KR102470396B1 - Manufacturing method of thin film transistor - Google Patents

Abstract

Forming a channel layer, preparing a metal ink containing metal particles and a solvent having a hydroxy group, forming the prepared metal ink on the channel layer, and on the channel layer There is provided a method of manufacturing a thin film transistor comprising the step of forming an electrode by optically sintering the metal ink formed thereon.

Description

Manufacturing method of thin film transistor {Manufacturing method of thin film transistor}

The present invention relates to a method for manufacturing a thin film transistor, and more specifically, to a method for manufacturing a thin film transistor having the same crystallinity of electrodes before and after optical sintering.

Recently, as the use and demand for electronic devices having high-definition pixels, large-area displays, and the like increase, research on thin film transistors (TFTs) is being actively conducted. Accordingly, an issue regarding contact characteristics between a channel layer of a thin film transistor and an electrode including a source and a drain is emerging.

A conventional thin film transistor uses a silicon-based material as a channel layer. Accordingly, a conventional thin film transistor uses a method of forming an ohmic contact by performing a high-concentration doping process on silicon at a contact portion between an electrode and a channel layer. However, since the contact portion of the conventional thin film transistor requires matching of the work function of the material and the presence or absence of a residual barrier, a method capable of implementing the thin film transistor using a new material is required.

Accordingly, an oxide semiconductor material such as indium gallium zinc oxide (IGZO) has recently emerged as a material for a channel layer of a thin film transistor. This is because an oxide semiconductor material such as indium gallium zinc oxide has advantages such as high electron mobility, transparency, and mechanical flexibility.

However, the manufacturing method of the thin film transistor electrode is still optimized for conventional silicon-based materials.

Accordingly, a new method for manufacturing a thin film transistor is required.

One technical problem to be solved by the present invention is to provide a method for manufacturing a thin film transistor having the same crystallinity of electrodes before and after optical sintering.

Another technical problem to be solved by the present invention is to provide a method for manufacturing a thin film transistor having a low electrical resistance value.

Another technical problem to be solved by the present invention is to provide a method for manufacturing a thin film transistor having excellent electrical conductivity.

The technical problem to be solved by the present invention is not limited to the above.

In order to solve the above technical problem, the present invention provides a method for manufacturing a thin film transistor.

According to an embodiment, the method of manufacturing the thin film transistor includes forming a channel layer, preparing a metal ink including metal particles and a solvent having a hydroxy group, and preparing the metal ink. It may include forming on the channel layer, and forming an electrode by photosintering the metal ink formed on the channel layer.

According to an embodiment, the crystallinity of the metal ink before the optical sintering and the electrode after the optical sintering may be the same.

According to an embodiment, in the metal ink, an X-ray diffraction peak corresponding to MoO ₂ is observed, and the electrode in which the metal ink is photosintered also has an X-ray diffraction peak corresponding to MoO ₂ can be observed

According to one embodiment, an X-ray diffraction peak corresponding to α-MoO ₃ may be non-observed in the electrode after light sintering.

According to one embodiment, the solvent may consist of only non-aqueous and non-aqueous solvents.

According to one embodiment, the metal particle is a spherical particle having a diameter of 1 nm or more and 1000 nm or less, and may include molybdenum.

According to one embodiment, the light sintering energy in the step of forming the electrode may be greater than or equal to 80 J/cm ² and less than 192 J/cm ² .

According to one embodiment, the solvent is ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, Propylene glycol, hexylene glycol, glycerine, isopropyl alcohol, 2-methoxy ethanol, pentyl alcohol, hexyl alcohol ( hexyl alcohol, butyl alcohol, octyl alcohol, ethyl alcohol, methyl alcohol, methyl ethyl ketone, formamide, acetone ), and α- terpineol (α-terpineol).

According to an embodiment, the metal ink further includes a polymer binder resin, wherein the polymer binder resin is polyvinyl pyrrolidone, polyvinyl alcohol, or polyvinyl butyral. ), polyethylene glycol, polymethyl methacrylate, dextran, azobis, and dodecylbenzene sodium sulfate. can

According to one embodiment, the channel layer may include indium gallium zinc oxide, zinc tin oxide, indium gallium tin oxide, or indium zinc oxide. , iodine oxide, zinc oxynitride, amorphous silicon, and poly silicon.

According to an embodiment of the present invention, forming a channel layer, preparing a metal ink containing metal particles and a solvent having a hydroxy group, forming the prepared metal ink on the channel layer A method of manufacturing a thin film transistor may be provided, including the steps of performing optical sintering of the metal ink formed on the channel layer to form an electrode.

The solvent may consist of only non-aqueous and non-aqueous solvents.

Accordingly, the crystallinity of the thin film transistor electrode manufactured according to the embodiment of the present invention before and after optical sintering may be the same. Therefore, the thin film transistor electrode may have excellent electron mobility and reliability.

In addition, according to an embodiment of the present invention, since the thin film transistor electrode is manufactured by optical sintering, the electrical resistance value is about 38 times or more and about 129 times or less than that of a thin film transistor manufactured by conventional thermal sintering. Low, and correspondingly, electrical conductivity may be excellent.

1 and 2 are views for explaining a method of manufacturing a thin film transistor according to an embodiment of the present invention.
3 to 13 are views for explaining thin film transistors according to experimental examples of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the technical spirit of the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosed content will be thorough and complete, and the spirit of the present invention will be sufficiently conveyed to those skilled in the art.

In this specification, when an element is referred to as being on another element, it means that it may be directly formed on the other element or a third element may be interposed therebetween. Also, in the drawings, shapes and thicknesses of regions are exaggerated for effective description of technical content.

In addition, although terms such as first, second, and third are used to describe various elements in various embodiments of the present specification, these elements should not be limited by these terms. These terms are only used to distinguish one component from another. Therefore, what is referred to as a first element in one embodiment may be referred to as a second element in another embodiment. Each embodiment described and illustrated herein also includes its complementary embodiments. In addition, in this specification, 'and/or' is used to mean including at least one of the elements listed before and after.

In the specification, expressions in the singular number include plural expressions unless the context clearly dictates otherwise. In addition, the terms "comprise" or "having" are intended to designate that the features, numbers, steps, components, or combinations thereof described in the specification exist, but one or more other features, numbers, steps, or components. It should not be construed as excluding the possibility of the presence or addition of elements or combinations thereof. In addition, in this specification, "connection" is used to mean both indirectly and directly connecting a plurality of components.

In addition, terms such as “… unit”, “… unit”, and “module” described in the specification mean a unit that processes at least one function or operation, which may be implemented as hardware or software or a combination of hardware and software. have.

In addition, in the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted.

Molybdenum can be highly oxidized.

Accordingly, the electrode made of molybdenum may also have a high degree of oxidation, and an oxide film may be easily formed inside the electrode due to the high degree of oxidation as described above. Accordingly, the electrode made of molybdenum requires a reduction step in the manufacturing process and has a difficult manufacturing process.

More specifically, in order to minimize the formation of an oxide film inside the electrode and to manufacture a high-purity electrode, molybdenum must be deposited on the channel layer in a vacuum atmosphere.

In addition, after the deposition, an inert gas atmosphere and a long time are required to minimize the reaction between the electrode and oxygen in the annealing process.

Accordingly, in the manufacturing process of manufacturing the electrode, there is a problem in that cost and time increase.

In addition, in order to use the electrodes as a source and a drain, a patterning process for patterning the deposited metal is required.

However, since the conventional patterning process is performed by methods such as exposure and etching, expensive equipment is required, and toxic chemicals must be used, there is a problem that is harmful to the human body and the environment.

In addition, since an additional heat treatment process is required after the patterning process as described above, the process cost and time increase as a matter of course.

In order to solve this problem, the present invention provides a method for manufacturing a thin film transistor, including manufacturing a thin film transistor electrode within a short time, for example, several milliseconds (~100 ms) in an atmospheric pressure atmosphere and room temperature.

Hereinafter, a method of manufacturing a thin film transistor according to an embodiment of the present invention will be described.

1 and 2 are views for explaining a method of manufacturing a thin film transistor according to an embodiment of the present invention.

Referring to FIG. 1 , the thin film transistor manufacturing method includes a channel layer forming step (S110), a metal ink preparation step (S120), a metal ink forming step on the channel layer (S130), and a metal ink light sintering step (S140). ) may include at least one of them.

Hereinafter, each step is explained in detail.

Step S110

In step S110 , a channel layer 100 may be formed on the substrate 10 .

To this end, an oxide semiconductor solution for forming the channel layer 100 may be prepared. The oxide semiconductor solution may be, for example, an oxide semiconductor solution based on indium, gallium, and zinc, an oxide semiconductor solution based on zinc and tin, and an oxide semiconductor solution based on indium, gallium, and tin. of oxide semiconductor solutions, indium and zinc-based oxide semiconductor solutions, iodine-based oxide semiconductor solutions, zinc and nitride-based oxide semiconductor solutions, amorphous silicon-based oxide semiconductor solutions, And it may include at least one of poly silicon (poly silicon) based oxide semiconductor solution.

According to an embodiment, prior to forming the oxide semiconductor solution on the substrate 10, the substrate 10 may be surface modified. The substrate 10 may be, for example, doped silicon on which a dielectric layer is formed. Alternatively, for another example, the substrate 10 may include polyethylene terephthalate, colorless polyimide, polyethylene naphthalate, polycarbonate, glass, polydimethylsiloxane (polydimethylsiloxane), and at least one of silicon wafers.

In addition, the surface modification is performed after washing the substrate 10 with at least one of acetone, isopropyl alcohol, and distilled water, and then at least one of UV-ozone treatment, plasma treatment, and block-co-polymer treatment. can be performed by either.

Accordingly, the prepared oxide semiconductor solution may be formed on the surface-reformed substrate 10 .

According to an embodiment, the oxide semiconductor solution formed on the substrate 10 may be light-dried. For example, the oxide semiconductor solution formed on the substrate 10 may be light-dried by at least one of near-infrared light and far-infrared light.

The oxide semiconductor solution on the substrate 10 may be light-dried and then light-sintered. Accordingly, the channel layer 100 may be formed on the substrate 10 .

As described above, the semiconductor solution is, for example, an oxide semiconductor solution based on indium, gallium, and zinc, an oxide semiconductor solution based on zinc and tin, indium, and gallium , and tin-based oxide semiconductor solutions, indium and zinc-based oxide semiconductor solutions, iodine-based oxide semiconductor solutions, zinc and nitride-based oxide semiconductor solutions, amorphous silicon-based oxide semiconductor solutions The channel layer 100 formed by optical sintering, which includes at least one of an oxide semiconductor solution and a poly silicon-based oxide semiconductor solution, is, for example, indium gallium zinc oxide (indium gallium oxide). zinc oxide), zinc tin oxide, indium gallium tin oxide, indium zinc oxide, iodine oxide, zinc oxynitride, Of course, at least one of amorphous silicon and poly silicon may be included.

Step S120

Metal ink may be prepared in step S120.

More specifically, in step S120, metal ink including metal particles and a solvent may be prepared.

The metal particles may be, for example, molybdenum spherical particles having a diameter of 1 nm or more and 1000 nm or less.

According to an embodiment of the present invention, when the metal ink is sintered into the electrode 200 in a step described later by the fact that the metal particle is a molybdenum particle, the electrode 200 includes the channel layer 100, It has low contact resistance and may have chemical stability. This will be described in detail in a step to be described later.

The solvent may consist of only non-aqueous solvents among non-aqueous and aqueous solvents. More specifically, the solvent may include, for example, at least one of a solvent having a hydroxy group and an organic solvent. More specifically, the solvent is, for example, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol , dipropylene glycol, hexylene glycol, glycerine, isopropyl alcohol, 2-methoxy ethanol, pentyl alcohol, hexyl Hexyl alcohol, butyl alcohol, octyl alcohol, ethyl alcohol, methyl alcohol, methyl ethyl ketone, formamide, acetone (acetone), and α- terpineol (α-terpineol) may include at least one of.

Accordingly, according to an embodiment of the present invention, when the metal ink is optically sintered to manufacture the electrode 200 in a step described later, the electron mobility of the electrode 200 may be excellent.

On the other hand, when the solvent is made of a water-based material and the metal ink is photo-sintered in a step to be described later to be manufactured as an electrode, the electron mobility of the electrode may decrease. This may be because, when the solvent is made of a water-based solvent, the channel layer reacts with the solvent made of a water-based material while the electrode is manufactured by the optical sintering.

However, according to an embodiment of the present invention, as described above, since the solvent is made of a non-aqueous material, when the metal ink is optically sintered to manufacture the electrode 200 in a step described later, the electrode 200 is prepared as described above. The electron mobility of (200) may be excellent.

According to one embodiment, the metal ink may further include at least one of a dispersant and a binder.

The binder may be a polymeric binder resin. The polymer binder resin, for example, polyvinyl pyrrolidone, polyvinyl alcohol, polyvinyl butyral, polyethylene glycol, polymethyl methacrylate ( polymethyl methacrylate), dextran, azobis, and dodecylbenzene sodium sulfate.

According to an embodiment, the viscosity of the metal ink may be adjusted in step S120. More specifically, the viscosity of the metal ink may be adjusted by adjusting the mass ratio of the metal particles, for example, molybdenum, included in the metal ink to 10 wt% or more and 70 wt% or less.

Accordingly, the viscosity of the metal ink may be optimized according to a method of forming the metal ink on the channel layer 100 in a step described later. For example, when the metal ink is formed on the channel layer 100 by an inkjet printing method in a step described later, the metal ink may be adjusted to have a low viscosity in this step. For another example, when the metal ink is formed on the channel layer 100 by a screen printing method in a step to be described later, the metal ink may be adjusted to have a high viscosity in this step. Like the screen printing method described above, in order to make the metal ink into a high-viscosity paste, according to an embodiment, a grading agent may be added to the metal ink. Accordingly, the viscosity of the metal ink may be increased.

On the other hand, unlike the embodiment of the present invention, when the mass ratio of the metal particles, for example, molybdenum, included in the metal ink is adjusted to a range of 80 wt% or more, so that the viscosity of the metal ink is adjusted, the A mass ratio of other materials, eg, the solvent, the dispersant, and the binder, to that of the metal particles in the metal ink may be reduced. Accordingly, dispersibility and fluidity of the metal ink may be deteriorated.

However, according to an embodiment of the present invention, as described above, the viscosity of the metal ink is adjusted to a mass ratio of the metal particles included in the metal ink to a range of 10 wt% or more and 70 wt% or less. , The decrease in dispersibility and fluidity of the metal ink is minimized, but the viscosity of the metal ink can be optimized according to a method of forming the metal ink in a step described below.

Step S130

In step S130 , the metal ink may be formed on the channel layer 100 .

According to one embodiment, the method of forming the metal ink on the channel layer 100, for example, screen printing (screen printing), inkjet printing (inkjet printing), micro-contact printing (micro-contact printing) , Gravure printing, gravure-offset printing, flexography printing, and reverse-offset printing may include at least one of them.

Alternatively, according to another embodiment, the method of forming the metal ink on the channel layer 100 includes bar coating, spin-coating, spray-coating, and screen printing. It may include at least one of (screen printing).

According to an embodiment, a method of forming the metal ink on the channel layer 100 may be diversified according to an application example of the electrode 200 described below. For example, when the electrode 200 is applied to a display and a sensor, a method of forming the metal ink on the channel layer 100 is an ink-jet or roll off-set method. , And may include at least one of screen printing (screen printing). Meanwhile, as described above, when the electrode 200 is applied to a display and a sensor, the pattern size may be diversified according to the field of application of the display and the sensor. For example, when the electrode is applied to a relatively simple low-quality display such as a liquid crystal display, it may be formed in a pattern of several tens of microns. Alternatively, for another example, when the electrode is applied to a high-definition display, it may be formed in a pattern of several microns.

According to an embodiment, a step of light drying may be further included between step S130 and step S140 described below.

The light-drying may include irradiating the metal ink formed on the channel layer 100 with at least one of near-infrared light and far-ultraviolet light. For example, in the light drying step, the metal ink formed on the channel layer 100 is dried for 0 minutes or more and 10 minutes or less with light energy of 0 W/cm ² or more and 50 W/cm ² or less. It can dry for hours.

In this case, a temperature at which the metal ink is light-dried in the light-drying step may be lower than a temperature at which the metal ink is light-sintered in the light-sintering step described later.

Accordingly, in this step, materials other than the metal particles included in the metal ink, for example, the solvent, the dispersant, and the binder are removed, and the electrode 200 manufactured by the light sintering step described later The step defect is minimized, and the purity and density of the metal particles of the electrode 200 can be improved.

On the other hand, if the light-drying step is omitted and the metal ink is light-sintered in a step to be described later, a defective electrode may be manufactured. This may be because the temperature of the metal ink rapidly increases when the light drying step is omitted and the light sintering step described later is performed. As the temperature of the metal ink rapidly increases, materials other than the metal particles, for example, the solvent, the dispersant, and the binder rapidly evaporate, resulting in defective steps in the electrode.

However, according to an embodiment of the present invention, as the light drying step is first performed as described above and the light sintering step described later is performed, sequential temperatures may be provided to the metal ink. Accordingly, a step defect is minimized in the electrode 200 manufactured by the light sintering step to be described later, and the purity and density of the metal particles of the electrode 200 can be improved.

Step S140

In step S140 , the metal ink formed on the channel layer 100 may be light-sintered to form the electrode 200 .

To this end, referring to FIG. 2 , extreme-wave white light (ipl) may be irradiated to the metal ink formed on the channel layer 100 from a light source ls, for example, a xenon lamp.

A light sintering energy range of the ultrashort white light (ipl) irradiated onto the metal ink may be, for example, 80 J/cm ² or more and 192 J/cm ² or less.

In addition, a light irradiation time of the extreme short wave white light (ipl) irradiated onto the metal ink may be, for example, 1 second or less. Alternatively, for another example, the irradiation time of the white light (ipl) may be 5 seconds or more and 20 seconds or less.

In addition, the number of pulses of the extreme short wave white light (ipl) irradiated to the metal ink is, for example, 10 or more and 100 or less, the pulse width is, for example, 10 ms or more and 200 ms or less, and the pulse The interval may be, for example, 20 ms or more and 100 ms or less.

Accordingly, the electrode 200 may be formed by optically sintering the metal ink.

According to an embodiment of the present invention, in this step, the electrode 200 after the optical sintering may have the same crystallinity as that of the metal ink before the optical sintering.

More specifically, when the metal ink includes molybdenum as the metal particles, in the metal ink, an X-ray diffraction peak corresponding to MoO ₂ may be observed. In addition, even in the electrode 200 where the metal ink is photosintered in this step, an X-ray diffraction peak corresponding to the MoO ₂ can be observed.

Meanwhile, in the photo-sintered electrode 200, an X-ray diffraction peak corresponding to α-MoO ₃ may be non-observable. Here, the X-ray diffraction peak corresponding to α-MoO ₃ may be an X-ray diffraction peak not included in the metal ink. In other words, the X-ray diffraction peak corresponding to α-MoO ₃ may mean that molybdenum included as the metal particles in the metal ink is oxidized at a high temperature.

That is, unlike the embodiment of the present invention, when the metal ink is thermally sintered to produce an electrode, the molybdenum may be oxidized at a high temperature, and in the thermally sintered electrode, X corresponding to α-MoO ₃ A line diffraction peak can be observed. This may be because heat treatment is required for a long time at a high temperature in order to manufacture the electrode from the metal ink through thermal sintering.

However, as described above, according to an embodiment of the present invention, the electrode 200 may be formed by light-sintering the metal ink within a short time, for example, within a few seconds.

Accordingly, the electrode 200 after the optical sintering may have the same crystallinity as that of the metal ink before the optical sintering.

Therefore, the thin film transistor manufactured by optical sintering according to the embodiment of the present invention may have excellent electron mobility and reliability.

On the other hand, as described above, according to an embodiment of the present invention, when the metal ink is sintered into the electrode 200 in this step because the metal particle is a molybdenum particle, the electrode 200 It may have low contact resistance and chemical stability with the channel layer 100 .

This is because the electrode 200 is made of molybdenum as described above, so that the thermal strain rate is low while the oxidation degree is high. Accordingly, when the electrode 200 is exposed to air, a natural oxide film may be formed on the electrode surface. Accordingly, the electrode 200 may be protected from the outside by the oxide film, that is, pure metal inside the oxide film, that is, pure molybdenum. Thus, the stability of the electrode 200 can be improved.

In the above, the manufacturing method of the thin film transistor according to the embodiment of the present invention has been described.

Hereinafter, an experimental example of the present invention manufactured according to the manufacturing method of the thin film transistor will be described.

According to Experimental Example 1 thin film transistor

Indium, gallium, and zinc precursors were mixed in a mass ratio of 7:1:2, and 10 ml of an oxide semiconductor solution was prepared to have a molar concentration of 0.15 M.

The oxide semiconductor solution was stirred for 12 hours or more using a magnetic bar.

A silicon dioxide (SiO ₂ ) substrate was prepared, the substrate was washed with acetone, isopropyl alcohol, and distilled water, and the surface of the substrate was modified by UV-ozone treatment.

Using a spin coater, the oxide semiconductor solution was provided on the surface-modified substrate under conditions of 3000 rpm and 30 seconds to form a thickness of 10 nm.

The formed oxide semiconductor solution was irradiated with near-infrared light and far-infrared light to light dry, and irradiated with extreme-wave white light to form an indium gallium zinc oxide (IGZO) channel layer.

A metal ink including molybdenum metal particles having a diameter of 10 nm or more and 40 nm or less, a solvent with a hydroxyl group, a dispersant, and an additive was prepared.

The prepared metal ink was formed on the channel layer, irradiated with near-infrared light and light-dried, and subjected to ultrashort white light with a pulse number of 10 or more and 100 or less, a pulse width of 20 ms, and a pulse interval of 30 ms. was irradiated and sintered to manufacture a thin film transistor according to Experimental Example 1.

According to Experimental Example 1-1 thin film transistor

In Experimental Example 1 described above, a thin film transistor according to Experimental Example 1-1 was manufactured by light sintering with a light irradiation energy of 120 J/cm ² .

According to Experimental Example 1-2 thin film transistor

In Experimental Example 1 described above, the thin film transistor according to Experimental Example 1-2 was manufactured by light sintering with a light irradiation energy of 156 J/cm ² .

According to Experimental Examples 1-3 thin film transistor

In the above-described Experimental Example 1, light sintering was performed with a light irradiation energy of 192 J/cm ² to manufacture thin film transistors according to Experimental Examples 1-3.

According to Experimental Examples 1-4 thin film transistor

In Experimental Example 1 described above, the thin film transistor according to Experimental Example 1-4 was fabricated by light sintering with a light irradiation energy of 228 J/cm ² .

According to Experimental Example 2-1 thin film transistor

In Experimental Example 1 described above, a thin film transistor according to Experimental Example 2-1 was prepared by using α-terpineol as the hydroxy group-accompanied solvent and light-sintering with a light irradiation energy of 60 J/cm ² . .

According to Experimental Example 2-2 thin film transistor

In Experimental Example 1 described above, a thin film transistor according to Experimental Example 2-2 was prepared by using α-terpineol as the hydroxy group-accompanied solvent and light-sintering with a light irradiation energy of 80 J/cm ² . .

According to Experimental Example 2-3 thin film transistor

In the above-described Experimental Example 1, α-terpineol was used as the hydroxy group-accompanied solvent, and light sintered with a light irradiation energy of 100 J/cm ² , A thin film transistor according to Experimental Example 2-3 was prepared. .

According to Comparative Example 1 thin film transistor

In Experimental Example 1 described above, a thin film transistor according to Comparative Example 1 was manufactured by forming the prepared metal ink on the channel layer and performing thermal sintering in a chamber-type oven instead of the optical sintering.

According to Comparative Example 1-1 thin film transistor

In Comparative Example 1 described above, a thin film transistor according to Comparative Example 1-1 was manufactured by thermally sintering at a temperature of 300° C. in the chamber-type oven.

According to Comparative Example 1-2 thin film transistor

In Comparative Example 1 described above, the thin film transistor according to Comparative Example 1-2 was manufactured by thermally sintering at a temperature of 400° C. in the chamber-type oven.

According to Comparative Examples 1-3 thin film transistor

In Comparative Example 1 described above, thin film transistors according to Comparative Examples 1-3 were manufactured by thermally sintering at a temperature of 500° C. in the oven of the chamber type.

According to Comparative Example 2-1 thin film transistor

In the above-described Experimental Example 1, a thin film transistor according to Comparative Example 2-1 was manufactured by using an aqueous solvent instead of the hydroxyl group-accompanied solvent and performing light sintering with a light irradiation energy of 60 J/cm ² .

According to Comparative Example 2-2 thin film transistor

In the above-described Experimental Example 1, a thin film transistor according to Comparative Example 2-2 was manufactured by using an aqueous solvent instead of the hydroxy group-accompanied solvent and performing light sintering with a light irradiation energy of 80 J/cm ² .

According to Comparative Example 2-3 thin film transistor

In Experimental Example 1 described above, thin film transistors according to Comparative Examples 2-3 were manufactured by using an aqueous solvent instead of the hydroxy group-accompanied solvent and performing light sintering with a light irradiation energy of 100 J/cm ² .

According to Comparative Examples 2-4 thin film transistor

In Experimental Example 1 described above, a thin film transistor according to Comparative Examples 2-4 was obtained by using the hydroxy group-accompanied solvent and the aqueous solvent at a mass ratio of 1:2 and light-sintering with a light irradiation energy of 60 J/cm ² . was manufactured.

According to Comparative Example 2-5 thin film transistor

In the above-described Experimental Example 1, a thin film transistor according to Comparative Example 2-5 was obtained by using the hydroxy group-accompanied solvent and the aqueous solvent at a mass ratio of 1:2 and light-sintering with a light irradiation energy of 80 J/cm ² . was manufactured.

Thin film transistor according to Comparative Example 2-6

In the above-described Experimental Example 1, a thin film transistor according to Comparative Examples 2-6 was obtained by using the hydroxy group-accompanied solvent and the aqueous solvent at a mass ratio of 1:2 and light-sintering with a light irradiation energy of 100 J/cm ² . was manufactured.

Thin film transistor according to Comparative Example 2-7

In the above-described Experimental Example 1, a thin film transistor according to Comparative Examples 2-7 was obtained by using the hydroxy group-accompanied solvent and the aqueous solvent at a mass ratio of 2:1 and light-sintering with a light irradiation energy of 60 J/cm ² . was manufactured.

Thin film transistor according to Comparative Example 2-8

In Experimental Example 1 described above, a thin film transistor according to Comparative Examples 2-8 was obtained by using the hydroxy group-accompanied solvent and the aqueous solvent at a mass ratio of 2:1 and light-sintering with a light irradiation energy of 80 J/cm ² . was manufactured.

Thin film transistor according to Comparative Example 2-9

In the above-described Experimental Example 1, a thin film transistor according to Comparative Examples 2-9 was obtained by using the hydroxy group-accompanied solvent and the aqueous solvent at a mass ratio of 2:1 and light-sintering with a light irradiation energy of 100 J/cm ² . was manufactured.

3 to 13 are views for explaining thin film transistors according to experimental examples of the present invention.

Referring to FIG. 3, the thin film transistor manufactured according to Experimental Example 1 of the present invention includes an indium gallium zinc oxide (IGZO) channel layer 100 and a molybdenum on a silicon dioxide (SiO ₂ ) substrate 10. It can be observed that the denium electrodes 200 are sequentially formed.

In addition, through the cross section of the molybdenum electrode 200 shown in FIG. 3, it can be observed that pores are not formed and have a dense structure.

This may be because, as described above, in the present invention, ultrashort wave white light is irradiated to the metal ink to perform light sintering.

Meanwhile, referring to FIG. 4 , it can be observed that the metal ink is irradiated with ultrashort white light, and the molybdenum metal particles form crystals.

In contrast, referring to FIG. 5 , it can be observed that the thin film transistor electrode manufactured according to Comparative Example 1 grew in the form of a nanobelt (nb) rather than forming a crystal as in Experimental Example 1 of the present invention. The nano belt (nb) may be α-MoO ₃ in which molybdenum is oxidized at a high temperature. This may be because, in Comparative Example 1, unlike Experimental Example 1 of the present invention, the metal ink was thermally sintered in a chamber-type oven.

In order to examine the crystallinity of the thin film transistor electrodes manufactured according to the experimental examples and comparative examples of the present invention in more detail, X-ray diffraction peaks were analyzed.

Referring to FIG. 6 , X-ray diffraction peaks corresponding to MoO ₂ can be observed in the thin film transistor electrode and molybdenum metal particles according to Experimental Example 1 of the present invention.

Meanwhile, X-ray diffraction peaks corresponding to α-MoO ₃ may be non-observed in the thin film transistor electrode and molybdenum metal particles according to Experimental Example 1 of the present invention.

This may mean that the thin film transistor electrode manufactured according to Experimental Example 1 of the present invention has the same crystallinity as the molybdenum metal particles included in the metal ink before optical sintering.

Unlike this, in the thin film transistor electrodes according to Comparative Examples 1-2 and 1-3, the X-ray diffraction peak corresponding to MoO ₂ is non-observed, and the X-ray diffraction peak corresponding to α-MoO ₃ can be observed. can

Unlike Experimental Example 1 of the present invention, this is because the thin film transistor electrodes manufactured according to Comparative Examples 1-2 and 1-3 are oxidized at a high temperature, which is different from the molybdenum metal particles included in the metal ink before light sintering. This may be due to its crystallinity.

Referring to FIG. 7 , electrical conductivity of the thin film transistors according to Experimental Examples 1-1 to 1-4 of the present invention can be observed.

It can be seen that when the light sintering energy is increased according to Experimental Example 1-1 to Experimental Example 1-4 of the present invention, the electrical resistance value is reduced and the electrical conductivity is improved.

In particular, through Experimental Example 1-2 of the present invention, in the case of light sintering with light irradiation energy of 156 J/cm ² , the electrical resistance value was measured to be about 45 μΩ cm or less, and through Experimental Example 1-3 of the present invention , 192 J / cm ² In the case of light sintering with light irradiation energy, the electrical resistance value was measured to be less than about 37 μΩ cm, which is a smaller value, and through Experimental Examples 1-4 of the present invention, 228 J / cm ² In the case of light sintering with light irradiation energy, the electrical resistance value was measured at a smaller value of about 35 μΩ cm.

In addition, referring to FIG. 7 , it can be observed that the surface of the thin film transistor electrode manufactured according to the experimental example of the present invention has turned gray. From this, it can be seen that the metal ink was optically sintered into an electrode.

Meanwhile, referring to FIG. 8 , electrical conductivities of the thin film transistors according to Comparative Examples 1-1 to 1-3 can be observed.

Unlike the experimental example of the present invention, it can be seen that when the thermal sintering temperature increases according to Comparative Examples 1-1 to 1-3, the electrical resistance value increases and the electrical conductivity decreases.

According to Comparative Example, the lowest electrical resistance value of the thin film transistor manufactured according to Comparative Example 1-1 at the lowest thermal sintering temperature was measured as about 3,500 μΩ·cm.

Comparing the electrical resistance values of the thin film transistor according to the comparative example manufactured by thermal sintering and the thin film transistor according to the experimental example of the present invention manufactured by optical sintering, the experimental example of the present invention is about 38 times larger than the comparative example. It can be seen that it has a low electrical resistance value of more than and about 129 times or less.

Therefore, it goes without saying that the electrical conductivity of the thin film transistor manufactured according to the experimental example of the present invention may be about 38 times higher and about 129 times higher than that of the comparative example.

Also, referring to FIG. 8 , unlike the experimental example of the present invention, it can be observed that the surface of the thin film transistor electrode manufactured according to the comparative example has turned white. This may be because, in the case of thermal sintering according to the comparative example, as the sintering temperature increases, the sheet resistance increases and the electrical conductivity decreases. This is because, in general, materials with low oxygen reactivity, such as silver, are concentrated as the sintering temperature increases, improving electrical conductivity, while molybdenum has a higher oxidation degree than the above-mentioned silver. This may be because it readily reacts with oxygen in the air.

Referring to FIGS. 9 to 13 , semiconductor characteristics of thin film transistors manufactured according to experimental examples and comparative examples of the present invention can be observed.

Referring to FIG. 9, when a solvent having a hydroxyl group is used and light sintered with a light irradiation energy of 156 J/cm ² according to Experimental Example 1-2 of the present invention, the manufactured thin film transistor has an electron mobility of 7.8 In terms of cm ² /Vs, it can be seen that the semiconductor properties are superior to those of Experimental Example 1-1 and Experimental Example 1-3.

Referring to FIG. 10, according to Experimental Example 2-3 of the present invention, α-terpineol is used as the hydroxyl group-accompanied solvent, and light sintering is performed with a light irradiation energy of 100 J/cm ² , a thin film prepared The electron mobility of the transistor is 8.102 cm ² /Vs, which is superior to that of Experimental Example 2-1, and the electron mobility of the thin film transistor manufactured according to Experimental Example 2-2 is also superior to 6.312 cm ² /Vs. .

This is because, according to the experimental example of the present invention, the solvent is non-aqueous, that is, made of α-terpineol, and the non-aqueous solvent and the channel layer are non-reactive while the electrode is manufactured by the light sintering. it may be because

Meanwhile, referring to FIG. 11, when an aqueous solvent is used instead of the hydroxy group-accompanied solvent according to Comparative Examples 2-1 to 2-3, the manufactured thin film transistor has very low electron mobility can be observed

This may be because, when the solvent is made of a water-based solvent according to the comparative example, the channel layer reacts with the solvent made of a water-based material while the electrode is manufactured by the light sintering as described above.

Meanwhile, referring to FIG. 12, when the hydroxy group-accompanied solvent and the aqueous solvent are used in a mass ratio of 1: 2 according to Comparative Examples 2-4 to 2-6, the electron mobility of the manufactured thin film transistor is, It increased compared to Comparative Example 2-1 to Comparative Example 2-3 described above, but it can be observed that it is still very low.

This may be because, as described above, since the solvent includes a water-based solvent according to the comparative example, the water-based solvent and the channel layer react while the electrode is manufactured by the optical sintering.

Meanwhile, referring to FIG. 13, when the hydroxy group-accompanied solvent and the aqueous solvent are used in a mass ratio of 2: 1 according to Comparative Examples 2-7 to 2-9, the electron mobility of the manufactured thin film transistor is, Although it increased compared to Comparative Examples 2-4 to Comparative Examples 2-6 described above, it can be observed that the electron mobility is also low. Although semiconductor characteristics were observed in the thin film transistor according to Comparative Examples 2-9, electron mobility was measured as a low value of 0.0850 cm ² /Vs.

This may be because, as described above, since the solvent includes a water-based solvent according to the comparative example, while the electrode is manufactured by the light sintering, the water-based solvent and the channel layer still react.

The embodiments of the present invention described above are not limited to the above-described thin film transistors. For example, the embodiments of the present invention can be applied to various electronic products and display devices driven at high temperatures, such as electronic devices and sensors applied to automobiles.

In addition, the embodiments of the present invention described above can be applied to electrodes requiring large-area and mass production while minimizing process costs. For example, the embodiment of the present invention is suitable for high-temperature products such as wearable electronics, large-area displays, automotive PCB devices, etc., which require large-area and mass-production of a white light sintering process that can be linked with a roll-to-roll process. It can be applied to electrodes used in high value-added products in which driving, structural stability, and reliability must be secured.

In addition, although the above-described embodiments and experimental examples have been described assuming that the metal particles are molybdenum, the metal particles are not limited to molybdenum.

In the above, the present invention has been described in detail using preferred embodiments, but the scope of the present invention is not limited to specific embodiments, and should be interpreted according to the appended claims. In addition, those skilled in the art should understand that many modifications and variations are possible without departing from the scope of the present invention.

10: substrate
100: channel layer
200: electrode

Claims (10)

forming a channel layer;
preparing a metal ink containing metal particles and a solvent accompanied by a hydroxy group;
forming the prepared metal ink on the channel layer; and
Forming a source electrode and a drain electrode by optically sintering the metal ink formed on the channel layer with light energy irradiated in a range of 80 J/cm ² or more and less than 192 J/cm ² ; including, the channel layer As this is switched, electron mobility between the source electrode and the drain electrode is controlled,
The crystallinity of the metal ink before optical sintering and the source electrode and drain electrode after optical sintering are the same,
In the source electrode and the drain electrode after the optical sintering, the X-ray diffraction peak corresponding to α-MoO ₃ is non-observed.
delete According to claim 1,
The metal ink,
An X-ray diffraction peak corresponding to MoO ₂ is observed,
The source electrode and the drain electrode in which the metal ink is optically sintered are also
A method of manufacturing a thin film transistor in which an X-ray diffraction peak corresponding to MoO ₂ is observed.
delete According to claim 1,
The solvent is
A method for manufacturing a thin film transistor consisting of non-aqueous and non-aqueous only non-aqueous materials.
According to claim 1,
The metal particles,
Spherical particles having a diameter of 1 nm or more and 1000 nm or less,
Method for manufacturing a thin film transistor containing molybdenum.
delete According to claim 1,
The solvent is
Ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, hexylene glycol (hexylene glycol), glycerine, isopropyl alcohol, 2-methoxy ethanol, pentyl alcohol, hexyl alcohol, butyl alcohol , octyl alcohol, ethyl alcohol, methyl alcohol, methyl ethyl ketone, formamide, acetone, and α-terpineol (α -terpineol), a method of manufacturing a thin film transistor comprising at least one of them.
According to claim 1,
The metal ink further includes a polymeric binder resin,
The polymer binder resin is polyvinyl pyrrolidone, polyvinyl alcohol, polyvinyl butyral, polyethylene glycol, polymethyl methacrylate, A method for manufacturing a thin film transistor comprising at least one of dextran, azobis, and dodecyl benzene sodium sulfate.
According to claim 1,
The channel layer,
Indium gallium zinc oxide, zinc tin oxide, indium gallium tin oxide, indium zinc oxide, iodine oxide, zinc oxy A method for manufacturing a thin film transistor comprising at least one of zinc oxynitride, amorphous silicon, and poly silicon.

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