KR101260679B1 - Method for manufacturing ge-igzo transparency electrode - Google Patents

Abstract

PURPOSE: A method for manufacturing a Ge-IGZO transparent electrode is provided to optimize the conditions for a sputtering process, thereby improving electrical characteristics. CONSTITUTION: A method for manufacturing a Ge-IGZO transparent electrode comprises a first step of preparing a substrate(10); a second step of sputtering for forming a Ge-IGZO thin film(20) on the substrate; and a third step of performing heat treatment of the Ge-IGZO thin film. In the first step, the substrate is a glass substrate which includes a base material of glass and a blocking layer(12) which is formed on the base material. The blocking layer is formed on both of the top and the bottom surface of the substrate.

Description

METHOD FOR MANUFACTURING Ge-IGZO TRANSPARENCY ELECTRODE}

The present invention relates to a method of manufacturing a Ge-IGZO transparent electrode, and more particularly, a transparent electrode material doped with Ge (germanium) in IGZO (indium-potassium-zinc-oxide), which has excellent electrical and optical properties. It relates to a method for manufacturing a Ge-IGZO transparent electrode that can replace the ITO material.

BACKGROUND ART [0002] Transparent conductive thin films based on oxides are usefully used as transparent electrodes for various optical and electric / electronic devices. For example, a flat panel display such as a liquid crystal display (LCD), a plasma display panel (PDP), a field emission display (FED), a light emitting device display (LED display), or the like. Widely used in the field.

In general, transparent electrodes are manufactured by depositing (film forming) a transparent conductive material on a substrate by a method such as sputtering. For example, Korean Patent Laid-Open Publication No. 10-2007-0050143 (Patent Document 1) discloses a method for manufacturing an electrode by ion beam sputtering a transparent oxide target on a substrate under reduced pressure in a vacuum chamber. have.

The transparent conductive material may include ITO (Indium Tin Oxide) in which 5 to 10 wt% of tin oxide (SnO ₂ ) is mixed with indium oxide (In ₂ O ₃ ) A metal oxide thin film such as IZO (Indium Zinc Oxide) in which 5 to 10 wt% of zinc oxide (ZnO) is mixed with In ₂ O ₃ is mainly used. At present, ITO accounts for more than 90% of the transparent conductive material, which is a key material of the display industry, and the remaining 10% is mostly IZO.

Both ITO and IZO use 90% by weight or more of indium oxide (In ₂ O ₃ ) powder, and the transparent electrode material industry of the display accounts for about 70% or more of the indium (In) market. However, the price of indium (In) has risen sharply in recent years, and the price of transparent electrode materials used in display panels has increased exponentially. Indium (In) reserves are also small, increasing the price increase. In addition, ITO has a low resistance to device instability and moist heat, which is accompanied by deterioration of the device due to diffusion of indium (In), high reduction of indium (In) and tin (Sn) under hydrogen (H ₂ ) plasma, and the like. Problems such as resistance and high film formation temperature have been raised.

Accordingly, in recent years, practical applications have been made for Fluoride doped tin oxide (FTO), SnO ₂ (Tin oxide), and ZnO (Zinc oxide) as transparent electrode materials to replace ITO. However, they have a relatively high resistance compared to ITO and are limited to touch panels or lower transparent electrodes. In particular, in the case of ZnO, although the material cost is low, there is a problem in the manufacturing method and the etching characteristics, there is a problem in the stability of the thin film. In addition, FTO has a disadvantage in that mass production is difficult due to a manufacturing process problem caused by the use of toxic gas.

In addition, IGZO (Indium Gallium Zinc Oxide; Indium Gallium Zinc Oxide) having a compound structure complementing the properties of ITO, that is, a flat panel display using IGZO material consisting of In ₂ O ₃ and Ga ₂ O ₅ and ZnO Research has been attempted to commercialize the transparent electrode of the.

For example, Korean Patent Laid-Open Publication No. 10-2010-0094597 (Patent Document 2) discloses an atomic ratio of In (indium) to an amount of In (indium) and Ga (gallium), and In (indium) and Ga (gallium). A method for producing an IGZO oxide thin film which specifies the atomic ratio of zinc (Zn) to the total amount of Zn) and Zn (zinc), and forms a film on a substrate at an appropriate sputter power density. In addition, Japanese Patent Application Laid-Open No. 2007-073701 (Patent Document 3) discloses a technology for an IGZO oxide thin film having a composition ratio of In (indium), Ga (gallium), and zinc (Zn) of 1: 1: 1.

However, the conventional IGZO thin film is difficult to replace the ITO thin film due to the lack of electrical characteristics and low optical properties (light transmittance, etc.). Therefore, in order to lead the core technology in the next-generation display field, transparent electrodes that can replace ITO with excellent electrical and optical characteristics are urgently required.

Korean Patent Publication No. 10-2007-0050143 Republic of Korea Patent Publication No. 10-2010-0094597 Japanese Patent Laid-Open No. 2007-073701

Accordingly, an object of the present invention is to provide a method for manufacturing a Ge-IGZO transparent electrode which can replace ITO with excellent electrical and optical properties. More specifically, the present invention is formed by sputtering a Ge-IGZO thin film doped with Ge (germanium) to IGZO (indium-potassium-zinc-oxide) as a transparent conductive thin film. By optimizing the sputtering process conditions, the Ge-IGZO transparent electrode can replace the existing expensive ITO material with a sheet resistance of 400 µs / sq or less (preferably 200 µs / sq or less) and a high light transmittance of 80% or more. Its purpose is to provide a method of manufacture.

The present invention to achieve the above object,

A first step of preparing a substrate; And

A second step of forming a Ge-IGZO thin film by sputtering a Ge-IGZO target on the substrate,

Wherein the injection gas flow rate ratio of the applied power of 40W-60W, the working pressure 0.5mTorr ~ 6mTorr, argon (Ar) and oxygen (O ₂₎ In step _{2 (Ar: O 2) 40} : 0 ~ 0.3sccm, a deposition time from 30 minutes to Provided is a method of manufacturing a Ge-IGZO transparent electrode, which is sputtered under a condition of 180 minutes to form a Ge-IGZO thin film.

In this case, the Ge-IGZO target, preferably 0.01 to 6% by weight of Ge based on the total weight of the target.

In addition, the method of manufacturing a Ge-IGZO transparent electrode according to the present invention, it is preferable to further include the step of heat-treating the Ge-IGZO thin film formed on the substrate. And the first step is to prepare a glass substrate comprising a glass substrate and a blocking layer formed on the glass substrate, (1) a coating process for coating a blocking solution containing a metal oxide on the glass substrate; (2) a first firing step of first baking the coated blocking solution at 120 ° C. to 160 ° C. for 5 minutes to 30 minutes; And (3) after the first firing, a second firing step of second firing at 420 ° C. to 520 ° C. for 30 minutes to 150 minutes.

According to the present invention, a sputtering process of a Ge-IGZO thin film is formed by sputtering a Ge-IGZO thin film doped with Ge (germanium) to IGZO (indium-potassium-zinc-oxide) as a transparent conductive thin film. Conditions are optimized to have excellent electrical and optical properties. Specifically, it has a sheet resistance of 400 mW / sq or less (preferably 200 mW / sq or less) and a high light transmittance of 80% or more, and has an effect of replacing existing expensive ITO materials.

Figure 1 illustrates a cross-sectional configuration of the Ge-IGZO transparent electrode prepared according to the present invention.
2 to 5 are graphs showing the results of evaluation of the light transmittance of the Ge-IGZO transparent electrode manufactured according to the embodiment of the present invention.
6 is a graph showing the sheet resistance characteristic distribution according to the number of depositions as a result of reproducibility evaluation of the Ge-IGZO transparent electrode manufactured according to the embodiment of the present invention.

As described above, the IGZO (indium-gallium-zinc-oxide) transparent electrode is difficult to replace the ITO thin film because of its low electrical and optical properties. Accordingly, the present inventors have conducted studies on IGZO transparent electrodes, but doped (added) Ge (germanium) to IGZO, but in the case of optimizing the sputtering process conditions when depositing a thin film, it has excellent electrical characteristics and high optical characteristics. It was found that the ITO thin film could be replaced.

Hereinafter, the present invention will be described in detail.

The transparent electrode manufactured according to the present invention includes a Ge-IGZO thin film doped (added) with Ge (germanium) in IGZO (indium-potassium-zinc-oxide) as a conductive thin film. Figure 1 illustrates a cross-sectional configuration of the Ge-IGZO transparent electrode prepared according to the present invention. As shown in FIG. 1, the IGZO transparent electrode manufactured according to the present invention includes a substrate 10 and a Ge-IGZO thin film 20 formed on the substrate 10. In this case, when the glass substrate is applied as the substrate 10, the transparent electrode manufactured according to the present invention preferably further includes a blocking layer 12, the blocking layer 12 is shown in FIG. As shown, it may be formed on both upper and lower surfaces of the substrate 10.

The method of manufacturing a Ge-IGZO transparent electrode according to the present invention includes a first step of preparing a substrate 10 and a second step of forming a Ge-IGZO thin film 20 on the substrate 10. In the second step, the Ge-IGZO target is sputtered to form a Ge-IGZO thin film, with an applied power of 40 W to 60 W, a working pressure of 0.5 mTorr to 6 mTorr, argon (Ar) and oxygen. (O ₂₎ flow rate of the injection gas (Ar: O ₂₎ 40: to form a 0 ~ 0.3sccm (㎤ / min) , Ge-IGZO thin film by sputtering under the conditions of deposition time 30-180 minutes. In addition, according to a preferred embodiment, the method of manufacturing a Ge-IGZO transparent electrode according to the present invention further includes a third step of heat-treating the Ge-IGZO thin film 20 formed on the substrate 10. Each step will be described as follows.

1. Preparation of the substrate (Step 1)

In the present invention, the substrate 10 is not particularly limited, but is preferably selected from the glass substrate 10. In this case, the glass substrate 10 includes a glass substrate and a blocking layer 12 formed on the glass substrate. This glass substrate 10 is prepared as follows.

The glass substrate is commonly used in the art, and is selected from a soda-lime glass panel containing a small amount of a salt such as sodium (Na). Such glass substrates can be pretreated. The glass substrate may be pretreated by, for example, a washing process using water or ultrasonic waves, a surface treatment process using plasma, or the like.

At this time, when the Ge-IGZO thin film 20 is immediately formed on the glass substrate, salts such as sodium (Na) contained in the glass substrate are eluted and the electrical characteristics of the Ge-IGZO thin film 20 are inferior. Accordingly, the blocking layer 12 is first formed before the Ge-IGZO thin film 20 is formed on the glass substrate. The blocking layer 12 is formed on at least one side of the glass substrate, that is, the surface in contact with the Ge-IGZO thin film 20, which may also be formed on both sides of the glass substrate. The blocking layer 12 is preferably formed on both sides of the glass substrate as shown in FIG. 1.

The blocking layer 12 is formed using a coating method that is advantageous in cost, double-sided forming process, and the like. At this time, the blocking layer 12 is preferably formed through the coating process and the second baking process according to the present invention. Specifically, the blocking layer 12 includes (1) a coating process of coating a blocking solution on a glass substrate; (2) a first firing step of first baking the coated blocking solution; And (3) a second firing step of secondary firing after primary firing.

In the coating process, the blocking solution can be used as usual. The blocking solution contains at least metal oxides. Specifically, the blocking solution includes a metal oxide and a solvent. In addition, the blocking solution may include a dispersant for uniform dispersion of the metal oxide, in addition to the metal oxide and the solvent; A binder for initial adhesion with the glass substrate before firing; And other additives may optionally be further included. In this case, the binder and the additives are not limited, and the binder may be selected from synthetic resins such as olefin resins (polyethylene, polypropylene, etc.), acrylic resins, urethane resins, and the like.

The metal oxide is not limited as long as it can block elution of salts such as sodium (Na) contained in the glass substrate. As the metal oxide, for example, one or more selected from silicon oxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), cesium oxide (CeO ₂ ), zirconium oxide (ZrO ₂ ), titanium oxide (TiO ₂ ), and the like may be used. Can be. The metal oxide preferably contains silicon oxide (SiO ₂ ). Specifically, the metal oxide may use silicon oxide (SiO ₂ ) alone, or a mixture of one or more selected from the metal oxides listed above in silicon oxide (SiO ₂ ) (eg, Al ₂ O _3, etc.). The silicon oxide (SiO ₂ ) not only has a salt elution barrier property, but also insulates the electrical properties of the organic substrate and the Ge-IGZO thin film 20 and reduces the refractive index of the glass substrate to improve the light transmittance. Useful for

In addition, the metal oxide is not particularly limited, but may be included in an amount of 0.1 wt% to 80 wt% based on the total weight of the blocking solution. The remaining balance is the solvent (and dispersant, etc.). At this time, if the content of the metal oxide is too low, the salt elution barrier property may be insignificant, if too high, the viscosity may be high and the coating property may be inferior.

The solvent is not limited. The solvent may be any one capable of providing a suitable viscosity to the blocking solution to enable coating. The solvent can be selected from water, organic solvents, and the like. Although the said organic solvent is not specifically limited, C6-C20 nonpolar hydrocarbon, cellosolve type, alcohol type (methanol, ethanol, isopropyl alcohol, etc.), ketone type (methyl ethyl ketone, etc.), and formamide type (dimethylform) Amides and the like).

The dispersant should just be able to disperse | distribute a metal oxide uniformly. The dispersant is preferably selected from organic substances having a functional group capable of forming a complex on the surface of the particulate metal oxide, and examples thereof include alkyl amines, carboxylic acid amides, aminocarboxylates, sodium citrate salts, and the like. Can be used. In this case, the alkyl group of the alkyl amine is preferably 4 to 20 carbon atoms, preferably 4 to 12 carbon atoms so that the metal oxide can be sufficiently uniformly dispersed in the solvent. Such a dispersant may be included, for example, 0.01 wt% to 10 wt% based on the total weight of the blocking solution.

The blocking solution as described above may be coated on the glass substrate in various ways. Coatings are, for example, spin coating, dip coating, bar coating, spray, ink-jet printing, gravure and screen printing. -printing) or the like.

The coating preferably combines dipping and spin. Specifically, first, the glass substrate is immersed in the blocking solution to dip to both sides of the glass substrate, and then have a uniform thickness through spin. At this time, the thickness of the blocking layer 12 is determined according to the rotational speed during spin. Preferably, the blocking solution 12 is dipped and then spin-coated at a rotational speed of 2 to 130 rpm, and the thickness of the blocking layer 12 after firing. It is desirable to have 80 to 120 nm. When the blocking layer 12 has the thickness in the above range through the rotation speed, the coating property is good and the light transmittance is improved.

In addition, as described above, in the case of using silicon oxide (SiO ₂ ) or the like as the blocking layer 12, light transmittance may be improved. In this case, the lower the rotation speed, the lower the thickness of the blocking layer 12 is. May be increased to increase light transmittance. However, if the rotational speed is too low as less than 2rpm, the light transmittance is increased due to the increase in thickness, but uniform coating is difficult and undesirable in terms of time. In addition, when the rotational speed is low, the salt dissolution barrier property may not be locally good due to a local thickness difference of the blocking layer 12. And if the rotation speed is too high exceeding 130rpm, the coating property is good but the thickness is low, the light transmittance is low. Therefore, in consideration of the coating property and light transmittance, it is preferable to spin-coating at a rotational speed of 2 ~ 130rpm, it is good to have a thickness of 80nm ~ 120nm at this rotational speed. In addition, when the blocking layer 12 has a thickness of 80 nm to 120 nm, an optical property is improved by having an excellent light transmittance of 92% or more, preferably 94% or more.

After coating the blocking solution as described above, the second baking process is performed. That is, a first firing process of first baking the blocking solution at a low temperature of 120 ° C. to 160 ° C. for 5 minutes to 30 minutes, and then a second firing process for 30 minutes to 150 minutes at a high temperature of 420 ° C. to 520 ° C. 2 proceed the firing process. Such a baking process can use heat sources, such as an electric furnace and a microwave, for example. At this time, after the first firing, rather than proceeding to the second firing immediately at a temperature of 420 ℃ to 520 ℃, it is preferable to gradually increase the temperature for 30 minutes to 50 minutes, and then proceed with the secondary firing. For example, after primary firing, the secondary firing may be performed by increasing the temperature at a temperature increase rate of 6 ° C / minute to 12 ° C / minute.

First, the primary firing is carried out for 5 minutes to 30 minutes at a temperature of 120 ℃ ~ 160 ℃ as described above, by the first firing is gradually agglomerated the metal oxide particles contained in the blocking solution to dense tissue between the particles , The adsorption force (adhesive force) with the glass substrate is enhanced. At this time, in the primary firing, when the temperature is less than 120 ° C. and the time is less than 5 minutes, the compactness of the structure and the adsorption force are insignificant. And when the temperature exceeds 160 ℃ and the time exceeds 30 minutes, the synergistic effect with excess temperature and time is not so great, and is not preferable in terms of energy loss and workability. For this reason, the primary firing is carried out at the temperature and time conditions in the above range, preferably 10 minutes to 20 minutes at a temperature of 135 ℃ to 145 ℃.

In addition, the secondary firing is a substantial firing process, which proceeds under high temperature conditions for crystallization (sintering) of the metal oxide as well as adhesion between the metal oxide and the glass substrate. Specifically, the secondary firing is carried out for 30 minutes to 150 minutes at the temperature of 420 ℃ to 520 ℃ as described above, depending on the type of metal oxide may be sintered below 420 ℃, but the secondary firing temperature is 420 If it is less than ℃ and the time is less than 30 minutes, it is difficult to expect the excellent salt elution barrier properties desired in the present invention. That is, in the case of secondary firing at 420 ° C. or higher, good crystallization may be performed to have excellent salt elution barrier property of 0.3 mg / cm 2 or less. And when the firing temperature exceeds 520 ° C and the time exceeds 150 minutes, the synergistic effect with the excess temperature and time is not so great, it is not preferable in terms of energy loss and workability. In addition, when the firing temperature is too high, fine cracking may occur depending on the type of metal oxide. For this reason, the secondary firing proceeds at the temperature and time conditions in the above range, and preferably 50 minutes to 100 minutes at a temperature of 450 ℃ to 500 ℃.

According to the present invention, the blocking solution is calcined over a second time at the appropriate temperature and time conditions as described above, and has excellent salt elution barrier property. That is, the salt elution barrier property is insignificant in the case of high temperature firing immediately after coating the blocking solution, but according to the present invention, the low temperature firing (first firing process) and the high temperature firing (second firing process) are continuously performed. When each baking process advances to the temperature and time conditions of the said range, it has the outstanding salt elution barrier property.

2. Formation of Ge-IGZO Thin Film (Second Step)

After preparing the substrate 10 as described above, the Ge-IGZO thin film 20 is formed (deposited) on the substrate 10. That is, the Ge-IGZO thin film 20 is formed on the blocking layer 12 of the substrate 10.

The Ge-IGZO thin film 20 is formed using an in-line sputter. Specifically, the Ge-IGZO thin film 20 is formed by depositing by a method such as RF sputtering, DC sputtering and ion beam sputtering. For example, in the RF sputtering apparatus that is commonly used, a Ge-IGZO target is mounted on a sputter gun to sputter the Ge-IGZO thin film 20 on the substrate 10. . At this time, the number of sputter guns installed in the sputtering apparatus may be one or plural. That is, one or more Ge-IGZO targets may be used.

At this time, according to the present invention, when RF sputtering the Ge-IGZO thin film 20, the applied power (deposition voltage) of the sputtering device 40W ~ 60W, working pressure 0.5mTorr ~ 6mTorr, argon (Ar) and oxygen (O ₂ ) The injection gas flow rate (Ar: O ₂ ) of 40: 0 to 0.3 sccm, deposition time 30 minutes to 180 minutes by sputtering to form a Ge-IGZO thin film 20. When the thin film 20 is deposited, the temperature of the substrate 10 may be maintained at a room temperature of 400 ° C. In addition, during the deposition of the thin film 20, it may be repeatedly deposited several times or more. For example, the deposition may be repeated several times over two to 100 times.

According to the present invention, in forming the Ge-IGZO thin film 20, when sputtering under the above conditions, it has excellent electrical and optical properties. Specifically, when sputtering under the above conditions, the sheet resistance of 400 kW / sq or less, preferably 200 kW / sq or less, has excellent electrical properties. And it has a light transmittance of 80% or more in the visible light region.

In the sputtering condition, first, when the temperature of the substrate 10 exceeds 400 ° C., the sheet resistance may increase, thereby lowering the electrical characteristics of the Ge-IGZO thin film 20. In addition, even when the applied power (deposition voltage) is less than 40W, the sheet resistance is increased, so that the electrical characteristics of the Ge-IGZO thin film 20 are inferior. In addition, as the applied power increases, the sheet resistance is lowered to improve the electrical characteristics, but when it is too high exceeding 60W, the light transmittance falls. In addition, even when the working pressure is less than 0.5mTorr or more than 6mTorr, the sheet resistance is increased, the electrical characteristics of the Ge-IGZO thin film 20 is reduced, and at the same time, when the working pressure is high, the remaining gas in the deposition chamber increases to increase impurities and The probability of reaction increases, so the light transmittance may decrease.

On the other hand, during sputtering, a gas is injected into the chamber, where gas is preferably injected at a flow rate of argon (Ar): oxygen (O ₂ ) = 40: 0 to 0.3 sccm (cm 3 / min). That is, the gas may use argon (Ar) alone or a mixed gas of argon (Ar) and oxygen (O ₂ ). At this time, when only argon (Ar) is injected and deposited, it has a low light transmittance due to oxygen deficiency, but when the oxygen (O ₂ ) is further injected into argon (Ar), the light transmittance is improved. However, when the injection amount of oxygen (O ₂ ) is too large, the sheet resistance is increased, the electrical characteristics are lowered. Accordingly, oxygen (O ₂ ) is injected at a flow rate of 0.3 sccm (cm 3 / min) to argon (Ar) 40 sccm (cm 3 / min), more specifically, at a flow rate of 0.05 to 0.3 sccm (cm 3 / min). good.

In addition, even if the deposition time is less than 30 minutes, the sheet resistance is higher, and as the deposition time increases, the sheet resistance may be lowered, but if it is too long beyond 180 minutes, the light transmittance is lowered.

Therefore, sputtering is performed under the above process conditions in consideration of electrical and optical characteristics. When sputtered under such conditions, the electrical / optical properties can be excellent to replace the existing ITO thin film. According to a preferred embodiment, sputtering is performed under conditions of an applied power of 45 W to 55 W, a working pressure of 3 mTorr to 6 mTorr, and a deposition time of 60 to 150 minutes. When sputtering under such preferable conditions, it has better electrical / optical properties.

In addition, the Ge-IGZO target used for the deposition of the Ge-IGZO thin film 20 is an oxide containing indium (In), gallium (Ga), zinc (Zn) and germanium (Ge) as a metal element, which is IGZO Doped (added) Ge is used for the basic composition of. Specifically, an appropriate amount of Ge doped (added) according to the present invention is used in the commonly used IGZO base composition. According to the present invention, the electrical properties are improved by doping (adding) Ge, and the amount of expensive indium (In) can be reduced.

In this case, the IGZO base may have a conventional composition, and specifically, the composition ratio (atomic mole fraction) of In (indium), Ga (gallium) and Zn (zinc) is 1: 0.5 to 2: 1 to 20 (In: Ga It is better to use Zn). That is, the IGZO base may be represented by a composition formula of In _x Ga _y Zn _z O, wherein when x = 1, it is preferable to use 0.5 ≦ y ≦ 2 and 1 ≦ z ≦ 20.

In addition, the target used in the present invention is one in which Ge is appropriately doped (added) to the IGZO base described above. Preferably, 0.01 to 6 wt% of Ge is doped (added) based on the total weight of the Ge-IGZO target. Used. That is, in the present invention, the Ge-IGZO target used for the deposition of the Ge-IGZO thin film 20 includes 0.01 to 6% by weight of Ge based on the total weight of the target. At this time, when the content of Ge is less than 0.01% by weight, the efficiency of improving electrical properties is low and the amount of replacement of indium (In) is small. And when the content of Ge exceeds 6% by weight, the sheet resistance may be too high, making it difficult to use as a transparent electrode. For this reason, the Ge-IGZO target preferably contains 0.01 to 6% by weight of Ge, more preferably 0.2 to 2% by weight. The Ge-IGZO target may be prepared by mixing, for example, indium oxide (In ₂ O ₃ ), gallium oxide (Ga ₂ O ₅ ), zinc oxide (ZnO), and germanium oxide (GeO ₂ ) in an appropriate blending ratio. have.

3. Heat treatment (3rd step)

After the Ge-IGZO thin film 20 is formed as described above, it is preferable to heat-treat the Ge-IGZO thin film 20 according to a preferred embodiment of the present invention. By such heat treatment, it is possible to achieve more improved electrical and optical properties in electrical properties and light transmittance than before heat treatment.

At this time, the heat treatment is preferably performed for 30 minutes to 5 hours at a temperature of 120 ~ 500 ℃. In this case, when the heat treatment temperature is less than 120 ° C., the effect of the heat treatment, that is, the electrical characteristics and the light transmittance improvement effect is insignificant, and when the heat treatment temperature exceeds 500 ° C., the thermal deformation may be applied to the substrate 10, which may not be desirable. In addition, when the heat treatment time is less than 30 minutes, the effect of the heat treatment is insignificant, and if it exceeds 5 hours, rather than before the heat treatment, the electrical / optical properties may not be good because it is not desirable. Preferably, the heat treatment is performed for 1 hour to 4 hours at a temperature of 220 to 400 ° C.

The Ge-IGZO transparent electrode manufactured according to the manufacturing method of the present invention described above is not particularly limited, but may be usefully used, for example, as a transparent electrode or a touch panel of an optical or electronic device. For example, a flat panel display such as a liquid crystal display (LCD), a plasma display panel (PDP), a field emission display (FED), a light emitting device display (LED display), or the like. It can be used in the field of (FPD: Flat Panel Display). In addition to the display, it can be used in mobile systems, flexible organic light emitting devices, electronic paper, wearable computers and solar cells, and the like, and its application is not limited.

According to the present invention described above, Ge is doped (added) to the IGZO, the sputtering process conditions of the thin film 20 is optimized, it is possible to manufacture a transparent electrode having excellent electrical and optical properties. Specifically, according to the present invention, the Ge-IGZO transparent electrode has a sheet resistance of 400 mW / sq or less, preferably 200 mW / sq or less, and has a light transmittance of 80% or more, preferably a high light transmittance of 85% or more. Can be prepared. Accordingly, it is possible to replace the existing expensive ITO transparent electrode, the amount of expensive indium (In) is reduced, it is possible to lower the price of the transparent electrode.

Hereinafter, embodiments of the present invention will be exemplified. The examples illustrated below are some of the experimental examples for helping to understand the present invention among many experimental examples for deriving the present invention, which are merely exemplary, and the technical scope of the present invention is limited thereto. no.

[Example]

1. Blocking layer (SiO ₂ ) formation

First, soda-lime glass (Soda-Lime glass panel) the washing with water and then dried, and then, dipping the washing / drying a glass plate on SiO ₂ solution, which was spin-coated SiO ₂ solution at a rotational speed of 4rpm. As the SiO ₂ solution, 25% by weight of SiO ₂ powder having an average particle diameter of 5 μm and 1.5% by weight of butylamine were sufficiently stirred in 73.5% by weight of methyl ethyl ketone.

Next, the glass plate coated with the SiO ₂ solution was put into an electric furnace and first baked, and then heated at a temperature rising rate of 10 ° C./min, and then second baked to form SiO ₂ layers on both sides of the glass plate. At this time, as shown in the following [Table 1], the temperature and time of the primary firing and the secondary firing were different according to each embodiment.

In addition, the elution amount of sodium (Na) was evaluated through ion chromatography analysis on the glass substrate on which the SiO ₂ layer was formed according to each of the above examples, and the results are shown together in the following [Table 1].

On the other hand, in contrast to the above, as shown in Table 1, the comparative specimens were prepared by varying the temperature and time of the primary firing and the secondary firing. For each comparative specimen, the elution amount of sodium (Na) was evaluated in the same manner as above, and the results are shown together in the following [Table 1]. At this time, Comparative Sample 1 in the following [Table 1] is a glass plate does not form a SiO ₂ layer.

Remarks Primary firing condition Secondary firing condition Na elution
(mg / ㎠) Firing temperature (캜) Firing time (min) Firing temperature (캜) Firing time (min) Comparative Psalm 1 - - - - 0.744 Comparative Psalm 2 - - 450 50 0.501 Comparative Psalm 3 100 20 450 80 0.324 Comparative Psalm 4 115 20 410 80 0.337 Conduct Psalm 1 125 30 425 120 0.281 Conduct Psalm 2 135 20 450 100 0.202 Conduct Psalm 3 140 15 470 80 0.208 Conduct Psalm 4 145 10 500 50 0.204 Conduct Psalm 5 160 5 515 30 0.217 Comparative Psalm 5 - - 550 30 0.629

<Evaluation of Na-eluted amount of glass substrate according to firing conditions>

The it can be seen that, but SiO comparison sample 1 is very high the amount of elution of Na ₂ layer is not formed, the elution amount of Na is reduced when the SiO ₂ layer is formed, as shown in Table 1. And it can be seen that the amount of Na eluted affects the firing conditions of the SiO ₂ layer. Specifically, in the case of Comparative Sample 2 in which only high temperature firing (secondary firing) was performed, elution amount of Na was decreased, but it was not good. In addition, even in the case where the first and second firings were carried out, Comparative Samples 3 and 4 having lower primary firing temperatures showed lower Na elution than Comparative Sample 2, but this was not good as 0.32 mg / cm 2 or more.

However, as in the test specimens 1 to 5, when the primary firing and the secondary firing proceeded at an appropriate temperature and time, it can be seen that the elution of Na is effectively prevented as less than 0.3 mg / cm 2. In particular, in Examples 2 to 4, the elution amount was about 0.2 mg / cm 2, indicating that the barrier properties were very excellent. On the other hand, in the case of Comparative Sample 5, it was confirmed that Na elution was large. This is presumed that the secondary firing temperature is too high to cause cracking.

On the other hand, in contrast to Example 3, except that the rotational speed was changed during the spin coating of the SiO ₂ solution was carried out the same. For each specimen, the thickness and the light transmittance (%) of the SiO ₂ layer were evaluated and the results are shown in the following [Table 2]. In addition, the evaluation results of Comparative Test Sample 1 and Test Sample 3 are shown in the following [Table 2].

Remarks Comparative Psalm 1 Conduct Psalm 3 Conduct Psalm 6 Conduct Psalm 7 Conduct Psalm 8 Rotation speed (rpm) - 4 32 128 136 SiO ₂ layer thickness (nm) - 112 106 82 74 Light transmittance (%) 90.875 94.358 93.647 92.647 91.841

<Evaluation results of light transmittance according to rotation speed>

As shown in Table 2, it can be seen that SiO ₂ improves the light transmittance. In addition, the light transmittance was found to be affected by the rotational speed during coating, that is, the layer thickness of SiO _{2. In} the case of Test Samples 3, 6 and 7, a high light transmittance of 92% or more was realized.

2. Formation of Transparent Conductive Thin Film (Ge-IGZO Thin Film)

A glass substrate having a SiO ₂ layer having a thickness of 112 nm exhibiting good results was used as a substrate, and a transparent conductive thin film was deposited on the SiO ₂ layer of the glass substrate using an RF magnetron sputtering device as follows.

Example 1

<Electrical / Optical Characteristics by Additives and Deposition Times>

First, to investigate the electrical and optical properties according to the type and the deposition time of the dopant (added) to the IGZO was performed as follows.

The target for thin film deposition was 4N purity, and in the IGZO having a mole ratio of 1: 1: 12 of In: Ga: Zn, Ge (Germanium), B (Boron), and Ba (Barium) based on the total weight of the target. ) Was used to add M-IGZO targets (M = Ge, B or Br) each added 5% by weight. In order to deposit a thin film, a vacuum was formed up to 5 x 10 ^-6 Torr (base pressure), which was then deposited at room temperature. The applied power (power) was 50 W, the distance between the target and the substrate was 90 mm, and the working pressure. ) Was 3 mTorr, and the injection gas was injected at 40 sccm (cm 3 / min) using only argon (Ar). At this time, the deposition time was deposited for each specimen by varying the deposition time. Specific deposition conditions are shown in the following [Table 3].

Item
(Parameter) Condition
(Condition) Distance between target and substrate
(TS distance) 90 mm Substrate temperature
(Substrate Temperature) Room temperature Working pressure
(Working pressure) 3mTorr Injection gas
(Injection gas) Ar 40sccm Deposition time
(Deposition time) 30 minutes, 1 hour, 1 hour 30 minutes Preliminary sputtering
(Pre-sputtering) 5 minutes RF power
(RF power) 50W

<Deposition Conditions of Thin Film-Deposition Time Change>

Sheet resistance (? / Sq) was measured for each of the prepared specimens, and the results are shown in the following [Table 4]. In addition, the light transmittance (%) was measured for each of the prepared specimens, and the results are shown graphically in FIGS. 2 to 4. At this time, the sheet resistance (Ω / Sq) and the light transmittance (%) is a measurement method generally used in the art, in the case of the sheet resistance was measured using a 4-point probe method (4-point probe), the light transmittance is JIS In accordance with K 7105 was measured using a UV-VIS spectrometer (Spectrometer).

Additive substance 30 minutes 1 hours 1 hour 30 minutes Ge 454 Ω / sq 245 Ω / sq 173 Ω / sq B 2.3 kΩ / sq 1.05 kΩ / sq 491.8 Ω / sq Ba 307 kΩ / sq 469 kΩ / sq 84.8 kΩ / sq

<Evaluation of Sheet Resistance According to Additives and Deposition Times>

First, as shown in [Table 4], when Ge is added (doped) as an additive material it can be seen that the sheet resistance is significantly lower than the case where other materials (B, Br) is added has excellent electrical properties.

In addition, the deposition time affects the electrical properties, it can be seen that as the deposition time increases the sheet resistance is lowered to have excellent electrical properties. In particular, Ge may be added (doped), but it can be seen that the sheet resistance is 250 kW / Sq or less at 1 hour and 1 hour 30 minutes of deposition time, and has excellent electrical properties.

Also, as shown in FIGS. 2 to 4, the optical properties of the thin film (M-IGZO thin film) to which the additives (Ge, B, Br) are added (doped) are all averaged over 80% in the visible region. It can be seen that the light transmittance is shown. In particular, it can be seen that the UV blocking ability to block all the ultraviolet region is excellent. This means that when used as a transparent electrode for solar cells, it can greatly contribute to improving durability by reducing the phenomenon that the life is shortened by ultraviolet rays. In this case, in the accompanying FIGS. 2 to 4, 'bare glass' is a specimen of a glass substrate on which a thin film (M-IGZO thin film) is not deposited.

[Example 2]

<Electrical / Optical Characteristics by Applied Power (Deposition Voltage)>

In order to determine the dependence of the applied power (deposition voltage), the Ge-IGZO thin film was sputtered by varying the applied power of the RF magnetron sputtering apparatus for each specimen. In this case, the Ge-IGZO target was used in which Ge was added in an amount of 5 wt% based on the total weight of the target in the basic composition (In: Ga: Zn = 1: 1: 12 molar ratio) of IGZO. Specific deposition conditions are shown in the following [Table 5].

Item
(Parameter) Condition
(Condition) Distance between target and substrate
(TS distance) 90 mm Substrate temperature
(Substrate Temperature) Room temperature Working pressure
(Working pressure) 3mTorr Injection gas
(Injection gas) Ar 40sccm Deposition time
(Deposition time) 1 hour 30 minutes Preliminary sputtering
(Pre-sputtering) 5 minutes RF power
(RF power) 30-70 W

<Deposition Conditions of Ge-IGZO Thin Film-Change of Applied Power>

The sheet resistance (Ω / Sq) was measured for each of the prepared specimens, and the results are shown in the following [Table 6]. In addition, the light transmittance (%) was measured for each of the prepared specimens, and the results are shown graphically in FIG. At this time, the measurement method of the sheet resistance (Ω / Sq) and the light transmittance (%) is as described above.

Applied power 30 W 40W 50W 60W 70 W Sheet resistance
[Ω / sq] 581.6 344.8 199 174 99

<Evaluation of Sheet Resistance According to Applied Power (Deposition Voltage)>

First, as shown in [Table 6], when the Ge-IGZO thin film is deposited, the applied power (deposition voltage) affects the electrical properties, and as the applied power increases, the sheet resistance decreases, indicating that the electrical properties are excellent. . Specifically, it can be seen that when the applied power is less than 40W, that is, the surface resistance is high at 30W, it is difficult to realize good electrical characteristics, and the surface resistance is 400 kW / Sq or less at 40W or more.

On the contrary, as shown in the accompanying FIG. 5, when looking at the optical characteristics, it can be seen that the optical characteristics (light transmittance) decrease as the applied power increases. In particular, the light transmittance at 550 nm wavelength, which is sensitive to the human eye, showed poor characteristics at 70 W of applied power.

Therefore, the applied power during the deposition of the Ge-IGZO thin film from the above experimental example affects the electrical and optical properties, the sheet resistance (electrical properties) of 400 Ω / Sq or less and the high light transmittance in the visible region in the 550 nm wavelength range (optical Characteristics), it can be seen that it is preferable to deposit at a power of 40W to 60W. In particular, it can be seen that the best characteristics at a power of 50W.

[Example 3]

<Electrical Characteristics According to Working Pressure>

In order to determine the dependence of the working pressure (working pressure) was carried out in the same manner as above, the Ge-IGZO thin film was sputtered by varying the working pressure for each specimen. At this time, the Ge-IGZO target was the same as above, and the Ge-IGZO target was used in which 5% by weight of Ge was added to the basic composition of IGZO (molar ratio of In: Ga: Zn = 1: 1: 1) based on the total weight of the target. Specific deposition conditions are shown in the following [Table 7].

Item
(Parameter) Condition
(Condition) Distance between target and substrate
(TS distance) 90 mm Substrate temperature
(Substrate Temperature) Room temperature Working pressure
(Working pressure) 0.1 to 11 mTorr Injection gas
(Injection gas) Ar 40sccm Deposition time
(Deposition time) 1 hour 30 minutes Preliminary sputtering
(Pre-sputtering) 5 minutes RF power
(RF power) 50W

<Deposition Conditions for Ge-IGZO Thin Films-Changing Working Pressure>

Sheet resistance (? / Sq) was measured for each of the prepared specimens, and the results are shown in the following [Table 8]. The measurement method of sheet resistance (Ω / Sq) is as above.

Working pressure 0.5mTorr 3mTorr 4mTorr 5 mTorr 6mTorr 7mTorr 9mTorr 11mTorr Sheet resistance [Ω / sq] 201 199 244 304 347 1k 639 632

<Evaluation of Sheet Resistance According to Working Pressure>

As shown in [Table 8], when the Ge-IGZO thin film is deposited, the working pressure affects the electrical properties, and when the working pressure is 6 mTorr or less, the sheet resistance is 400 Ω / Sq or less, which shows excellent electrical properties. have. That is, when the working pressure is 0.5 ~ 6mTorr it can be seen that it has excellent electrical properties of the sheet resistance of 400 Ω / Sq or less, preferably the sheet resistance of 200 Ω / Sq or less, in particular it can be seen that it has the most excellent properties at 3mTorr. . In addition, when the working pressure is more than 6mTorr and 7mTorr, 9mTorr and 11mTorr, the sheet resistance is high, it can be seen that the implementation of good electrical properties is difficult.

Example 4

<Electrical / Optical Characteristics by Flow Rate Ratio (Oxygen Partial Pressure) of Injection Gas>

In order to determine the dependence of the flow rate of the injection gas was carried out in the same manner as above, the Ge-IGZO thin film was sputtered by varying the flow rate (oxygen partial pressure) of the injection gas for each specimen. At this time, Ar was injected at 40 sccm, but the flow rate of oxygen (O ₂ ) was increased by 0.1, 0.3, 0.5, and 1.0 sccm in each of the specimens. The Ge-IGZO target was the same as above, and the Ge-IGZO target was used in which 5 wt% of Ge was added to the basic composition of IGZO (molar ratio of In: Ga: Zn = 1: 1: 1) based on the total weight of the target. Specific deposition conditions are shown in the following [Table 9].

Item
(Parameter) Condition
(Condition) Distance between target and substrate
(TS distance) 90 mm Substrate temperature
(Substrate Temperature) Room temperature Working pressure
(Working pressure) 3mTorr Injection gas
(Injection gas) Ar: O ₂ = 40: 0 ~ 1.0sccm Deposition time
(Deposition time) 1 hour 30 minutes Preliminary sputtering
(Pre-sputtering) 5 minutes RF power
(RF power) 50W

<Deposition Conditions for Ge-IGZO Thin Films-Changing Working Pressure>

The sheet resistance (시 / Sq) and the light transmittance (%) were measured for each of the prepared specimens, and the results are shown in the following [Table 10]. The measurement method of sheet resistance (Ω / Sq) and light transmittance (%) is as above.

Oxygen flow rate 0sccm 0.1sccm 0.3sccm 0.5sccm 1.0sccm Sheet resistance [Ω / sq] 199 244 304 1k - Light transmittance (550 nm) [%] 82.6 83.8 84.1 84.4 84.8

<Evaluation of Sheet Resistance and Light Transmittance According to Flow Rate of Injection Gas>

As shown in [Table 10], when the deposition of the Ge-IGZO thin film by injection of pure Ar only, the deposition has a low light transmittance due to oxygen deficiency, but when a further injection of oxygen (O ₂ ) in addition to Ar, It can be seen that the improvement. However, when the injection amount of oxygen (O ₂ ) is too large as 0.5 sccm or more, it can be seen that the sheet resistance is increased and electrical characteristics are deteriorated. In the case where the injection amount of oxygen (O ₂ ) was 1.0 sccm, the sheet resistance was too high to measure. This is believed to cause barrier formation when excess oxygen is adsorbed onto the Ge-IGZO thin film, and as a result, carriers are reduced and sheet resistance is increased.

Therefore, to improve the optical properties, gas injection is recommended to use a mixture of Ar and oxygen (O _2), also oxygen (O ₂₎ is injected at an appropriate flow rate in consideration of the electrical characteristics, that is, flow rates of less than 0.3sccm It can be seen that the injection with a good characteristics.

[Example 5]

<Electrical Characteristics of Heat Treatment of Ge-IGZO Thin Film>

In order to determine the dependence according to whether or not heat treatment is performed, the sheet resistance characteristics of each specimen prepared before and after the heat treatment were evaluated, and the results are shown in the following [Table 11] to [Table 13]. At this time, the heat treatment was performed for 2 hours at 350 ℃ put each prepared specimen in a vacuum oven.

Applied power 30 W 40W 50W 60W 70 W Sheet resistance
(Ω / sq) Before heat treatment 581.6 344.8 199 174 99 After heat treatment 497 313 186 124 66

<Evaluation of Sheet Resistance Before and After Heat Treatment According to Applied Power (Deposition Voltage)>

Working pressure 0.5mTorr 3mTorr 4mTorr 5 mTorr 6mTorr 7mTorr 9mTorr 11mTorr Sheet resistance
[Ω / sq] Before heat treatment 201 199 244 304 347 1k 639 632 After heat treatment 197 186 233 254 274 500 448 288

<Evaluation results of before and after heat treatment according to working pressure>

Oxygen flow rate 0sccm 0.1sccm 0.3sccm 0.5sccm 1.0sccm Sheet resistance
[Ω / sq] Before heat treatment 199 244 304 1k - After heat treatment 186 232 284 548 39k

<Evaluation of Sheet Resistance Before and After Heat Treatment According to Flow Rate of Injection Gas>

As shown in [Table 11] to [Table 13], it can be seen that the electrical resistance is improved by lowering the sheet resistance after all the specimens are heat treated. In addition, the phase did not change even after the heat treatment was found to have thermal stability.

[Example 6]

<Electrical Characteristics by Ge Content>

In order to determine the electrical properties according to the Ge content was carried out in the same manner as above, the Ge content of the Ge-IGZO target was different for each specimen. Specifically, Ge = 0 wt%, 0.5 wt%, 7.0 wt% based on the total weight of the target in the basic composition of IGZO (molar ratio of In: Ga: Zn = 1: 1: 12). Was used to sputter the Ge-IGZO thin film. Specific deposition conditions are shown in the following [Table 14].

Item
(Parameter) Condition
(Condition) Distance between target and substrate
(TS distance) 90 mm Substrate temperature
(Substrate Temperature) Room temperature Working pressure
(Working pressure) 3mTorr Injection gas
(Injection gas) Ar 40sccm Deposition time
(Deposition time) 1 hour 30 minutes Preliminary sputtering
(Pre-sputtering) 5 minutes RF power
(RF power) 50W Ge content 0 to 7% by weight

<Deposition Conditions of Ge-IGZO Thin Film-Ge Content Change>

The sheet resistance (시 / Sq) and the light transmittance were measured for each of the prepared specimens, and the results are shown in the following [Table 15]. And the content of Ge prepared above was compared with the specimen of 5.0% by weight. In addition, in order to compare the characteristics before and after the heat treatment, the sheet resistance measurement results after the heat treatment for 3 hours at 300 ℃ put in a vacuum oven for each specimen is shown together in the following [Table 15].

Oxygen flow rate Sheet resistance [Ω / sq] Light transmittance (550 nm) [%] Ge-IGZO
(Ge: 0 wt%) Before heat treatment 421 87.2 After heat treatment 380 - Ge-IGZO
(Ge: 0.5 wt%) Before heat treatment 364 86.36 After heat treatment 253 - Ge-IGZO
(Ge: 5.0 wt%) Before heat treatment 199 82.6 After heat treatment 184 - Ge-IGZO
(Ge: 7.0 wt%) Before heat treatment 46.3k 80.3 After heat treatment 18.44k -

<Evaluation of Sheet Resistance According to Ge Content>

As shown in Table 15, when the Ge is added (doped) it can be seen that the sheet resistance is lower than when not added, the electrical properties are excellent. And the sheet resistance varies depending on the content of Ge, it can be seen that the excellent results in Ge = 5.0% by weight or less. In addition, when the content of Ge is too high, that is, Ge = 7.0% by weight, the sheet resistance of several tens of kPa / sq was shown, making it difficult to use as a transparent electrode. In addition, when the content of Ge is 0.5% by weight, the light transmittance at 550 nm was 86% or more, which showed excellent results in optical properties.

[Example 7]

<Reproducibility Evaluation of Ge-IGZO Transparent Electrode>

In the same manner as described above, the Ge-IGZO transparent electrode having Ge = 0, 0.5, and 5.0% by weight was deposited several times to evaluate reproducibility. Specifically, the deposition conditions are carried out in the same manner as in Example 6, after the deposition was repeated for a total of 40 times using a Ge-IGZO target having a Ge content of 0% by weight, 0.5% by weight, and 5.0% by weight, respectively. The sheet resistance (대하여 / sq) was evaluated for the specimens. In addition, the sheet resistance of the Ge content of 0.5% by weight was evaluated even after the heat treatment. The results are shown in the following [Table 16] and attached FIG.

Deposition Times Ge = 0 wt% Ge = 0.5 wt% Ge = 0.5% by weight (after heat treatment) Ge = 5.0 wt% One 120 403 255 266 2 150 347 197 267 3 154 313 170 288 4 170 292 168 256 5 190 261 144 278 6 198 237 134 290 7 200 206 122 293 8 220 177 120 296 9 225 160 100 282 10 234 139 98 303 11 250 127 77 321 12 255 127 87 315 13 263 114 89 324 14 277 108 78 365 15 302 99 80 354 16 332 98 77 322 17 354 91 67 342 18 366 88 61 352 19 377 86 57 336 20 382 88 54 321 21 401 85 40 366 22 412 79 39 374 23 422 77 35 355 24 425 73 34 357 25 433 68 35 375 26 435 69 34 382 27 443 69 29 364 28 451 65 26 377 29 467 64 26 375 30 466 64 27 388 31 470 64 26 391 32 474 63 26 392 33 477 63 25 396 34 478 62 26 399 35 480 64 27 401 36 501 63 26 405 37 521 64 27 411 38 512 62 28 412 39 515 63 28 408 40 512 63 25 389

<Evaluation of sheet resistance according to the number of deposition of Ge-IGZO transparent electrode, unit: Ω / sq>

As shown in [Table 16] and FIG. 6, Ge-IGZO transparent electrodes having a Ge content of 0 wt% and 5.0 wt% showed a result of increasing sheet resistance as deposition was repeated, and a Ge content of 0.5 wt%. The Ge-IGZO transparent electrode, which is%, is gradually stabilized with repeated deposition, and the sheet resistance is lowered, thus showing excellent electrical characteristics.

As can be seen from the above examples, when Ge is doped (added) to the IGZO, the electrical and optical properties are improved, and the sputtering conditions, that is, the applied power, deposition time, working pressure, and the like during deposition of the Ge-IGZO thin film, It can be seen that the electrical and optical properties vary depending on the gas flow rate.

The above results show that the sputtering conditions during the deposition of Ge-IGZO thin film are optimized, and thus, Ge-IGZO transparent electrode can be manufactured as a new transparent conductive material that can replace the existing ITO with excellent electrical and optical properties. Can be. And the optimum process conditions when sputtering a Ge-IGZO thin film based on the above results are shown in Table 17 below.

Item
(Parameter) Condition
(Condition) Distance between target and substrate
(TS distance) 90 mm Substrate temperature
(Substrate Temperature) Room temperature Working pressure
(Working pressure) 3mTorr Injection gas
(Injection gas) Ar 40sccm Deposition time
(Deposition time) 1 hour 30 minutes Preliminary sputtering
(Pre-sputtering) 5 minutes RF power
(RF power) 50W Ge content 0.5% Heat treatment
(annealing) 300 ℃, 3 hours

<Optimal Sputtering Conditions for Ge-IGZO Thin Films>

In the case of sputtering under the above optimum conditions, amorphous Ge- having a light transmittance of 86.36% (at 550 nm) with excellent electrical properties of sheet resistance of 300 μs / sq or less and optimum resistance according to the number of depositions has a sheet resistance of 25 μs / sq. IGZO transparent electrode can be implemented.

10: substrate
12: blocking layer
20 Ge-IGZO thin film

Claims (6)

A first step of preparing a substrate; And
A second step of forming a Ge-IGZO thin film by sputtering a Ge-IGZO target on the substrate,
Wherein the injection gas flow rate ratio of the applied power of 40W-60W, the working pressure 0.5mTorr ~ 6mTorr, argon (Ar) and oxygen (O ₂₎ In step _{2 (Ar: O 2) 40} : 0 ~ 0.3sccm, a deposition time from 30 minutes to A sputtering under a condition of 180 minutes to form a Ge-IGZO thin film manufacturing method of a Ge-IGZO transparent electrode. The method of claim 1,
The Ge-IGZO target, Ge-IGZO transparent electrode manufacturing method characterized in that it comprises 0.01 to 6% by weight of Ge based on the total weight of the target. The method of claim 1,
In the first step, a glass substrate including a glass substrate and a blocking layer formed on the glass substrate is prepared,
(1) a coating process of coating a blocking solution containing a metal oxide on the glass substrate;
(2) a first firing step of first baking the coated blocking solution at 120 ° C. to 160 ° C. for 5 minutes to 30 minutes; And
(3) The method of manufacturing a Ge-IGZO transparent electrode, characterized in that it comprises a second firing process after the first firing, the second firing for 30 minutes to 150 minutes at 420 ℃ to 520 ℃. The method of claim 3,
In the first step, the Ge-IGZO transparent electrode is manufactured by spin coating a blocking solution on the organic substrate at 2 to 130 rpm in the coating process so that the blocking layer has a thickness of 80 nm to 120 nm. Way. The method according to any one of claims 1 to 4,
The method of manufacturing a Ge-IGZO transparent electrode further comprising the step of heat-treating the Ge-IGZO thin film formed on the substrate. The method of claim 5,
The heat treatment is a method for producing a Ge-IGZO transparent electrode, characterized in that for 1 to 4 hours at 200 ℃ to 400 ℃.

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