the group consisting of mixtures thereof.

As the substrate used in the coating step of (b), any substrate, such as glass, silicon wafer, polyethylene terephthalate, polycarbonate, polyethersulfone or polyethylene naphthalate, may be used.

As the coating method of the metal precursor solution, spin coating, dip coating, roll coating, screen coating, spray coating, spin casting, flow coating, screen printing, ink jetting, and drop casting may be used. It is most preferred to use spin coating or ink jetting in terms of convenience and uniformity. In the case of performing spin coating, the spin speed is preferably adjusted in the range of 100 to 10,000 rpm.

The heat treatment method of step (c) includes the step of baking the composition coated on the substrate and then curing. The baking step is heated in a nitrogen or air or vacuum atmosphere for 1 second to 5 minutes at a temperature of 50 to 250 ℃, the curing step is nitrogen, air or vacuum atmosphere for 10 minutes to 10 hours at a temperature of 100 to 1,000 ℃ Preference is given to performing under.

The heat treatment in this way yields a thin film of metal oxide represented by the formula (4).

M _x O _y

Wherein M is a metal of Groups 1 to 14,

x is 1 or 2,

1 ≦ y ≦ 10.

Preferred examples of such metal oxides are TiO ₂ , SiO ₂ , ZrO ₂ , HfO ₂ , Al ₂ O ₃ , Ta ₂ O ₅ And the like, but are not necessarily limited thereto.

The thickness of the dielectric thin film of the present invention is not particularly limited, but is preferably in the range of about 10 to about 10,000 GPa.

As described above, the dielectric thin film according to the present invention includes a metal oxide prepared by the non-hydrolyzable sol-gel method, and thus, hydroxyl groups may be excluded in the reaction process, so that the low temperature process is possible, and the dielectric constant is 10 or more. Since the electronic device to which the dielectric thin film is applied has excellent electrical properties, it exhibits excellent electrical properties satisfying both low driving voltage and high charge mobility. Therefore, the dielectric thin film of the present invention can be effectively applied to various electronic devices. That is, another aspect of the present invention relates to a transistor device including the metal oxide dielectric thin film and an electronic device including the transistor device.

The transistor device may be used for a low driving voltage device capable of printing, for example, a thin film transistor including a substrate, a gate electrode, a gate insulating layer including the dielectric thin film, a semiconductor layer, and a source / drain electrode pair. One example is this.

The structure of the thin film transistor according to the present invention is not particularly limited, and may have any structure such as a top contact structure, a bottom contact structure, or a top gate structure. Examples of the structure of a thin film transistor that can be manufactured using the metal oxide dielectric thin film of the present invention are schematically illustrated in FIGS. 1 and 2.

1 is a cross-sectional schematic view of a thin film transistor having a top contact structure, and FIG. 2 is a cross-sectional schematic view of a thin film transistor having a bottom contact structure.

For example, the thin film transistor of the present invention, as shown in FIG. 1, has a gate electrode 2, a gate insulating layer 3, a semiconductor layer 6, a source electrode 4 / drain on the substrate 1. The electrodes 5 are stacked in this order, or as shown in FIG. 2, the gate electrode 2, the gate insulating layer 3, the source electrode 4 and the drain electrode 5 on the substrate 1. And the semiconductor layer 6 may be stacked in this order.

As the substrate 1 of the thin film transistor, glass, a silicon wafer, polyethylene terephthalate, polycarbonate, polyether sulfone, polyethylene naphthalate, or the like may be used, but is not limited thereto.

As a material of the gate electrode 2 and the source / drain electrodes 5 and 6, a metal or a conductive polymer that is commonly used may be used. Specifically, the doped silicon or metal, such as gold, silver, aluminum, copper, nickel, chromium, molybdenum, tungsten, indium tin oxide, but may be exemplified, but is not limited thereto.

As the gate insulating layer 3, as described above, the metal oxide dielectric thin film according to the present invention may be used, and as the semiconductor layer 6, organic semiconductor materials and inorganic semiconductor materials that are commonly used may be used without limitation. . Specific examples of the organic semiconductor material include, but are not limited to, pentacene, copper phthalocyanine, polythiophene, polyaniline, polyacetylene, polypyrrole, polyphenylenevinylene or derivatives thereof. In addition, specific examples of the inorganic semiconductor material include silicon (Si), cadmium selenide (CdSe), cadmium sulfide (CdS), cadmium telluride (CdTe), zinc oxide (ZnO), tin dioxide (SnO ₂ ), and zinc sulfide ( ZnS) and the like, but any one having a property of a semiconductor can be used without limitation.

The transistor device may be applied without limitation as long as it is a low-voltage electronic device capable of printing by a conventional process known in the art. The electronic device may be a display device, memory devices (DRAMs), or complementary metal oxide semiconductor devices. (CMOS), photovoltaic devices, organic light emitting devices (OLEDs), sensors or integrated circuits, but are not limited thereto.

That is, the metal oxide dielectric thin film according to the present invention may be used as the capacitor storage layers (capacitor dielectrics) for the information storage or complementary metal oxide semiconductor device of the memory device, or the thin film transistor of the display device.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the following Examples are for illustrative purposes only and are not intended to limit the present invention.

Production Example  One : Dielectric film  Preparation of the composition (1)

A precursor mixture of 1 mol of zirconium tetrachloride (ZrCl ₄ ) and 1 mol of zirconium (4) isopropoxide isopropanol complex [Zr (OiPr) ₄ (iPrOH)] was added to 2-methoxyethanol. It was dissolved to prepare a zirconium oxide dielectric thin film composition having a content of 5% by weight of the precursor mixture.

Preparation Example 2 Preparation of Dielectric Thin Film Composition (2)

A zirconium oxide dielectric thin film composition was prepared in the same manner as in Preparation Example 1, except that the content of the precursor mixture was 15% by weight.

Example 1 Zirconium Oxide Dielectric film  Production (1)

The composition prepared in Preparation Example 1 was injected into a silicon wafer at room temperature, spin-coated at 500 rpm for 30 seconds, heat treated at 100 ° C. for 1 minute in an air atmosphere, and then heat treated at 300 ° C. for 1 hour and cured. A thick zirconium oxide (ZrO ₂ ) dielectric thin film was fabricated.

Example 2 Fabrication of Zirconium Oxide Dielectric Film (2)

Zirconium oxide having a thickness of 338 kPa was carried out in the same manner as in Example 1 except that the curing conditions were heat-treated at 100 ° C. for 1 minute, heat-treated at 200 ° C. for 5 minutes, and then heat-treated at 400 ° C. for 30 minutes. A dielectric thin film was produced.

Example 3: Zirconium Oxide Dielectric film  Production (3)

Zirconium oxide dielectric thin films were prepared in the same manner as in Example 1 except that the final curing conditions were heat treated at 100 ° C. for 1 minute under nitrogen atmosphere and then heat treated at 300 ° C. for 5 minutes.

Example 4 Zirconium Oxide Dielectric film  Production (4)

Zirconium oxide dielectric thin films were prepared in the same manner as in Example 1 except that the final curing conditions were heat treated at 100 ° C. for 1 minute under nitrogen atmosphere and then heat treated at 300 ° C. for 10 minutes.

Example 5 Fabrication of Zirconium Oxide Dielectric Film (5)

A final zirconium oxide dielectric thin film was prepared in the same manner as in Example 1 except that the final curing conditions were heat treated at 100 ° C. for 1 minute under nitrogen atmosphere and then heat treated at 300 ° C. for 3 hours.

Example 6: Zirconium Oxide Dielectric film  Production (6)

Zirconium oxide dielectric thin film was prepared in the same manner as in Example 1 except that the final curing conditions were heat-treated at 100 ° C. for 1 minute under nitrogen atmosphere and heat-treated at 300 ° C. for 1 hour.

Example 7 Fabrication of Thin Film Transistors (1)

A n-type doped silicon wafer was used as a gate electrode, and the dielectric thin film composition prepared in Preparation Example 2 was formed thereon using a spin coating method to form a film having a thickness of 1500 占 퐉, and then subjected to 1 at 100 ° C. under a nitrogen atmosphere. The solvent was removed by heat treatment for 1 minute, and then heat-treated and cured at 300 ° C. for 1 hour to form a gate insulating layer.

In the formation of the semiconductor layer, a 500 스핀 thick cadmium sulfide (CdS) thin film was formed on the gate insulating layer by using a spin coating method. On the semiconductor layer formed as described above, an aluminum (Al) source / drain electrode having a channel length of 20 μm and a channel width of 2 mm is formed by a lift-off method using photolithography. A thin film transistor having a top contact structure was fabricated.

Example 8 Fabrication of Thin Film Transistors (2)

Depositing a tungsten / molybdenum (W / Mo) alloy on a glass substrate to form a gate electrode having a thickness of 2000 Å, and forming a film having a thickness of 1500 Å by spin coating the dielectric thin film composition prepared in Preparation Example 2 thereon After removing the solvent by heat treatment at 100 ° C. for 1 minute under nitrogen atmosphere, heat treatment and curing at 300 ° C. for 1 hour to form a gate insulating layer.

In the formation of the semiconductor layer, a pentacene layer having a thickness of 700 Å was formed on the gate insulating layer by using a thermal evaporation method. A gold (Au) source / drain electrode was formed on the semiconductor layer formed as described above by a vacuum deposition method using a shadow mask having a channel length of 160 μm and a channel width of 1 mm to fabricate a thin film transistor having a top contact structure as shown in FIG. 4. .

Comparative Example 1: Fabrication of Thin Film Transistor

A thin film transistor having a top contact structure was fabricated in the same manner as in Example 7, except that a gate insulating layer having a thickness of 3,000 Å was formed by PECVD using silicon oxide (SiO ₂ ).

Experimental Example  1: composition analysis of thin film

In order to analyze the hydroxyl group remaining in the metal oxide dielectric thin film according to the present invention, by using the FT-IR analyzer, the composition of the thin film prepared in Examples 3 to 6 having a final curing temperature of 300 ℃ Is shown in FIG. 5.

Referring to FIG. 5, although a broad peak due to the remaining hydroxyl group appears in the vicinity of the wavelength of 3500 cm ⁻¹ regardless of the curing time, when the curing time is 3 hours (Example 5), In the vicinity of 3500cm ^-1 , the size of the peak is greatly reduced compared to other conditions, and the peak almost disappears, which is effective in the low temperature process at 300 ° C.

Experimental Example 3 Measurement of Electrical Properties of Thin Films

In order to measure electrical characteristics such as leakage current, dielectric constant, and the like of the metal oxide dielectric thin film according to the present invention, manufactured in Preparation Example 1 on an n-type silicon wafer doped with silicon (Si). A zirconium oxide dielectric thin film composition was applied, followed by spin coating, followed by heat treatment at 100 ° C. for 1 minute and 300 ° C. for 30 minutes to form an insulating layer having a thickness of 400 Å, followed by e-beam evaporation. By depositing 1500 Å of the aluminum thin film by the method to form the upper electrode, the device for measuring electrical characteristics as shown in FIG.

The leakage current, dielectric constant, and breakdown voltage were measured using the device fabricated above. In the above, the leakage current was calculated as a current value flowing per unit area when the electric field was 1 MV / cm.

In addition, the dielectric constant was measured at a frequency of about 100 kHz using a PRECISION LCR METER (HP4284A) equipped with a probe station (Micromanipulatior 6200 probe station). The permittivity was calculated by the same formula.

k = C xd / ε _o x A

k: dielectric ratio

C: capacitance

d: thickness of the low dielectric film

ε _o : dielectric constant of vacuum

A: contact cross section of the electrode

Referring to FIG. 7, in the curing process at 300 ° C., the blocking leakage current is 5 × 10 ⁻⁸ A / cm 2 or less, and the insulation breakdown voltage does not appear within 4.8 MV / cm, and the insulation breakdown voltage is 4.8 MV / cm or more. It can be seen that the dielectric constant calculated by the above formula is about 11, and it can be confirmed that the low dielectric constant and the excellent dielectric constant value at 300 ℃ low temperature process.

Experimental Example 4: Measurement of the electrical properties of the thin film transistor (1)

In order to measure the electrical characteristics of the thin film transistor according to the present invention, the threshold voltage, charge mobility and driving voltage of the thin film transistors manufactured in Example 7 and Comparative Example 1 using Keithley Semiconductor Analyzer (4200-SCS) Driving characteristics were measured as follows.

The charge mobility was extracted from the following saturation region current equation. From the following equation, a graph with (I _SD ) ^1/2 and V _G as variables was obtained from the slope.

Where I _SD is the source-drain current, μ or μ _FET is the charge mobility, C ₀ is the oxide capacitance, W is the channel width, L is the channel length, V _G is the gate voltage, V _T is the threshold voltage.

The threshold voltage is obtained from the intersection of the extension line of the linear part and the V _G axis in the graph between (I _D ) ^1/2 and V _G. The threshold voltage consumes less power when the absolute value is close to zero.

FIG. 8A shows the driving characteristics of the thin film transistor fabricated in Example 7 using zirconium oxide as the gate insulating layer and CdS as the semiconductor layer, and FIG. 9B using PECVD SiO ₂ as the gate insulating layer. The driving characteristics of the conventional thin film transistor produced by Comparative Example 1 are shown.

 8A and 8B, in the case of the thin film transistor according to the seventh embodiment, the threshold voltage is 2 V or less, which is much lower than the threshold voltage of 80 V or less, which is the threshold voltage of the conventional thin film transistor according to Comparative Example 1, and the charge mobility is 37.9 cm 2 / VS or less, significantly improved than the conventional thin film transistor, it can be seen that the driving voltage also decreases rapidly.

Experimental Example 5 Measurement of the Electrical Characteristics of the Thin Film Transistor (2)

In order to measure the electrical characteristics of the thin film transistor according to the present invention, the driving characteristics such as threshold voltage, charge mobility and I _on / I _off current ratio of the thin film transistor manufactured in Example 8 were measured as in Experimental Example 4. It was.

In the above, I _on / I _off is obtained by the ratio of the maximum current value in the on state and the minimum current value in the off state, and has the following relationship:

Where I _on is the maximum current value, I _off is the off-stae leakage current, μ is the charge mobility, σ is the conductivity of the thin film, q is the charge amount and N _A is the charge density, t is the thickness of the semiconductor film, C ₀ is the oxide capacitance, and V _D is the drain voltage.

 9A and 9B show driving characteristics of the thin film transistor fabricated in Example 8 using zirconium oxide as the gate insulating layer and pentacene as the semiconductor layer.

9A and 9B, the threshold voltage is -1.8V or less, the I _on / I _off current ratio is 2.14 X 10 ⁵ or less, and the charge mobility is 7.6 cm 2 / Vs or less. In the case of the applied thin film transistor according to the present invention, it can be seen that it has characteristics of low voltage driving and high charge mobility.

Although the present invention has been described in detail with reference to preferred embodiments of the present invention, these are merely exemplary, and those skilled in the art to which the present invention pertains have various modifications and equivalents therefrom. It will be appreciated that embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims. For example, the metal oxide dielectric thin film manufacturing method of the present invention can be applied to the production of a composite metal oxide thin film composed of two or more metal elements.

As described above, since the dielectric thin film composition according to the present invention can be thinned by a non-hydrolytic sol-gel method, the dielectric thin film composition of the present invention can form a dielectric thin film by a low temperature process, thereby reducing manufacturing costs. can do. In addition, since the dielectric thin film obtained by the present invention has low leakage current characteristics and high dielectric constant (high-k), the electronic device according to the present invention employing such a dielectric thin film has low driving voltage and high charge mobility. It can exhibit excellent electrical properties satisfying at the same time.

Claims (22)

A metal halide represented by the following Chemical Formula 1 as a metal oxide precursor; And at least one of a metal alkoxide and an ether compound and an organic solvent.  [Formula 1] M _a X _b Where M is a metal of Groups 1 to 14, X is a halogen element, a is an integer of 1 to 3, b is an integer from 1 to 10. The dielectric thin film composition of claim 1, wherein the metal (M) is any one selected from the group consisting of titanium, zirconium, hafnium (Hf), aluminum, tantalum (Ta), and silicon. The dielectric thin film composition according to claim 1, wherein the metal alkoxide is represented by the following Chemical Formula 2. [Formula 2] M _a (OR ₁ ) _n Where M _a is a metal of Groups 1 to 14, R ₁ is a hydrogen atom, a C1-C10 alkyl group, a C3-C10 cycloalkyl group or a C6-C15 aryl group, a C2-C30 acryloyl group, a C1-C10 acryloyloxy group, C1-C10 Alkyl group or cycloalkyl group substituted by epoxy group, C1-C10 vinyl group, C1-C10 allyl group, C1-C10 epoxy group, or C1-C10 alkoxy group, n is an integer of 1-6. The dielectric thin film composition according to claim 1, wherein the ether compound is represented by the following Chemical Formula 3. [Formula 3] R ₂ OR ₁ Where R ₁ and R ₂ each independently represent a hydrogen atom, a C1-C10 alkyl group, a C3-C10 cycloalkyl group or a C6-C15 aryl group, a C2-C30 acryloyl group, acryloyloxy group, or an epoxy group. It is a substituted alkyl group or a cycloalkyl group, a vinyl group, an allyl group, an epoxy group, or a C1-C10 alkoxy group. The composition of claim 1, wherein said composition is 0.1 to 50 weight percent of metal halides: 0.1 to 50% by weight of at least one of a metal alkoxide and an ether compound; And A dielectric thin film composition comprising a residual amount of an organic solvent. (a) a metal halide represented by Formula 1 below: and dissolving at least one of a metal alkoxide and an ether compound in an organic solvent to prepare a metal oxide precursor solution; (b) coating the metal oxide precursor solution prepared in the previous step onto the substrate; And (C) a method of manufacturing a metal oxide dielectric thin film comprising the step of heat-treating the coated substrate to obtain a thin film: [Formula 1] M _a X _b Where M is a metal of Groups 1 to 14, X is a halogen element, a is an integer of 1 to 3, b is an integer from 1 to 10. The method of claim 6, wherein the metal (M) is any one selected from the group consisting of titanium, zirconium, hafnium, aluminum, tantalum, and silicon. The method of claim 6, wherein the metal alkoxide is represented by the following Chemical Formula 2. [Formula 2] M _a (OR ₁ ) _n Where M _a is a metal of Groups 1 to 14, a is an integer of 1 to 3, R ₁ is a hydrogen atom, a C1-C10 alkyl group, a C3-C10 cycloalkyl group or a C6-C15 aryl group, a C2-C30 acryloyl group, a C1-C10 acryloyloxy group, C1-C10 An alkyl group or a cycloalkyl group substituted with 10 epoxy groups, a C1-10 vinyl group, a C1-10 allyl group, a C1-10 epoxy group or a C1-10 alkoxy group, n is an integer of 1-6. 7. The method of claim 6, wherein the ether compound is represented by the following Chemical Formula 3. [Formula 3] R ₂ OR ₁ Where R ₁ and R ₂ each independently represent a hydrogen atom, a C1-C10 alkyl group, a C3-C10 cycloalkyl group or a C6-C15 aryl group, a C2-C30 acryloyl group, acryloyloxy group, or an epoxy group. It is a substituted alkyl group or a cycloalkyl group, a vinyl group, an allyl group, an epoxy group, or a C1-C10 alkoxy group. 7. The process of claim 6, wherein the solvent is an aliphatic hydrocarbon solvent; Aromatic hydrocarbon solvents; Ketone solvents; Ether solvents; Acetate solvents; Alcohol solvents; Amide solvents; Silicone solvents; And at least one solvent selected from the group consisting of mixtures thereof. The method of claim 12, wherein the organic solvent is 2-methoxy ethanol or di (propylene glycol) methyl ether. . The method of claim 6, wherein the metal oxide precursor solution is Metal oxide precursor 0.1-50 wt%: 0.1 to 50% by weight of at least one of a metal alkoxide and an ether compound; And Method for producing a metal oxide dielectric thin film comprising a residual amount of an organic solvent. The method of claim 6, wherein the heat treatment is a step of preparing a metal oxide represented by Chemical Formula 4 by a non-hydrolytic sol-gel method. [Formula 4] M _x O _y Wherein M is a metal of Groups 1 to 14, x is 1 or 2, and 1 ≦ y ≦ 10. The method of claim 6, wherein the coating step is formed by a method selected from the group consisting of spin coating, dip coating, roll coating, screen coating, spray coating, spin casting, flow coating, screen printing, ink jetting and drop casting. Method for producing a metal oxide dielectric thin film, characterized in that. The method of claim 6, wherein the heat treatment comprises curing the coated substrate and then curing the coated substrate. The method of claim 15, wherein the baking step is a method of manufacturing a metal oxide dielectric thin film, characterized in that the heating at any one condition selected from nitrogen, air and vacuum atmosphere for 1 second to 5 minutes at a temperature of 50 to 250 ℃. The method of claim 15, wherein the curing step is performed for 10 minutes to 3 hours at a temperature of 100 to 1,000 ℃, under any one condition selected from nitrogen, air and vacuum atmosphere. . A metal oxide dielectric thin film obtained by thinning the dielectric thin film composition of any one of claims 1 to 5. A transistor device comprising the metal oxide dielectric thin film of claim 18. 20. The device of claim 19, wherein the device comprises a substrate; A gate electrode; An insulating layer comprising the dielectric thin film of claim 18; A semiconductor layer; And a thin film transistor comprising a source / drain electrode pair. An electronic device comprising the transistor device of claim 20. 22. The electronic device of claim 21, wherein the electronic device includes a display device, memory devices (DRAMs), complementary metal oxide semiconductor devices (CMOS), photovoltaic devices, organic light emitting devices (OLEDs), sensors, and integrated circuits. An electronic device, characterized in that selected from the group consisting of.

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