KR20090069886A - Ito(indium tin oxide) film for transparent electrode manufactured using low frequency sputtering apparatus, and method thereof - Google Patents

Abstract

An indium tin oxide film for a transparent electrode manufactured using a low frequency sputtering device and a manufacturing method thereof are provided to deposit the indium tin oxide film by the low frequency sputtering discharge in the room temperature. A manufacturing method for an indium tin oxide film for a transparent electrode manufactured using a low frequency sputtering device comprises: a step of coating a silicon oxide film on a matrix(S210); a step of loading the matrix coated with the silicon oxide film on the low frequency sputtering device(S220); a step of generating the power source using the low frequency power supply part with a protection circuit stabilizing the initial discharge voltage(S230); a step of sputtering-discharging on the matrix coated with the silicon oxide film using the indium and tin oxide as a target(S240); and a step of depositing the indium tin oxide film on the silicon oxide coated film be the sputtering discharge in the room temperature(S250). The matrix is a polymer film or a glass substrate.

Description

Indium tin oxide thin film for transparent electrode manufactured using low frequency sputtering apparatus and method for manufacturing same {ITO (Indium Tin Oxide) film for transparent electrode manufactured using low frequency sputtering apparatus, and method

The present invention relates to an indium tin oxide thin film for transparent electrodes, and more particularly, to an indium tin oxide thin film (ITO) thin film for transparent electrode manufactured using a low frequency sputtering apparatus, and a preparation thereof. It is about a method.

In general, display devices such as an organic light emitting diode (OLED), a liquid crystal display (LCD), and a plasma display panel (PDP) form a transparent conductive layer (transparent electrode layer) on a glass substrate, and the conductive layer is an electrode. It is built to have a working structure.

In the case of an organic light emitting diode (OLED), various organic material layers are deposited on a transparent electrode, where the organic material layer generally has a very thin thickness in the range of several tens of nm, and is bonded to the opposite electrode made of metal, and then sealed by The display device is completed. Here, ITO is generally used for a transparent electrode.

ITO is Indium-Tin Oxide, which is widely used as a transparent electrode in touch panels or display devices because it has excellent electrical conductivity and transparent band-gap in the visible range of 2.5 eV or more. Compared with the transparent electrode material, the electrode pattern has excellent workability, excellent chemical and thermal stability, and low film resistance during coating.

1A is a process flowchart of a method for manufacturing an ITO thin film for a transparent electrode according to the related art, and FIG. 1B is a cross-sectional view of a glass substrate manufactured by the method of FIG. 1A.

1A and 1B, in forming an ITO thin film according to the related art, after preparing a glass substrate 11 (S11), the glass substrate 11 is cut to a predetermined size (S12), and an ion beam After the polishing by the plasma treatment (S13), the polished glass substrate 11 is cleaned (S14). Thereafter, by discharging using a high frequency (RF) or direct current (DC) sputtering apparatus (S15), the ITO thin film 12 is formed (S16). Subsequently, a high temperature heat treatment process is performed to improve the sheet resistance and light transmittance of the ITO thin film 12 (S17), and a polishing process using ion beam and plasma treatment is performed to improve flatness (S18). The ITO thin film 12 is completed.

However, when the surface of the ITO thin film 12, which is a transparent electrode, is not smooth or has sharp edges or the like, the device may not only cause a short circuit or charge accumulation of the circuit, but also cause leakage current through the organic material layer of the OLED. It can cause various defects that deteriorate the characteristics of. In order to prevent this, the thickness of the ITO thin film 12 should have a very flat surface compared with the thickness of the organic material layer.

Specifically, the characteristics of the ITO thin film for transparent electrodes required in the OLED is very stringent, unlike the voltage-driven LCD. That is, the electrical resistance should have a value of about 10 mA / cm 2, which is the lowest electrical sheet resistance among the resistance values required by the LCD, and at the same time, the light transmittance should be maintained at about 80%. In addition, in the case of the surface roughness value (Rp-v) represented by the height difference between the peak and the valley, unlike the LCD of the current 20nm to 30nm level, it is 10 nm or less which does not affect the electrical properties of the organic layer. Should be lowered to.

The flat ITO thin film 12 having the above-mentioned high electrical conductivity and transparency is often difficult to obtain by one-time deposition through conventional direct current (DC) sputtering or high frequency (RF) sputtering apparatus, and therefore, expensive ion-assistance for this purpose. An ion-assisted sputtering or ion plating process is applied. However, the process is not only difficult, but due to the expensive equipment, its application is not easy. In addition, in the case of using a DC sputtering or RF sputtering apparatus which is a general sputtering apparatus, there is a problem in that electrical and optical properties are poor at low temperature deposition, and there is a problem in that surface roughness due to recrystallization of ITO occurs at high temperature deposition.

Therefore, when a conventional general sputtering source, particularly a process using a DC or RF sputtering apparatus, is applied, the ITO thin film 12 is glass as shown in FIG. 1B to secure excellent electrical, optical properties and flatness. After the substrate 11 is polished, an ITO thin film 12 is formed on a substrate having a temperature of at least a recrystallization temperature of the material (about 250 ° C. in the case of an ITO thin film), and the surface roughness described above after the high temperature process is performed. Additional mechanical polishing and subsequent processing must be carried out to meet the requirements. Accordingly, there is a problem that the manufacturing cost increases and the manufacturing process is complicated.

On the other hand, as a first prior art for solving the above-described problems, Korean Patent Publication No. 2006-9724 discloses the invention named "low frequency sputtering apparatus and method of forming a metal oxide layer". In addition, as a second prior art, Korean Patent Publication No. 2007-19317 discloses an invention entitled “ITIO thin film for transparent electrode and ITO thin film for transparent electrode manufactured using the same”.

Here, the Ithio thin film according to the second prior art is manufactured using the low frequency sputtering apparatus according to the first prior art, and the first and second prior art have been filed by some of the same applicants as the applicants of the present invention. It is incorporated herein by reference, and forms part of the invention.

2 is a block diagram of a low frequency power supply device in a low frequency sputtering apparatus for manufacturing an ITO thin film for a transparent electrode according to the prior art.

Referring to FIG. 2, the low frequency power supply device 20 according to the related art includes a voltage boosting unit 21, a voltage adjusting unit 22, a voltage measuring unit 23, a current measuring unit 24, and a stabilizer unit. And a terminal portion 26, first and second voltage input portions 27a and 27b, first and second power supply connection portions 28a and 28b, and a ground portion 29, thereby providing a low frequency sputtering apparatus. Supply low frequency power. Here, a detailed description of each component will be described later.

However, in the low frequency power supply device 20 according to the first prior art, a short phenomenon may occur due to a high voltage at the initial discharge of the low frequency sputtering device, thereby causing an unstable discharge output, thereby causing a defect in ITO thin film deposition. There is a problem.

The technical problem to be solved by the present invention is to form an ITO thin film on a glass substrate or various polymer film bases coated with a single layer or a multi-layer silicon oxide film, thereby having high gas barrier properties and light transmittance. At the same time, to provide an indium tin oxide thin film for transparent electrodes produced using a low frequency sputtering apparatus having a good surface roughness and a method of manufacturing the same.

Another technical problem to be achieved by the present invention is to use a low frequency sputtering apparatus capable of depositing an ITO thin film at low temperature sputtering discharge at room temperature by mounting a protection circuit to stabilize an initial discharge current at a low frequency power source. It is to provide an indium tin oxide thin film for a transparent electrode to be produced and a method of manufacturing the same.

Another technical problem to be solved by the present invention is to introduce a low frequency sputtering method to form an ITO thin film on a polymer film or a glass substrate by low frequency sputtering apparatus that can produce a non-abrasive ITO thin film that does not subsequently surface the ITO thin film It is to provide an indium tin oxide thin film for a transparent electrode produced by using and a method of manufacturing the same.

Another object of the present invention is to provide a touch panel and an organic light emitting display device including an ITO thin film for transparent electrodes manufactured by a method for manufacturing an ITO thin film for transparent electrodes manufactured using a low frequency sputtering apparatus. .

As a means for achieving the above-described technical problem, the method for producing a transparent electrode ITO thin film according to the present invention, in the method for producing an indium tin oxide (ITO) thin film for transparent electrodes using a low frequency sputtering apparatus a) coating a silicon oxide film on a matrix; b) mounting the substrate coated with the silicon oxide film on the low frequency sputtering device; c) generating power using the low frequency power supply device having a protection circuit which stabilizes the initial discharge voltage in the low frequency sputtering device; d) sputtering discharge on said silicon oxide film-coated base using indium and tin oxide as targets; And e) depositing an ITO thin film on the silicon oxide film-coated base by the sputtering discharge at room temperature.

Here, the base of step a) may be a polymer film or a glass substrate.

Here, the polymer film may be any one selected from the group consisting of PES (PolyEtherSulfone), PC (PolyCarbonate), PET (PolyEthylene Terephthalate) and PEN (PolyEthyleneNaphthalate).

Here, the silicon oxide film of step a) is a single layer silicon oxide film (SiO ₂ ) or a multi-layer silicon oxide film (SiO ₂ / SiO ₂ / SiO ₂ / SiO ₂ / SiO ₂ ), wherein the silicon oxide film has a cross section on the substrate. Or coated on both sides.

Here, when the ITO thin film of step e) is coated on the polymer film matrix, the ITO thin film has an average light transmittance of at least 77% with respect to a wavelength of 400 nm to 700 nm.

Here, when the ITO thin film of step e) is coated on the polymer film matrix, it has a sheet resistance of 20 ~ 2000 Ω / ㎠.

Here, when the ITO thin film of step e) is coated on the polymer film matrix, the average roughness value (Ra) is 0.7-2 nm, the squared average surface roughness value (Rms) is 0.7-2 nm, and the peak (Peak) Surface roughness value (Rp-v) represented by the height difference between the valley (Valley) is characterized in that 1 ~ 20nm.

Here, the ITO thin film of step e) may be formed by a small to large area roll to roll film manufacturing process.

Here, the protection circuit of step c) may be a variable resistor for stably adjusting the high current during the initial driving of the low frequency power supply.

According to the present invention, by forming an ITO thin film on a glass substrate coated with a single layer or a multilayer silicon oxide film or on various polymer film substrates, it is possible to have high gas barrier properties and light transmittance and at the same time have good surface roughness.

According to the present invention, an ITO thin film can be deposited by a low frequency sputtering discharge at room temperature by mounting a protection circuit to stabilize an initial discharge current in a low frequency power supply.

According to the present invention, by introducing a low frequency sputtering method to form an ITO thin film on a polymer film or a glass substrate, it is possible to produce a non-abrasive ITO thin film that does not subsequently surface-treated the ITO thin film.

According to the present invention, it is possible to provide a touch panel and an organic light emitting display device including the transparent electrode ITO thin film manufactured by the method for manufacturing the transparent electrode ITO thin film manufactured using a low frequency sputtering apparatus.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

An embodiment of the present invention relates to the manufacture of an ITO thin film on a glass substrate or a polymer film base coated with a single layer or a multilayer silicon oxide film (SiO ₂ ), respectively, which is used as a transparent electrode for a touch panel or a display device. do. Specifically, the transparent conductive ITO thin film according to the embodiment of the present invention is manufactured by a low frequency sputtering method, and the silicon oxide film (SiO ₂ ) is coated on a glass substrate or a polymer film substrate coated with a low temperature of 100 ° C. or less, respectively. Introduced a low-frequency power supply with advantages and equipped with a protection circuit.

3 is a process flowchart of a method of manufacturing an ITO thin film on a glass substrate by low frequency sputtering discharge according to an embodiment of the present invention.

Referring to FIG. 3, in the method of manufacturing an ITO thin film on a glass substrate by a low frequency sputtering discharge according to an embodiment of the present invention, first, a silicon oxide film is coated on the glass substrate (S110). Here, the silicon oxide film may be a single layer or multiple layers, and may be coated on one or both surfaces of the glass substrate. The reason why the silicon oxide film is coated is to increase adhesion and prevent moisture and oxygen penetration. In this case, the thickness of the silicon oxide film may be variously adjusted to 10 nm to 1000 nm.

Next, after cutting the glass substrate coated with the silicon oxide film, and cleans it (0), thereafter, the cleaned glass substrate is mounted in a low frequency sputtering apparatus (S130).

Next, in the low frequency sputtering device, power is generated by the low frequency power supply device having a protection circuit for stabilizing the initial discharge voltage (S140). In this case, the protection circuit may be a variable resistor for stably adjusting the high current during the initial driving of the low frequency power supply.

Specifically, an embodiment of the present invention focuses on eliminating a short circuit phenomenon due to high voltage during initial discharge, which is a disadvantage of the conventional low frequency power supply. That is, since the unstable discharge output causes a defect in the ITO thin film deposition process, a protection circuit is configured at the output terminal of the low frequency power supply device to improve this. In the embodiment of the present invention, the protection circuit is a variable resistor, and can be adjusted at values of 50W to 200W and 50ΩJ to 200ΩJ, and values of 100W and 100ΩJ are preferable.

As a result of repeating the thin film deposition process by mounting such a protection circuit, a stable current can be supplied due to the role of controlling a high current in the protection circuit.

Next, an ITO thin film is formed by sputtering discharge (S150) on a glass substrate coated with a silicon oxide film using indium and tin oxide as targets (S160).

As a result, a method of manufacturing an ITO thin film on a glass substrate by a low frequency sputtering discharge according to an embodiment of the present invention, after cutting the glass substrate and undergoing a cleaning process, a low frequency (LF) sputtering discharge under a high temperature atmosphere To form an ITO film. This has the advantage of not requiring any polishing process. In this case, the high temperature atmosphere is not necessarily essential, and ITO may be formed through low frequency sputtering discharge of the frequency range on a room temperature or a heated base, if necessary. The temperature of the glass substrate may be any temperature below the recrystallization temperature of ITO, and preferably, the temperature of the glass substrate is at most 400 ° C. in terms of securing optical and electrical properties of ITO and securing flatness, and more preferably. Preferably it is 250 ± 25 ℃.

On the other hand, in recent years, as the size of flat panel displays increases, development of products using polymer substrates having superior impact resistance and bendability, rather than fragile glass substrates, has been actively conducted. The method of imparting conductivity to the surface of the polymer film substrate has been of interest because of its physical properties such as economics and flexibility such as the use of inexpensive polymer film substrates.

Therefore, a technique of depositing a metal or a metal oxide at room temperature is essential in manufacturing a durable transparent or opaque conductive electrode by imparting conductivity to a polymer film base. In particular, the transparent conductive layer is common for applying power to liquid crystal display (LCD), electrochromic display (ECD), organic light emitting display (OLED), solar cell, plasma display panel (PDP), electronic paper, touch panel, etc. It is widely used as an electrode or a pixel electrode.

4 is a process flowchart of a method of manufacturing an ITO thin film on a polymer film by low frequency sputtering discharge according to an embodiment of the present invention.

Referring to FIG. 4, in the method of manufacturing an ITO thin film on a polymer film by low frequency sputtering discharge according to an embodiment of the present invention, first, a silicon oxide film is coated on the polymer film (S210). Here, the silicon oxide film may be a single layer or multiple layers, and may be coated on one or both surfaces of the glass substrate. The reason why the silicon oxide film is coated is to increase adhesion and prevent moisture and oxygen penetration. In this case, the thickness of the silicon oxide film may be variously adjusted to 10 nm to 1000 nm.

Next, the polymer film coated with the silicon oxide film is mounted in the low frequency sputtering apparatus (S220).

Next, in the low frequency sputtering device, power is generated by the low frequency power supply device having the protection circuit for stabilizing the initial discharge voltage (S230). At this time, the protection circuit is a variable resistor for stably adjusting the high current during the initial driving of the low-frequency power supply, it can be adjusted at the value of 50W ~ 200W and 50ΩJ ~ 200ΩJ, the value of 100W and 100ΩJ is preferred.

As a result of repeating the thin film deposition process by mounting such a protection circuit, it is possible to supply a stable current due to the role of controlling the high current in the protection circuit.

Next, an ITO thin film is formed at room temperature by sputtering discharge (S240) on a polymer film coated with a silicon oxide film using indium and tin oxide as targets (S250).

In this case, the polymer film may be PES (PolyEtherSulfone), PC (PolyCarbonate), PET (PolyEthyleneTerephthalate), PEN (PolyEthyleneNaphthalate), etc. Of these, PES is 180 ℃, PC is 120 ℃, PET and PEN substrate up to about 150 ℃ Can be heated. Accordingly, the polymer film base according to the embodiment of the present invention can form an ITO thin film without a separate cooling device, and also has the advantage of not requiring any polishing process.

As a result, in the method of manufacturing the ITO thin film on the polymer film by the low frequency sputtering discharge according to the embodiment of the present invention, the ITO film is formed by cutting the polymer film and using the low frequency sputtering discharge in a room temperature atmosphere. Likewise, it has the advantage of not requiring any polishing process. The room temperature atmosphere is not necessarily essential, and ITO may be formed through low frequency sputtering discharge of the frequency range on a room temperature or a heated base, if necessary. The temperature of the polymer film matrix may be any temperature below the temperature that does not damage the polymer film. Preferably, the polymer film matrix has a maximum temperature of 200 ° C. in terms of securing optical and electrical properties and flatness of ITO. It is good for the protection of polymer film matrix.

On the other hand, Figure 5 is a cross-sectional view showing the production of an ITO thin film on a single layer of silicon oxide film (SiO ₂ ) coated PET (PolyEthylene Terephthalate) film base according to an embodiment of the present invention, Figure 6 is an embodiment of the present invention Fig. 1 is a cross-sectional view showing the manufacture of an ITO thin film on a multilayer polysilicon oxide film coated PET (PolyEthylene Terephthalate) film base.

FIG. 5 illustrates the ITO thin film 130 using a low frequency sputtering device on a polymer film base 110 coated with a single layer of silicon oxide film (SiO ₂ ) 120, for example, a polyethylene terephthalate (PET) film base 110. This is shown.

6 is a polymer film base 110 coated with a multilayer silicon oxide film (SiO ₂ / SiO ₂ / SiO ₂ / SiO ₂ / SiO ₂ ) 140a to 140e, for example, a PET (PolyEthylene Terephthalate) film base 110 The ITO thin film 130 is formed using a low frequency sputtering device on the?

On the other hand, Figure 7 is a block diagram of a low frequency sputtering apparatus according to an embodiment of the present invention.

Referring to FIG. 7, the low frequency sputtering apparatus 200 according to the embodiment of the present invention includes a shutter 210a and 210b, a turbomolecular pump 220, a permanent magnet 230a and 230b, and a gas supply control unit 240a, 240b), substrate parts 250a and 250b, window part 260, chamber 270, substrate heating parts 280a and 280b, motor 290, targets 310a and 310b, rotary pump 320 and low frequency The power supply device 400 is included, and the low frequency power supply device 400 includes a protection circuit 500.

The shutters 210a and 210b are disposed on the front surface of the substrate to control the deposition in the deposition process.

The gas supply adjusting units 240a and 240b supply stable gas such as argon and oxygen to the chamber 270.

The chamber 270 is a space where sputtering is performed, and the substrate parts 250a and 250b mount a substrate, which is a base on which sputter deposition is performed, in the chamber 270. The substrate parts 250a and 250b are preferably stepped to mount a substrate (base), and a cooling device is installed therein so that various polymer substrates can be used in addition to the high temperature polymer substrate. The deposition takes place at low temperatures, which reduces the temperature.

The window unit 260 is located at the front side and the left side, respectively, to determine the process progress state.

The substrate heating units 280a and 280b may control substrate heating and substrate temperature, and the motor 290 may rotate the substrate to improve the quality of the thin film.

Targets 310a and 310b are mounted on the chamber 270, and the targets 310a and 310b may be configured to mount permanent magnets 230a and 230b thereunder, and at this time, permanent magnets 230a and 230b. ) Is installed for ideal discharge.

The shape of the target 310a, 310b may be configured in a variety of known shapes, such as circular, flat, such as, for example, the center of the S pole, the circumference of the N pole in the lower portion of the target (310a, 310b) Permanent magnets 230a and 230b having a ring shape may be disposed. Through this, plasma can be collected by the magnetic field, thereby increasing the sputtering yield.

The turbomolecular pump 220 is installed for vacuum evacuation to ultra high vacuum, and the rotary pump 320 is installed for evacuation to high vacuum.

The low frequency power supply 400 according to the embodiment of the present invention includes a protection circuit 500 for stably adjusting high current during initial driving, which will be described later with reference to FIG. 8.

As a result, the low frequency sputtering apparatus according to the embodiment of the present invention may be a low temperature process, so that a cooling apparatus may not be additionally added, and if the cooling of the substrate to be mounted on the substrates 250a and 250b is required, In addition, a separate cooling device may be further included in the substrate parts 250a and 250b.

In the low frequency sputtering apparatus according to the embodiment of the present invention, a low frequency power source of 50 to 500 Hz, preferably 60 Hz, is applied between the targets 310a and 310b and the substrate in order to form an ITO thin film by sputtering on a substrate. do.

In addition, in order to manufacture a flexible display device or a touch panel, a low temperature process of 100 ° C. or less is essential on a polymer substrate such as PES, PET, PC, or PEN. The low frequency sputtering device according to an embodiment of the present invention In addition, since the temperature of the substrate at the time of film formation is less than 100 ℃ has the advantage that the film can be formed without a separate cooling device on the substrate. In this case, the temperature of the substrate may vary depending on the voltage applied to the low frequency power supply.

8 is a configuration diagram of a low frequency power supply having a protection circuit in a low frequency sputtering apparatus according to an embodiment of the present invention.

Referring to FIG. 8, the low frequency power supply device 400 according to the embodiment of the present invention includes a voltage boosting unit 410, a voltage adjusting unit 420, a voltage measuring unit 430, and a current measuring unit 440. The device unit 450, the terminal unit 460, the first and second voltage input units 470a and 470b, the power connection units 480a and 480b, the ground unit 490, and the protection circuit unit 500 are included. That is, compared with the low frequency power supply device 20 according to the related art shown in FIG. 2, the protection circuit unit 500 is further configured.

The voltage booster 410 raises the voltage of the power input into the low frequency sputtering device, and the voltage booster 410 may boost 1: 9 by the coil ratio of the transformer. That is, when the input is 220 volts (V) AC, the output can be boosted to 0 to 2000 volts (V) AC.

The voltage controller 420 adjusts the voltage of the power boosted from the voltage booster 410. That is, the voltage adjusting unit 420 has a separate transducer for power control during discharge, and the output range is 0 to 140 volts (AC).

The voltage measuring unit 430 monitors the input power voltage and the boosted power supply voltage to measure the potential difference of the polarity of the transformer boosted by the power supply during discharge. It is preferable to measure this mainly with the volt (V) meter 120, and the output range is AC (AC) 0-1999 volts (V).

The current measuring unit 440 is for measuring the flow of current of the power supply at the time of discharge. This is preferably measured in amperes (A) meter 130, the output range of which is AC (AC) 0-1.999 amps (A). In addition, in the case of a general high frequency (RF) (13.56MHz) sputtering device, a matching box is provided separately for stabilizing complex plasma due to the high frequency, but the embodiment of the present invention uses a commercially available low frequency (LF) of 60 Hz. This eliminates the need for a separate matching box.

The stabilizer unit 450 is installed to prevent overload due to an overcurrent supply when power is supplied. For example, 250V and 5A fuses may be installed.

The terminal portion 460 serves to apply a discharge voltage, and the first and second voltage input portions 470a and 470b provide appropriate voltages, and are the first and second power connection portions 480a and 480b, for example. It may be a connector.

The ground part 490 is for protecting a circuit and generally represents ground.

The protection circuit unit 500 is a variable resistor that stably regulates high current during initial driving of the low frequency power supply device. Specifically, the protection circuit unit 500 is used to remove a short circuit phenomenon due to high voltage during initial discharge, which is a disadvantage of the conventional low frequency power supply device. A protection circuit 500 is further configured at the output of the device. In the embodiment of the present invention, the protection circuit 500 is a variable resistor, and can be adjusted at a value of 50W to 200W and 50ΩJ to 200ΩJ, and values of 100W and 100ΩJ are preferable.

As a result, the low frequency power supply 400 according to the embodiment of the present invention may include the protection circuit 500 to generate an improved plasma due to the stable current supply, and to improve the density due to the multilayering of the same material. It can reduce the surface roughness of the ITO thin film, and can improve the electrical conductivity.

Meanwhile, specific first to third experimental examples according to embodiments of the present invention are as described below, and will be described in comparison with first to third experimental examples according to the prior art.

1st to 3rd Experimental Example

9A and 9B are tables showing the process conditions of the first to third experimental examples for manufacturing the ITO thin film on the PES substrate using the conventional technique and the low frequency sputtering apparatus according to the embodiment of the present invention, respectively.

Referring to FIG. 9A, the first to third experimental examples according to the prior art show experimental conditions for depositing an ITO thin film on a polymer film base using a plasma discharge technique. Here, the vacuum at low frequency sputtering discharge is 2.5 mTorr, argon injection of 25 SCCM, applied voltage of 280 V, frequency of 60 Hz, distance between target and substrate is 100 mm, deposition time is 10 minutes, 15 minutes, and 20 minutes, respectively. The thicknesses of the substrates were 79.2 nm, 118.8 nm and 158.4 nm, respectively. At this time, the conventional experimental example was to produce the ITO thin film with the substrate temperature at room temperature.

Referring to FIG. 9B, experiments for depositing the ITO thin film 130 on the polymer film base 110 as process conditions for the first, second and third experimental examples according to an embodiment of the present invention. Indicates a condition.

In the first to third experimental examples according to the embodiment of the present invention, the silicon oxide film 120 or the multilayer (SiO ₂ / SiO ₂ / SiO ₂ / SiO ₂ ) of the single layer (SiO ₂ ) illustrated in FIGS. 6A and 6B described above. / SiO ₂ ) the ITO thin film 130 is deposited on the polymer film base 110 coated with the silicon oxide films 140a to 140e by using a plasma discharge technique. Here, the vacuum during the low-frequency sputtering discharge was 2.2mTorr, the process was performed with argon injection of 30SCCM, applied voltage of 320V, frequency of 60Hz, distance between the target and the substrate was 100mm, and the deposition time was 10 minutes. In this case, in the first to third experimental examples according to the embodiment of the present invention, the ITO thin film 130 was formed at the substrate temperature at room temperature.

10A and 10B are tables showing surface resistance, 400 nm to 700 nm average light transmittance and surface roughness of the ITO thin films prepared by the conventional techniques and the first to third experimental examples according to the embodiments of the present invention, respectively. to be. Here, sheet resistance represents electrical characteristics, average light transmittance represents optical characteristics, and surface roughness represents structural characteristics, respectively.

Referring to Figure 10a, in the first experimental example according to the prior art, the sheet resistance value is 307Ω / ㎠, 400nm ~ 700nm average light transmittance is 80%, surface roughness value is Ra: 0.754nm, Rms: 1.043nm and Rp-v: measured at 4.435 nm. In the second experimental example according to the prior art, the sheet resistance value is 794 Ω / cm 2, 400 nm to 700 nm average light transmittance is 80%, surface roughness value is Ra: 0.811 nm, Rms: 1.193 nm and Rp-v: 5.711 nm Was measured. In a third experimental example according to the prior art, the sheet resistance value is 57 Ω / cm 2, 400 nm to 700 nm average light transmittance is 79%, surface roughness value is Ra: 0.928 nm, Rms: 1.256 nm and Rp-v: 5.833 nm Was measured. Here, Ra is an average roughness value, Rms is a square mean surface roughness value, and Rp-v represents a surface roughness value represented by the height difference between peak and valley, respectively.

Referring to FIG. 10B, a first experimental example according to an embodiment of the present invention is a polymer film base coated with a silicon oxide layer 140a to 140e of a multilayer (SiO ₂ / SiO ₂ / SiO ₂ / SiO ₂ / SiO ₂ ). The result of coating the ITO thin film 130 on the (110) is shown. Specifically, the sheet resistance value is 107 Ω / cm 2, 400 nm to 700 nm average light transmittance is 77%, and the surface roughness value is Ra: 1.27 nm, Rms: 1.58 Nm, Rp-v: measured at 8.55 nm.

The second experimental example according to the embodiment of the present invention shows a result of coating the ITO thin film 130 on the polymer film substrate 110 coated with the single layer (SiO ₂ ) silicon oxide film 120, and specifically, the sheet resistance value. Silver 164 Ω / cm 2, average light transmittance of 400 nm to 700 nm were 80%, and surface roughness values of Ra: 1.82 nm, Rms: 2.24 nm, and Rp-v: 11.59 nm.

According to the third experimental example according to the embodiment of the present invention, as a result of coating the ITO thin film 130 on the polymer film substrate 110, the sheet resistance value is 115 Ω / cm 2, 400 nm to 700 nm average light transmittance is 79%, and surface roughness. The value was measured as Ra: 1.33 nm, Rms: 1.66 nm and Rp-v: 8.79 nm.

Therefore, according to the measurement results of the first to third experimental examples according to the embodiment of the present invention, the ITO thin film 130 prepared by each experimental example is used as a transparent electrode inside the display device, respectively, electrical, optical and structure It can be seen that a typical measurement result shows an appropriate value. In this case, the electrical value, the optical value, and the structural value may vary depending on the parameters applied to the low frequency power source 500 and the sputtering device 200, and thus, appropriate conditions should be considered.

For example, the smaller the sheet resistance value is, the better the average light transmittance is, and the smaller the surface roughness value is, the better.

As a result, it can be seen that the measurement result according to the first experimental example according to the embodiment of the present invention shows better results in the electrical evaluation and the structural evaluation than the measurement results in the second and third experimental examples.

This is because, due to the characteristics of the plasma discharge, in the case of the multilayer silicon oxide films 140a to 140e in which the same material is divided and deposited several times, rather than the thick single layer silicon oxide film 120 structure, the particle density becomes high, thereby And it can be seen that the structural measurement results show satisfactory results. The electrical and structural aspects of the multilayer silicon oxide films 140a to 140e are closely related to the orientation of the particles.

Meanwhile, embodiments of the present invention can form an ITO thin film on a polymer substrate at a low deposition temperature such that high light transmittance, smooth and excellent adhesion to the substrate, and at the same time there is no deformation of the polymer substrate. The ITO thin film manufactured as described above may be used in a transparent conductive electrode for various display devices or a touch panel.

For example, a typical 4-wire touch panel (Touch Panel) is a structure that overlaps the glass and the film, the inside of the overlapping conductive material, that is, ITO is coated so that the current flows well, and the silver electrode on the glass and the conductive material Formed. At this time, according to an embodiment of the present invention, the touch panel is manufactured to form a transparent conductive layer, for example, an ITO thin film on a glass substrate or on various polymer film substrates, and to have the structure to operate the conductive layer as an electrode. do.

In addition, the ITO thin film according to an embodiment of the present invention can be manufactured in a small to large area roll-to-roll (Roll To Roll) method, where the roll-to-roll (Roll To Roll) method is to use a roll wound The roll-to-roll method overcomes problems such as reduced production and increased processing time of the existing sheet method, and reduces processing time, manpower and cost.

The description of the present invention is for the purpose of illustration, and it will be understood by those skilled in the art that the present invention may be easily modified in other specific forms without changing the technical spirit or essential features of the present invention. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

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

1A is a process flowchart of a method for manufacturing an ITO thin film for a transparent electrode according to the related art, and FIG. 1B is a cross-sectional view of a glass substrate manufactured by the method of FIG. 1A.

2 is a block diagram of a low frequency power supply device in a low frequency sputtering apparatus for manufacturing an ITO thin film for a transparent electrode according to the prior art.

3 is a process flowchart of a method of manufacturing an ITO thin film on a glass substrate by low frequency sputtering discharge according to an embodiment of the present invention.

4 is a process flowchart of a method of manufacturing an ITO thin film on a polymer film by low frequency sputtering discharge according to an embodiment of the present invention.

FIG. 5 is a cross-sectional view illustrating the manufacture of an ITO thin film on a PET (PolyEthyleneTerephthalate) film base coated with a single layer silicon oxide film (SiO ₂ ) according to an exemplary embodiment of the present invention.

FIG. 6 is a cross-sectional view illustrating the manufacture of an ITO thin film on a PET (PolyEthyleneTerephthalate) film base coated with a multilayer silicon oxide film (SiO ₂ / SiO ₂ / SiO ₂ / SiO ₂ / SiO ₂ ) according to an embodiment of the present invention. .

7 is a configuration diagram of a low frequency sputtering apparatus according to an embodiment of the present invention.

8 is a configuration diagram of a low frequency power supply having a protection circuit in a low frequency sputtering apparatus according to an embodiment of the present invention.

9A and 9B are tables showing the process conditions of the first to third experimental examples for manufacturing an ITO thin film on a PES substrate using the conventional technique and the low frequency sputtering apparatus according to the embodiment of the present invention, respectively.

10A and 10B are tables showing surface resistance, 400 nm to 700 nm average light transmittance, and surface roughness of the ITO thin films prepared by the conventional techniques and the first to third experimental examples according to the embodiments of the present invention, respectively.

<Brief Description of Drawings>

110: PET film matrix 120: single layer silicon oxide film

130: ITO thin film 140a ~ 140e: multilayer silicon oxide film

200: low frequency sputtering device

210a and 210b: first and second shutters 220: turbomolecular pump

230a, 230b: permanent magnet 240a: argon gas supply control unit

240b: oxygen gas supply adjusting unit 250a, 250b: first and second substrate units

260: monitoring unit 270: chamber

280a and 280b: first and second substrate heating units 290: motor

310a, 310b: first and second targets 320: rotary pump

400: low frequency power supply

410: voltage transformer 420: voltage regulator

430: voltage measuring unit 440: current measuring unit

450: stabilizer portion 460: terminal portion

470a and 470b: first and second voltage inputs

480a and 480b: first and second power connection portions 490: grounding portion

500: protection circuit part (variable resistor)

Claims (13)

In the method of manufacturing an indium tin oxide (ITO) thin film for transparent electrodes using a low frequency sputtering apparatus, a) coating a silicon oxide film on a matrix; b) mounting the substrate coated with the silicon oxide film on the low frequency sputtering device; c) generating power using the low frequency power supply device having a protection circuit which stabilizes the initial discharge voltage in the low frequency sputtering device; d) sputtering discharge on said silicon oxide film-coated base using indium and tin oxide as targets; And e) depositing an ITO thin film on the silicon oxide film-coated base by the sputtering discharge at room temperature ITO thin film manufacturing method for a transparent electrode comprising a. The method of claim 1, The base of step a) is a polymer film (Polymer film) or glass (Glass) substrate, characterized in that the ITO thin film manufacturing method for a transparent electrode. The method of claim 2, The polymer film is a method for producing a transparent electrode ITO thin film, characterized in that any one selected from the group consisting of PES (PolyEtherSulfone), PC (PolyCarbonate), PET (PolyEthylene Terephthalate) and PEN (PolyEthyleneNaphthalate). The method of claim 1, The silicon oxide film of step a) is a single layer silicon oxide film (SiO ₂ ) or a multilayer silicon oxide film (SiO ₂ / SiO ₂ / SiO ₂ / SiO ₂ / SiO ₂ ) characterized in that the ITO thin film manufacturing method for a transparent electrode. The method of claim 4, wherein The silicon oxide film is a transparent electrode ITO thin film manufacturing method characterized in that the coating on the base in one or both sides. The method of claim 2, When the ITO thin film of step e) is coated on the polymer film substrate, the ITO thin film manufacturing method for a transparent electrode, characterized in that it has an average light transmittance of at least 77% with respect to the wavelength 400nm to 700nm. The method of claim 2, When the ITO thin film of step e) is coated on the polymer film substrate, ITO thin film manufacturing method for a transparent electrode, characterized in that it has a sheet resistance of 20 ~ 2000 Ω / ㎠. The method of claim 2, When the ITO thin film of step e) is coated on the polymer film matrix, the average roughness value (Ra) is 0.7-2 nm, the squared average surface roughness value (Rms) is 0.7-2 nm, and the peak (Peak) The surface roughness value (Rp-v) shown by the height difference of a valley is 1-20 nm, The manufacturing method of the ITO thin film for transparent electrodes characterized by the above-mentioned. The method of claim 1, The ITO thin film of step e) is ITO thin film manufacturing method for a transparent electrode, characterized in that formed from a small to large area roll to roll film manufacturing process. The method of claim 1, The protective circuit of step c) is a variable resistance for the ITO thin film manufacturing method characterized in that the variable resistor for stably adjusting the high current during the initial drive of the low-frequency power supply. ITO thin film for transparent electrodes manufactured by the manufacturing method of any one of Claims 1-10. A touch panel comprising an ITO thin film for transparent electrodes manufactured by the manufacturing method of any one of claims 1 to 10. An organic electroluminescent device comprising an ITO thin film for transparent electrodes prepared by the method of any one of claims 1 to 10.

Images