KR101407298B1 - Compound of semiconductor conductor and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a semiconductor liquid composition which is easy to manufacture by forming a semiconductor liquid of a thin film transistor through a solution process and is capable of stable performance in the atmosphere and excellent semiconductor properties, and a method for producing the same.

A semiconductor liquid composition according to the present invention comprises at least one metal acetate; And a sol stabilizer comprising an acid.

Semiconductor liquid, metal acetate, solution process

Description

Technical Field [0001] The present invention relates to a semiconductor liquid composition and a method of manufacturing the same. BACKGROUND ART [0002]

The present invention relates to a semiconductor liquid composition which is easy to manufacture by forming a semiconductor liquid of a thin film transistor through a solution process and is capable of stable performance in the atmosphere and excellent semiconductor properties, and a method for producing the same.

2. Description of the Related Art Demand and interest in thin film type displays such as liquid crystal displays (LCDs) and organic light emitting diodes (OLED) have been increasing. Currently, researches for improvement of FPD performance and price competitiveness are being actively carried out, and researches for realizing a next-generation flexible display that can be used without bending or warping property are getting more advanced. However, the photolithograph method, which is a currently used fine pattern manufacturing technique, is subjected to an exposure-etching process after vacuum deposition, and expensive vacuum equipment is required at this time, which causes a rise in display production cost. It is limited to the conventional rigid substrate and thus it is limited to be applied to the next generation flexible display device. As an alternative to the optical patterning method, there are Soft Lighography, Nano Imprinting, Ink-jet Printing, Direct Laser Writing, and Dip-pen Nano-Lighography. They do not require expensive vacuum equipments. effective.

One of the main components of the next-generation information electronics and displays is a thin film transistor. This is a basic unit element that acts as a kind of switch, and is central to all information / electronic and display devices / components. Polycrystalline silicon, which is widely used as a semiconductor of a thin film transistor, has advantages in terms of physical properties, lifetime and performance stability. However, in order to form a film, a vacuum deposition and a laser annealing process are necessary. It is required to develop a semiconductor solution material for forming a high-performance semiconductor film through a solution process.

Accordingly, the present invention is directed to a semiconductor liquid composition which is easy to manufacture by forming a semiconductor liquid of a thin film transistor through a solution process, is stable in the atmosphere and exhibits excellent semiconductor properties, and a method for producing the same.

According to an aspect of the present invention, there is provided a semiconductor liquid composition comprising at least one metal acetate and a sol-stabilizing agent.

According to an aspect of the present invention, there is provided a method for preparing a semiconductor liquid composition, comprising: dissolving and stirring metal acetate in a mixed organic solvent; Dissolving zinc acetate in a mixed solution of the mixed organic solvent and the metal acetate and stirring to prepare a sol-gel solution; Adding the acid which improves the solubility of the metal acetate and zinc acetate dihydrate solution in the sol-gel solution by primary heat agitation of the sol-gel solution; Checking the volume of the sol-gel solution; Adding a sol stabilizer to the sol-gel solution to ensure stability of the sol-gel solution; And stirring the sol-gel solution to which the sol stabilizer is added.

The solution composition according to the present invention and the method for fabricating the thin film transistor using the ZTO semiconductor liquid form a thin film transistor. Here, the ZTO semiconductor liquid is an oxide semiconductor excellent in atmospheric stability and semiconductor properties and has excellent mobility. In addition, the ZTO semiconductor liquid can be easily formed at low cost by being formed by a solution process.

Accordingly, it can be used at a low cost in a variety of information electronic parts and display industries such as a next generation display, RFID (Radio Frequency Identification), passive components, electronic circuit boards and sensors.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to FIGS. 1 to 9. FIG.

The thin film transistor causes a pixel signal supplied to the data line 104 to be charged and held in the pixel electrode in response to a scan signal supplied to the gate line 102. For this purpose, the thin film transistor includes a gate electrode 106, a source electrode 108, a drain electrode 110, and a semiconductor film 116.

The gate electrode 106 is connected to the gate line 102 so that a scan signal from the gate line 102 is supplied. The source electrode 108 is connected to the data line 104 so that the pixel signal from the data line 104 is supplied. The drain electrode 110 is formed to face the source electrode 108 with the channel portion of the semiconductor film 116 interposed therebetween and supplies the pixel signal from the data line 104 to the pixel electrode 122. The semiconductor film 116 overlaps the gate electrode 106 with the gate insulating film 112 interposed therebetween to form a channel portion between the source and drain electrodes 108 and 110. This semiconductor film 116 is formed to overlap with the data line 104 as well as the source and drain electrodes 108 and 110 in the process.

Meanwhile, the semiconductor film 116 of the present invention uses an inorganic oxide semiconductor, for example, a Zinc Tin Oxide (ZTO). Since the inorganic oxide semiconductor has a sufficiently wide band gap, the inorganic oxide semiconductor is transparent and can be used as a channel material of the transparent transistor. Further, in the case of an oxide semiconductor made of a transition metal, the mobility is not significantly reduced as compared with the case of having an amorphous state. In other words, in the case of inorganic oxide semiconductors, the kinds of chemical bonds are close to ionic bonds, and the conduction band is made of ns orbitals rather than P orbitals, so that the conduction band is isotropic. - Metal connections can be made. Since the oxide semiconductor using the transition metal does not greatly influence the crystallinity of the mobility, stable element performance in the atmosphere can be achieved even at a low temperature process.

The inorganic oxide semiconductor of the present invention is excellent in mobility and performance stability. Vacuum deposition and high temperature heat treatment are required to form an inorganic oxide semiconductor, but the inorganic oxide semiconductor of the present invention is formed through a solution process and is easy to manufacture and has excellent stability in the atmosphere.

FIG. 2 is a flowchart illustrating a method of manufacturing a thin film transistor according to an embodiment of the present invention, and FIGS. 3A to 3E are cross-sectional views illustrating a method of manufacturing a thin film transistor according to an embodiment of the present invention.

Referring to FIG. 3A, a gate metal pattern including a gate line (not shown) and a gate electrode 102 is formed on a lower substrate 101 (step S2)

Specifically, a gate metal layer is formed on the lower substrate 101 through a deposition method such as a sputtering method. The gate metal layer may be formed of a single metal material such as molybdenum (Mo), titanium (Ti), copper (Cu), aluminum neodymium (AlNd), aluminum (Al), chromium (Cr), Mo alloy, Cu alloy, Layer, or a structure in which two or more layers are stacked using the metal. Then, the gate metal layer is patterned by a photolithography process and an etching process, thereby forming a gate metal pattern including the gate line and the gate electrode 102. [

Referring to FIG. 3B, a gate insulating layer 106 is formed on a lower substrate 101 on which a gate metal pattern is formed. The gate insulating film 106 is formed of an inorganic insulating material such as silicon oxide (SiOx), silicon nitride (SiNx), etc. (S4)

3C, a ZTO semiconductor liquid is coated on a lower substrate 101 on which a gate insulating film 106 is formed and then spin-coated to form a ZTO semiconductor film 116. (Step S6) A method of forming a ZTO semiconductor liquid Will be described below.

Specifically, before applying the ZTO semiconductor liquid, the lower substrate 101 on which the gate insulating film 106 was formed was cleaned by ultrasonic treatment in a sulfuric acid (Hydroperoxide = 4: 1) for 5 minutes. Wash in the same way. The cleaned substrate 101 is dried with an IR lamp (IR-lamp) for 30 minutes to remove moisture. The ZTO semiconductor solution is spin-coated at 500 rpm for 3 seconds and at 400 rpm for 17 seconds to form a ZTO semiconductor film 114. [ Pre-bake for 10 minutes on a hot plate at 300 ° C with ZTO semiconductor liquid spin-coated.

3D, the ZTO semiconductor film 116 formed on the lower substrate 101 is heat-treated (step S8)

Specifically, the ZTO semiconductor film 116 formed on the lower substrate 101 is heat-treated in an air atmosphere at 500 캜 for 4 hours, for example.

On the other hand, the heat treatment can be performed in an air atmosphere at 500 ° C for 4 hours, and the heat treatment method of another embodiment can be carried out as follows. The ZTO semiconductor liquid applied on the lower substrate 101 is first baked in an air atmosphere at 300 DEG C, pre-annealed in an air atmosphere at 500 DEG C, and finally annealed in a hydrogen or nitrogen atmosphere at 300 DEG C for 1 minute . When a ZTO semiconductor liquid is coated on the lower substrate 101 and spin-coated to form a ZTO semiconductor film and subjected to heat treatment at 300 ° C, 400 ° C, 500 ° C, or 600 ° C, crystallinity is shown as shown in FIG. 5 is a result of XRD analysis after heat treatment of the ZTO semiconductor film at 300 ° C, 400 ° C, 500 ° C, and 600 ° C, respectively.

3E, a data metal pattern including a data line, a source electrode 108 and a drain electrode 110 is formed on the semiconductor film 116. In step S10, The pattern is formed by one mask process using a slit mask or a halftone.

4 is a flowchart of a solution processing method for forming a ZTO semiconductor liquid according to an embodiment of the present invention.

The ZTO semiconductor liquid is formed by a solution process using zinc acetate and tin metal acetate, organic solvent and sol stabilizer. At this time, the ZTO semiconductor liquid has a chemical formula such as (ZnO) _x (SnO ₂ ) _1-x, and X has a range of 0 <X <1.

On the other hand, in the ZTO semiconductor liquid, when the mole number of zinc acetate dihydrate is 100, the number of moles of tin acetate is 11 to 100. Further, the ZTO semiconductor liquid is formed by controlling the contents of zinc acetate (diacetate dihydrate) and tin acetate (tin acetate), respectively. For example, the ZTO semiconductor liquid can be injected with 4.5 to 10g of Zinc acetate dihydrate and 0 to 4.5g of tin acetate.

The ZTO semiconductor liquid will be described by taking a solution process of a ZTO semiconductor liquid having a chemical formula of (ZnO) _0.7 (SnO ₂ ) _{0. 3} as an example. Here, zinc acetate (Zinc acetate dihydrate) is injected, for example, in an amount of 5.88 g to form a ZTO semiconductor liquid having the formula of (ZnO) _0.7 (SnO ₂ ) _{0. 3} , and tin acetate is, for example, 4.03 g .

First, tin acetate is dissolved and stirred in a mixed organic solvent of ethanolamine and 2-methoxyethanol (step S12)

At this time, the metal acetate, tin acetate _{(Sn (CH 3 COO) 4} ) (Ga (CH 3 COO) 3) In addition, gallium acetate, but the use of indium acetate _{(In (CH 3 COO) 3} ), zirconium acetate (ZrO (CH ₃ COO) ₂₎ it may be used, such as metal acetate.

Specifically, the mixed organic solvent is mixed with 10 to 40 ml of ethanolamine and 1 ml to 5 ml of 2-methoxyethanol, and stirred for 1 to 20 minutes. Preferably, the mixed organic solvent is mixed with 31 ml of ethanolamine and 2 ml of 2-methoxyethanol and stirred for 5 minutes. At this time, the mixed organic solvent is used to form a precursor solution of a desired concentration because of low solubility of tin acetate and zinc acetate dihydrate. In other words, Ethanolamine enhances solubility in the solution of high concentration of metal acetate in solution. The content of ethanolamine is 20-100 parts by weight based on 100 parts by weight of Zinc acetate dihydrate and tin acetate. That is, when the content of zinc acetate dihydrate and tin acetate is 9.91 g, the content of ethanolamine can be in the range of 1.982 g to 9.91 g. To this mixed organic solvent, 4.03 g of tin acetate is added as an example, and the solution is completely melted and stirred for 5 to 15 minutes until a colorless transparent liquid is obtained, preferably stirred for 10 minutes.

Next, zinc acetate (Zinc acetate dihydrate) was dissolved in a mixed organic solvent and tin acetate and stirred to prepare a sol-gel solution containing tin acetate and zinc acetate dihydrate as starting materials. Gel solution is prepared (step S14)

Then, a sol-gel solution containing tin and zinc is first heat-agitated and an acid is added to improve solubility in zinc acetate and zinc acetate dihydrate solution. (Step S16)

Specifically, the sol-gel solution was first heat-stirred for 10 minutes on a hot plate at a temperature of 60 ° C, for example, so that tin acetate and zinc acetate dihydrate completely dissolved and became a colorless transparent liquid, 5 ml of acid is used as an example. In this case, although the temperature of the hot plate is 60 ° C, the temperature of the hot plate may be adjusted to 30 ° C to 90 ° C. Depending on the temperature of the hot plate or the state of the sol-gel solution, 15 minutes.

The acid may be acetic acid. The content of acetic acid may be 5-15 parts by weight, preferably 10 parts by weight, based on 100 parts by weight of zinc acetate (zinc acetate dihydrate) and tin acetate (Tin acetate) .

Gel solution is added to the sol-gel solution and the volume of the sol-gel solution is inspected after the addition of the primary heat agitation and the acid (step S18). If the volume of the solution is not the desired result, 2-Methoxyethanol is injected (Step S20). In the second heat agitation, the temperature of the hot plate is kept at 60 캜 under the same temperature as that of the first heat agitation, and 5 The mixture is stirred for a further minute, and 1 ml to 6 ml of 2-methoxyethanol is further injected, preferably 4.1 ml, in order to adjust the volume of the solution. If the volume of the solution is the desired result, the next step of the sol stabilizer is injected without the step of injecting the second heat agitation and 2-methoxyethanol (step S22)

Next, a sol-stabilizing agent is added to the solution according to the result of the volume check of the solution to ensure the stability of the sol-gel solution (step S22).

Specifically, 1 ml to 5 ml of formamide, which is a sol stabilizer, is added to the solution, preferably 3 ml of formamide is added. The content of formamide may be 3 to 9 parts by weight, preferably 6 parts by weight, based on 100 parts by weight of zinc acetate (zinc acetate dihydrate) and tin acetate (Tin acetate) . The addition of formamide as a sol stabilizer allows the precursor solution to remain stable for a long period of time and the content of ethanolamine, which is a conventional sol stabilizer, which is difficult to evaporate and remains in the membrane, Can be minimized.

Finally, the sol-gel solution is stirred for 10 to 20 hours (step S24) to complete a ZTO semiconductor liquid having the formula (ZnO) _0.7 (SnO ₂ ) _{0. 3} (step S26)

6, the viscosity of the ZTO semiconductor liquid formed through the solution process in steps S12 to S26 is constantly in the range of 13.7 to 13.8 mPa-s. When the ZTO semiconductor liquid is thermally analyzed, As shown in Fig.

(ZnO) _0.7 (SnO ₂ ) _{0. 3} in the second embodiment of the present invention, tin acetate is not injected to form Undoped Pure ZnO semiconductor liquid, and zinc acetate acetate dihydrate) is injected as an example. Thus, the contents of tin acetate and zinc acetate dihydrate are adjusted as described above, and Undoped Pure ZnO semiconductor liquid is formed through the solution process of steps S12 to S26 described above.

An example of the third embodiment according to the present invention (ZnO) _0.9 (SnO ₂₎ tin acetate (Tin acetate) to form a ZTO semiconductor solution having a formula of _0.1 is an example, and injecting 1.34g, zinc acetate (Zinc acetate dihydrate) is injected as an example. As a result, the contents of tin acetate and zinc acetate dihydrate were adjusted as described above, and the solution of (ZnO) _0.9 (SnO ₂ ) to form a ZTO semiconductor solution having a formula of _0.1.

An example of the fourth embodiment according to the present invention (ZnO) _0.8 (SnO ₂₎ tin acetate (Tin acetate) to form a ZTO semiconductor solution having a formula of _0.2 is an example, and injecting 2.69g, zinc acetate (Zinc acetate dihydrate) is injected as an example. Thus, the contents of tin acetate and zinc acetate dihydrate were adjusted as described above, and ZnO _0.8 (SnO ₂ ) was added through the solution process of steps S12 to S26 as in the first embodiment. ) to form a ZTO semiconductor solution having a formula of _0.2.

FIGS. 8A and 8B are graphs showing the results of measurement of physical properties of a semiconductor thin film formed according to the first to fourth embodiments of the present invention, and FIG. 9 is a graph showing the surface and cross-sectional views of thin films formed according to the first to fourth examples (FE-SEM) photographs. 9 (a) is the surface of the thin film formed according to the second embodiment, (b) is the surface of the thin film formed according to the third embodiment, and (c) The surface of the thin film formed according to the embodiment is shown.

The voltage-current (VI) characteristic curve of the thin film transistor formed using the ZTO semiconductor liquid of the first to fourth embodiments shows the gate-on voltage (V _G ) of the thin film transistor in the X axis direction, The drain current Id is expressed in the Y-axis direction.

The ZTO semiconductor liquid formed according to the first to fourth embodiments was coated and a thin film transistor was formed using the ZTO semiconductor film formed through spin coating. At this time, source and drain electrodes of a semiconductor film are formed to form a thin film transistor, and then heat treatment is performed in a hydrogen atmosphere at 300 캜 for one minute. The channel width (W) of the semiconductor film is 5000 m, the channel length (L) is 50 m, and the ratio of the channel width / channel length (W / L) is 100. On the other hand, the ZTO semiconductor film formed by applying the ZTO semiconductor liquid and spin-coating is heat-treated at 500 ° C.

Referring to Figure 9, a graph that displays Sn 0% is the voltage of the thin film transistor formed by using the Undoped Pure ZnO semiconductor solution - a current (VI) characteristic curve, a graph that displays Sn 10% was (ZnO) _0.9 (SnO ₂₎ the voltage of the thin film transistor formed by using the ZTO semiconductor solution having a formula of _0.1 - and current (VI) characteristic curve, a graph that displays 20% Sn is _{(ZnO) 0.8 (SnO 2)} 0. ₂ having the formula ZTO voltage of the thin film transistor formed using the semiconductor solution, - a current (VI) characteristic curve, a graph that displays 30% Sn is _{(ZnO) 0.7 (SnO 2)} ZTO having the formula _0.3 Current (VI) characteristic curve of a thin film transistor formed using a semiconductor liquid. At this time, the thin film transistor formed using the ZTO semiconductor liquid of the first embodiment can switch at a high mobility of 0.5 cm 2 / Vs, a gate voltage of 3 V, and a flashing ratio of 10 ⁴ .

The thin film transistor formed using the ZTO semiconductor liquid according to the first to fourth embodiments of the present invention has a voltage-current characteristic curve of the thin film transistor according to each of FIG. Therefore, a thin film transistor having a voltage-to-current characteristic curve of a desired thin film transistor can be easily formed by a solution process of injecting different composition ratios of zinc acetate (diacetate) and tin acetate.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be defined by the claims.

1 is a cross-sectional view illustrating a thin film transistor according to an embodiment of the present invention.

2 is a flowchart illustrating a method of manufacturing a thin film transistor according to an embodiment of the present invention.

3A to 3E are cross-sectional views illustrating a method of manufacturing a thin film transistor according to an embodiment of the present invention.

4 is a flowchart of a solution processing method for forming a ZTO semiconductor liquid according to an embodiment of the present invention.

5 is a graph showing the results of XRD analysis after heat treatment of the ZTO semiconductor films at 300 ° C, 400 ° C, 500 ° C, and 600 ° C, respectively.

6 is a graph showing the viscosity of a ZTO semiconductor liquid according to the first embodiment of the present invention.

7 is a result of thermal analysis of the ZTO semiconductor liquid according to the first embodiment of the present invention.

8A and 8B are graphs showing the results of measurement of the physical properties of the semiconductor thin film formed according to the first to fourth embodiments of the present invention.

9 is a scanning electron microscope (FE-SEM) photograph of the surface and cross-sectional views of thin films formed according to the first to fourth examples.

DESCRIPTION OF THE REFERENCE SYMBOLS

101: lower substrate 102: gate electrode

106: gate insulating film 108: source electrode

110: drain electrode 116: semiconductor film

Claims (12)

At least one metal acetate; And And a sol-stabilizing agent containing an acid. The method according to claim 1, The metal acetate has a high concentration of 0.5 to 1 mol / L, The metal acetate is composed of a main component or an auxiliary component and the main component is zinc acetate dihydrate and the auxiliary component is composed of tin (Sn), indium (In), zirconium (Zr) and gallium (Ga) Is formed by mixing any of the metal acetates or the metal acetates comprising the metals. The method of claim 1, wherein The sol stabilizers are acetic acid and formamide. The acetic acid is 5 to 15 parts by weight based on 100 parts by weight of the total solution of the semiconductor liquid composition and the formamide is 3 to 9 parts by weight based on 100 parts by weight of the total solution of the semiconductor liquid composition &Lt; / RTI &gt; The method according to claim 1, Wherein the at least one metal acetate and the sol stabilizer are formed as a semiconductor film through at least one heat treatment process after being applied on a substrate, and the semiconductor film is made of a semiconductor film of a thin film transistor. 5. The method of claim 4, The annealing process is first baked in an air atmosphere of 200 ° C to 400 ° C, pre-annealed in an air atmosphere of 400 ° C to 600 ° C, and finally annealed in a hydrogen or nitrogen atmosphere at 200 ° C to 400 ° C for 1 minute to 5 minutes . The method according to claim 1, Wherein the at least one metal acetate is composed of zinc acetate and tin acetate, and the molar ratio of the zinc acetate to the main acetate is 11 to 100 moles of tin acetate when the mole number of zinc is 100. Dissolving and stirring the metal acetate in the mixed organic solvent; Dissolving zinc acetate in a mixed solution of the mixed organic solvent and the metal acetate and stirring to prepare a sol-gel solution; Adding the acid which improves the solubility of the metal acetate and zinc acetate dihydrate solution in the sol-gel solution by primary heat agitation of the sol-gel solution; Checking the volume of the sol-gel solution; Adding a sol stabilizer to the sol-gel solution to ensure stability of the sol-gel solution; And agitating the sol-gel solution to which the sol stabilizer is added. 8. The method of claim 7, The metal acetate is tin acetate _{(Sn (CH 3 COO) 4} ), gallium acetate _{(Ga (CH 3 COO) 3} ), indium acetate _{(In (CH 3 COO) 3} ), zirconium acetate (ZrO (CH ₃ COO) ₂ ). &Lt; / RTI &gt; 8. The method of claim 7, Wherein the mixed organic solvent is ethanolamine and 2-methoxyethanol, and the sol-stabilizing agent is formamide. 8. The method of claim 7, The step of adding the acid which improves the solubility of the metal acetate and zinc acetate dihydrate solution in the sol-gel solution by primary heat agitation of the sol-gel solution, Wherein the sol-gel solution is subjected to primary heat agitation at a temperature of 30 ° C to 90 ° C on a hot plate for 1 minute to 15 minutes, and the acid is acetic acid. Gt; 11. The method of claim 10, In the step of checking the volume of the sol-gel solution, secondary heat agitation and 2-methoxyethanol are added to the next step of the first heat agitation and the acid injection step according to the results of the volumetric examination of the sol- Adding a step of adjusting the volume of the sol-gel solution desired by the user, Wherein the secondary heat agitation is carried out at the same temperature as the hot plate of the primary heat agitation for 1 minute to 10 minutes. 8. The method of claim 7, Wherein the step of stirring the sol-gel solution to which the sol stabilizer is added is stirred for 10 to 20 hours.

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