KR102057675B1 - Polyurea, method for preparing the same and thin-film transistor comprising the same - Google Patents

Abstract

The present invention relates to a polyurea, a thin film transistor including the same, and a method of preparing polyurea, and more specifically, to a polyurea represented by structural formula 1. In structural formula 1, Ar^1 is a substituted or unsubstituted C_6-C_14 arylene group, Ar^2 is a valence bond or substituted or unsubstituted C_6-C_14 arylene group, R^1 is a valence bond or straight-chain or branched C_1-C_10 alkylene group, R^2 is hydrogen atom or a straight-chain or branched C_1-C_10 alkyl group, R^3 and R^4, which are the same as or different from each other, are each independently a hydrogen atom or a straight-chain or branched C_1-C_10 alkyl group, n is an integer of 2 to 500 as a repeating unit repetition count, and substituents corresponding to the above-mentioned substitution are a straight-chain or branched C_1-C_5 alkyl group. According to the present invention, polyurea enabling a solution process for large area and low costs can be provided. The polyurea according to the present invention may have high insulating properties even at a high dielectric constant and a thin thickness. Furthermore, the present invention may provide a thin film transistor which can be driven at a low voltage.

Description

POLYUREA, METHOD FOR PREPARING THE SAME AND THIN-FILM TRANSISTOR COMPRISING THE SAME

The present invention relates to a polyurea, a method for manufacturing the same, and a thin film transistor including the same. More particularly, the present invention relates to a polyurea, a method for manufacturing the same, and a thin film transistor including the same.

For low voltage driving of the organic transistor, an organic insulator having a high capacitance is required. In order to realize high capacitance, there is a method of increasing the dielectric constant or decreasing the thickness of the organic insulator. In order to develop a dielectric material having a high dielectric constant, a large number of polar groups must be included. However, since the polar group may be a charge transfer path in the manufacture of a thin film, it may be a factor that decreases the insulation characteristics by increasing the leakage current. Therefore, a material and a process technology capable of manufacturing an organic insulating thin film having a very dense structure are needed.

Organic insulators tend to be inferior in electrical insulation properties due to pinholes or unexpected surface defects at lower thicknesses than inorganic insulators such as SiO ₂ and SiN _x . Therefore, a process technology for producing an ultra-thin film having a very dense structure has been developed. As a representative technique, Tobin Marks Group of Northwestern University, USA, reported an insulator technology using a self-assembled monolayer (or multilayer) film called Self-Assembled Nanodielectrics (SAND). A very dense thin film was prepared using a self-assembled monolayer material. In addition, KAIST researchers have recently developed chemical vapor deposition (iCVD) using initiators. A very dense polymer thin film can be produced by polymerizing the polymer monomer on a desired substrate surface by vapor phase evaporation. In addition, a molecular layer deposition (MLD) method has been reported in which polyurea monomers are alternately deposited to form a polyurea thin film on a desired substrate.

However, since the SAND, iCVD, and MLD methods are basically deposition methods, there is a problem that a large area solution process is impossible.

An object of the present invention is to solve the above problems, and to provide a polyurea capable of a solution process for large area cost reduction.

In addition, another object of the present invention is to provide a polyurea having a high dielectric properties and a high insulation even at a low thickness and a method of manufacturing the same.

It is also an object of the present invention to provide a thin film transistor capable of low voltage driving.

According to one aspect of the present invention, a polyurea represented by the following Structural Formula 1 is provided.

[Formula 1]

In the above formula 1,

Ar ¹ is a substituted or unsubstituted C6 to C14 arylene group,

Ar ² is a C6 to C14 arylene group having a valence bond or a substituted or unsubstituted group,

R ¹ is a valence bond or a straight or branched C1 to C10 alkylene group,

R ² is a hydrogen atom or a straight or branched C 1 to C 10 alkyl group,

R ³ and R ⁴ are the same as or different from each other, and are each independently a hydrogen atom or a straight or branched C1 to C10 alkyl group,

n is a repeating unit repeating number, an integer of 2 to 500,

Substituents corresponding to the above substitutions are linear or branched C1 to C5 alkyl groups.

Also in the formula 1,

이고,Ar ¹ is

ego,

R ⁵ is a hydrogen atom or a straight or branched C 1 to C 5 alkyl group,

이고,Ar ² is a valence bond or

ego,

R ⁶ is a hydrogen atom or a straight or branched C 1 to C 5 alkyl group,

R ¹ is a valence bond or a straight or branched C1 to C5 alkylene group,

R ² is a hydrogen atom or a straight or branched C 1 to C 3 alkyl group,

R ³ and R ⁴ are the same as or different from each other, and may each independently be a hydrogen atom or a straight or branched C1 to C5 alkyl group.

Also in the formula 1,

또는

이고,Ar ¹ is

or

ego,

R ⁵ is a hydrogen atom or a straight or branched C 1 to C 5 alkyl group,

또는

이고,Ar ² is a valence bond,

or

ego,

R ⁶ is a hydrogen atom or a straight or branched C 1 to C 5 alkyl group,

R ¹ is a valence bond or a straight or branched C1 to C5 alkylene group,

R ² is a hydrogen atom or a straight or branched C 1 to C 3 alkyl group,

R ³ and R ⁴ are the same as or different from each other, and may each independently be a hydrogen atom or a straight or branched C1 to C5 alkyl group.

Also in the formula 1,

또는

이고,Ar ¹ is

or

ego,

R ⁵ is a hydrogen atom or a straight or branched C 1 to C 5 alkyl group,

Ar ² is a valence bond,

R ¹ is a valence bond or a straight or branched C1 to C5 alkylene group,

R ² is a hydrogen atom or a straight or branched C 1 to C 3 alkyl group,

R ³ and R ⁴ are the same as or different from each other, and may each independently be a hydrogen atom or a straight or branched C1 to C5 alkyl group.

Also in the formula 1,

이고,Ar ¹ is

ego,

R ⁵ is a straight C1 to C3 alkyl group,

Ar ² is a valence bond,

R ¹ is a straight C1 to C3 alkylene group,

R ² is a hydrogen atom,

R ³ and R ⁴ may be a hydrogen atom.

The polyurea may have a number average molecular weight of 300 to 200,000.

In addition, the polyurea may have a dielectric constant of 3 to 8.

According to another aspect of the present invention, in accordance with Scheme 1, compound 1 and compound 2 to prepare a compound 3 by step-growth polymerization reaction at -20 to 20 ℃ in an aprotic polar solvent A method for producing a polyurea is provided.

 Scheme 1

In Scheme 1,

Ar ¹ is a substituted or unsubstituted C6 to C14 arylene group,

Ar ² is a C6 to C14 arylene group having a valence bond or a substituted or unsubstituted group,

R ¹ is a valence bond or a straight or branched C1 to C10 alkylene group,

R ² is a hydrogen atom or a straight or branched C 1 to C 10 alkyl group,

R ³ and R ⁴ are the same as or different from each other, and are each independently a hydrogen atom or a straight or branched C1 to C10 alkyl group,

n is a repeating unit repeating number, an integer of 2 to 500,

Substituents corresponding to the above substitutions are linear or branched C1 to C5 alkyl groups.

According to another aspect of the invention, there is provided an electronic device comprising an organic insulating layer comprising the polyurea.

According to another aspect of the invention, the gate electrode formed on the substrate; An organic insulating layer formed on the gate electrode; A semiconductor layer formed on the organic insulating layer; And a source electrode and a drain electrode formed on the semiconductor layer, wherein the organic insulating layer includes the polyurea.

In addition, the thickness of the organic insulating layer may be 10 to 400nm.

According to another aspect of the invention, (a) forming a gate electrode on the substrate; (b) forming an organic insulating layer on the gate electrode; (c) forming a semiconductor layer on the organic insulating layer; And (d) forming a source electrode and a drain electrode on the semiconductor layer, wherein step (b) is one selected from spin coating, ink jet printing, roll coating, screen printing, transfer method, and dipping method. According to the above solution process method, a method of manufacturing a thin film transistor, which is a step of forming an organic insulating layer using a polyurea solution containing a polyurea represented by Structural Formula 1, is provided.

[Formula 1]

In the above formula 1,

Ar ¹ is a substituted or unsubstituted C6 to C14 arylene group,

Ar ² is a C6 to C14 arylene group having a valence bond or a substituted or unsubstituted group

R ¹ is a valence bond or a straight or branched C1 to C10 alkylene group,

R ² is a hydrogen atom or a straight or branched C 1 to C 10 alkyl group,

R ³ and R ⁴ are the same as or different from each other, and are each independently a hydrogen atom or a straight or branched C1 to C10 alkyl group,

n is a repeating unit repeating number, an integer of 2 to 500,

Substituents corresponding to the above substitutions are linear or branched C1 to C5 alkyl groups.

According to the present invention, it is possible to provide a polyurea and a method for producing the same that enable a solution process for large area cost reduction.

In addition, according to the present invention, the polyurea of the present invention may have high insulation properties even at high dielectric constant and low thickness.

In addition, according to the present invention, it is possible to provide a thin film transistor capable of low voltage driving.

1 shows the FTIR spectra of polyureas prepared according to Examples 1, 2 and 3.
Figure 2a shows the capacitance according to the frequency of the MIM capacitor manufactured according to the device example 1, device example 2 and device example 3.
Figure 2b shows the leakage current density according to the electric field of the MIM capacitor manufactured according to device Example 1, Device Example 2 and Device Example 3.
Figure 3a shows the capacitance according to the frequency of the MIM capacitor manufactured according to the device example 1, device example 4 and device example 5.
Figure 3b shows the leakage current density according to the electric field of the MIM capacitor manufactured according to device Example 1, Device Example 4 and Device Example 5.
Figure 4a shows the transfer characteristics (Transfer characteristics) of the DNTT-TFT prepared according to the device example 6.
Figure 4b shows the output characteristics (Output characteristics) of the DNTT-TFT manufactured according to the device example 6.
4C illustrates transfer characteristics of DNTT-TFT having an insulating film prepared according to Example 9 of the device.
4D illustrates output characteristics of the DNTT-TFT on which an insulating film prepared according to Example 9 is surface treated.
FIG. 5A is an image of a DPPT-TT-TFT prepared in accordance with Device Example 10 wound on a 3.5 mm diameter glass pipette. FIG.
Figure 5b shows a bending test at a radius of 3mm performed using a bending tester DPPT-TT-TFT prepared in accordance with device Example 10.
Figure 5c shows the transfer characteristics before and after the bending test of the DPPT-TT-TFT prepared according to Example 10 of the device.
Figure 6a shows the thermogravimetric analysis (TGA) results of PU-11 prepared according to Example 1.
Figure 6b shows the thermogravimetric analysis (TGA) results of PU-12 prepared according to Example 2.
Figure 6c shows the thermogravimetric analysis (TGA) results of PU-13 prepared according to Example 3.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all transformations, equivalents, and substitutes included in the spirit and scope of the present invention. In the following description of the present invention, if it is determined that the detailed description of the related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted.

In addition, terms including ordinal numbers such as first and second to be used below may be used to describe various components, but the components are not limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component.

In addition, when a component is referred to as being "formed" or "laminated" on another component, it may be directly attached to, or laminated to, the front or one side on the surface of the other component, It will be understood that other components may exist in the.

Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

As used herein, "atom bond" means a single bond, a double bond or a triple bond unless otherwise defined.

In the present specification, "hydrogen" means monotium, dihydrogen, or tritium unless otherwise defined.

As used herein, unless otherwise defined, an "alkyl group" means an aliphatic hydrocarbon group.

The alkyl group may also be a "saturated alkyl group" that does not contain any double or triple bonds.

The alkyl group may also be an "unsaturated alkyl group" containing at least one double or triple bond.

The alkyl group may also be straight, branched or cyclic.

For example, the alkyl group is methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, pentyl, hexyl, ethenyl, propenyl, butenyl, cyclopropyl, cyclo A butyl group, a cyclopentyl group, a cyclohexyl group, etc. are meant.

"Aryl groups" also include monocyclic, bicyclic or fused ring polycyclics (ie, rings that divide adjacent pairs of carbon atoms).

For example, the aryl group means a phenyl group, biphenyl group, naphthyl group, anthryl group, phenanthryl group and the like.

Hereinafter, the polyurea of the present invention will be described.

The present invention provides a polyurea represented by the following structural formula (1).

[Formula 1]

In the above formula 1,

, 보다 바람직하게는

또는

, 보다 더욱 바람직하게는

또는

, 보다 더욱 바람직하게는

이고,Ar ¹ is a substituted or unsubstituted C6 to C14 arylene group, preferably

, More preferably

or

Even more preferably

or

Even more preferably

ego,

R ⁵ is a hydrogen atom, a straight or branched C1 to C5 alkyl group, preferably a hydrogen atom, a straight or branched C1 to C5 alkyl group, more preferably a straight C1 to C3 alkyl group,

, 보다 바람직하게는 원자가 결합,

또는

이고, 보다 더욱 바람직하게는 원자가 결합이고,Ar ² is a valence bond, a substituted or unsubstituted C6 to C14 arylene group, preferably a valence bond,

More preferably a valence bond,

or

Even more preferably a valence bond,

R ⁶ is a hydrogen atom, a straight or branched C1 to C5 alkyl group, preferably a hydrogen atom, a straight or branched C1 to C5 alkyl group,

R ¹ is a valence bond, a straight or branched C1 to C10 alkylene group, preferably a valence bond, a straight or branched C1 to C5 alkylene group, more preferably a straight C1 to C3 alkylene group,

R ² is a hydrogen atom, a straight or branched C 1 to C 10 alkyl group, preferably a hydrogen atom, a straight or branched C 1 to C 3 alkyl group, more preferably a hydrogen atom,

R ³ and R ⁴ are the same as or different from each other, and are each independently a hydrogen atom, a straight or branched C1 to C10 alkyl group, preferably a hydrogen atom, a straight or branched C1 to C5 alkyl group, and more preferably a hydrogen atom ,

n is a repeating unit repeating number, an integer of 2 to 500, preferably an integer of 4 to 200, more preferably an integer of 5 to 100, even more preferably an integer of 6 to 50,

Substituents corresponding to the substitution may be a linear or branched C1 to C5 alkyl group.

In addition, the polyurea may have a number average molecular weight of 300 to 200,000, preferably 800 to 70,000, more preferably 1,000 to 35,000, even more preferably 1,200 to 20,000. When the number average molecular weight is less than 300, the bad mechanical properties are not preferable, and when the number average molecular weight is more than 200,000, the solubility in the solvent is lowered, so that the solution process is difficult when manufacturing an electronic device, which is not preferable.

In addition, the polyurea may have a dielectric constant of 3 to 8, preferably 5 to 8, and more preferably 5.5 to 8.

Hereinafter, the method for producing the polyurea of the present invention will be described.

The present invention provides a method for preparing polyurea for preparing compound 3 by step-growth polymerization of compound 1 and compound 2 at -20 to 20 ° C. in an aprotic polar solvent according to Scheme 1 below. to provide. If the temperature is less than -20 ℃ is not preferable because the reaction rate is too slow, if it exceeds 20 ℃ gelation phenomenon due to excessive reaction is not preferable.

 Scheme 1

In Scheme 1,

Ar ¹ is a substituted or unsubstituted C6 to C14 arylene group,

Ar ² is a C6 to C14 arylene group having a valence bond or a substituted or unsubstituted group,

R ¹ is a valence bond or a straight or branched C1 to C10 alkylene group,

R ² is a hydrogen atom or a straight or branched C 1 to C 10 alkyl group,

R ³ and R ⁴ are the same as or different from each other, and are each independently a hydrogen atom or a straight or branched C1 to C10 alkyl group,

n is a repeating unit repeating number, an integer of 2 to 500,

Substituents corresponding to the above substitutions are linear or branched C1 to C5 alkyl groups.

The polyurea may be prepared in two steps.

First, Compound 2 is dissolved in a solvent to prepare a first solution.

Compound 2 is ethylene diamine, 1,2-propylene diamine, 1,2-propylene diamine, N, N'-di-tert-butylethylene diamine (N, N'-Di-tert-butylethylene diamine ), 2,4-diaminotoluene, 4.4'-methylene dianiline, p-phenylene diamine, 4,4'- In oxydianiline (4,4'-oxydianiline), carbonyldiamine, 1,3-diaminopropane and 1,4-diaminobutane It may be one or more selected, preferably ethylene diamine.

The solvent may be at least one selected from N-methyl-2-pyrrolidinone (NMP), dimethylformamide (DMF), dimethylacetamide (DMAc), dimethyl sulfoxide (DMSO), and acetone, and preferably NMP.

Next, compound 1 is added to the first solution to react compound 2 with compound 1 to produce compound 3.

The compound 1 is toluene 2,4-diisocyanate, 1,4-phenylene diisocyanate, methylene diphenyl diisocyanate and hexamethylene It may be at least one selected from diisocyanate (Hexamethylene diisocyanate), preferably toluene 2,4-diisocyanate.

The present invention provides an electronic device including an organic insulating layer including the polyurea.

Hereinafter, the thin film transistor of the present invention will be described.

The present invention is a gate electrode formed on a substrate; An organic insulating layer formed on the gate electrode; A semiconductor layer formed on the organic insulating layer; And a source electrode and a drain electrode formed on the semiconductor layer, wherein the organic insulating layer includes the polyurea.

In addition, the thickness of the organic insulating layer may be 10 to 400nm, preferably 30 to 300nm, more preferably 50 to 150nm. When the thickness of the organic insulating layer is less than 10nm, it is not preferable that the insulation characteristics are very poor due to the pinhole or surface bonding structure generated during coating, and when the organic insulating layer exceeds 400nm, the capacitance is too small to manufacture a low voltage driving device. Not desirable to

Hereinafter, the manufacturing method of the thin film transistor of the present invention will be described.

Step (a): First, a gate electrode is formed on a substrate.

The substrate is a silicon wafer, polyethylene terephthalate (PET), polyparaxylylene (poly (p-xylylene), parylene), polydimethylsiloxane (PDMS), cytop, polystyrene, PS ), Poly (methyl methacrylate (PMMA), polyvinyl pyrrolidone (PVP), polyimide (PI), polyamide, polyurea, polyurethane It may be at least one selected from polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyethylene and polypropylene, preferably silicon wafer or polyethylene terephthalate (PET).

The gate electrode is Au, Al, Ag, Be, Bi, Co, Cu, Cr, Cd, Fe, Ga, Hf, In, Ir, Mn, Mo, Mg, Ni, Nb, Pb, Pd, Pt, Rh, At least one selected from Re, Ru, Sb, Sn, Ta, Te, Ti, V, W, Zr, and Zn, and preferably Al.

Step (b): Next, an organic insulating layer is formed on the gate electrode.

The step (b) is organic by using a polyurea solution comprising a polyurea represented by formula 1 by at least one solution process selected from spin coating, inkjet printing, roll coating, screen printing, transfer method and dipping method An insulating layer can be formed.

[Formula 1]

In the above formula 1,

Ar ¹ is a substituted or unsubstituted C6 to C14 arylene group,

Ar ² is a C6 to C14 arylene group having a valence bond or a substituted or unsubstituted group,

R ¹ is a valence bond or a straight or branched C1 to C10 alkylene group,

R ² is a hydrogen atom or a straight or branched C 1 to C 10 alkyl group,

R ³ and R ⁴ are the same as or different from each other, and are each independently a hydrogen atom or a straight or branched C1 to C10 alkyl group,

n is a repeating unit repeating number, an integer of 2 to 500,

Substituents corresponding to the substitution may be a linear or branched C1 to C5 alkyl group.

The polyurea may include 0.1 to 10 wt% based on the polyurea solution, preferably 1 to 4 wt%. If it is less than 0.1wt%, the reaction does not proceed, or even if the reaction is not preferable because the molecular weight does not increase sufficiently, if it exceeds 10wt% it is not preferable because the gelation occurs due to excessive hydrogen bonding of the synthesized polyurea.

After step (b), the method may further include (b ') forming a surface modified layer by surface treating the surface of the organic insulating layer by a metal-oxide-assisted surface treatment method. have.

The surface modification layer is octadecylphosphonic acid (octadecylphosphonic acid), n-octylphosphonic acid (n-octylphosphonic acid (OPA), n-dodecylphosphonic acid (DDPA), anthryl-termination Self-assembled monolayers (SAMs) formed by surface treatment with any one selected from anthryl-terminated alkyl-phosphonic acid, hexamethyldisilazane (HMDS) and octadecyltrichlorosilane (OTS). Self-assembled Monolayers), preferably octadecylphosphonic acid.

Step (c): Next, a semiconductor layer is formed on the organic insulating layer.

The semiconductor layer is composed of DNTT (Dinaphtho [2,3-b: 2 ′, 3′-f] thieno [3,2-b] thiophene), DPPT-TT (Diketopyrrolopyrrole-thienothiophene copolymer), pentacene, tetra Tetracene, oligo thiophene, polythiophene, metal phthalocyanine, polyphenylene, polyvinylenephenylene, polyfluorene, Fullerene (C ₆₀ ), 2,7-dioctylbenzothienobenzothiophene (2,7-dioctylbenzothienobenzothiophene, C8-BTBT), 2,7-didecylbenzothienobenzothiophene (2,7-didecylbenzothienobenzothiophene, C10 -BTBT), and 2-decyl-7-phenyl- [1] benzothieno [3,2-b] [1] benzothiophene (2-decyl-7-phenyl- [1] benzothieno [3,2- b] [1] benzothiophene, Ph-BTBT-C10) may be one or more selected, preferably DNTT or DPPT-TT.

Step (d): forming a source electrode and a drain electrode on the semiconductor layer.

The source electrode and the drain electrode are Au, Al, Ag, Be, Bi, Co, Cu, Cr, Cd, Fe, Ga, Hf, In, Ir, Mn, Mo, Mg, Ni, Nb, Pb, Pd, Pt It may be at least one selected from Rh, Re, Ru, Sb, Sn, Ta, Te, Ti, V, W, Zr and Zn, preferably Au.

Hereinafter, preferred examples are provided to aid in understanding the present invention. However, the following examples are merely provided to more easily understand the present invention, and the contents of the present invention are not limited by the examples.

EXAMPLE

Example 1: Polyurea (PU-11)

Under nitrogen, 0.5 mmol of ethylene diamine (DA-1) monomer was dissolved in 3.43 g of NMP solvent with stirring at 200 rpm. When the monomer was completely dissolved, 0.5 mmol of toluene 2,4-diisocyanate (DI-1) monomer was slowly added at a rate of 0.1 mL / min using a syringe pump to prepare a mixture. The mixture was cooled in an ice bath for 2 hours below 10 ° C. to prepare a solution comprising polyurea (PU-11). The number average molecular weight of polyurea was 5,600, and the molecular weight distribution was 1.22.

Example 2: Polyurea (PU-12)

A solution containing polyurea (PU-12) was prepared in the same manner as in Example 1 except that 1,2-propylene diamine (DA-2) was used instead of ethylene diamine (DA-1). The number average molecular weight of polyurea was 7,420 and molecular weight distribution was 1.16.

Example 3: Polyurea (PU-13)

A solution comprising polyurea (PU-13) in the same manner as in Example 1, except that N, N'-di-tert-butylethylenediamine (DA-3) was used instead of ethylene diamine (DA-1). Was prepared. The number average molecular weight of polyurea was 2,600, and the molecular weight distribution was 1.01.

Example 4: Polyurea (PU-21)

The polymerization was carried out in the same manner as in Example 1, except that 1,4-phenylene diisocyanate (DI-2) was used instead of toluene 2,4-diisocyanate (DI-1) to obtain polyurea (PU-21). )

Example 5: Polyurea (PU-22)

1,4-phenylene diisocyanate (DI-2) is used instead of toluene 2,4-diisocyanate (DI-1), and 1,2-propylene diamine (DA-2) is used instead of ethylene diamine (DA-1). Polyurea (PU-22) was obtained by polymerization in the same manner as in Example 1 except that was used.

Example 6: Polyurea (PU-23)

1,4-phenylene diisocyanate (DI-2) is used instead of toluene 2,4-diisocyanate (DI-1), and N, N'-di-tert-butyl is substituted for ethylene diamine (DA-1). Polymerization was carried out in the same manner as in Example 1 except for using ethylene diamine (DA-3) to obtain polyurea (PU-23).

Device Example 1: Metal-insulator-metal Capacitor

Insulation film manufacturing

Si wafers used as substrates were cleaned by sequential sonication every 20 minutes in detergent, deionized water, acetone and 2-propanol. A 30 nm thick aluminum electrode was deposited on the Si substrate via thermal evaporation. After spin-coating the solution of Example 1 on the aluminum electrode, it was annealed at 65 ° C. for 1 minute, 90 ° C. for 10 minutes, and 160 ° C. for 40 minutes in a hot plate in ambient air. Prepared.

MIM Capacitor Manufacturing

MIM capacitors were prepared by depositing gold on the insulating film using a thermal evaporator.

Device Example 2: MIM Capacitor

A MIM capacitor was manufactured in the same manner as in Example 1 except that the insulating film was formed using the solution of Example 2 instead of using the solution of Example 1.

Device Example 3: MIM Capacitor

A MIM capacitor was manufactured in the same manner as in Example 1, except that the insulating film was formed using the solution of Example 3 instead of using the solution of Example 1.

Device Example 4: MIM Capacitor

A MIM capacitor was manufactured in the same manner as in Example 1, except that the thickness of the insulating film was set to 30 nm instead of 60 nm.

Device Example 5: MIM Capacitors

A MIM capacitor was manufactured in the same manner as in Example 1, except that the thickness of the insulating film was set to 100 nm instead of 60 nm.

Device Example 6 DNTT-TFT (thin-film transistor)

A 60 nm thick DNTT semiconductor layer was deposited on the insulating film of device example 1 through a shadow mask using thermal evaporation at a pressure of 3Х10 ⁻⁶ torr. A source and drain gold electrode having a thickness of 50 nm was deposited on the DNTT semiconductor layer using a shadow mask using thermal evaporation, thereby preparing a DNTT-TFT having a length and a width of 100 μm and 1,500 μm, respectively.

Device Example 7: DNTT-TFT

A DNTT-TFT was manufactured in the same manner as in Example 6, except that the insulating layer of Element Example 2 was used instead of the insulating layer of Element Example 1.

Device Example 8: DNTT-TFT

A DNTT-TFT was manufactured in the same manner as in Example 6, except that the insulating layer of Element Example 3 was used instead of the insulating layer of Element Example 1.

Device Example 9 DNTT-TFT Surface-Insulated

Shadow coating using thermal evaporation at a pressure of 3Х10 ^-6 torr after continuous coating of α-Al ₂ O ₃ and octadecylphosphonic acid (ODPA) to the thickness of 22-23 nm on the insulating film surface of device example 1 A 60 nm thick DNTT semiconductor layer was deposited through a shadow mask. A 50 nm thick source and drain gold electrode was deposited through a shadow mask using thermal evaporation on the DNTT semiconductor layer to prepare a DNTT-TFT surface-treated with an insulating film.

Device Example 10: DPPT-TT-TFT

A 60 nm thick insulating film was formed by spin-coating the solution of Example 1 on an aluminum electrode deposited on a 120 μm thick PET substrate. A DPPT-TT chloroform solution (30 mg / mL) was spin-coated at 2,000 rpm for 60 seconds on the insulating film, and then thermally annealed at 150 ° C. for 30 minutes on a hot plate in an ambient atmosphere to form a 60 nm thick DPPT-TT layer. . A DPPT-TT-TFT was prepared by depositing a 50 nm thick gold electrode through thermal evaporation on the DPPT-TT layer.

Table 1 shows the substrates, dielectric layers, surface treatment layers, and semiconductor layers of the MIM capacitors, DNTT-TFT, and DPPT-TT-TFT manufactured according to Device Examples 1 to 10.

Board Dielectric layer Surface treatment layer Semiconductor layer Kinds thickness
(nm) Kinds thickness
(nm) Kinds thickness
(nm) Device Example 1 Si wafer Example 1 60 - - - - Device Example 2 Si wafer Example 2 60 - - - - Device Example 3 Si wafer Example 3 60 - - - - Device Example 4 Si wafer Example 1 30 - - - - Device Example 5 Si wafer Example 1 100 - - - - Device Example 6 Si wafer Example 1 60 - - DNTT 60 Device Example 7 Si wafer Example 2 60 - - DNTT 60 Device Example 8 Si wafer Example 3 60 - - DNTT 60 Device Example 9 Si wafer Example 1 60 α-Al ₂ O ₃ / ODPA 22-23 DNTT 60 Device Example 10 PET Example 1 60 - - DPPT-TT 60

[Test Example]

Test Example 1: FTIR Spectrum Analysis

1 shows the FTIR spectra of polyureas prepared according to Examples 1, 2 and 3. Referring to FIG. 1, the characteristic peaks due to urea binding were (C═O) and (NH) at 1654 and 1540 cm ⁻¹ , respectively. Also, a band of ˜2930 cm ⁻¹ v (CH) shows CH ₂ absorption of diamine units.

In Example 1 FTIR spectra of, NH stretch peak of ethylenediamine in a 2270cm of 2,4-toluene diisocyanate in a NCO peak ^-1 and 3356cm ^-1 and 3280cm ^-1 used as a monomer was observed. There was no unreacted isocyanate and amine groups in the prepared gate insulating layer, it was confirmed that both monomers were completely reacted to form a urea bond.

Hydrogen bonds can occur between the hydrogen atom of the amide NH group and the oxygen atom of the carbonyl group of the adjacent chain. The sharp v (C═O) peak of 1654 cm ^{−1 in} the FTIR spectrum is due to the well-aligned hydrogen bonded polyurea chain. The effect of hydrogen bonding is also observed in the v (NH) mode, which appears as a broad peak in the 3250-3450 cm ⁻¹ range.

Similar FTIR results were obtained for Example 2.

However, Example 3 was not fully synthesized in this synthetic route. Characteristic peaks of NCO groups at 2270 cm ⁻¹ from unreacted toluene 2,4-diisocyanate or NCO-terminated prepolymers were slightly observed as shown in FIG. 1.

Test Example 2: Analysis of capacitance and leakage current density according to the number of alkyl substituents

Figure 2a shows the capacitance according to the frequency of the MIM capacitor manufactured according to the device example 1, device example 2 and device example 3. Referring to FIG. 2A, when an alkyl substituent is additionally introduced into the polymer backbone, the dielectric constant may be reduced.

Figure 2b shows the leakage current density according to the electric field of the MIM capacitor manufactured according to device Example 1, Device Example 2 and Device Example 3. Referring to Figure 2b, it was confirmed that the leakage current density increases significantly with the number of alkyl groups in the polymer backbone.

Table 2 below shows the dielectric and insulating properties of the insulating film of device example 1, device example 2 and device example 3.

Insulating film
(60nm) Capacitance at 10 kHz
[nF cm ^-2 ] Dielectric constant at 10 kHz Leakage Current Density at 2MV cm ^-1
[A cm ^-2 ] Surface RMS Roughness
[nm] Device Example 1 88.79 5.82 6.2 Х 10 ^-10 0.34 Device Example 2 81.53 5.16 5.5 Х 10 ^-6 0.25 Device Example 3 71.59 4.85 6.7 Х 10 ^-6 0.41

Test Example 3 Analysis of Capacitance and Leakage Current Density According to Thickness

Figure 3a shows the capacitance according to the frequency of the MIM capacitor manufactured according to the device example 1, device example 4 and device example 5. Referring to FIG. 3A, it can be seen that the capacitance greatly increases as the thickness decreases.

Figure 3b shows the leakage current density according to the electric field of the MIM capacitor manufactured according to device Example 1, Device Example 4 and Device Example 5. Referring to FIG. 3B, it was confirmed that the insulating film having a thickness of 60 nm had excellent insulating properties. However, the insulating film having a thickness of 30 nm showed a significant decrease in the insulating properties which is understood to be due to the defect structure of the film surface.

Table 3 below shows the dielectric and insulating properties of the insulating films of Device Example 1, Device Example 4, and Device Example 5.

thickness
[nm] Insulating film Capacitance at 10 kHz
[nF cm ^-2 ] Dielectric constant at 10 kHz Leakage Current Density at 2MV cm ^-1
[A cm ^-2 ] Surface RMS Roughness
[nm] 30 Device Example 4 130.40 4.76 4.24 Х 10 ^-2 0.32 60 Device Example 1 88.79 5.82 6.16 Х 10 ^-10 0.34 100 Device Example 5 50.11 5.60 1.95 Х 10 ^-10 0.30

Test Example  4: TFT's transfer and output characterization

4A and 4B show Transfer characteristics and Output characteristics of DNTT-TFT prepared according to Device Example 6, respectively. 4C and 4D show transfer and output characteristics of the DNTT-TFT surface-treated with the insulating film prepared according to Example 9 of the device, respectively.

4A-4D, as the negative gate voltage (V _gs ) increases, the DNTT-TFT with ODPA / α-Al ₂ O ₃ surface treated insulating film is much more than the untreated surface DNTT-TFT. It was confirmed that high I _ds was shown.

Table 4 shows the electrical properties of the DNTT-TFT of device example 6, device example 7, device example 8, and device example 9.

Mobility
[cm ² / Vs] V _th [V] S-slope [V / decade] I _on / I _off Device Example 6 0.066 ± 0.05 -0.10 0.27 1.19 Х 10 ⁵ Device Example 7 0.005 ± 0.06 -0.61 0.56 1.37 Х 10 ³ Device Example 8 inactive - - - Device Example 9 1.390 ± 0.03 -1.22 0.37 5.48 Х 10 ⁵

Test Example 5 bending test

5A is an image of a DPPT-TT-TFT prepared in accordance with Device Example 10 wound on a glass pipette having a diameter of 3.5 mm, and FIG. 5B is a DPPT-TT-TFT prepared in accordance with Device Example 10 using a bending tester. The bending test at 3 mm radius was shown. Figure 5c shows the transfer characteristics before and after the bending test of the DPPT-TT-TFT prepared according to Example 10 of the device.

5A to 5C, it was confirmed that no significant decrease in TFT performance was observed even after the bending test.

Table 5 shows the electrical properties before and after the bending test of the DPPT-TT-TFT prepared according to Example 10 of the device.

Device Example 10 Mobility
[cm ² / Vs] V _th [V] S-slope [V / decade] I _on / I _off Before bending test 0.037 ± 0.05 -1.00 0.37 2.01 Х 10 ³ After Bending Test (× 1,000) 0.036 ± 0.06 -0.88 0.36 2.39 Х 10 ³

Test Example 6: TGA test

Thermogravimetric analysis (TGA) was performed under nitrogen using a TA instrument TGA Q500 analyzer at a heating rate of 10 ° C./min.

6a to 6c show the results of thermogravimetric analysis (TGA) of polyureas prepared according to Examples 1, 2 and 3. 6A to 6C, it was confirmed that PU-13 had an unreacted monomer. PU-11 and PU-12 had thermal resistances of 230 ° C. and 211 ° C. based on T _d 3%, respectively, and for PU-13, the unreacted monomers evaporated at ˜140 ° C. and then partially synthesized. PU-13 was pyrolyzed again at ˜210 ° C.

The scope of the present invention is shown by the following claims rather than the above description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention. do.

Claims (12)

(a) forming a gate electrode on the substrate;
(b) forming an organic insulating layer on the gate electrode;
(c) forming a semiconductor layer on the organic insulating layer; And
(d) forming a source electrode and a drain electrode on the semiconductor layer;
The step (b) is a polyurea solution comprising a polyurea represented by the following structural formula 1 by at least one solution process selected from spin coating, inkjet printing, roll coating, screen printing, transfer method and dipping method Forming an organic insulating layer,
The organic insulating layer has a thickness of 50 to 150 nm,
The polyurea is a method of manufacturing a thin film transistor having a number average molecular weight of 1,200 to 20,000.
[Formula 1]

In the above formula 1,
Ar ¹ is

ego,
R ⁵ is a C1 alkyl group,
Ar ² is a valence bond,
R ¹ is a C1 alkylene group,
R ² is a hydrogen atom or a C1 alkyl group,
R ³ and R ⁴ are hydrogen atoms,
n is a repeating unit repeating number and an integer of 2 to 500. delete delete delete delete delete The method of claim 1,
The polyurea has a dielectric constant of 3 to 8, characterized in that the thin film transistor manufacturing method. The method of claim 1,
The manufacturing method of the thin film transistor
Before step (b), (b ') according to Scheme 1 below, compound 1 and compound 2 are subjected to step-growth polymerization at -20 to 20 ° C. in an aprotic polar solvent to be compound 3 Method of manufacturing a thin film transistor, characterized in that further comprising the step of manufacturing the polyurea:
Scheme 1

In Scheme 1,
Ar ¹ is

ego,
R ⁵ is a C1 alkyl group,
Ar ² is a valence bond,
R ¹ is a C1 alkylene group,
R ² is a hydrogen atom or a C1 alkyl group,
R ³ and R ⁴ are hydrogen atoms,
n is a repeating unit repeating number and an integer of 2 to 500. delete delete delete delete

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