KR100546632B1 - A multi-layered ito for transparent electrode using both ion-beam sputtering and dc-sputtering, method for manufacturing the same and apparatus for manufacturing the same - Google Patents

Abstract

According to the present invention, an ITO composite layer for transparent electrodes having a very high deposition rate and flat surface roughness, wherein ion beam sputtering is deposited on the glass substrate with a sputtering gas supplied from an ion source with an oxygen atmosphere on the glass substrate. A first ITO layer having a first thickness; And an ITO composite layer for transparent electrodes, a copper deposition method, and a copper deposition apparatus including a second ITO layer having a second thickness that is DC sputter deposited on the first ITO layer.

ITO, Ion Beam Sputtering Deposition, DC Sputtering Deposition, Grain

Description

I multi-layered ITO for transparent electrode using both Ion-beam sputtering and DC-sputtering, method for manufacturing the same and apparatus for manufacturing the same}             

1 is a schematic view showing the overall configuration of an ITO composite layer deposition apparatus of the present invention.

2 is a schematic view showing the configuration of an ion beam sputtering evaporation section of the present invention.

3 is a schematic view showing the configuration of the DC sputtering deposition unit of the present invention.

4 is a configuration diagram showing a longitudinal section of the ITO composite layer for transparent electrodes according to the present invention.

5 is a photograph showing the surface of the grain structure of the ITO composite layer for transparent electrodes according to the present invention.

6 is a photograph showing the surface of the domain structure of the ITO composite layer for transparent electrodes according to the conventional DC sputter deposition method.

FIG. 7 is a graph in which the transparent electrode ITO composite layer according to the present invention and the transparent electrode ITO layer according to the conventional DC sputter deposition method are analyzed by XRD.

8 is an AFM analysis photograph of a domain structure of an ITO film according to a conventional DC sputter deposition method.

9 is an AFM analysis photograph of the grain structure of the ITO composite layer according to the present invention.

10 is a photograph analyzing the transmittance of the grain structure of the ITO composite layer according to the present invention.

The present invention relates to an ITO composite layer and a copper deposition method for forming a transparent conductive film used in the manufacture of a screen display device, and more particularly, a first ITO layer having a first thickness of ion beam sputter deposited on a glass substrate, and the first deposition method. 1 relates to an ITO composite layer for a transparent electrode, a copper deposition method and a copper deposition apparatus including a second ITO layer having a second thickness deposited on a ITO layer.

 Recently, flat panel displays (FPDs), such as liquid crystal displays (LCDs) and organic light emitting diodes (OLEDs), which are thinner and lighter than cathode ray tubes (CRTs), Application as a screen display device is increasing, and the demand of the transparent electrode used as a pixel electrode is also increasing. The transparent electrode should be a material having a low specific resistance and at the same time having a high visible light transmittance.

 Currently, oxide semiconductors are generally used as transparent electrodes, and indium tin oxide (ITO) thin films doped with tin are mainly liquid crystal displays (LCDs) and plasma panel displays ( It is widely used in flat panel display fields such as plasma display panel (PDP) and organic light emitting diode (OLED). This is because the film has the lowest specific resistance, can be deposited at a relatively low temperature (below 200 ° C.), has a high transmittance of visible light, and has an advantage of easy wet etching.

In particular, OLED, a next-generation flat panel display, has been spotlighted as a next-generation flat panel display due to its self-luminous characteristics, driving at low voltage, fast response speed, low power consumption, and wide viewing angle. However, since OLED uses a current driving method, charge builds up at the protruding end of the electrode surface, and sparks easily occur, which causes the device to be deteriorated or damaged by electric shock.

Therefore, the planarized surface characteristics of the ITO thin film used as the anode electrode of the organic EL have become very important along with the electrical (low resistance) and optical characteristics.

The flat surface characteristics of the ITO thin film are greatly influenced by the crystal structure of the ITO thin film. The crystal structure of the ITO thin film is largely divided into a domain structure and a grain structure. The domain structure consists of a number of domains (one sub-domain has the same crystal orientation and crystal plane) and the corresponding boundary planes, and the grain structure consists of a large number of grain boundaries without domain boundaries. ) The grains of the grain structure have the same crystal plane and crystal direction.

Looking at the characteristics of the crystal structure of the ITO film, first, the domain structure has a height difference along the domain interface because each sub-domain has a structure different from the crystal plane and the crystal direction is separated by the interface. Roughness becomes high.

Next, since the grain structure is entirely in the same crystal plane and crystal direction, the surface of which the energy is stable (222) is generated over the entire surface, resulting in a structure having almost no surface roughness. Therefore, the crystal structure most suitable for the requirements of the OLED is a grain structure with low roughness.

Conventional methods for depositing such an ITO thin film on a substrate include ion beam sputtering, DC-sputtering, RF-sputtering, and electron beam evaporation. Physical vapor deposition, such as reactive evaporation, and chemical vapor deposition, such as sol-gel and spray pyrolysis, have been used.

The conventional deposition method of the ITO electrode using only ion beam sputtering has a problem that the deposition rate is very low and the surface roughness is not satisfactory. Due to the low deposition rate, it was not practical to apply the deposition method of ITO electrode using only ion beam sputtering in mass production.

On the other hand, the conventional DC sputtering method is very advantageous in productivity because the deposition rate is very high, but the crystal structure of the ITO layer forms a domain structure, and the surface flatness is very bad. Had the problem.

SUMMARY OF THE INVENTION An object of the present invention is to provide an ITO composite layer for transparent electrodes, a copper deposition method, and a copper deposition apparatus, which have a very good deposition rate and a flat surface roughness.

In order to achieve the above object, the ITO composite layer for transparent electrodes according to the present invention,

A first ITO layer which is ion-sputtered and sputter-deposited on the glass substrate with a sputtering gas supplied from an ion source with the atmosphere on the glass substrate as an oxygen atmosphere;

And a second ITO layer deposited by DC sputter deposition on the first ITO layer.

The thickness of the first ITO layer is characterized in that it is thinner than the thickness of the second ITO layer.

The sputtering gas used for the first ITO layer and the second ITO layer is an argon gas, respectively.

Preferably, when making the total thickness which combined the said 1st thickness and the said 2nd thickness into 1500 kPa, the said 1st thickness shall be 50-300 kPa, and the 2nd thickness may be 1200-1450 kPa.

If the ratio of the said 1st thickness and said 2nd thickness with respect to the said total thickness is maintained as it is, the 1st thickness and the 2nd thickness can be set also about another whole thickness.

Preferably, the first ITO layer has a grain structure grown in the [111] direction of the (222) plane, and the second ITO layer is formed in the same manner as the first ITO layer along the first ITO layer ( 222) has a grain structure grown in the [111] direction of the plane.

ITO composite layer deposition method for a transparent electrode according to the present invention,

Depositing a first ITO layer of a first thickness on the glass substrate at a first deposition rate with a sputtering gas supplied from an ion source with the atmosphere on the glass substrate as an oxygen atmosphere; And

DC sputter depositing a second ITO layer of a second thickness on said first ITO layer at a second deposition rate.

The sputtering gas used in the first step and the second step is argon gas, respectively.

Preferably, the first ITO layer has a grain structure grown in the [111] direction of the (222) plane,

The second ITO layer also has a grain growth structure grown in the [111] direction of the (222) plane of the first ITO layer.

Preferably, the first deposition rate is 2.5 ~ 4.5 dl / s and the second deposition rate is 200 ~ 400 dl / s.

Preferably, when the total thickness obtained by adding the first thickness and the second thickness is 1500 kPa, the first thickness is 50 to 300 kPa, and the second thickness is 1200 to 1450 kPa.

The first thickness to the total thickness is independent of the ratio with the second thickness, and the first thickness means a preferred thickness capable of having a grain structure of the substrate. Therefore, the second thickness is independent of the first thickness ratio, and the thickness of the second ITO layer can be changed as much as possible in consideration of other characteristics such as the use of the substrate, resistance, and transmittance.

According to the present invention, an ITO composite layer deposition apparatus for a transparent electrode,

A first ITO layer deposition unit for depositing a first ITO layer having a first thickness on the surface of the glass substrate with a sputtering gas supplied from an ion source with the atmosphere on the glass substrate as an oxygen atmosphere;

A second ITO layer deposition unit for depositing a second ITO layer having a second thickness by DC sputter deposition on the surface of the first ITO layer; And

And a buffer unit configured to guide the substrate, which is ion beam sputter deposited by the first ITO layer deposition unit, to the second ITO layer deposition unit.

Sputtering gases used in the first ITO layer deposition unit and the second ITO layer deposition unit are each an argon gas.

Preferably, when making the total thickness which combined the said 1st thickness and the said 2nd thickness into 1500 kPa, the said 1st thickness shall be 50-300 kPa, and the 2nd thickness may be 1200-1450 kPa.

The first thickness to the total thickness is independent of the ratio with the second thickness, and the first thickness means a preferred thickness capable of having a grain structure of the substrate. Therefore, the second thickness is independent of the first thickness ratio, and the thickness of the second ITO layer can be changed as much as possible in consideration of other characteristics such as the use of the substrate, resistance, and transmittance.

The first ITO layer is first grown in the [111] direction of the (222) plane.

The buffer unit serially connects the first ITO layer deposition unit and the second ITO layer deposition unit, and sequentially converts the vacuum to the front and rear stages using an independent buffer chamber.

 Preferably, the buffer unit uses a buffer chamber and gates are disposed at both ends of the connection unit to move the substrate advanced in the first ITO layer deposition unit to the buffer chamber by opening the front gate of the buffer chamber and closing the gate. Inert gas (argon) is injected in accordance with the working vacuum degree of the second ITO layer deposition unit to make the same vacuum degree as the second ITO layer deposition unit, and the rear gate is opened to move the substrate to the second ITO layer deposition unit, and then the rear gate is closed. The vacuum degree of the buffer chamber is converted by the same method to the same vacuum degree as that of the first ITO layer deposition part in order to receive the substrate of the first ITO layer deposition part. Due to this continuous operation, the first ITO layer deposition unit and the second ITO layer deposition unit may be continuously operated despite the different working vacuum degrees.

(Example)

Hereinafter, a preferred embodiment according to the present invention will be described with reference to FIGS.

 1 is a schematic view showing the overall configuration of an ITO composite layer deposition apparatus for a transparent electrode according to an embodiment of the present invention. As shown in FIG. 1, a loader unit 10 for loading a substrate, an ion gun deposition unit 20 for depositing a first ITO layer using an ion gun on a surface of the loaded substrate, and an ion gun deposition unit ( 20. The substrate 30 coated with the buffer unit 30 and the first ITO layer waited in the buffer unit 30 are temporarily accepted for charging the substrate having passed through the DC sputtering deposition unit 40. A DC sputtering deposition unit 40 for depositing a second ITO layer on the ITO layer, and an unloader unit 5 for receiving a substrate after depositing the second ITO layer in the deposition unit 40.

In FIG. 1, the first ITO layer deposition unit 20, which forms a first ITO layer having a first thickness by ion beam sputter deposition on a glass substrate input from the loader unit 10, has an ECR (Electron Cyclotron Resonance) ion beam sputtering. A vapor deposition apparatus is used.

The second ITO layer deposition unit 40 for forming a second ITO layer having a second thickness by DC sputter deposition on the surface of the first ITO layer formed on the glass substrate passing through the buffer unit uses a DC magnetron sputter deposition apparatus. .

FIG. 2 is a schematic diagram illustrating a configuration of the first ITO layer deposition unit 20 of FIG. 1.

The first ITO layer deposition unit 10 is a vacuum chamber 12 for providing a sealed space for depositing the first ITO layer adjacent to the lower portion of the glass substrate with respect to the glass substrate 21 that is linearly horizontally moved. ), A heating heater 13 spaced apart at a predetermined distance from the upper portion of the glass substrate in parallel to the substrate direction, and installed on one of the walls perpendicular to the glass substrate among the walls of the chamber 12 to generate an ion beam. ECR ion source 14 to be generated, a vacuum pump 15 installed on the wall of the chamber 12 opposite the ECR ion source 14, is installed inside the lower end of the chamber to fix the target 16 A target holder 17 which is rotatable at an angle and a target 16 having the same chemical composition as the ITO film to be deposited and supported by the target holder are included.

The ion gun used in the first ITO layer deposition unit has a relatively linear oscillation area of the ion beam, advantageous for beam profile control, linear ion source, and a rectangular two-stage grid in the oscillation part of the ion beam. It uses an ECR ion gun installed to accelerate ions.

As a process variable, the working vacuum degree of the first ITO layer deposition unit is about 10 ⁻⁴ Torr and O ₂ is used as the working gas Ar and the reactive gas. The working temperature of the first ITO layer deposition unit is set to 200 ~ 350 ℃ level.

In the deposition procedure of the first ITO layer deposition unit, after argon gas is ionized by the ECR effect, ionized argon cations are oscillated toward the target 16. The oscillated argon cations collide with the surface of the target 16 with an energy of about 500 to 900 eV, and the impact causes the physical force to be applied to the target 16 and the atoms of the target 16 are bounced by the physical force. I'm going. Atoms of the target 16 bounced out collide with the glass substrate 21 input through the loader unit 10 and are deposited on the glass substrate 21 while being sequentially deposited on the glass substrate 21 (222). The first ITO layer having a thickness of 50 to 300 mW is formed at a deposition rate of 2.5 to 4.5 mW / s. At this time, atoms of the target 16 having hundreds of eV energy are deposited on the glass substrate 21 supplied with sufficient thermal energy in the oxygen atmosphere flowing near the glass substrate 21. During the continuous operation, the injected oxygen chemically reacts with the target atom deposited on the glass substrate 21, and at the same time, some oxygen atoms are anionized to apply physical force to the surface of the substrate. It is due to the electrical and crystallographic properties due to the interaction of the above conditions.

Next, the buffer unit 31 is installed in the buffer unit 30, and gates 32a and b are provided at both ends of the connection unit to serve as a buffer unit. The working vacuum degree of the second ITO layer deposition unit 40 after the substrate advanced in the first ITO layer deposition unit 20 is moved to the buffer chamber by opening the front gate 32a of the buffer chamber 31 and closing the gate 32a. After injecting an inert gas (argon) into the same vacuum as that of the second ITO layer deposition unit, the rear gate 32b is opened to move the substrate to the second ITO layer deposition unit 40, and then the rear gate 32b is moved. Close it. The vacuum degree of the buffer chamber 31 is converted by the same method to the same vacuum degree as that of the first ITO layer deposition unit 20 in order to receive the substrate of the first ITO layer deposition unit 20. Due to this continuous operation, the glass substrate on which the first ITO layer is formed is sent to the second ITO layer deposition unit 40.

FIG. 3 is a schematic diagram illustrating a configuration of the second ITO layer deposition unit 40, that is, the DC sputter deposition unit, which is schematically shown in FIG. 1.

The second ITO layer deposition unit 40 includes a vacuum chamber 41 as the second ITO layer forming chamber, vacuum control means (not shown) for controlling the vacuum state in the vacuum chamber 41, and DC high pressure for plasma discharge. Sputtering cathode portion 42 connected to the DC high voltage power supply via the power supply and power line, a sputtering gas supply portion for supplying a working gas such as a pallet and Ar positioned opposite to the sputtering cathode portion formed in a manner spaced apart by a predetermined distance to the vacuum chamber ( (Not shown), the sputtering cathode portion 42 includes an ITO target plate 42a, a backing plate 42b and a permanent magnet 42c and the target plate 42a is on the backing plate 42b. It is fixedly disposed and the permanent magnet 42c is disposed behind the backing plate 42b.

As the process variable, the working vacuum is about 10 ^-3 Torr and the working gas Ar and the reactive gas O ₂ are used. The working temperature of the second ITO layer deposition unit is set to 200 to 350 ° C.

Referring to the deposition procedure of the second ITO layer deposition unit, the permanent magnet 42c forms a magnetic field on the upper end of the ITO target plate 42a and applies a negative voltage to the cathode 42 which is the cathode at DC power. The injected argon gas is ionized near the formed magnetic field. This mild argon cation accelerates and rushes in the cathode with negative voltage. The accelerated argon cation impinges on the surface of the ITO target plate 42a attached to the cathode. At this time, the atoms of the target are bounced off by the collision energy in the opposite direction of the collision, i.e., in the direction of the first ITO layer passing through the first deposition portion. The deposition is performed by the continuous operation to form a second ITO layer having a thickness of 1200 to 1450 kW continuously grown in the [111] direction on the (222) plane on the first ITO layer at a deposition rate of 200 to 400 kW / s. As can be seen here, the deposition rate of the second ITO layer is about 100 times the deposition rate of the first ITO layer.

The targets used in the first ITO layer deposition unit 20 and the second ITO layer deposition unit 40 are mainly 9% by weight of 99.99% containing 4 wt% of In ₂ 0 ₃ and Sn ₂ O _{3 in a} weight percent ratio (4 ITO of more than nine) is used, and the weight percentage ratio may be different depending on the device characteristics and the function of the thin film.

6 shows the structure of the ITO composite layer for transparent electrodes according to the present invention and FIG. 5 showing the structure of the ITO layer deposited using a conventional DC sputtering deposition method.

The ITO film deposited by the conventional DC sputtering deposition method shows a domain structure with a large surface roughness, whereas the ITO composite layer deposited according to the present invention exhibits a crystal structure with excellent surface flatness.

In addition, XRD analysis results of the ITO film deposited by the conventional DC sputtering deposition method and the crystal structure of the ITO composite layer deposited according to the present invention, Figure 7 shows the XRD analysis results for the composite ITO film according to the present invention In view of the superior peak value on the (222) plane and no other peak, it can be seen that almost all target atoms are deposited on the (222) plane in the [111] direction. In contrast, the ITO film formed by the conventional DC deposition method not only has a peak on the (222) plane but also a peak on the (400), (440) plane, etc., so that it does not appear to grow first on a specific surface in a specific direction. At this time, it can be seen that the deposition layer deposited only by the conventional DC sputter deposition method has a domain structure and is inferior in surface roughness.

In the present invention, since most of the first ITO layer and the second ITO layer are grown in the [111] direction on the (222) plane, the deposition surface and the deposition direction of the first ITO layer are deposited on the deposition surface of the second ITO layer. It can be seen that the direction was determined, and that the deposition rate of the second ITO layer is about 100 times the deposition rate by the deposition method using ion beam sputtering, the method of the present invention is stable in terms of energy and has the highest roughness ( As the grains grow in the [111] direction on the 222) plane, an excellent deposition rate can be obtained.

In addition, comparing the results of the AFM (Atomic force microscope) of the domain structure formed by the conventional DC deposition method of Figure 8 and the AFM measurement results of the grain structure of the present invention of Figure 9, the ITO composite layer according to the present invention It shows that surface roughness is greatly improved.

Fig. 10 shows that the ITO composite layer deposited by the method according to the present invention has a high value almost equal in terms of transmittance as compared to ITO deposited by the conventional DC deposition method. In short, it is understood that the ITO composite layer according to the present invention significantly improves productivity and surface properties while maintaining almost the same level of electrical and optical properties as compared to the ITO film when the conventional DC deposition or ion beam deposition is applied alone. Can be.

According to the present invention, the effect of the first ITO layer grown in the [111] direction on the (222) plane by the ion beam sputter deposition method is grown on the first ITO layer and the (222) direction in the [111] direction, thereby providing an excellent surface. A flatness can be obtained, and an excellent ITO composite layer, a copper deposition method, and a copper deposition apparatus can be obtained in which the deposition rate of the second ITO layer is drastically improved than the conventional ion beam sputter deposition rate, thereby solving the productivity problem.

Embodiments of the invention are merely exemplary, and various changes, additions and substitutions may be made by those skilled in the art without departing from the scope and spirit of the invention as set forth in the appended claims.

Claims (16)

A first ITO layer having a first thickness sputtered on the glass substrate with a sputtering gas supplied from an ion source in an atmosphere of an oxygen atmosphere on the glass substrate; And An ITO composite layer for transparent electrodes comprising a second ITO layer of a second thickness deposited by DC sputter deposition on said first ITO layer. The ITO composite layer for transparent electrodes according to claim 1, wherein the sputtering gas used for the first ITO layer and the second ITO layer is an argon gas, respectively. The ITO composite layer for transparent electrodes according to claim 1, wherein the second ITO layer has a grain structure. The ITO composite layer for transparent electrodes according to claim 1, wherein both the first ITO layer and the second ITO layer have a grain structure grown in the [111] direction on the (222) plane. The ITO composite layer for transparent electrodes according to claim 1, wherein the first thickness is 50 to 300 GPa and the second thickness is 1200 to 1450 GPa. Depositing a first ITO layer of a first thickness on the glass substrate at a first deposition rate with a sputtering gas supplied from an ion source with the atmosphere on the glass substrate as an oxygen atmosphere; And DC sputtering deposition of a second thickness of the second ITO layer of the second thickness on the first ITO layer at a second deposition rate. 7. The method for depositing an ITO composite layer for a transparent electrode according to claim 6, wherein the sputtering gas used in the first step and the second step is an argon gas, respectively. The method of claim 6, wherein the first ITO layer has a grain structure grown in the [111] direction of the (222) plane. The method of claim 6, wherein the second ITO layer has a grain structure grown in the [111] direction of the (222) plane of the first ITO layer. The method of claim 6, wherein the first deposition rate is 2.5 to 4.5 kW / s and the second deposition rate is 200 to 400 kW / s. 7. The method for depositing an ITO composite layer for transparent electrodes according to claim 6, wherein the first thickness is 50 to 300 GPa and the second thickness is 1200 to 1450 GPa. A first ITO layer deposition unit for sputtering and depositing an ion beam onto a first ITO layer having a first thickness on the glass substrate with a sputtering gas supplied from an ion source in an atmosphere of an oxygen atmosphere on the glass substrate; A second ITO layer deposition unit for depositing a second ITO layer having a second thickness by DC sputter deposition on the surface of the first ITO layer; And And a buffer unit for guiding the ion beam sputter deposited by the first ITO layer deposition unit to the second ITO layer deposition unit. 13. The ITO composite layer deposition apparatus for a transparent electrode according to claim 12, wherein the sputtering gas used in the first ITO layer deposition unit and the second ITO layer deposition unit is an argon gas, respectively. The ITO composite layer deposition apparatus of claim 10, wherein the buffer unit connects the first ITO layer deposition unit and the second ITO layer deposition unit in series. The ITO composite layer deposition apparatus of claim 10, wherein the buffer unit guides the glass substrate, which is ion beam sputter deposited by the first ITO layer deposition unit, to the second ITO layer deposition unit using an independent buffer chamber. The ITO composite layer deposition apparatus for a transparent electrode according to claim 10, wherein the first thickness is 50 to 300 GPa, and the second thickness is 1200 to 1450 GPa.

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