WO2014017793A1 - Method for forming metal particle layer, and light-emitting element produced using same - Google Patents

Method for forming metal particle layer, and light-emitting element produced using same Download PDF

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Publication number
WO2014017793A1
WO2014017793A1 PCT/KR2013/006540 KR2013006540W WO2014017793A1 WO 2014017793 A1 WO2014017793 A1 WO 2014017793A1 KR 2013006540 W KR2013006540 W KR 2013006540W WO 2014017793 A1 WO2014017793 A1 WO 2014017793A1
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Prior art keywords
acid
metal
light emitting
indium
layer
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PCT/KR2013/006540
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French (fr)
Korean (ko)
Inventor
한희
김경준
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주식회사 엘지화학
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Priority to JP2015501606A priority Critical patent/JP5876189B2/en
Priority to US14/405,113 priority patent/US10161046B2/en
Priority to CN201380037834.3A priority patent/CN104769733B/en
Priority claimed from KR1020130086065A external-priority patent/KR101548420B1/en
Publication of WO2014017793A1 publication Critical patent/WO2014017793A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/02—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2933/00—Details relating to devices covered by the group H01L33/00 but not provided for in its subgroups
    • H01L2933/0091—Scattering means in or on the semiconductor body or semiconductor body package

Definitions

  • the present invention relates to a method of forming a metal layer having an uneven structure by a simpler method and a method of manufacturing a light emitting device capable of improving light extraction efficiency using the same.
  • a light emitting device is a semiconductor device that generates light by flowing a current through a PN junction in a forward direction.
  • Light emitting devices using semiconductors are attracting attention in next-generation lighting equipment applications because they have high efficiency for converting electrical energy into light energy, have a long lifespan of more than 5 to 10 years, and can greatly reduce power consumption and maintenance costs. .
  • a sapphire substrate is mainly used for growing a gallium nitride compound semiconductor for manufacturing a light emitting device.
  • a low-power gallium nitride-based light emitting device is fabricated by placing a sapphire substrate with a crystal structure on a lead frame and then connecting two electrodes to the top.
  • the sapphire substrate is thinned to a thickness of about 80 microns or less and attached to the lead frame. Since the thermal conductivity of the sapphire substrate is about 50 W / m ⁇ K, even if its thickness is about 80 microns, the thermal resistance is very large, so that it is difficult to obtain a desired heat emission specification.
  • a flip chip bonding method is used to further improve heat dissipation characteristics.
  • Flip chip bonding inverts a chip made of a light emitting diode structure to a submount such as a silicon wafer (thermal conductivity of about 150 W / m ⁇ K) having excellent thermal conductivity or an AlN ceramic substrate (180 W / m ⁇ K of thermal conductivity).
  • a submount such as a silicon wafer (thermal conductivity of about 150 W / m ⁇ K) having excellent thermal conductivity or an AlN ceramic substrate (180 W / m ⁇ K of thermal conductivity).
  • heat dissipation efficiency may be improved than when heat is released through the sapphire substrate.
  • the degree of improvement is not satisfactory and the manufacturing process is complicated. .
  • a vertical LED manufactured by removing a sapphire substrate has been attracting attention.
  • Vertical LEDs can be manufactured by removing and packaging the sapphire substrate by a laser lift-off (LLO) method from the light emitting structure and are known to have the best heat dissipation efficiency.
  • LLO laser lift-off
  • the laser lift-off method has an advantage in that the manufacturing process is simple, unlike the flip chip bonding method.
  • the light emitting area is about 60% of the chip area, whereas in the case of the vertical LED with the sapphire substrate removed, the light emitting area is about 90% of the chip area. Excellent properties.
  • the vertical LED with the sapphire substrate removed shows a lower light extraction efficiency than the conventional light emitting device because of the following reasons.
  • a light emitting device is fabricated by covering an LED structure from which a sapphire substrate is removed and a molding material such as epoxy or a molding material mixed with phosphors.
  • a molding material such as epoxy or a molding material mixed with phosphors.
  • GaN gallium nitride
  • a large portion of is not emitted to the outside but totally reflected and then proceeds toward the light emitting structure again and disappears.
  • the refractive index of gallium nitride is about 2.6, if the refractive index of the molding material is assumed to be about 1.5, the amount of light totally reflected at the bonding surface of the two materials is about 9%, which requires much improvement in light extraction efficiency.
  • an object of the present invention is to provide a method for forming a metal layer having a concave-convex structure in a simpler process and a light emitting device that can improve the light extraction efficiency using the same. .
  • Base material that can be oxidized to generate electrons
  • the substrate is oxidized by the organic acid activator to generate electrons
  • the metal particle layer may have a nano-sized uneven structure.
  • the irregularities may be one having a height of 10 to 1,000nm.
  • the substrate may include one or more selected from the group consisting of indium, tin, zinc, aluminum, gallium, antimony, iridium, ruthenium, nickel, silver, and gold.
  • the substrate may further include removing a metal oxide film formed by meeting oxygen in air.
  • the forming of the metal particle layer may be performed by immersing the substrate in the activation solution one or more times.
  • the metal compound is any one selected from the group consisting of metal salts, metal oxides and metal hydrates including palladium, silver, gold, copper, gallium, titanium, tantalum, ruthenium, tin, platinum or alloys thereof. It may contain the above.
  • the concentration of the metal compound in the activation solution may be 0.001 to 5g / L.
  • the organic acid activator may be an organic acid having 1 to 10 carbon atoms.
  • the organic acid activator citric acid (citric acid), oxalic acid (oxalic acid), malonic acid (malonic acid), malic acid (malic acid), tartaric acid, acetic acid (acetic acid), fumaric acid (fumaric acid) , Lactic acid, formic acid, propionic acid, propionic acid, butyric acid, iminodiacetic acid, glyoxylic acid and ascorbic acid It may include any one or more selected from the group.
  • the organic acid activator may be aliphatic polycarboxylic acid having 2 to 10 carbon atoms.
  • the complexing agent may include any one or more selected from the group consisting of HCl, HF, and NHF 3 .
  • the activation solution may further include an alkylene glycol monoalkyl ether.
  • the present invention also provides a device comprising a metal particle layer made of metal particles precipitated by reduction of a metal compound, prepared by the above-described method.
  • a light emitting device in which a light emitting structure, an electrode layer, and a metal particle layer are sequentially formed on a substrate, wherein the metal particle layer is formed of metal particles precipitated by reduction of a metal compound according to the above-described method.
  • a light emitting device is provided.
  • the light emitting structure may have a structure in which the n-type semiconductor layer / active layer / p-type semiconductor layer is sequentially stacked.
  • the electrode layer is indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium aluminum zinc oxide (IAZO), indium gallium zinc oxide (IGZO), Using at least one selected from the group consisting of indium gallium tin oxide (IGTO), aluminum zinc oxide (AZO), antimony tin oxide (ATO), gallium zinc oxide (GZO), IrOx, RuOx, Ni, Ag, and Au It may be formed.
  • ITO indium tin oxide
  • IZO indium zinc oxide
  • IZTO indium aluminum zinc oxide
  • IAZO indium aluminum zinc oxide
  • IGZO indium gallium zinc oxide
  • IrOx IrOx
  • RuOx Ni, Ag, and Au It may be formed.
  • the light emitting device may be a low power light emitting diode, a high power flip type light emitting diode, a vertical light emitting diode, or an organic light emitting diode.
  • the metal compound layer is reduced by a wet process of contacting the metal compound with an activation solution containing an organic acid activator to precipitate metal particles, thereby forming a metal particle layer having an uneven structure.
  • the metal particle layer according to the present invention is applied to a light emitting device, the light extraction efficiency of the light emitting device can be improved by a simpler process.
  • FIG. 2 is a view showing an optical path when an uneven structure metal particle layer is formed on an electrode layer according to an embodiment of the present invention.
  • FIG 3 is a photograph of the surface of the uneven structure metal particle layer according to the magnification using a scanning electron microscope (SEM) according to an embodiment of the present invention.
  • SEM scanning electron microscope
  • first and second are used to describe various components, and the terms are used only for the purpose of distinguishing one component from another component.
  • each layer or element when each layer or element is referred to as being formed “on” or “on” of each layer or element, it means that each layer or element is formed directly on each layer or element, or It is meant that a layer or element can additionally be formed between each layer, on the object, the substrate.
  • the method according to the present invention comprises the step of contacting a substrate capable of being oxidized to generate electrons with an activation solution comprising a metal compound, an organic acid activator, and a complexing agent, wherein the substrate is formed by the organic acid activator. It is oxidized to generate electrons, and the metal compound is reduced by the electrons to precipitate as metal particles on the surface of the substrate to form a metal particle layer.
  • the metal particle layer since the metal particle layer is formed by the metal particles precipitated by the reduction reaction of the metal compound, it may include a plurality of naturally-sized nano-sized uneven structure.
  • the nano-size corresponds to the size of the metal particles of the uneven structure is stone w, can be several tens of nanometers to thousands of nanosizes.
  • the metal particle layer may form an uneven structure having a height of about 10 to about 1,000 nm, preferably about 30 to about 500 nm.
  • the height of the uneven structure can be controlled by adjusting the contact time or the number of times of contact between the substrate and the activation solution. For example, by repeatedly immersing the substrate in the activation solution several times or more times, more metal particles can be precipitated to increase the height of the uneven structure.
  • the substrate may include one or more selected from the group consisting of indium, tin, zinc, aluminum, gallium, antimony, iridium, ruthenium, nickel, silver, and gold.
  • the substrate includes a component that can be oxidized by contact with an organic acid activator to generate electrons.
  • the substrate may be a transparent electrode of the light emitting device, in this case indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium aluminum zinc oxide), IGZO (indium gallium zinc oxide), IGTO (indium gallium tin oxide), AZO (aluminum zinc oxide), ATO (antimony tin oxide), GZO (gallium zinc oxide), IrOx, RuOx, Ni, Ag, Au It may include any one or more selected from the group consisting of. Examples of when two or more components are included may be RuOx / ITO, Ni / IrOx / Au, and Ni / IrOx / Au / ITO.
  • the concentration of the metal compound in the activation solution may be about 0.001 to about 5 g / L, preferably about 0.001 to about 0.5 g / L. If the concentration is too low, less than 0.001 g / L, the metal nanoparticles can not be formed, if the concentration is too high exceeding 5 g / L there is a problem that the metal particles are too large.
  • the activator is characterized in that the organic acid, not the inorganic acid.
  • the organic acid activator serves to promote a reduction reaction of the metal compound.
  • the organic acid activator may be an organic acid having 1 to 10 carbon atoms, and promotes reduction of the metal compound without excessively etching the substrate as compared to the inorganic acid, and thus is more advantageous for forming the metal particle layer of the nanostructure.
  • the organic acid activator citric acid (citric acid), oxalic acid (oxalic acid), malonic acid (malonic acid), malic acid (malic acid), tartaric acid, acetic acid (acetic acid), fumaric acid (fumaric acid) , Lactic acid, formic acid, propionic acid, propionic acid, butyric acid, iminodiacetic acid, glyoxylic acid and ascorbic acid It may include any one or more selected from the group.
  • the formation of the metal particle layer may be easier.
  • the aliphatic polycarboxylic acid having 2 to 10 carbon atoms is used, the uneven structure of the metal particle layer is further increased. It is most preferable because it can be formed finely and uniformly.
  • the complexing agent serves to form ligands with the metal ions of the metal compound.
  • HF HF, NHF 4 , or HCl
  • HCl hydrochloric acid
  • the complexing agent forms a ligand with metal ions of the metal compound and then reacts with the metal of the metal compound to precipitate nano-sized metal particles on the surface of the substrate.
  • metal ions of the metal compound For example, when palladium chloride is used as the metal compound and hydrochloric acid is used as the complexing agent, palladium particles may be precipitated on the surface of the substrate by a reaction as in Scheme 1 below to form a metal particle layer having an uneven structure.
  • the activation solution may further include an alkylene glycol monoalkyl ether for stability of the solution.
  • the alkylene glycol monoalkyl ether is, for example, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, diethylene glycol monomethyl ether, di Ethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether, triethylene Glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monopropyl ether, triethylene glycol monobutyl ether, tripropylene glycol monomethyl ether,
  • the method for forming a metal particle layer according to the present invention can be used to manufacture a variety of devices that require nano-sized uneven structure. For example, there is a light emitting element.
  • a light emitting device in which a light emitting structure, an electrode layer, and a metal particle layer are sequentially formed on a substrate, wherein the metal particle layer is formed of metal particles precipitated by reduction of a metal compound according to the above-described method.
  • a light emitting device is provided.
  • the light emitting device using the method for forming a metal particle layer of the present invention forming a light emitting structure on a substrate, forming an electrode layer on the light emitting structure, and forming a metal particle layer on the electrode layer by using a wet method according to the present invention. It can be prepared by the step.
  • the light emitting device manufactured according to the present invention has a metal particle layer having an uneven structure on the electrode layer by depositing metal nanoparticles by a wet process of metal salt reduction in order to minimize the total internal reflection of light emitted from the light emitting structure. It is characterized by forming.
  • FIGS. 1A to 1C are cross-sectional views schematically illustrating a structure according to a manufacturing process of a light emitting device according to an embodiment of the present invention.
  • a light emitting structure 160 is first formed on a substrate 100 for manufacturing a light emitting device according to an embodiment of the present invention.
  • the substrate 100 may be formed of, for example, at least one of sapphire (Al 2 O 3 ), silicon carbide (SiC), gallium nitride (GaN), zinc oxide (ZnO), or aluminum nitride (AlN). .
  • the substrate 100 may be a sapphire substrate.
  • Sapphire (Al 2 O 3 ) is a crystal in which alumina is grown as a single crystal at 2300 ° C. or more.
  • the sapphire (Al 2 O 3 ) is chemically and thermally stable and thus has a high temperature process and has a high binding energy and dielectric constant.
  • the light emitting structure 160 may be formed by growing a plurality of nitride-based semiconductor layers.
  • the light emitting structure 160 includes, for example, an n-type semiconductor layer 120, an active layer 130, and a p-type semiconductor layer 140, and electrons and p-types provided from the n-type semiconductor layer 120. Holes provided from the semiconductor layer 140 may be recombined in the active layer 130 to generate light.
  • the n-type semiconductor layer 120 and the p-type semiconductor layer 140 may be a gallium nitride-based semiconductor material having a composition formula of Al x Ga (1-x) N (where 0 ⁇ x ⁇ 1), and the gallium nitride By controlling the component ratio of the compound, a light emitting diode from a long wavelength to a short wavelength can be freely produced.
  • the n-type semiconductor layer 120 is a layer for supplying electrons to the active layer 130 and may be formed of a GaN layer or a GaN / AlGaN layer doped with n-type conductive impurities.
  • n-type conductive impurity for example, Si, Ge, Sn or the like can be used.
  • the n-type semiconductor layer 120 is a Si-doped GaN layer Or a GaN / AlGaN layer.
  • the n-type semiconductor layer 120 is illustrated as a single layer in FIGS. 1A to 1C, the n-type semiconductor layer 120 may be formed as a single layer or a multilayer, but the present invention is not limited thereto.
  • the active layer 130 is formed on the n-type semiconductor layer 120 and may be formed of an InGaN / GaN layer having a multi-quantum well structure, or may be formed of one quantum well layer or a double hetero structure. have.
  • the p-type semiconductor layer 140 may be formed of a GaN layer or a GaN / AlGaN layer doped with a p-type conductive impurity.
  • a p-type conductive impurity for example, Mg, Zn, Be or the like can be used.
  • the p-type semiconductor layer 140 may be formed of a GaN layer or a GaN / AlGaN layer doped with Mg.
  • the p-type semiconductor layer 140 is illustrated as a single layer in FIGS. 1A to 1C, the p-type semiconductor layer 140 may also be formed as a single layer or a multilayer, and the present invention is not limited thereto. Accordingly, the light emitting structure 160 may include at least one of an N-P junction, a P-N junction, an N-P-N junction, and a P-N-P junction structure.
  • a buffer layer 110 may be further formed between the light emitting structure 160 and the substrate 100 to alleviate the lattice constant difference between the two.
  • the buffer layer 110 may be formed of a pure undoped GaN layer, and may be omitted depending on the characteristics of the device and the process conditions.
  • the light emitting structure 160 may be an organic light emitting diode (OLED) having a top emission or a bottom emission structure.
  • OLED organic light emitting diode
  • An organic light emitting diode is an element that emits light when an exciton formed by recombining injected electrons and holes in an organic material by arranging an organic material layer between two electrodes and applying an electric field to a ground state.
  • the organic light emitting diodes may be classified into various materials according to materials, light emitting mechanisms, light emitting directions, driving methods, and the like.
  • the organic light emitting diodes may be divided into bottom emission and bottom glass emitting light toward the glass substrate. It can be divided into a top emission (emission).
  • the manufacturing method of the light emitting device of the present invention can be applied to the organic light emitting diode of the bottom emission (for example, bottom emission) can improve the light extraction efficiency.
  • an electrode layer 150 is formed on the light emitting structure 160 after the light emitting structure 160 is formed.
  • the electrode layer 150 may be a transparent conductive layer having electrical conductivity.
  • the electrode layer 150 may be indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium aluminum zinc oxide (IAZO), indium gallium zinc oxide (IGZO), or indium IGTO (IGTO).
  • the electrode layer 150 may be formed by an e-beam evaporation method or a sputtering method, but is not limited thereto. Conventionally used methods may be used.
  • the electrode layer 150 meets oxygen in the air and may naturally generate a metal oxide film. Therefore, the process of removing the metal oxide film may be further performed.
  • the metal oxide film removing process may be performed by immersing the substrate on which the light emitting structure 160 and the electrode layer 150 are formed in an organic acid solution.
  • the organic acid may be the same as or different from the activator added to the activation solution.
  • citric acid oxalic acid, malonic acid, malic acid, malic acid, tartaric acid, acetic acid, fumaric acid, lactic acid
  • Organic acids such as formic acid, propionic acid, butyric acid, iminodiacetic acid, glyoxylic acid, or ascorbic acid.
  • the metal particle layer 200 including the nano-sized uneven structure is formed on the electrode layer 150.
  • the metal particle layer 200 is formed to improve light extraction of the light emitting structure 160. That is, instead of performing a physical or chemical etching process to form an unevenness to improve light extraction, metal nanoparticles are precipitated by a wet process by metal salt reduction to form a metal particle layer 200 including a nano-sized uneven structure. . According to the method of the present invention, problems such as damage to the light emitting structure 160 by the physicochemical etching process may be solved.
  • the substrate 100 on which the light emitting structure 160 and the electrode layer 150 are formed is immersed in an activating solution containing a metal compound, an organic acid activator, and a complexing agent to deposit metal particles on the electrode layer 150.
  • a metal particle layer 200 including an uneven structure of size is formed.
  • the metal compound may be palladium, silver, gold, copper, gallium, titanium, tantalum, ruthenium, tin, platinum or metal salts including alloys thereof, metal chlorides, metal oxides, metal hydrates, and the like, but is not limited thereto.
  • a metal chloride such as palladium chloride (PdCl 2 ) may be used as the metal compound.
  • the concentration of the metal compound in the activation solution may be about 0.001 to about 5 g / L, preferably about 0.001 to about 0.5 g / L. If the concentration is too low, less than 0.001 g / L, the metal nanoparticles can not be formed, if the concentration is too high exceeding 5 g / L there is a problem that the metal particles are too large.
  • the organic acid activator serves to promote a reduction reaction of the metal compound. In addition, by finely etching the electrode layer 150 may serve as a double to reduce the total reflection.
  • the activator for example, citric acid (citric acid), oxalic acid (oxalic acid), malonic acid (malonic acid), malic acid (malic acid), tartaric acid, acetic acid (acetic acid), fumaric acid (fumaric acid), Lactic acid, formic acid, propionic acid, butyric acid, iminodiacetic acid, glyoxylic acid, ascorbic acid, or other Organic acids such as aliphatic polycarboxylic acids can be used.
  • an organic acid such as citric acid to promote the reduction reaction of the metal compound without excessively etching the electrode layer 150 as the activator.
  • the pH of the activation solution is adjusted to 1 to 6, including the organic acid as the activator, the formation of the metal particle layer 200 may be easier.
  • the activator includes an organic acid, particularly a polycarboxylic acid such as citric acid, the uneven structure of the metal particle layer 200 may be more finely and uniformly formed.
  • the complexing agent serves to form ligands with the metal ions of the metal compound.
  • HF HF, NHF 4 , or HCl
  • HCl hydrochloric acid
  • the complexing agent may form a metal ion and a ligand of the metal compound, and then perform a substitution reaction with the metal of the metal compound, thereby depositing a metal to a nano size on the surface of the electrode layer 150 to form the metal particle layer 200.
  • a metal ion and a ligand of the metal compound For example, when palladium chloride is used as the metal compound and hydrochloric acid is used as the complexing agent, palladium particles are deposited on the surface of the electrode layer 150 in the same reaction as in Scheme 1 to form a metal particle layer 200 having an uneven structure. Can be.
  • the metal particle layer 200 is formed of the metal particles precipitated by the reduction reaction of the metal compound, the metal particle layer 200 includes a plurality of nano-sized uneven structures.
  • the nano-size corresponds to the size of the metal particles of stone w, may be several tens of nanometers to thousands of nanometers in size. According to one embodiment of the invention, it is possible to form the uneven structure having a height of about 10 to about 1,000 nm, preferably about 30 to about 500 nm.
  • a step of depositing the metal nanoparticles on the electrode layer 150 by immersing the substrate in the activation solution may be repeatedly performed as necessary. It is possible to form the metal particle layer 200 having a concave-convex structure of an appropriate size by adjusting the number of times immersed in the activation solution.
  • a high refractive index can be achieved by forming an uneven structure made of nano-sized metal on the electrode layer, and the light extraction center can be moved upward to improve light extraction efficiency.
  • the present invention can significantly reduce the total reflection of light, thereby significantly improving the light extraction efficiency of the light emitting device.
  • a light emitting device including a metal particle layer having an uneven structure on an electrode layer may include a low power light emitting diode, a high power flip light emitting diode, a vertical light emitting diode, an organic light emitting diode (OLED), or other light emitting devices. Applicable without limitation.
  • the substrate 100 may be removed using a laser lift-off process.
  • a laser lift-off process After etching the surface of the n-type semiconductor layer separated from the substrate 100 to form an unevenness, a plurality of n-type electrodes are formed at predetermined intervals by depositing a conductive material on the surface of the n-type semiconductor layer.
  • trenches for depositing the n-type electrode may be previously formed at predetermined intervals.
  • a chip breaking process may be performed to separate the LEDs into individual LED devices, thereby completing the LED device.
  • MOCVD metal-organic chemical vapor deposition
  • ITO indium tin oxide
  • FIG. 3 is a photograph of the surface of the metal particle layer including the concave-convex structure formed according to an embodiment of the present invention according to the magnification with a scanning electron microscope (SEM).
  • SEM scanning electron microscope
  • Figure 4 shows the results of analyzing the elemental composition on the surface of the metal particle layer including the concave-convex structure formed according to the embodiment using a field emission scanning electron microscope (FE-SEM). Referring to FIG. 4, it can be seen that an uneven structure including Pd is formed.
  • FE-SEM field emission scanning electron microscope
  • FIG. 5 is an SEM image of the surface of the ITO substrate and the metal particle layer prepared in Examples and Comparative Examples after pretreatment. It can be seen from FIG. 5 that the metal particle layer in the case of using the organic acid according to the embodiment of the present invention has a smaller size and a higher density of the metal particles than in the case of the comparative example using the inorganic acid. In addition, it was also found that the surface of the ITO substrate was etched in the comparative example, so that Pd metal particles were not easily produced.
  • the metal particle layer formed by the method according to the present invention forms a uniform nanoparticle layer, light extraction efficiency of 20% or more can be expected to be increased when a light emitting device is applied, and a small efficiency reduction of 5% or less can be expected even when a high power device is operated. Can be.
  • the metal compound layer is reduced by a wet process of contacting the metal compound with an activation solution containing an organic acid activator to precipitate metal particles, thereby forming a metal particle layer having an uneven structure.
  • the metal particle layer according to the present invention is applied to a light emitting device, the light extraction efficiency of the light emitting device can be improved by a simpler process.

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Abstract

The present invention relates to a method for forming, in a simpler manner, a metal layer having an uneven structure, and to a method for producing a light-emitting element using same to improve optical extraction efficiency. The present invention includes a step of bringing a base material that is oxidized so as to be capable of generating electrons into contact with an activation solution which contains a metal compound, an organic acid activating agent, and a complexing agent. The base material is oxidized by the organic acid activating agent so as to generate the electrons, and the metal compound is reduced by the electrons and is extracted as metal particles onto the surface of the base material to form a metal particle layer.

Description

금속입자층 형성 방법 및 이를 이용하여 제조된 발광소자Metal particle layer forming method and light emitting device manufactured using the same
본 발명은 요철 구조를 갖는 금속층을 보다 간단한 방법으로 형성할 수 있는 방법 및 이를 이용하여 광추출 효율을 향상시킬 수 있는 발광소자의 제조방법에 관한 것이다. The present invention relates to a method of forming a metal layer having an uneven structure by a simpler method and a method of manufacturing a light emitting device capable of improving light extraction efficiency using the same.
발광소자(light emitting device)는 PN 접합에 순방향으로 전류를 흐르게 함으로써 빛을 발생시키는 반도체 소자이다.A light emitting device is a semiconductor device that generates light by flowing a current through a PN junction in a forward direction.
반도체를 이용한 발광소자는 전기 에너지를 빛 에너지로 변환하는 효율이 높고 수명이 5~10년 이상으로 길며 전력 소모와 유지 보수 비용을 크게 절감할 수 있는 장점이 있어서 차세대 조명 기기 응용 분야에서 주목 받고 있다.Light emitting devices using semiconductors are attracting attention in next-generation lighting equipment applications because they have high efficiency for converting electrical energy into light energy, have a long lifespan of more than 5 to 10 years, and can greatly reduce power consumption and maintenance costs. .
발광소자 제조를 위한 질화갈륨계 화합물 반도체의 성장에는 주로 사파이어 기판이 이용된다. 일반적으로 저출력 질화갈륨계 발광소자는 결정 구조가 성장된 사파이어 기판을 리드프레임에 올린 후 두 개의 전극을 상부에 연결하는 방식으로 제작된다. 이때 열 방출 효율을 개선하기 위하여 사파이어 기판을 약 80 마이크론 이하의 두께로 얇게 하여 리드 프레임에 붙이게 된다. 사파이어 기판의 열전도도는 약 50 W/m·K 이기 때문에 그 두께를 80 마이크론 정도로 하더라도 열저항이 매우 커서 원하는 열방출 특정을 얻기 어렵다. A sapphire substrate is mainly used for growing a gallium nitride compound semiconductor for manufacturing a light emitting device. In general, a low-power gallium nitride-based light emitting device is fabricated by placing a sapphire substrate with a crystal structure on a lead frame and then connecting two electrodes to the top. In this case, in order to improve heat dissipation efficiency, the sapphire substrate is thinned to a thickness of about 80 microns or less and attached to the lead frame. Since the thermal conductivity of the sapphire substrate is about 50 W / m · K, even if its thickness is about 80 microns, the thermal resistance is very large, so that it is difficult to obtain a desired heat emission specification.
따라서 고출력 질화갈륨계 발광소자의 경우는 열방출 특성을 보다 개선하기 위하여 플립칩 본딩 방식이 사용되고 있다. 플립칩 본딩 방식은 발광 다이오드 구조가 만들어진 칩을 열전도도가 우수한 실리콘 웨이퍼(열전도도 약 150 W/m·K ) 또는 AlN 세라믹 기판(열전도도 약 180 W/m·K) 등의 서브마운트에 뒤집어 부착시키는 것으로, 이 경우 서브마운트 기판을 통하여 열이 방출되므로 사파이어 기판을 통하여 열을 방출하는 경우보다 열방출 효율이 향상될 수 있으나, 그 향상 정도가 만족할 만한 수준은 아니고 제조 공정이 복잡한 문제점이 있다.Accordingly, in the case of a high output gallium nitride-based light emitting device, a flip chip bonding method is used to further improve heat dissipation characteristics. Flip chip bonding inverts a chip made of a light emitting diode structure to a submount such as a silicon wafer (thermal conductivity of about 150 W / m · K) having excellent thermal conductivity or an AlN ceramic substrate (180 W / m · K of thermal conductivity). In this case, since heat is released through the submount substrate, heat dissipation efficiency may be improved than when heat is released through the sapphire substrate. However, the degree of improvement is not satisfactory and the manufacturing process is complicated. .
이러한 문제점들을 해결하기 위하여 최근에는 사파이어 기판을 제거하여 제조하는 수직형 LED가 주목받고 있다. 수직형 LED는 발광 구조물로부터 레이저 리프트 오프(laser lift-off; LLO) 방법으로 사파이어 기판을 제거한 후 패키징함으로써 제조할 수 있으며 열방출 효율이 가장 우수한 구조로 알려져 있다. 또한 레이저 리프트 오프 방법은 플립칩 본딩 방식과는 달리 제조공정이 간단하다는 장점이 있다. In order to solve these problems, recently, a vertical LED manufactured by removing a sapphire substrate has been attracting attention. Vertical LEDs can be manufactured by removing and packaging the sapphire substrate by a laser lift-off (LLO) method from the light emitting structure and are known to have the best heat dissipation efficiency. In addition, the laser lift-off method has an advantage in that the manufacturing process is simple, unlike the flip chip bonding method.
또한 플립칩 방식의 경우 발광 면적이 칩 면적의 약 60% 정도인데 비하여 사파이어 기판이 제거된 수직형 LED의 경우 발광면적이 칩 면적의 90% 정도에 이르므로 사파이어 기판이 제거된 구조를 갖는 것이 보다 우수한 특성을 나타낸다. In addition, in the case of the flip chip method, the light emitting area is about 60% of the chip area, whereas in the case of the vertical LED with the sapphire substrate removed, the light emitting area is about 90% of the chip area. Excellent properties.
그러나, 사파이어 기판이 제거된 수직형 LED는 종래의 발광소자에 비해 낮은 광추출 효율을 보이는데 그 이유는 다음과 같다. 사파이어 기판이 제거된 LED 구조에 에폭시와 같은 몰딩재 또는 형광체가 혼합된 몰딩재를 씌워서 발광소자가 제작되는데, 이때, 질화갈륨(GaN)과 몰딩재 간의 큰 굴절률 차에 의하여 LED 구조에서 발생된 빛의 상당 부분이 외부로 방출되지 않고 전반사되어 다시 발광 구조물 쪽으로 진행하여 소멸하게 된다. 질화갈륨의 굴절률은 약 2.6 이므로, 몰딩재의 굴절률을 약 1.5 정도로 가정할 경우 두 물질의 접합 면에서 전반사되는 빛의 양은 약 9% 정도가 되어 광추출 효율의 많은 개선이 요구된다.However, the vertical LED with the sapphire substrate removed shows a lower light extraction efficiency than the conventional light emitting device because of the following reasons. A light emitting device is fabricated by covering an LED structure from which a sapphire substrate is removed and a molding material such as epoxy or a molding material mixed with phosphors. In this case, light generated in the LED structure due to a large difference in refractive index between gallium nitride (GaN) and the molding material is produced. A large portion of is not emitted to the outside but totally reflected and then proceeds toward the light emitting structure again and disappears. Since the refractive index of gallium nitride is about 2.6, if the refractive index of the molding material is assumed to be about 1.5, the amount of light totally reflected at the bonding surface of the two materials is about 9%, which requires much improvement in light extraction efficiency.
이를 해결하기 위해서 사파이어 기판을 제거하고 전극 배선을 형성하기 전 혹은 후의 단계에서 노출된 p-형 질화갈륨층의 표면에 요철을 형성하는 방법에 대한 연구가 수행되고 있다. 예를 들어 전반사시 발생되는 소멸파를 이용한 기술로서, V자형 융기부가 생겨진 기판 위에 융기형 구조를 성장시켜 발광 구조물을 만들게 되면 구조물의 디자인에 따라 소멸파의 보강 결합이 발생되어 광추출이 향상되도록 하는 기술이 개시되어 있다[Appl. Phys. Lett. 94, 091102 (2009)]. 그러나, 충분한 광추출 효율 개선을 위해서 추가의 연구가 필요한 실정이다.In order to solve this problem, researches have been made on a method of forming irregularities on the surface of the p-type gallium nitride layer exposed before or after removing the sapphire substrate and forming the electrode wiring. For example, as a technique using evanescent waves generated during total reflection, when a ridge-type structure is grown on a substrate on which a V-shaped ridge is formed, a light-emitting structure is generated, and reinforcement coupling of evanescent waves is generated according to the design of the structure, thereby improving light extraction. Techniques for achieving this are disclosed [Appl. Phys. Lett. 94, 091102 (2009). However, further studies are needed to sufficiently improve the light extraction efficiency.
상기와 같은 종래 기술의 문제점을 해결하고자, 본 발명은 보다 간단한 공정으로 요철 구조를 갖는 금속층을 형성할 수 있는 방법 및 이를 이용하여 광추출 효율을 향상시킬 수 있는 발광소자를 제공하는 것을 목적으로 한다.In order to solve the problems of the prior art as described above, an object of the present invention is to provide a method for forming a metal layer having a concave-convex structure in a simpler process and a light emitting device that can improve the light extraction efficiency using the same. .
상기의 목적을 달성하기 위하여, 본 발명은 In order to achieve the above object, the present invention
산화되어 전자를 발생할 수 있는 기재를, Base material that can be oxidized to generate electrons,
금속화합물, 유기산 활성화제 및 착화제를 포함하는 활성화 용액과 접촉시키는 단계를 포함하며, Contacting with an activating solution comprising a metal compound, an organic acid activator and a complexing agent,
상기 기재는 상기 유기산 활성화제에 의해 산화되어 전자를 발생시키고, The substrate is oxidized by the organic acid activator to generate electrons,
상기 금속화합물은 상기 전자에 의해 환원되어 상기 기재의 표면 상에 금속입자로 석출되어 금속입자층을 형성하는 것인, 금속입자층 형성 방법을 제공한다. The metal compound is reduced by the electrons to precipitate as metal particles on the surface of the substrate to provide a metal particle layer forming method.
본 발명에 있어서, 상기 금속입자층은 나노 크기의 요철 구조를 가질 수 있다. In the present invention, the metal particle layer may have a nano-sized uneven structure.
본 발명의 바람직한 실시예에 따르면, 상기 요철은 10 내지 1,000nm의 높이를 갖는 것일 수 있다.According to a preferred embodiment of the present invention, the irregularities may be one having a height of 10 to 1,000nm.
본 발명에 있어서, 상기 기재는 인듐, 주석, 아연, 알루미늄, 갈륨, 안티몬, 이리듐, 루테늄, 니켈, 은, 금으로 이루어진 군에서 선택되는 하나 이상을 포함하는 것일 수 있다. In the present invention, the substrate may include one or more selected from the group consisting of indium, tin, zinc, aluminum, gallium, antimony, iridium, ruthenium, nickel, silver, and gold.
본 발명의 일 실시예에 있어서, 상기 기재는 ITO(indium tin oxide), IZO(indium zinc oxide), IZTO(indium zinc tin oxide), IAZO(indium aluminum zinc oxide), IGZO(indium gallium zinc oxide), IGTO(indium gallium tin oxide), AZO(aluminum zinc oxide), ATO(antimony tin oxide), GZO(gallium zinc oxide), IrOx, RuOx, Ni, Ag, Au로 이루어진 군에서 선택되는 어느 하나 이상을 포함하는 것일 수 있다. In one embodiment of the present invention, the substrate is indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium aluminum zinc oxide (IAZO), indium gallium zinc oxide (IGZO), Including one or more selected from the group consisting of indium gallium tin oxide (IGTO), aluminum zinc oxide (AZO), antimony tin oxide (ATO), gallium zinc oxide (GZO), IrOx, RuOx, Ni, Ag, Au It may be.
본 발명의 일 실시예에 따르면, 상기 금속입자층을 형성하기 이전에 상기 기재가 공기 중의 산소와 만나 형성되는 금속산화막을 제거하는 단계를 더 포함할 수 있다. According to an embodiment of the present invention, before the metal particle layer is formed, the substrate may further include removing a metal oxide film formed by meeting oxygen in air.
본 발명에 있어서, 상기 금속입자층을 형성하는 단계는 상기 기재를 상기 활성화 용액에 1회 이상 침지하여 수행될 수 있다. In the present invention, the forming of the metal particle layer may be performed by immersing the substrate in the activation solution one or more times.
본 발명에 있어서, 상기 금속화합물은 팔라듐, 은, 금, 구리, 갈륨, 티타늄, 탄탈륨, 루테늄, 주석, 백금 또는 이들의 합금을 포함하는 금속염, 금속 산화물 및 금속 수화물로 이루어진 군에서 선택되는 어느 하나 이상을 포함할 수 있다. In the present invention, the metal compound is any one selected from the group consisting of metal salts, metal oxides and metal hydrates including palladium, silver, gold, copper, gallium, titanium, tantalum, ruthenium, tin, platinum or alloys thereof. It may contain the above.
본 발명의 일 실시예에 있어서, 상기 활성화 용액 중 금속화합물의 농도는 0.001 내지 5g/L 일 수 있다. In one embodiment of the present invention, the concentration of the metal compound in the activation solution may be 0.001 to 5g / L.
본 발명의 바람직한 실시예에 있어서, 상기 유기산 활성화제는 탄소수 1 ~ 10 의 유기산일 수 있다. In a preferred embodiment of the present invention, the organic acid activator may be an organic acid having 1 to 10 carbon atoms.
구체적으로, 상기 유기산 활성화제는 구연산(citric acid), 옥살산(oxalic acid), 말론산(malonic acid), 사과산(malic acid), 주석산(tartaric acid), 초산(acetic acid), 푸마르산(fumaric acid), 젖산(lactic acid), 포름산(formic acid), 프로피온산(propionic acid), 부티르산(butyric acid), 이미노디아세트산(iminodiacetic acid), 글리옥실산(glyoxylic acid) 및 아스코르빈산(ascorbic acid)으로 이루어진 군에서 선택되는 어느 하나 이상을 포함하는 것일 수 있다. Specifically, the organic acid activator citric acid (citric acid), oxalic acid (oxalic acid), malonic acid (malonic acid), malic acid (malic acid), tartaric acid, acetic acid (acetic acid), fumaric acid (fumaric acid) , Lactic acid, formic acid, propionic acid, propionic acid, butyric acid, iminodiacetic acid, glyoxylic acid and ascorbic acid It may include any one or more selected from the group.
본 발명의 바람직한 실시예에 있어서, 상기 유기산 활성화제는 탄소수 2 내지 10 의 지방족 폴리카르본산(aliphatic polycarboxylic acid) 일 수 있다. In a preferred embodiment of the present invention, the organic acid activator may be aliphatic polycarboxylic acid having 2 to 10 carbon atoms.
본 발명에 있어서, 상기 착화제는 HCl, HF, 및 NHF3으로 이루어진 군에서 선택되는 어느 하나 이상을 포함하는 것일 수 있다. In the present invention, the complexing agent may include any one or more selected from the group consisting of HCl, HF, and NHF 3 .
본 발명의 일 실시예에 있어서, 상기 활성화 용액은 알킬렌글리콜 모노알킬 에테르를 더 포함할 수 있다. In one embodiment of the present invention, the activation solution may further include an alkylene glycol monoalkyl ether.
본 발명은 또한 전술한 방법으로 제조된, 금속화합물의 환원에 의해 석출된 금속입자로 이루어진 금속입자층을 포함하는 소자를 제공한다. The present invention also provides a device comprising a metal particle layer made of metal particles precipitated by reduction of a metal compound, prepared by the above-described method.
본 발명의 일 실시예에 따르면, 기판 상에 발광 구조물, 전극층 및 금속입자층이 순차적으로 형성되어 있는 발광소자로서, 상기 금속입자층이 전술한 방법에 따른 금속화합물의 환원에 의해 석출된 금속 입자로 형성된 것인 발광소자가 제공된다. According to an embodiment of the present invention, a light emitting device in which a light emitting structure, an electrode layer, and a metal particle layer are sequentially formed on a substrate, wherein the metal particle layer is formed of metal particles precipitated by reduction of a metal compound according to the above-described method. A light emitting device is provided.
본 발명의 일 실시예에 있어서, 상기 발광 구조물은 n형 반도체층/활성층/p형 반도체층이 순차적으로 적층된 구조를 갖는 것일 수 있다. In one embodiment of the present invention, the light emitting structure may have a structure in which the n-type semiconductor layer / active layer / p-type semiconductor layer is sequentially stacked.
본 발명의 일 실시예에 있어서, 상기 전극층은 ITO(indium tin oxide), IZO(indium zinc oxide), IZTO(indium zinc tin oxide), IAZO(indium aluminum zinc oxide), IGZO(indium gallium zinc oxide), IGTO(indium gallium tin oxide), AZO(aluminum zinc oxide), ATO(antimony tin oxide), GZO(gallium zinc oxide), IrOx, RuOx, Ni, Ag 및 Au로 이루어진 군에서 선택되는 어느 하나 이상을 이용하여 형성된 것일 수 있다. In one embodiment of the present invention, the electrode layer is indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium aluminum zinc oxide (IAZO), indium gallium zinc oxide (IGZO), Using at least one selected from the group consisting of indium gallium tin oxide (IGTO), aluminum zinc oxide (AZO), antimony tin oxide (ATO), gallium zinc oxide (GZO), IrOx, RuOx, Ni, Ag, and Au It may be formed.
본 발명의 일 실시예에 있어서, 상기 발광소자는 저출력용 발광 다이오드, 고출력 플립형 발광 다이오드, 수직형 발광 다이오드, 또는 유기 발광 다이오드일 수 있다.In one embodiment of the present invention, the light emitting device may be a low power light emitting diode, a high power flip type light emitting diode, a vertical light emitting diode, or an organic light emitting diode.
본 발명에 따르면, 금속화합물을 유기산 활성화제를 포함하는 활성화 용액과 접촉시키는 습식 공정에 의해 환원시켜 금속입자를 석출함으로써 보다 간단한 공정으로 요철 구조의 금속입자층을 형성할 수 있다. 본 발명에 따른 금속입자층을 발광소자에 적용시 보다 간단한 공정으로 발광소자의 광추출 효율을 향상시킬 수 있다.According to the present invention, the metal compound layer is reduced by a wet process of contacting the metal compound with an activation solution containing an organic acid activator to precipitate metal particles, thereby forming a metal particle layer having an uneven structure. When the metal particle layer according to the present invention is applied to a light emitting device, the light extraction efficiency of the light emitting device can be improved by a simpler process.
도 1a 내지 도 1c는 본 발명의 일 실시예에 따른 발광소자의 제조과정에 따른 구조를 개략적으로 도시하는 단면도이다.1A to 1C are cross-sectional views schematically illustrating a structure of a light emitting device according to an embodiment of the present invention.
도 2는 본 발명의 일 실시예에 따라 전극층 상에 요철 구조 금속입자층이 형성된 경우의 광 경로를 도시하는 도면이다.FIG. 2 is a view showing an optical path when an uneven structure metal particle layer is formed on an electrode layer according to an embodiment of the present invention.
도 3은 본 발명의 일 실시예에 따른 요철 구조 금속입자층의 표면을 주사전자현미경(SEM)을 이용하여 배율에 따라 관찰한 사진이다.3 is a photograph of the surface of the uneven structure metal particle layer according to the magnification using a scanning electron microscope (SEM) according to an embodiment of the present invention.
도 4는 본 발명의 일 실시예에 따른 요철 구조 금속입자층의 Pd 성분을 전계 방출형 주사전자현미경(FE-SEM)을 이용하여 확인한 결과이다.Figure 4 is a result of confirming the Pd component of the uneven structure metal particle layer according to an embodiment of the present invention using a field emission scanning electron microscope (FE-SEM).
도 5는 본 발명의 실시예 및 비교예에 따라 제조된 금속입자층을 관찰한 SEM 사진이다.5 is a SEM photograph of the metal particle layer prepared according to the Examples and Comparative Examples of the present invention.
이하, 도면을 참조하여 본 발명을 보다 상세하게 설명한다.Hereinafter, the present invention will be described in more detail with reference to the drawings.
본 발명에서, 제1, 제2 등의 용어는 다양한 구성요소들을 설명하는데 사용되며, 상기 용어들은 하나의 구성 요소를 다른 구성 요소로부터 구별하는 목적으로만 사용된다. In the present invention, terms such as first and second are used to describe various components, and the terms are used only for the purpose of distinguishing one component from another component.
또한 본 발명에 있어서, 각 층 또는 요소가 각 층들 또는 요소들의 "상에" 또는 "위에" 형성되는 것으로 언급되는 경우에는 각 층 또는 요소가 직접 각 층들 또는 요소들의 위에 형성되는 것을 의미하거나, 다른 층 또는 요소가 각 층 사이, 대상체, 기재 상에 추가적으로 형성될 수 있음을 의미한다.Also in the present invention, when each layer or element is referred to as being formed "on" or "on" of each layer or element, it means that each layer or element is formed directly on each layer or element, or It is meant that a layer or element can additionally be formed between each layer, on the object, the substrate.
본 발명은 다양한 변경을 가할 수 있고 여러 가지 형태를 가질 수 있는 바, 특정 실시예들을 예시하고 하기에서 상세하게 설명하고자 한다. 그러나, 이는 본 발명을 특정한 개시 형태에 대해 한정하려는 것이 아니며, 본 발명의 사상 및 기술 범위에 포함되는 모든 변경, 균등물 내지 대체물을 포함하는 것으로 이해되어야 한다.As the invention allows for various changes and numerous modifications, particular embodiments will be illustrated and described in detail below. However, this is not intended to limit the present invention to the specific disclosed form, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.
본 발명은 습식법에 의해 균일한 나노 크기의 요철구조를 갖는 금속입자층을 형성할 수 있는 방법에 관한 것이다. The present invention relates to a method capable of forming a metal particle layer having a uniform nano-sized uneven structure by the wet method.
구체적으로 본 발명에 따른 방법은, 산화되어 전자를 발생할 수 있는 기재를, 금속화합물, 유기산 활성화제 및 착화제를 포함하는 활성화 용액과 접촉시키는 단계를 포함하며, 상기 기재는 상기 유기산 활성화제에 의해 산화되어 전자를 발생시키고, 상기 금속화합물은 상기 전자에 의해 환원되어 상기 기재의 표면 상에 금속입자로 석출되어 금속입자층을 형성하도록 한다. Specifically, the method according to the present invention comprises the step of contacting a substrate capable of being oxidized to generate electrons with an activation solution comprising a metal compound, an organic acid activator, and a complexing agent, wherein the substrate is formed by the organic acid activator. It is oxidized to generate electrons, and the metal compound is reduced by the electrons to precipitate as metal particles on the surface of the substrate to form a metal particle layer.
본 발명은 물리적 또는 화학적 식각 공정을 수행하는 대신 금속염 환원에 의한 습식 공정에 의해 금속 나노 입자를 석출시켜 나노 크기의 요철 구조를 포함하는 금속입자층을 형성할 수 있다. 본 발명의 방법에 따르면, 물리화학적 식각 공정에 의한 구조물 손상 등의 문제점을 해결할 수 있다. Instead of performing a physical or chemical etching process, the present invention may precipitate metal nanoparticles by a wet process using metal salt reduction to form a metal particle layer including nano-sized concave-convex structure. According to the method of the present invention, problems such as damage to a structure due to a physicochemical etching process can be solved.
본 발명에 있어서, 금속입자층은 금속 화합물의 환원 반응에 의해 석출된 금속 입자에 의해 형성되기 때문에 자연스럽게 형성된 나노 크기의 요철 구조를 복수 개로 포함할 수 있다. 상기 나노 크기는 요철 구조는 석 w된 금속 입자의 크기와 상응하며, 수십 나노 내지 수천 나노 크기가 될 수 있다. 본 발명의 일 실시예에 따르면, 금속입자층은 약 10 내지 약 1,000nm, 바람직하게는 약 30 내지 약 500 nm의 높이를 갖는 요철 구조물을 형성할 수 있다. In the present invention, since the metal particle layer is formed by the metal particles precipitated by the reduction reaction of the metal compound, it may include a plurality of naturally-sized nano-sized uneven structure. The nano-size corresponds to the size of the metal particles of the uneven structure is stone w, can be several tens of nanometers to thousands of nanosizes. According to one embodiment of the invention, the metal particle layer may form an uneven structure having a height of about 10 to about 1,000 nm, preferably about 30 to about 500 nm.
한편, 상기 요철 구조물의 높이는 기재와 활성화 용액의 접촉시간을 조절하거나 접촉횟수를 조절함으로써 제어할 수 있다. 예를 들면, 상기 기재를 상기 활성화 용액에 1회 이상 수회 반복하여 침지함으로써 석출되는 금속입자가 보다 많아져 요철 구조의 높이가 커지도록 할 수 있다. On the other hand, the height of the uneven structure can be controlled by adjusting the contact time or the number of times of contact between the substrate and the activation solution. For example, by repeatedly immersing the substrate in the activation solution several times or more times, more metal particles can be precipitated to increase the height of the uneven structure.
본 발명에 있어서, 상기 기재는 인듐, 주석, 아연, 알루미늄, 갈륨, 안티몬, 이리듐, 루테늄, 니켈, 은, 금으로 이루어진 군에서 선택되는 하나 이상을 포함하는 것일 수 있다. 상기 기재에는 유기산 활성화제와 접촉함으로써 산화되어 전자를 발생할 수 있는 성분이 포함되는 것이 바람직하다. In the present invention, the substrate may include one or more selected from the group consisting of indium, tin, zinc, aluminum, gallium, antimony, iridium, ruthenium, nickel, silver, and gold. Preferably, the substrate includes a component that can be oxidized by contact with an organic acid activator to generate electrons.
본 발명의 일 실시예에 있어서, 상기 기재가 발광소자의 투명 전극일 수 있는데, 이 경우 ITO(indium tin oxide), IZO(indium zinc oxide), IZTO(indium zinc tin oxide), IAZO(indium aluminum zinc oxide), IGZO(indium gallium zinc oxide), IGTO(indium gallium tin oxide), AZO(aluminum zinc oxide), ATO(antimony tin oxide), GZO(gallium zinc oxide), IrOx, RuOx, Ni, Ag, Au로 이루어진 군에서 선택되는 어느 하나 이상을 포함하는 것일 수 있다. 둘 이상의 성분이 포함되는 경우를 예로 들면, RuOx/ITO, Ni/IrOx/Au, 및 Ni/IrOx/Au/ITO 일 수 있다. In one embodiment of the present invention, the substrate may be a transparent electrode of the light emitting device, in this case indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium aluminum zinc oxide), IGZO (indium gallium zinc oxide), IGTO (indium gallium tin oxide), AZO (aluminum zinc oxide), ATO (antimony tin oxide), GZO (gallium zinc oxide), IrOx, RuOx, Ni, Ag, Au It may include any one or more selected from the group consisting of. Examples of when two or more components are included may be RuOx / ITO, Ni / IrOx / Au, and Ni / IrOx / Au / ITO.
본 발명의 일 실시예에 따르면, 상기 기재는 산화가 가능한 성분을 포함하고 있기 때문에, 상기 금속입자층을 형성하기 이전에 상기 기재가 공기 중의 산소와 만나 형성되는 금속산화막을 형성할 수 있다. 따라서 금속입자층을 형성하기 전에 이러한 금속산화막을 제거하는 것이 바람직할 수 있다. According to an embodiment of the present invention, since the substrate includes a component capable of oxidizing, the substrate may form a metal oxide film in which the substrate is formed to meet oxygen in air before forming the metal particle layer. Therefore, it may be desirable to remove this metal oxide film before forming the metal particle layer.
본 발명에 있어서, 기재와 접촉되는 활성화 용액은 금속화합물, 유기산 활성화제 및 착화제를 포함하고 있다. In the present invention, the activating solution in contact with the substrate contains a metal compound, an organic acid activator, and a complexing agent.
상기 금속화합물은 팔라듐, 은, 금, 구리, 갈륨, 티타늄, 탄탈륨, 루테늄, 주석, 백금 또는 이들의 합금을 포함하는 금속염, 금속 산화물 및 금속 수화물로 이루어진 군에서 선택되는 어느 하나 이상을 포함할 수 있다. The metal compound may include any one or more selected from the group consisting of metal salts, metal oxides, and metal hydrates including palladium, silver, gold, copper, gallium, titanium, tantalum, ruthenium, tin, platinum, or alloys thereof. have.
상기 활성화 용액 내의 금속 화합물의 농도는 약 0.001 내지 약 5g/L, 바람직하게는 약 0.001 내지 약 0.5g/L 일 수 있다. 농도가 0.001 g/L 미만으로 너무 낮으면 금속 나노 입자를 형성할 수 없고, 5g/L을 초과하여 너무 높으면 금속 입자가 지나치게 커지는 문제점이 있다. The concentration of the metal compound in the activation solution may be about 0.001 to about 5 g / L, preferably about 0.001 to about 0.5 g / L. If the concentration is too low, less than 0.001 g / L, the metal nanoparticles can not be formed, if the concentration is too high exceeding 5 g / L there is a problem that the metal particles are too large.
본 발명에 있어서, 활성화제는 무기산이 아닌 유기산인 것을 특징으로 한다. 상기 유기산 활성화제는 금속 화합물의 환원 반응을 촉진하는 역할을 한다. 상기 유기산 활성화제는 탄소수 1 ~ 10 의 유기산일 수 있으며, 무기산과 비교하여 기재를 과도하게 식각하지 않으면서 금속화합물의 환원을 촉진하므로 나노구조의 금속입자층 형성에 더욱 유리하다. In the present invention, the activator is characterized in that the organic acid, not the inorganic acid. The organic acid activator serves to promote a reduction reaction of the metal compound. The organic acid activator may be an organic acid having 1 to 10 carbon atoms, and promotes reduction of the metal compound without excessively etching the substrate as compared to the inorganic acid, and thus is more advantageous for forming the metal particle layer of the nanostructure.
구체적으로, 상기 유기산 활성화제는 구연산(citric acid), 옥살산(oxalic acid), 말론산(malonic acid), 사과산(malic acid), 주석산(tartaric acid), 초산(acetic acid), 푸마르산(fumaric acid), 젖산(lactic acid), 포름산(formic acid), 프로피온산(propionic acid), 부티르산(butyric acid), 이미노디아세트산(iminodiacetic acid), 글리옥실산(glyoxylic acid) 및 아스코르빈산(ascorbic acid)으로 이루어진 군에서 선택되는 어느 하나 이상을 포함하는 것일 수 있다. Specifically, the organic acid activator citric acid (citric acid), oxalic acid (oxalic acid), malonic acid (malonic acid), malic acid (malic acid), tartaric acid, acetic acid (acetic acid), fumaric acid (fumaric acid) , Lactic acid, formic acid, propionic acid, propionic acid, butyric acid, iminodiacetic acid, glyoxylic acid and ascorbic acid It may include any one or more selected from the group.
본 발명의 바람직한 실시예에 있어서, 상기 유기산 활성화제는 탄소수 2 내지 10 의 지방족 폴리카르본산(aliphatic polycarboxylic acid) 일 수 있으며, 더욱 바람직하게는 2개 내지 10개의 카르복실기를 함유할 수 있다. In a preferred embodiment of the present invention, the organic acid activator may be aliphatic polycarboxylic acid having 2 to 10 carbon atoms, more preferably may contain 2 to 10 carboxyl groups.
상기 유기산 활성화제를 사용하여 활성화 용액의 pH를 1 내지 6 으로 조절하는 경우 금속입자층의 형성이 더 용이할 수 있으며, 특히 탄소수 2 내지 10의 지방족 폴리카르본산을 사용할 때 금속입자층의 요철 구조가 더욱 세밀하고 균일하게 형성될 수 있어 가장 바람직하다.When the pH of the activating solution is adjusted to 1 to 6 using the organic acid activator, the formation of the metal particle layer may be easier. Particularly, when the aliphatic polycarboxylic acid having 2 to 10 carbon atoms is used, the uneven structure of the metal particle layer is further increased. It is most preferable because it can be formed finely and uniformly.
상기 착화제는 상기 금속 화합물의 금속 이온과 리간드를 형성하는 역할을 한다. 상기 착화제로는 예를 들어 HF, NHF4, 또는 HCl 등을 사용할 수 있으며, 본 발명의 일 실시예에 따르면, 금속화합물이 염화물인 경우 염산(HCl)을 착화제로 사용하는 것이 바람직하다. The complexing agent serves to form ligands with the metal ions of the metal compound. For example, HF, NHF 4 , or HCl may be used as the complexing agent. According to one embodiment of the present invention, when the metal compound is a chloride, hydrochloric acid (HCl) is preferably used as the complexing agent.
상기 착화제는 금속 화합물의 금속 이온과 리간드를 형성한 후 상기 금속 화합물의 금속과 치환반응을 함으로써 기재 표면에 나노 크기의 금속입자가 석출되도록 한다. 예를 들어, 상기 금속 화합물로 염화팔라듐을 사용하고 상기 착화제로 염산을 사용할 경우 하기 반응식 1과 같은 반응으로 기재 표면에 팔라듐 입자가 석출되어 요철 구조를 갖는 금속입자층이 형성될 수 있다.The complexing agent forms a ligand with metal ions of the metal compound and then reacts with the metal of the metal compound to precipitate nano-sized metal particles on the surface of the substrate. For example, when palladium chloride is used as the metal compound and hydrochloric acid is used as the complexing agent, palladium particles may be precipitated on the surface of the substrate by a reaction as in Scheme 1 below to form a metal particle layer having an uneven structure.
[반응식 1] Scheme 1
(PdCl4)2- + 2e- -> Pd + 4Cl- (PdCl 4) 2- + 2e - -> Pd + 4Cl -
상기 활성화 용액은 용액의 안정성을 위하여 알킬렌글리콜 모노알킬 에테르를 더 포함할 수 있다. 상기 알킬렌글리콜 모노알킬에테르는 예를 들어, 에틸렌글리콜 모노에틸에테르, 에틸렌글리콜 모노부틸에테르, 프로필렌글리콜 모노메틸에테르, 프로필렌글리콜 모노에틸에테르, 프로필렌글리콜 모노부틸에테르, 디에틸렌글리콜 모노메틸에테르, 디에틸렌글리콜 모노에틸에테르, 디에틸렌글리콜 모노프로필에테르, 디에틸렌글리콜 모노부틸에테르, 디프로필렌글리콜 모노메틸에테르, 디프로필렌글리콜 모노에틸에테르, 디프로필렌글리콜 모노프로필에테르, 디프로필렌글리콜 모노부틸에테르, 트리에틸렌글리콜 모노메틸에테르, 트리에틸렌글리콜 모노에틸에테르, 트리에틸렌글리콜 모노프로필에테르, 트리에틸렌글리콜 모노부틸에테르, 트리프로필렌글리콜 모노메틸에테르, 트리프로필렌글리콜 모노에틸에테르, 트리프로필렌글리콜 모노프로필에테르 및 트리프로필렌글리콜 모노부틸에테르로 구성된 군에서 선택된 적어도 하나의 화합물일 수 있으나, 이에 제한되지는 않는다. The activation solution may further include an alkylene glycol monoalkyl ether for stability of the solution. The alkylene glycol monoalkyl ether is, for example, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, diethylene glycol monomethyl ether, di Ethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether, triethylene Glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monopropyl ether, triethylene glycol monobutyl ether, tripropylene glycol monomethyl ether, tripropylene glycol monoethyl ether, tripropylene glycol monoprop At least one compound selected from the group consisting of filether and tripropylene glycol monobutyl ether may be, but is not limited thereto.
본 발명에 따른 금속입자층 형성 방법은 나노 크기의 요철 구조가 필요한 다양한 소자 제조에 사용될 수 있다. 예를 들면, 발광 소자 등이 있다. The method for forming a metal particle layer according to the present invention can be used to manufacture a variety of devices that require nano-sized uneven structure. For example, there is a light emitting element.
본 발명의 일 실시예에 따르면, 기판 상에 발광 구조물, 전극층 및 금속입자층이 순차적으로 형성되어 있는 발광소자로서, 상기 금속입자층이 전술한 방법에 따른 금속화합물의 환원에 의해 석출된 금속 입자로 형성된 것인 발광소자가 제공된다. According to an embodiment of the present invention, a light emitting device in which a light emitting structure, an electrode layer, and a metal particle layer are sequentially formed on a substrate, wherein the metal particle layer is formed of metal particles precipitated by reduction of a metal compound according to the above-described method. A light emitting device is provided.
이하에서는 본 발명의 일 실시예로서 발광소자를 구체적으로 설명하나 본 발명의 범위가 이에 한정되는 것은 아님은 물론이다. Hereinafter, a light emitting device will be described in detail as an embodiment of the present invention, but the scope of the present invention is not limited thereto.
본 발명의 금속입자층 형성방법을 이용한 발광소자는, 기판 상에 발광 구조물을 형성하는 단계, 상기 발광 구조물 상에 전극층을 형성하는 단계 및 상기 전극층 상에 본 발명에 따른 습식법을 이용하여 금속입자층을 형성하는 단계에 의해 제조될 수 있다. In the light emitting device using the method for forming a metal particle layer of the present invention, forming a light emitting structure on a substrate, forming an electrode layer on the light emitting structure, and forming a metal particle layer on the electrode layer by using a wet method according to the present invention. It can be prepared by the step.
본 발명에 따라 제조된 발광소자는 발광 구조물로부터 방출되는 빛의 내부 전반사를 최소화함으로써 광추출 효율 증대를 도모하고자 금속염 환원의 습식 공정에 의해 금속 나노입자를 석출시킴으로써 요철 구조의 금속입자층을 전극층 상에 형성하는 것을 특징으로 한다.The light emitting device manufactured according to the present invention has a metal particle layer having an uneven structure on the electrode layer by depositing metal nanoparticles by a wet process of metal salt reduction in order to minimize the total internal reflection of light emitted from the light emitting structure. It is characterized by forming.
도 1a 내지 도 1c는 본 발명의 일 실시예에 따른 발광소자의 제조과정에 따른 구조를 개략적으로 도시한 단면도이다.1A to 1C are cross-sectional views schematically illustrating a structure according to a manufacturing process of a light emitting device according to an embodiment of the present invention.
도 1a 에서, 본 발명의 일 실시예에 따른 발광소자의 제조를 위해 먼저 기판(100) 상에 발광 구조물(160)을 형성한다. In FIG. 1A, a light emitting structure 160 is first formed on a substrate 100 for manufacturing a light emitting device according to an embodiment of the present invention.
기판(100)은 예를 들어, 사파이어(Al2O3), 실리콘 카바이드(SiC), 갈륨 나이트라이드(GaN), 징크 옥사이드(ZnO), 또는 알루미늄 나이트라이드(AlN) 중 적어도 하나로 형성될 수 있다. 본 발명의 바람직한 실시예에 따르면, 기판(100)은 사파이어 기판일 수 있다. 사파이어(Al2O3)는 알루미나가 2300℃ 이상에서 단결정으로 성장된 결정체로서, 화학적, 열적으로 안정적이어서 고온 공정이 가능하고 높은 결합에너지와 유전 상수를 갖는 장점이 있다. The substrate 100 may be formed of, for example, at least one of sapphire (Al 2 O 3 ), silicon carbide (SiC), gallium nitride (GaN), zinc oxide (ZnO), or aluminum nitride (AlN). . According to a preferred embodiment of the present invention, the substrate 100 may be a sapphire substrate. Sapphire (Al 2 O 3 ) is a crystal in which alumina is grown as a single crystal at 2300 ° C. or more. The sapphire (Al 2 O 3 ) is chemically and thermally stable and thus has a high temperature process and has a high binding energy and dielectric constant.
본 발명의 일 실시예에 따르면, 발광 구조물(160)은 복수의 질화물계 반도체층을 성장시켜 형성할 수 있다. 구체적으로 발광 구조물(160)은 예를 들어, n형 반도체층(120), 활성층(130) 및 p형 반도체층(140)을 포함하며, n형 반도체층(120)으로부터 제공되는 전자 및 p형 반도체층(140)으로부터 제공되는 정공이 활성층(130)에서 재결합(recombination)됨으로써 빛을 생성할 수 있다.According to an embodiment of the present invention, the light emitting structure 160 may be formed by growing a plurality of nitride-based semiconductor layers. Specifically, the light emitting structure 160 includes, for example, an n-type semiconductor layer 120, an active layer 130, and a p-type semiconductor layer 140, and electrons and p-types provided from the n-type semiconductor layer 120. Holes provided from the semiconductor layer 140 may be recombined in the active layer 130 to generate light.
발광 구조물(160)은 예를 들어, 금속 유기 화학 증착법(MOCVD; Metal Organic Chemical Vapor Deposition), 화학 증착법(CVD; Chemical Vapor Deposition), 플라즈마 화학 증착법(PECVD; Plasma-Enhanced Chemical Vapor Deposition), 분자선 성장법(MBE; Molecular Beam Epitaxy), 또는 수소화물 기상 성장법(HVPE; Hydride Vapor Phase Epitaxy) 등의 방법을 이용하여 형성될 수 있으나, 이에 한정되지는 않는다. 본 발명의 바람직한 실시예에 따르면, 발광 구조물(160)은 금속 유기화학 기상 증착법을 이용하여 형성될 수 있다. The light emitting structure 160 may include, for example, Metal Organic Chemical Vapor Deposition (MOCVD), Chemical Vapor Deposition (CVD), Plasma-Enhanced Chemical Vapor Deposition (PECVD), and molecular beam growth. Molecular Beam Epitaxy (MBE) or Hydride Vapor Phase Epitaxy (HVPE) may be used, but is not limited thereto. According to a preferred embodiment of the present invention, the light emitting structure 160 may be formed using a metal organic chemical vapor deposition method.
n형 반도체층(120) 및 p형 반도체층(140)은 AlxGa(1-x)N의 조성식(여기서, 0≤x≤1)을 갖는 질화갈륨계 반도체 물질일 수 있으며, 상기 질화갈륨계 화합물의 성분비를 조절함으로써 장파장에서부터 단파장까지의 발광다이오드를 자유롭게 제작할 수 있다.The n-type semiconductor layer 120 and the p-type semiconductor layer 140 may be a gallium nitride-based semiconductor material having a composition formula of Al x Ga (1-x) N (where 0 ≦ x ≦ 1), and the gallium nitride By controlling the component ratio of the compound, a light emitting diode from a long wavelength to a short wavelength can be freely produced.
n형 반도체층(120)은 활성층(130)에 전자를 공급하는 층으로서, n형 도전성 불순물이 도핑된 GaN 층 또는 GaN/AlGaN 층으로 형성될 수 있다. 상기 n형 도전성 불순물로는 예를 들면 Si, Ge, Sn 등을 사용할 수 있다. 본 발명의 일 실시예에 따르면, n형 반도체층(120)은 Si가 도핑된 GaN 층 또는 GaN/AlGaN 층으로 형성할 수 있다. The n-type semiconductor layer 120 is a layer for supplying electrons to the active layer 130 and may be formed of a GaN layer or a GaN / AlGaN layer doped with n-type conductive impurities. As the n-type conductive impurity, for example, Si, Ge, Sn or the like can be used. According to an embodiment of the present invention, the n-type semiconductor layer 120 is a Si-doped GaN layer Or a GaN / AlGaN layer.
도 1a 내지 1c에는 n형 반도체층(120)을 예시적으로 단층으로 도시하였으나, n형 반도체층(120)은 단층 또는 다층으로 형성될 수 있으며, 본 발명은 이에 대해 한정하지는 않는다.  Although the n-type semiconductor layer 120 is illustrated as a single layer in FIGS. 1A to 1C, the n-type semiconductor layer 120 may be formed as a single layer or a multilayer, but the present invention is not limited thereto.
활성층(130)은 n형 반도체층(120) 상에 형성되며, 다중 양자우물(Multi-Quantum Well) 구조의 InGaN/GaN층으로 형성되거나, 하나의 양자 우물층 또는 더블헤테로 구조로도 형성될 수 있다.The active layer 130 is formed on the n-type semiconductor layer 120 and may be formed of an InGaN / GaN layer having a multi-quantum well structure, or may be formed of one quantum well layer or a double hetero structure. have.
p형 반도체층(140)은 p형 도전성 불순물이 도핑된 GaN 층 또는 GaN/AlGaN 층으로 형성될 수 있다. 상기 p형 도전성 불순물로는 예를 들면 Mg, Zn, Be 등을 사용할 수 있다. 본 발명의 일 실시예에 따르면, p형 반도체층(140)은 Mg가 도핑된 GaN 층 또는 GaN/AlGaN 층으로 형성할 수 있다. The p-type semiconductor layer 140 may be formed of a GaN layer or a GaN / AlGaN layer doped with a p-type conductive impurity. As the p-type conductive impurity, for example, Mg, Zn, Be or the like can be used. According to an embodiment of the present invention, the p-type semiconductor layer 140 may be formed of a GaN layer or a GaN / AlGaN layer doped with Mg.
도 1a 내지 1c에는 p형 반도체층(140)을 예시적으로 단층으로 도시하였으나, p형 반도체층(140)도 단층 또는 다층으로 형성될 수 있으며, 본 발명은 이에 대해 한정하지는 않는다. 이에 따라 발광 구조물(160)은 N-P 접합, P-N 접합, N-P-N 접합 및 P-N-P 접합 구조 중 적어도 하나를 포함할 수 있다.Although the p-type semiconductor layer 140 is illustrated as a single layer in FIGS. 1A to 1C, the p-type semiconductor layer 140 may also be formed as a single layer or a multilayer, and the present invention is not limited thereto. Accordingly, the light emitting structure 160 may include at least one of an N-P junction, a P-N junction, an N-P-N junction, and a P-N-P junction structure.
한편 도 1a 에 도시된 바와 같이, 발광 구조물(160) 및 기판(100) 사이에는 둘 사이의 격자 상수 차이를 완화하기 위해 버퍼층(110)이 더 형성될 수도 있다. 본 발명의 일 실시예에 따르면, 버퍼층(110)은 도핑되지 않은 순수한 GaN 층으로 형성될 수 있으며, 소자의 특성 및 공정 조건에 따라 생략될 수도 있다.Meanwhile, as shown in FIG. 1A, a buffer layer 110 may be further formed between the light emitting structure 160 and the substrate 100 to alleviate the lattice constant difference between the two. According to an embodiment of the present invention, the buffer layer 110 may be formed of a pure undoped GaN layer, and may be omitted depending on the characteristics of the device and the process conditions.
본 발명의 다른 실시예에 따르면, 발광 구조물(160)은 전면 발광 또는 배면 발광 구조를 갖는 유기 발광 다이오드(organic light emitting diode, OLED)일 수 있다. According to another embodiment of the present invention, the light emitting structure 160 may be an organic light emitting diode (OLED) having a top emission or a bottom emission structure.
유기 발광 다이오드는 두 개의 전극 사이에 유기물층을 배열하고 전계를 가하여 주입된 전자와 정공이 유기물 내에서 재결합하여 형성되는 여기자(exciton)가 기저 상태로 떨어지면서 빛을 내는 소자이다. 상기 유기 발광 다이오드는 재료, 발광 메커니즘, 발광 방향, 구동 방법 등에 따라서 다양하게 분류할 수 있는데, 발광 구조에 따라서 나누어 보면 유리 기판 방향으로 빛을 방출하는 배면 발광(bottom emission)과 유리 기판의 반대 방향으로 방출하는 전면 발광(top emission)으로 나눌 수 있다. 본 발명의 발광소자의 제조 방법은, 예를 들어 배면 발광(bottom emission)의 유기 발광 다이오드에 적용하여 광추출 효율을 향상시킬 수 있다. An organic light emitting diode is an element that emits light when an exciton formed by recombining injected electrons and holes in an organic material by arranging an organic material layer between two electrodes and applying an electric field to a ground state. The organic light emitting diodes may be classified into various materials according to materials, light emitting mechanisms, light emitting directions, driving methods, and the like. The organic light emitting diodes may be divided into bottom emission and bottom glass emitting light toward the glass substrate. It can be divided into a top emission (emission). The manufacturing method of the light emitting device of the present invention can be applied to the organic light emitting diode of the bottom emission (for example, bottom emission) can improve the light extraction efficiency.
도 1b 에 도시된 바와 같이, 발광 구조물(160) 형성 후 발광 구조물(160) 상에 전극층(150)이 형성된다.As shown in FIG. 1B, an electrode layer 150 is formed on the light emitting structure 160 after the light emitting structure 160 is formed.
전극층(150)은 전기전도성을 가지는 투명 도전층일 수 있다. 예를 들어, 전극층(150)은 ITO(indium tin oxide), IZO(indium zinc oxide), IZTO(indium zinc tin oxide), IAZO(indium aluminum zinc oxide), IGZO(indium gallium zinc oxide), IGTO(indium gallium tin oxide), AZO(aluminum zinc oxide), ATO(antimony tin oxide), GZO(gallium zinc oxide), IrOx, RuOx, RuOx/ITO, Ni, Ag, Ni/IrOx/Au, 및 Ni/IrOx/Au/ITO 으로 이루어진 군에서 선택되는 어느 하나 이상을 이용하여 단층 또는 다층으로 형성할 수 있다. 본 발명의 일 실시예에 따르면, 전극층(150)은 e-빔 증착(e-beam evaporation) 방법 또는 스퍼터링(sputtering) 방법 등으로 형성될 수 있으나, 이에 제한되지는 않으며 본 발명이 속하는 기술분야에서 통상적으로 사용하는 방법이 이용될 수 있다. The electrode layer 150 may be a transparent conductive layer having electrical conductivity. For example, the electrode layer 150 may be indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium aluminum zinc oxide (IAZO), indium gallium zinc oxide (IGZO), or indium IGTO (IGTO). gallium tin oxide), aluminum zinc oxide (AZO), antimony tin oxide (ATO), gallium zinc oxide (GZO), IrOx, RuOx, RuOx / ITO, Ni, Ag, Ni / IrOx / Au, and Ni / IrOx / Au It can be formed in a single layer or multiple layers using any one or more selected from the group consisting of / ITO. According to an embodiment of the present invention, the electrode layer 150 may be formed by an e-beam evaporation method or a sputtering method, but is not limited thereto. Conventionally used methods may be used.
이때, 전극층(150)과 공기 중의 산소가 만나 자연 발생적으로 금속 산화막이 발생할 수 있다. 따라서, 상기 금속 산화막을 제거하는 공정을 더 수행할 수 있다. 상기 금속 산화막 제거 공정은 발광 구조물(160) 및 전극층(150)이 형성된 기판을 유기산 용액에 침지하여 실시될 수 있다. At this time, the electrode layer 150 meets oxygen in the air and may naturally generate a metal oxide film. Therefore, the process of removing the metal oxide film may be further performed. The metal oxide film removing process may be performed by immersing the substrate on which the light emitting structure 160 and the electrode layer 150 are formed in an organic acid solution.
본 발명의 일 실시예에 따르면, 금속 산화막 제거공정은 유기산 및 탈이온수(de-ionized water)를 포함하는 약 0.2 내지 약 20 중량%의 유기산 수용액에 약 30초 내지 약 10분간 침지시켜 실시될 수 있다. 이후 다시 순수한 탈이온수에 침지하여 세정한 후 질소 기체로 기판을 건조시킴으로써 금속 산화막을 제거할 수 있다. According to an embodiment of the present invention, the metal oxide film removing process may be performed by immersing in an aqueous solution of about 0.2 to about 20 wt% organic acid containing organic acid and de-ionized water for about 30 seconds to about 10 minutes. have. Subsequently, the metal oxide film may be removed by again immersing in pure deionized water, followed by washing the substrate with nitrogen gas.
상기 유기산은 활성화 용액에 첨가되는 활성화제와 동일하거나 다를 수 있다. 예를 들어 구연산(citric acid), 옥살산(oxalic acid), 말론산(malonic acid), 사과산(malic acid), 주석산(tartaric acid), 초산(acetic acid), 푸마르산(fumaric acid), 젖산(lactic acid), 포름산(formic acid), 프로피온산(propionic acid), 부티르산(butyric acid), 이미노디아세트산(iminodiacetic acid), 글리옥실산(glyoxylic acid), 또는 아스코르빈산(ascorbic acid)과 같은 유기산을 사용할 수 있으나 이에 한정되는 것은 아니다. The organic acid may be the same as or different from the activator added to the activation solution. For example citric acid, oxalic acid, malonic acid, malic acid, malic acid, tartaric acid, acetic acid, fumaric acid, lactic acid ), Organic acids such as formic acid, propionic acid, butyric acid, iminodiacetic acid, glyoxylic acid, or ascorbic acid. However, it is not limited thereto.
다음으로 도 1c에 도시된 바와 같이, 전극층(150) 상에 나노 크기의 요철 구조를 포함하는 금속입자층(200)이 형성된다.Next, as shown in FIG. 1C, the metal particle layer 200 including the nano-sized uneven structure is formed on the electrode layer 150.
본 발명의 일 실시예에 따른 발광소자의 제조방법에서, 발광 구조물(160)의 광추출 향상을 위해 금속입자층(200)을 형성한다. 즉, 광추출 향상에 유리한 요철 형성을 위해 물리적 또는 화학적 식각 공정을 수행하는 대신 금속염 환원에 의한 습식 공정에 의해 금속 나노 입자를 석출시켜 나노 크기의 요철 구조를 포함하는 금속입자층(200)을 형성한다. 본 발명의 방법에 따르면, 물리화학적 식각 공정에 의한 발광 구조물(160) 손상 등의 문제점을 해결할 수 있다. In the method of manufacturing a light emitting device according to an embodiment of the present invention, the metal particle layer 200 is formed to improve light extraction of the light emitting structure 160. That is, instead of performing a physical or chemical etching process to form an unevenness to improve light extraction, metal nanoparticles are precipitated by a wet process by metal salt reduction to form a metal particle layer 200 including a nano-sized uneven structure. . According to the method of the present invention, problems such as damage to the light emitting structure 160 by the physicochemical etching process may be solved.
보다 구체적으로, 발광 구조물(160) 및 전극층(150)이 형성된 기판(100)을 금속 화합물, 유기산 활성화제 및 착화제를 포함하는 활성화 용액에 침지시켜 전극층(150) 상에 금속 입자를 석출시킴으로써 나노 크기의 요철 구조를 포함하는 금속입자층(200)을 형성한다. More specifically, the substrate 100 on which the light emitting structure 160 and the electrode layer 150 are formed is immersed in an activating solution containing a metal compound, an organic acid activator, and a complexing agent to deposit metal particles on the electrode layer 150. A metal particle layer 200 including an uneven structure of size is formed.
상기 금속 화합물은 팔라듐, 은, 금, 구리, 갈륨, 티타늄, 탄탈륨, 루테늄, 주석, 백금 또는 이들의 합금을 포함하는 금속염, 금속 염화물, 금속 산화물, 금속 수화물 등이 될 수 있으나 이에 제한되는 것은 아니다. 본 발명의 일 실시예에 따르면, 상기 금속 화합물로 염화팔라듐(PdCl2)과 같은 금속 염화물을 사용할 수 있다. The metal compound may be palladium, silver, gold, copper, gallium, titanium, tantalum, ruthenium, tin, platinum or metal salts including alloys thereof, metal chlorides, metal oxides, metal hydrates, and the like, but is not limited thereto. . According to an embodiment of the present invention, a metal chloride such as palladium chloride (PdCl 2 ) may be used as the metal compound.
상기 활성화 용액 내의 금속 화합물의 농도는 약 0.001 내지 약 5g/L, 바람직하게는 약 0.001 내지 약 0.5g/L 일 수 있다. 농도가 0.001 g/L 미만으로 너무 낮으면 금속 나노 입자를 형성할 수 없고, 5g/L을 초과하여 너무 높으면 금속 입자가 지나치게 커지는 문제점이 있다. The concentration of the metal compound in the activation solution may be about 0.001 to about 5 g / L, preferably about 0.001 to about 0.5 g / L. If the concentration is too low, less than 0.001 g / L, the metal nanoparticles can not be formed, if the concentration is too high exceeding 5 g / L there is a problem that the metal particles are too large.
상기 유기산 활성화제는 금속 화합물의 환원 반응을 촉진하는 역할을 한다. 또한 전극층(150)을 미세하게 식각하여 전반사를 감소시키는 이중의 역할을 할 수 있다. 상기 활성화제로는 예를 들어 구연산(citric acid), 옥살산(oxalic acid), 말론산(malonic acid), 사과산(malic acid), 주석산(tartaric acid), 초산(acetic acid), 푸마르산(fumaric acid), 젖산(lactic acid), 포름산(formic acid), 프로피온산(propionic acid), 부티르산(butyric acid), 이미노디아세트산(iminodiacetic acid), 글리옥실산(glyoxylic acid), 아스코르빈산(ascorbic acid), 또는 기타 지방족 폴리카르본산(aliphatic polycarboxylic acid) 등과 같은 유기산을 사용할 수 있다. The organic acid activator serves to promote a reduction reaction of the metal compound. In addition, by finely etching the electrode layer 150 may serve as a double to reduce the total reflection. As the activator, for example, citric acid (citric acid), oxalic acid (oxalic acid), malonic acid (malonic acid), malic acid (malic acid), tartaric acid, acetic acid (acetic acid), fumaric acid (fumaric acid), Lactic acid, formic acid, propionic acid, butyric acid, iminodiacetic acid, glyoxylic acid, ascorbic acid, or other Organic acids such as aliphatic polycarboxylic acids can be used.
본 발명의 일 실시예에 따르면, 상기 활성화제로는 전극층(150)을 과도하게 식각하지 않으면서 금속 화합물의 환원 반응을 촉진하기 위해서 구연산과 같은 유기산을 사용하는 것이 바람직하다. 상기 활성화제로 유기산을 포함하여 상기 활성화 용액의 pH를 1 내지 6로 조절하는 경우 금속입자층(200)의 형성이 더 용이할 수 있다. 또한 상기 활성화제로 유기산, 특히 구연산과 같은 폴리카르본산을 포함할 때 금속입자층(200)의 요철 구조가 더 세밀하고 균일하게 형성될 수 있다.According to one embodiment of the present invention, it is preferable to use an organic acid such as citric acid to promote the reduction reaction of the metal compound without excessively etching the electrode layer 150 as the activator. When the pH of the activation solution is adjusted to 1 to 6, including the organic acid as the activator, the formation of the metal particle layer 200 may be easier. In addition, when the activator includes an organic acid, particularly a polycarboxylic acid such as citric acid, the uneven structure of the metal particle layer 200 may be more finely and uniformly formed.
상기 착화제는 상기 금속 화합물의 금속 이온과 리간드를 형성하는 역할을 한다. 상기 착화제로는 예를 들어 HF, NHF4, 또는 HCl 등을 사용할 수 있으며, 본 발명의 일 실시예에 따르면, 상기 착화제로 염산(HCl)을 사용할 수 있다. The complexing agent serves to form ligands with the metal ions of the metal compound. For example, HF, NHF 4 , or HCl may be used as the complexing agent. According to one embodiment of the present invention, hydrochloric acid (HCl) may be used as the complexing agent.
상기 착화제는 금속 화합물의 금속 이온과 리간드를 형성한 후 상기 금속 화합물의 금속과 치환반응을 함으로써 전극층(150)의 표면에 금속이 나노 크기로 석출되어 금속입자층(200)이 형성될 수 있다. 예를 들어, 상기 금속 화합물로 염화팔라듐을 사용하고 상기 착화제로 염산을 사용할 경우 하기 반응식 1과 같은 반응으로 전극층(150)의 표면에 팔라듐 입자가 석출되어 요철 구조를 갖는 금속입자층(200)이 형성될 수 있다.The complexing agent may form a metal ion and a ligand of the metal compound, and then perform a substitution reaction with the metal of the metal compound, thereby depositing a metal to a nano size on the surface of the electrode layer 150 to form the metal particle layer 200. For example, when palladium chloride is used as the metal compound and hydrochloric acid is used as the complexing agent, palladium particles are deposited on the surface of the electrode layer 150 in the same reaction as in Scheme 1 to form a metal particle layer 200 having an uneven structure. Can be.
금속입자층(200)은 금속 화합물의 환원 반응에 의해 석출된 금속 입자에 의해 형성되기 때문에 나노 크기의 요철 구조를 복수 개로 포함한다. 또한 상기 나노 크기는 석 w된 금속 입자의 크기와 상응하며, 수십 나노 내지 수천 나노 크기가 될 수 있다. 본 발명의 일 실시예에 따르면, 약 10 내지 약 1,000nm, 바람직하게는 약 30 내지 약 500 nm의 높이를 갖는 요철 구조물을 형성할 수 있다. Since the metal particle layer 200 is formed of the metal particles precipitated by the reduction reaction of the metal compound, the metal particle layer 200 includes a plurality of nano-sized uneven structures. In addition, the nano-size corresponds to the size of the metal particles of stone w, may be several tens of nanometers to thousands of nanometers in size. According to one embodiment of the invention, it is possible to form the uneven structure having a height of about 10 to about 1,000 nm, preferably about 30 to about 500 nm.
또한 금속입자층(200)의 요철 구조물의 크기를 보다 크게 하기 위하여, 필요에 따라 활성화 용액에 기판을 침지시켜 전극층(150) 상에 금속 나노 입자를 석출시키는 단계를 반복하여 실시할 수 있다. 상기 활성화 용액에 침지시키는 회수를 조절함으로써 적절한 크기의 요철 구조를 갖는 금속입자층(200)을 형성하는 것이 가능하다.In addition, in order to increase the size of the concave-convex structure of the metal particle layer 200, a step of depositing the metal nanoparticles on the electrode layer 150 by immersing the substrate in the activation solution may be repeatedly performed as necessary. It is possible to form the metal particle layer 200 having a concave-convex structure of an appropriate size by adjusting the number of times immersed in the activation solution.
도 2는 본 발명의 일 실시예에 따라 전극층 상에 요철 구조의 금속입자층이 형성된 경우의 광 경로를 도시하는 도면이다.FIG. 2 is a view showing an optical path when a metal particle layer having a concave-convex structure is formed on an electrode layer according to an embodiment of the present invention.
도 2를 참고하면, 전극층 상에 나노 크기의 금속으로 이루어진 요철 구조가 형성됨으로써 고굴절율을 달성할 수 있고 광구속 중심이 상향으로 이동하여 광추출 효율이 향상될 수 있다. Referring to FIG. 2, a high refractive index can be achieved by forming an uneven structure made of nano-sized metal on the electrode layer, and the light extraction center can be moved upward to improve light extraction efficiency.
따라서, 평탄한 표면을 갖는 전극층에 비하여 본 발명은 빛의 전반사를 현저하게 감소시켜 발광소자의 광추출 효율을 현저하게 향상시킬 수 있다.Therefore, compared with the electrode layer having a flat surface, the present invention can significantly reduce the total reflection of light, thereby significantly improving the light extraction efficiency of the light emitting device.
본 발명에 따라 전극층 상에 요철 구조의 금속입자층을 구비하는 발광소자는, 저출력용 발광 다이오드, 고출력 플립형 발광 다이오드, 수직형 발광 다이오드, 유기 발광 다이오드(Organic Light Emitting Diode; OLED) 또는 그 외 발광소자에 제한 없이 적용 가능하다. According to the present invention, a light emitting device including a metal particle layer having an uneven structure on an electrode layer may include a low power light emitting diode, a high power flip light emitting diode, a vertical light emitting diode, an organic light emitting diode (OLED), or other light emitting devices. Applicable without limitation.
상기 습식 공정에 의해 전극층 상에 요철 구조의 금속입자층을 형성하는 단계 이후 각 종 소자 제조방법은 본 발명이 속하는 기술분야에서 알려진 통상적인 방법에 따라 제조될 수 있다. After the step of forming the metal particle layer of the concave-convex structure on the electrode layer by the wet process, each device manufacturing method may be prepared according to a conventional method known in the art.
예를 들어, 본 발명의 일 실시예에 따르면 레이저 리프트-오프 공정을 이용하여 기판(100)을 제거할 수 있다. 상기 레이저 리프트-오프 공정을 수행하여 기판(100)으로부터 분리되어 노출된 n형 반도체층의 표면을 식각하여 요철을 형성 후, n형 반도체층의 표면에 도전성 물질을 증착하여 n형 전극을 일정 간격으로 복수 개 형성한다. 이때, n형 전극 증착을 위한 트렌치를 일정 간격으로 미리 형성할 수 있다. 이후, 레이저 스크라이빙(scribing)이나 다이싱(dicing) 후, 칩 브레이킹(chip breaking) 공정을 수행하여 개별 LED 소자로 분리하여 발광 다이오드 소자를 완성할 수 있다.For example, according to an embodiment of the present invention, the substrate 100 may be removed using a laser lift-off process. By performing the laser lift-off process After etching the surface of the n-type semiconductor layer separated from the substrate 100 to form an unevenness, a plurality of n-type electrodes are formed at predetermined intervals by depositing a conductive material on the surface of the n-type semiconductor layer. In this case, trenches for depositing the n-type electrode may be previously formed at predetermined intervals. Thereafter, after laser scribing or dicing, a chip breaking process may be performed to separate the LEDs into individual LED devices, thereby completing the LED device.
이하에서, 본 발명에 따른 실시예를 참조하여 본 발명을 더욱 상세히 설명하기로 한다. 다만, 이러한 실시예는 발명의 예시로 제시된 것에 불과하며, 이에 의해 발명의 권리범위가 정해지는 것은 아니다.Hereinafter, the present invention will be described in more detail with reference to embodiments according to the present invention. However, these embodiments are only presented as an example of the invention, whereby the scope of the invention is not determined.
실시예Example
사파이어(Al2O3) 기판(100) 상에 MOCVD(metal-organic chemical vapor deposition)의 방법으로 GaN 을 포함하는 버퍼층(110), Si가 도핑된 GaN을 포함하는 n형 반도체층(120), InGaN/GaN의 활성층(130) 및 Mg가 도핑된 GaN을 포함하는 p형 반도체층(140)을 차례로 형성하였다. A buffer layer 110 including GaN, an n-type semiconductor layer 120 including GaN doped with Si by a method of metal-organic chemical vapor deposition (MOCVD) on a sapphire (Al 2 O 3 ) substrate 100, An active layer 130 of InGaN / GaN and a p-type semiconductor layer 140 including GaN doped with Mg were sequentially formed.
상기 p형 반도체층(140) 상에 스퍼터링의 방법으로 100 nm 두께의 ITO(indium tin oxide) 투명 전극층(150)을 형성하였다. 상기 투명 전극층(150)이 형성된 기판을 1 중량%의 구연산 및 탈이온수를 포함하는 수용액에 3분간 침지시킨 후 다시 탈이온수에 1분간 침지하였다. 다음에 질소(N2) 기체로 건조하여 투명 전극층 상에 형성된 산화막을 제거하였다.An indium tin oxide (ITO) transparent electrode layer 150 having a thickness of 100 nm was formed on the p-type semiconductor layer 140 by sputtering. The substrate on which the transparent electrode layer 150 was formed was immersed in an aqueous solution containing 1 wt% citric acid and deionized water for 3 minutes and then immersed in deionized water for 1 minute. Next, the oxide film formed on the transparent electrode layer was removed by drying with nitrogen (N 2 ) gas.
0.01g/L의 염화팔라듐(PdCl2), 10 g/L의 구연산, 및 35 중량%의 염산(HCl)이 혼합된 활성화 용액에 10분간 침지시킨 후, 탈이온수에서 10초 동안 침지를 2번 실시함으로써 투명 전극층 상에 나노 크기의 요철 구조를 포함하는 금속입자층을 형성하였다. 10 minutes of immersion in an activated solution containing 0.01 g / L of palladium chloride (PdCl 2 ), 10 g / L of citric acid, and 35% by weight of hydrochloric acid (HCl), followed by two immersions in deionized water for 10 seconds. By performing, the metal particle layer containing nano-sized uneven structure was formed on the transparent electrode layer.
비교예Comparative example
구연산 대신 불산(HF)을 사용한 것을 제외하고는 실시예와 동일한 방법으로 금속입자층을 형성하였다. A metal particle layer was formed in the same manner as in Example except that hydrofluoric acid (HF) was used instead of citric acid.
실험 결과Experiment result
도 3은 본 발명의 실시예에 따라 형성된 요철 구조를 포함하는 금속입자층 표면을 주사전자현미경(Scanning Electron Microscope, SEM)으로 배율에 따라 관찰한 사진이다. 도 3에서, 사진 (a) 내지 (f)는 각각 2,500배, 10,000배, 50,000배, 80,000배, 130,000배, 및 200,000배로 확대한 것이다. 도 3을 참조하면, 약 10 내지 약 200nm의 높이를 갖는 나노 크기의 요철 구조가 형성되었음을 알 수 있다. 3 is a photograph of the surface of the metal particle layer including the concave-convex structure formed according to an embodiment of the present invention according to the magnification with a scanning electron microscope (SEM). In Fig. 3, photographs (a) to (f) are magnified 2,500 times, 10,000 times, 50,000 times, 80,000 times, 130,000 times, and 200,000 times, respectively. Referring to Figure 3, it can be seen that the nano-sized uneven structure having a height of about 10 to about 200nm is formed.
도 4는 실시예에 따라 형성된 요철 구조를 포함하는 금속입자층 표면을 전계 방출형 주사전자현미경(Field Emission Scanning Electron Microscope, FE-SEM)을 이용하여 원소 구성을 분석한 결과를 나타낸 것이다. 도 4를 참고하면, Pd를 포함하는 요철 구조가 형성되었음을 알 수 있다.Figure 4 shows the results of analyzing the elemental composition on the surface of the metal particle layer including the concave-convex structure formed according to the embodiment using a field emission scanning electron microscope (FE-SEM). Referring to FIG. 4, it can be seen that an uneven structure including Pd is formed.
도 5는 전처리후 ITO 기판 표면 및 실시예 및 비교예에서 제조된 금속입자층을 관찰한 SEM 이미지이다. 도 5로부터 본 발명의 실시예에 따라 유기산을 사용한 경우의 금속입자층은 무기산을 사용한 비교예의 경우보다 금속입자의 크기가 작아지고 밀도는 확연히 증가하였음을 알 수 있다. 또한 비교예의 경우 ITO 기판 표면이 식각되어 Pd 금속입자가 생성이 원활하지 않은 것도 발견되었다.5 is an SEM image of the surface of the ITO substrate and the metal particle layer prepared in Examples and Comparative Examples after pretreatment. It can be seen from FIG. 5 that the metal particle layer in the case of using the organic acid according to the embodiment of the present invention has a smaller size and a higher density of the metal particles than in the case of the comparative example using the inorganic acid. In addition, it was also found that the surface of the ITO substrate was etched in the comparative example, so that Pd metal particles were not easily produced.
이와 같이 본 발명에 따른 방법으로 형성된 금속입자층은 균일한 나노입자층을 형성하기 때문에 발광소자 적용시 20% 이상의 광추출 효율 증대를 기대할 수 고, 고출력 소자 동작시에도 5% 이하의 적은 효율 감소를 기대할 수 있다.As described above, since the metal particle layer formed by the method according to the present invention forms a uniform nanoparticle layer, light extraction efficiency of 20% or more can be expected to be increased when a light emitting device is applied, and a small efficiency reduction of 5% or less can be expected even when a high power device is operated. Can be.
본 발명에 따르면, 금속화합물을 유기산 활성화제를 포함하는 활성화 용액과 접촉시키는 습식 공정에 의해 환원시켜 금속입자를 석출함으로써 보다 간단한 공정으로 요철 구조의 금속입자층을 형성할 수 있다. 본 발명에 따른 금속입자층을 발광소자에 적용시 보다 간단한 공정으로 발광소자의 광추출 효율을 향상시킬 수 있다.According to the present invention, the metal compound layer is reduced by a wet process of contacting the metal compound with an activation solution containing an organic acid activator to precipitate metal particles, thereby forming a metal particle layer having an uneven structure. When the metal particle layer according to the present invention is applied to a light emitting device, the light extraction efficiency of the light emitting device can be improved by a simpler process.

Claims (19)

  1. 산화되어 전자를 발생할 수 있는 기재를, Base material that can be oxidized to generate electrons,
    금속화합물, 유기산 활성화제 및 착화제를 포함하는 활성화 용액과 접촉시키는 단계를 포함하며, Contacting with an activating solution comprising a metal compound, an organic acid activator and a complexing agent,
    상기 기재는 상기 유기산 활성화제에 의해 산화되어 전자를 발생시키고, The substrate is oxidized by the organic acid activator to generate electrons,
    상기 금속화합물은 상기 전자에 의해 환원되어 상기 기재의 표면 상에 금속입자로 석출되어 금속입자층을 형성하는 것인, 금속입자층 형성 방법.And the metal compound is reduced by the electrons to precipitate as metal particles on the surface of the substrate to form a metal particle layer.
  2. 제1항에 있어서, The method of claim 1,
    상기 금속입자층은 나노 크기의 요철 구조를 갖는 것인 방법.The metal particle layer has a nano-sized uneven structure.
  3. 제2항에 있어서, 상기 요철은 10 내지 1,000nm의 높이를 갖는 것인 방법.The method of claim 2, wherein the unevenness has a height of 10 to 1,000 nm.
  4. 제1항에 있어서, The method of claim 1,
    상기 기재는 인듐, 주석, 아연, 알루미늄, 갈륨, 안티몬, 이리듐, 루테늄, 니켈, 은, 금으로 이루어진 군에서 선택되는 하나 이상을 포함하는 것인 방법.Wherein said substrate comprises at least one selected from the group consisting of indium, tin, zinc, aluminum, gallium, antimony, iridium, ruthenium, nickel, silver, gold.
  5. 제4항에 있어서, The method of claim 4, wherein
    상기 기재는 ITO(indium tin oxide), IZO(indium zinc oxide), IZTO(indium zinc tin oxide), IAZO(indium aluminum zinc oxide), IGZO(indium gallium zinc oxide), IGTO(indium gallium tin oxide), AZO(aluminum zinc oxide), ATO(antimony tin oxide), GZO(gallium zinc oxide), IrOx, RuOx, Ni, Ag 및 Au 로 이루어진 군에서 선택되는 어느 하나 이상을 포함하는 것인 방법.The substrate is indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium aluminum zinc oxide (IZAO), indium gallium zinc oxide (IGZO), indium gallium tin oxide (IGTO), AZO (aluminum zinc oxide), antimony tin oxide (ATO), gallium zinc oxide (GZO), IrOx, RuOx, Ni, Ag, and Au.
  6. 제1항에 있어서, The method of claim 1,
    상기 금속입자층을 형성하기 이전에 상기 기재가 공기 중의 산소와 만나 형성되는 금속산화막을 제거하는 단계를 더 포함하는 방법.And removing the metal oxide film in which the substrate is formed with oxygen in the air before forming the metal particle layer.
  7. 제1항에 있어서, The method of claim 1,
    상기 금속입자층을 형성하는 단계는 상기 기재를 상기 활성화 용액에 1회 이상 침지하여 수행되는 것인 방법.The forming of the metal particle layer is performed by immersing the substrate in the activation solution one or more times.
  8. 제1항에 있어서, The method of claim 1,
    상기 금속화합물은 팔라듐, 은, 금, 구리, 갈륨, 티타늄, 탄탈륨, 루테늄, 주석, 백금 또는 이들의 합금을 포함하는 금속염, 금속 산화물 및 금속 수화물로 이루어진 군에서 선택되는 어느 하나 이상을 포함하는 것인 방법.The metal compound includes one or more selected from the group consisting of metal salts, metal oxides and metal hydrates including palladium, silver, gold, copper, gallium, titanium, tantalum, ruthenium, tin, platinum or alloys thereof. How to be.
  9. 제1항에 있어서, The method of claim 1,
    상기 활성화 용액 중 금속화합물의 농도는 0.001 내지 5g/L인 방법.The concentration of the metal compound in the activation solution is 0.001 to 5g / L.
  10. 제1항에 있어서, The method of claim 1,
    상기 유기산 활성화제는 탄소수 1 ~ 10 의 유기산인 방법.The organic acid activator is a method having 1 to 10 carbon atoms organic acid.
  11. 제1항에 있어서, The method of claim 1,
    상기 유기산 활성화제는 구연산(citric acid), 옥살산(oxalic acid), 말론산(malonic acid), 사과산(malic acid), 주석산(tartaric acid), 초산(acetic acid), 푸마르산(fumaric acid), 젖산(lactic acid), 포름산(formic acid), 프로피온산(propionic acid), 부티르산(butyric acid), 이미노디아세트산(iminodiacetic acid), 글리옥실산(glyoxylic acid) 및 아스코르빈산(ascorbic acid)으로 이루어진 군에서 선택되는 어느 하나 이상을 포함하는 것인 방법. The organic acid activator is citric acid (citric acid), oxalic acid (oxalic acid), malonic acid (malonic acid), malic acid (malic acid), tartaric acid (acetic acid), fumaric acid (fumaric acid), lactic acid ( lactic acid, formic acid, propionic acid, butyric acid, butyric acid, iminodiacetic acid, glyoxylic acid and ascorbic acid Comprising any one or more of the above.
  12. 제1항에 있어서, The method of claim 1,
    상기 유기산 활성화제는 탄소수 2 내지 10 의 지방족 폴리카르본산(aliphatic polycarboxylic acid) 인 방법. The organic acid activator is aliphatic polycarboxylic acid having 2 to 10 carbon atoms.
  13. 제1항에 있어서, The method of claim 1,
    상기 착화제는 HCl, HF, 및 NHF3으로 이루어진 군에서 선택되는 어느 하나 이상을 포함하는 것인 방법. Wherein said complexing agent comprises any one or more selected from the group consisting of HCl, HF, and NHF 3 .
  14. 제1항에 있어서, 상기 활성화 용액은 알킬렌글리콜 모노알킬 에테르를 더 포함하는 것인 방법. The method of claim 1, wherein the activation solution further comprises an alkylene glycol monoalkyl ether.
  15. 제1항 내지 제14항 중 어느 한 항에 따른 방법으로 제조된, 금속화합물의 환원에 의해 석출된 금속입자로 이루어진 금속입자층을 포함하는 소자. A device comprising a metal particle layer made of metal particles precipitated by reduction of a metal compound, prepared by the method according to any one of claims 1 to 14.
  16. 기판 상에 발광 구조물, 전극층 및 금속입자층이 순차적으로 형성되어 있는 발광소자이며, 상기 금속입자층은 제1항 내지 제14항 중 어느 한 항에 따른 방법으로 금속화합물의 환원에 의해 석출된 금속 입자로 형성된 것인 발광소자. A light emitting device in which a light emitting structure, an electrode layer and a metal particle layer are sequentially formed on a substrate, wherein the metal particle layer is a metal particle precipitated by reduction of a metal compound by the method according to any one of claims 1 to 14. The light emitting device is formed.
  17. 제16항에 있어서, The method of claim 16,
    상기 발광 구조물은 n형 반도체층/활성층/p형 반도체층이 순차적으로 적층된 구조를 갖는 것인 발광소자.The light emitting device has a structure in which the n-type semiconductor layer / active layer / p-type semiconductor layer is laminated in sequence.
  18. 제16항에 있어서, The method of claim 16,
    상기 전극층은 ITO(indium tin oxide), IZO(indium zinc oxide), IZTO(indium zinc tin oxide), IAZO(indium aluminum zinc oxide), IGZO(indium gallium zinc oxide), IGTO(indium gallium tin oxide), AZO(aluminum zinc oxide), ATO(antimony tin oxide), GZO(gallium zinc oxide), IrOx, RuOx, Ni, Ag 및 Au 로 이루어진 군에서 선택되는 어느 하나 이상을 이용하여 형성된 것인 발광소자. The electrode layer may be indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium aluminum zinc oxide (IZAO), indium gallium zinc oxide (IGZO), indium gallium tin oxide (IGTO), or AZO. (Aluminum zinc oxide), ATO (antimony tin oxide), gallium zinc oxide (GZO), IrOx, RuOx, Ni, Ag and Au formed using any one or more selected from the group consisting of.
  19. 제16항에 있어서, 상기 발광소자는 저출력용 발광 다이오드, 고출력 플립형 발광 다이오드, 수직형 발광 다이오드, 또는 유기 발광 다이오드인 발광소자.The light emitting device of claim 16, wherein the light emitting device is a low power light emitting diode, a high output flip light emitting diode, a vertical light emitting diode, or an organic light emitting diode.
PCT/KR2013/006540 2012-07-24 2013-07-22 Method for forming metal particle layer, and light-emitting element produced using same WO2014017793A1 (en)

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