WO2019066411A1 - Reflective electrode for micro light emitting element, micro light emitting element having same, and method for manufacturing reflective electrode for micro light emitting element - Google Patents

Reflective electrode for micro light emitting element, micro light emitting element having same, and method for manufacturing reflective electrode for micro light emitting element Download PDF

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Publication number
WO2019066411A1
WO2019066411A1 PCT/KR2018/011258 KR2018011258W WO2019066411A1 WO 2019066411 A1 WO2019066411 A1 WO 2019066411A1 KR 2018011258 W KR2018011258 W KR 2018011258W WO 2019066411 A1 WO2019066411 A1 WO 2019066411A1
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layer
electrode layer
reflective
transparent electrode
reflective layer
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PCT/KR2018/011258
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French (fr)
Korean (ko)
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김태근
오상훈
손경락
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고려대학교 산학협력단
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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
    • H01L33/36—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 electrodes
    • H01L33/40—Materials therefor
    • H01L33/405—Reflective materials
    • 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
    • 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
    • H01L33/0004—Devices characterised by their operation
    • H01L33/0008—Devices characterised by their operation having p-n or hi-lo junctions
    • 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
    • H01L33/10—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 with a light reflecting structure, e.g. semiconductor Bragg reflector
    • 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
    • H01L33/36—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 electrodes
    • H01L33/40—Materials therefor
    • 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
    • H01L33/36—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 electrodes
    • H01L33/40—Materials therefor
    • H01L33/42—Transparent materials
    • 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
    • H01L33/48—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 body packages
    • H01L33/62—Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls
    • 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
    • H01L2933/0008—Processes
    • H01L2933/0016—Processes relating to electrodes

Definitions

  • the present invention relates to a reflective electrode for a micro light emitting device, a micro light emitting device having the same, and a method of manufacturing a reflective electrode for a micro light emitting device.
  • the p-electrode used for current injection in the micro light emitting device absorbs or blocks the light emitted from the active layer in the pixel, light to be emitted from the micro light emitting device to the outside is reduced.
  • the present invention has been made in view of the above problems, and it is an object of the present invention to provide a reflective electrode for a micro light emitting device having a high reflectivity to an ultraviolet (UV) And a method of manufacturing a reflective electrode for a micro light emitting device.
  • UV ultraviolet
  • a reflective electrode provided in a micro light emitting device in which a substrate, an n-type semiconductor layer, an active layer, and a p-type semiconductor layer are sequentially stacked, ;
  • a reflective layer formed on the transparent electrode layer, the reflective layer including a conductive filament connecting the transparent electrode layer and the p-type electrode layer in an insulator that reflects light emitted from the active layer through the transparent electrode layer;
  • a p-type electrode layer formed on the reflective layer and electrically connected to the transparent electrode layer through the conductive filament of the reflective layer.
  • the conductive filament of the reflective layer is formed by an electric field applied through the transparent electrode layer and the p-type electrode layer after the transparent electrode layer, the reflective layer, and the p-type electrode layer are sequentially laminated.
  • the reflective layer is a distributed Bragg reflector (DBR) in which different resistance change materials are alternately repeatedly laminated.
  • DBR distributed Bragg reflector
  • the resistance-changing material forming the reflective layer is selected from the group consisting of Al 2 O 3 , SiO 2 , HfO 2 , TiO 2 , ZnO, ), trioxide, tungsten (WO 3), molybdenum oxide (MoO 3), nickel oxide (NiO), Mn-doped tin oxide (MTO), Zn doped tin oxide (ZTO), Ga doped ZnO (GZO), Sn x O y , Zr x O y, Co x O y, Cr x O y, V x O y, Nb x O y ZnMgBeO, Mg x O y, Mg x N y, Ti x N y, In x N y, Ga x N y , Ga x O y , boron nitride (BN), Ni x N y , Si x N y , Al doped ZnO (AZO), M
  • the p-type electrode layer includes a plurality of layers in which at least two materials among chromium (Cr), nickel (Ni), gold (Au), aluminum (Al) .
  • the present invention provides a semiconductor device comprising: an n-type semiconductor layer laminated on a substrate; An active layer stacked on the n-type semiconductor layer; A p-type semiconductor layer laminated on the active layer; A transparent electrode layer formed on the p-type semiconductor layer; A reflective layer formed on the transparent electrode layer, the reflective layer including a conductive filament connecting the transparent electrode layer and the p-type electrode layer in an insulator that reflects light emitted from the active layer through the transparent electrode layer; And a p-type electrode layer formed on the reflective layer and electrically connected to the transparent electrode layer through the conductive filament of the reflective layer.
  • the conductive filament of the reflective layer is formed by an electric field applied through the transparent electrode layer and the p-type electrode layer after the transparent electrode layer, the reflective layer, and the p-type electrode layer are sequentially laminated.
  • the reflective layer is a distributed Bragg reflector (DBR) in which different resistance change materials are alternately repeatedly laminated.
  • DBR distributed Bragg reflector
  • the resistance-changing material forming the reflective layer is selected from the group consisting of Al 2 O 3 , SiO 2 , HfO 2 , TiO 2 , ZnO, ), trioxide, tungsten (WO 3), molybdenum oxide (MoO 3), nickel oxide (NiO), Mn-doped tin oxide (MTO), Zn doped tin oxide (ZTO), Ga doped ZnO (GZO), Sn x O y , Zr x O y, Co x O y, Cr x O y, V x O y, Nb x O y ZnMgBeO, Mg x O y, Mg x N y, Ti x N y, In x N y, Ga x N y , Ga x O y , boron nitride (BN), Ni x N y , Si x N y , Al doped ZnO (AZO), M
  • the p-type electrode layer includes a plurality of layers in which at least two materials among chromium (Cr), nickel (Ni), gold (Au), aluminum (Al) .
  • the present invention also provides a method of manufacturing a reflective electrode provided in a micro light emitting device in which a substrate, an n-type semiconductor layer, an active layer and a p-type semiconductor layer are sequentially laminated, comprising the steps of: (1) forming a transparent electrode layer on the p- ; (2) forming a reflective layer on the transparent electrode layer to reflect light emitted from the active layer and flowing through the transparent electrode layer; (3) forming a p-type electrode layer electrically connected to the transparent electrode layer through the reflective layer on the reflective layer; And (4) forming a conductive filament in the reflective layer to electrically connect the transparent electrode layer and the p-type electrode layer to each other.
  • the conductive filament of the reflective layer formed in the step (4) is formed by sequentially laminating the transparent electrode layer, the reflective layer and the p-type electrode layer, and then the transparent electrode layer and the p- Lt; / RTI >
  • the reflective layer formed in step (2) is a distributed Bragg reflector (DBR) in which different resistance change materials are alternately repeatedly laminated.
  • DBR distributed Bragg reflector
  • the resistance change material forming the reflective layer in the step (2) is at least one selected from the group consisting of aluminum oxide (Al 2 O 3 ), silicon dioxide (SiO 2 ), hafnium oxide (HfO 2 ) 2), zinc oxide (ZnO), antimony trioxide of tungsten (WO 3), molybdenum (MoO 3), nickel oxide (NiO), Mn-doped tin oxide (MTO), Zn doped tin oxide (ZTO) oxide, Ga doped ZnO ( GZO), Sn x O y, Zr x O y, Co x O y, Cr x O y, V x O y, Nb x O y ZnMgBeO, Mg x O y, Mg x N y, Ti x N y, In selected from x N y, Ga x N y , Ga x O y, boron nitride (BN), Ni x N y
  • the p-type electrode layer formed in step (3) is at least two of chromium (Cr), nickel (Ni), gold (Au), aluminum (Al)
  • Cr chromium
  • Ni nickel
  • Au gold
  • Al aluminum
  • the material is formed of a plurality of layers which are sequentially stacked.
  • a light emitting device comprising: a transparent electrode layer formed on a p-type semiconductor layer of a micro light emitting device; a light emitting layer formed on the transparent electrode layer and emitting light from the active layer of the micro light emitting device, And a p-type electrode layer formed on the reflective layer and including a conductive filament connecting the transparent electrode layer and the p-type electrode layer and electrically connected to the transparent electrode layer through the conductive filament of the reflective layer, It is possible to provide a reflective electrode having an improved reflection efficiency and an excellent conductivity as compared with the metal electrode, and in particular, the reflection efficiency in the ultraviolet (UV) region can be improved.
  • UV ultraviolet
  • the present invention has the effect of improving the efficiency of reflection by the reflective electrode, thereby improving the efficiency of the micro-light emitting device itself.
  • FIG. 1 is a view for explaining a micro light emitting device according to an embodiment of the present invention.
  • FIG. 2 is a view for explaining a detailed configuration of a reflective electrode for a micro light emitting device according to an embodiment of the present invention.
  • FIG. 3 is a view for explaining a reflection layer of a reflection electrode for a micro light-emitting device
  • FIGS. 4 and 5 are diagrams for explaining the reflectivity of a reflective electrode for a micro light-emitting device.
  • FIG. 6 is a view for explaining a p-type electrode layer of a reflective electrode for a micro light-emitting element
  • FIG. 7 is a view for explaining a method of manufacturing a reflective electrode for a micro light emitting device according to an embodiment of the present invention.
  • FIG. 1 is a view for explaining a micro light emitting device according to an embodiment of the present invention.
  • a micro light emitting device includes a reflective electrode 100 for a micro light emitting device, an n-type nitride semiconductor layer 200, an active layer 300, a p-type nitride semiconductor layer 400, And a reflector layer 500.
  • the reflective electrode 100 for a micro light-emitting device may be formed on a top surface of a micro light-emitting device formed on a substrate 10, and the micro light-emitting device may include an n-type nitride semiconductor layer 200, an active layer 300, and a p-type nitride semiconductor layer 400 sequentially stacked.
  • the n-type nitride semiconductor layer 200 is deposited on the substrate 10.
  • the n-type nitride semiconductor layer 200 may be formed of gallium nitride (GaN) or n-type gallium nitride (N-GaN).
  • the active layer 300 is deposited on the n-type nitride semiconductor layer 200.
  • the active layer 300 may be formed of a multi quantum well (MQW) structure, and may be formed by growing a GaN-based compound.
  • the active layer 300 functions as a light emitting layer for emitting light.
  • MQW multi quantum well
  • the p-type nitride semiconductor layer 400 is stacked on the active layer 300.
  • the p-type nitride semiconductor layer 400 may be formed of p-type gallium nitride (P-GaN).
  • the reflective electrode 100 for the micro light emitting device may be formed on the p-type nitride semiconductor layer 400.
  • the reflective electrode 100 for a micro light-emitting device may supply an externally applied current to the p-type nitride semiconductor layer 400, reflect the light emitted from the active layer 300, Can be improved.
  • the reflector layer 500 may be formed on the lower surface of the substrate 10.
  • the reflector layer 500 functions to reflect light entering through the substrate 10, thereby further improving the efficiency of the micro light emitting device.
  • FIG. 2 is a view for explaining a detailed configuration of a reflective electrode for a micro light emitting device according to an embodiment of the present invention
  • FIG. 3 is a view for explaining a reflective layer of a reflective electrode for a micro light emitting device
  • 6 is a view for explaining a p-type electrode layer of a reflective electrode for a micro light-emitting element.
  • the reflective electrode 100 for a micro light emitting device includes a transparent electrode layer 110, a reflective layer 120, and a p-type electrode layer 130.
  • the transparent electrode layer 110 is formed on the p-type nitride semiconductor layer 400.
  • the transparent electrode layer 110 may be formed by depositing a transparent conductive oxide (TCO).
  • the deposition process of the transparent electrode layer 110 can be performed by chemical vapor deposition (CVD), electron beam evaporation, pulsed laser deposition, or sputtering .
  • CVD chemical vapor deposition
  • electron beam evaporation electron beam evaporation
  • pulsed laser deposition pulsed laser deposition
  • sputtering sputtering
  • the transparent electrode layer 110 may be formed of an ITO single layer formed by depositing indium tin oxide (ITO), but a transparent synthetic electrode having a multilayer thin film structure in which a metal layer is disposed between the conductive oxide layers composite electrode, TCE).
  • ITO indium tin oxide
  • TCE conductive oxide layers composite electrode
  • the reflective layer 120 is stacked on the transparent electrode layer 110 and reflects light emitted from the active layer 300 through the transparent electrode layer 110.
  • the reflective layer 120 may be formed of an insulator including a conductive filament 125 electrically connecting the transparent electrode layer 110 and a p-type electrode layer 130, which will be described later.
  • the conductive filament 125 of the reflective layer 120 may be formed on the entire or part of the reflective layer 120. Since the transparent electrode layer 110, the reflective layer 120, and the p-type electrode layer 130 are sequentially stacked And then applying an electric field to the reflective layer 120 through the transparent electrode layer 110 and the p-type electrode layer 130.
  • the resistance state of the insulator is changed from a high resistance state to a low resistance state. It is preferable to be formed of a resistance change material which changes in a resistance state and exhibits conductivity.
  • the resistance change material forming the reflective layer may be at least one selected from the group consisting of aluminum oxide (Al 2 O 3 ), silicon dioxide (SiO 2 ), hafnium oxide (HfO 2 ), titanium dioxide (TiO 2 ), zinc oxide (ZnO), tungsten trioxide (WO 3), molybdenum oxide (MoO 3), nickel oxide (NiO), Mn-doped tin oxide (MTO), Zn doped tin oxide (ZTO), Ga doped ZnO (GZO), Sn x O y, Zr x O y, Co x O y, Cr x O y, V x O y, Nb x O y ZnMgBeO, Mg x O y, Mg x N y, Ti x N y, In x N y, Ga x N y, Ga x O y , boron nitride (BN), Ni x N y , Si x N
  • the reflection layer 120 may be formed of a distributed Bragg reflector (DBR) having a multilayer structure in which at least two resistance change materials are alternately repeatedly stacked for reflection of light. At this time, it is preferable that the two resistance change materials forming the reflective layer 120 have different refractive indexes.
  • DBR distributed Bragg reflector
  • Such a distributed Bragg reflector can greatly improve the reflectivity of light in a specific wavelength range, and in particular, reflectivity of light in the ultraviolet (UV) range can be improved depending on the thickness and number of the laminated resistance change material.
  • UV ultraviolet
  • the reflective layer 120 is formed by forming a first reflective layer 121a made of any one of the above-described resistance changing materials on the transparent electrode layer 110, A second reflective layer 121b made of a resistance-change material different from the reflective layer 121a is formed. A third reflective layer 122a and a fourth reflective layer 122b are sequentially stacked on the second reflective layer 121b and a fifth reflective layer 123a and a sixth reflective layer 123b are formed thereon, May be formed as a laminated structure.
  • the first reflection layer 121a and the second reflection layer 121b form a pair
  • the third reflection layer 122a and the fourth reflection layer 122b form another pair
  • the fifth reflection layer 123a and the sixth reflective layer 123b form another pair.
  • the first reflective layer 121a, the third reflective layer 122a, and the fifth reflective layer 123a are formed of the same resistance change material, and the second reflective layer 121b, the fourth reflective layer 122b, 123b may be provided with the same resistance change material.
  • the reflective layer 120 can improve the reflection efficiency in the ultraviolet (UV) region while having an improved reflection efficiency as compared with the conventional metal electrode.
  • FIG. 4 shows reflectivity of a reflective electrode formed of silver (Ag) and reflectivity of a reflective layer (DBR) of a three-layer structure in which titanium dioxide (TiO 2 ) and aluminum oxide (Al 2 O 3 )
  • a reflective layer DBR
  • TiO 2 titanium dioxide
  • Al 2 O 3 aluminum oxide
  • FIG. 5 shows the relationship between the reflectance of a reflective electrode formed of general silver (Ag) and the reflective layer (DBR) of a three-layered structure in which titanium dioxide (TiO 2 ) and aluminum oxide (Al 2 O 3 ) -Type electrode layer is shown in the figure.
  • the p-type electrode layer 130 is laminated on the reflective layer 120 to apply a current to the transparent electrode layer 110 through the conductive filament 125 of the reflective layer 120 and ultimately to form the transparent electrode layer 110, Type nitride semiconductor layer 400.
  • the p-type nitride semiconductor layer 400 is formed of a nitride semiconductor.
  • the p-type electrode layer 130 may be deposited or patterned to have the same width as the reflective layer 120 described above.
  • the p-type electrode layer 130 may be formed of a metal having electrical conductivity and may be formed of any one of chromium (Cr), nickel (Ni), gold (Au), aluminum (Al) Lt; / RTI >
  • the p-type electrode layer 130 may be formed of a single material, but it is preferable that different materials are sequentially stacked to form a plurality of layers. That is, when forming the p-type electrode layer 130, a metal material having properties excellent in adhesion to other substrates or other metals is formed first, and a metal material having a work function similar to the p-type nitride semiconductor layer 400 is formed thereon. And an ohmic contact is made to improve the current injection efficiency.
  • a first electrode layer 131 made of chromium (Cr) is formed on the reflective layer 120, a second electrode layer 132 made of nickel (Ni) And a third electrode layer 133 made of gold (Au) is formed thereon. Since the work function of nickel (Ni) has a work function of 5.15 eV and the work function of gold (Au) is 5.10 eV, ohmic contact with the p-type nitride semiconductor layer 400 described above is easier Lt; / RTI >
  • the reflective electrode 100 for a micro light emitting device can improve the reflectivity in the ultraviolet (UV) region and prevent the reduction in the reflection efficiency of the micro light emitting device, Can also be improved.
  • UV ultraviolet
  • FIG. 7 is a view for explaining a method of manufacturing a reflective electrode for a micro light emitting device according to an embodiment of the present invention.
  • FIG. 7 a method of fabricating a reflective electrode for a micro light emitting device, which is performed to fabricate a reflective electrode for a micro light emitting device according to an embodiment of the present invention, will be described.
  • a transparent electrode layer is formed on the micro light-emitting device (S110).
  • the above-mentioned micro light emitting device may be formed in a structure in which an n-type nitride semiconductor layer, an active layer and a p-type nitride semiconductor layer are sequentially laminated on a substrate, and a transparent electrode layer is deposited on the above- can do.
  • the process of depositing the transparent electrode layer may be performed by chemical vapor deposition (CVD), electron beam evaporation, pulsed laser deposition, or sputtering,
  • the transparent electrode layer may be formed of a transparent composite electrode (TCE) structure having a multilayer thin film structure in which a metal layer is disposed between the conductive oxide layers.
  • CVD chemical vapor deposition
  • TCE transparent composite electrode
  • a reflective layer is formed on the transparent electrode layer (S120).
  • the reflective layer is a distributed Bragg reflector (DBR) made of an insulator, and reflects light emitted from the active layer and introduced through the transparent electrode layer.
  • DBR distributed Bragg reflector
  • the resistance change material forming the reflective layer may be at least one selected from the group consisting of aluminum oxide (Al 2 O 3 ), silicon dioxide (SiO 2 ), hafnium oxide (HfO 2 ), titanium dioxide (TiO 2 ), zinc oxide (ZnO), tungsten trioxide (WO 3), molybdenum oxide (MoO 3), nickel oxide (NiO), Mn-doped tin oxide (MTO), Zn doped tin oxide (ZTO), Ga doped ZnO (GZO), Sn x O y, Zr x O y, Co x O y, Cr x O y, V x O y, Nb x O y ZnMgBeO, Mg x O y, Mg x N y, Ti x N y, In x N y, Ga x N y, Ga x O y , boron nitride (BN), Ni x N y , Si x N
  • the two resistance change materials forming the reflective layer have different refractive indexes.
  • the reflectance of light in a specific wavelength range can be greatly improved, and the reflectivity of light in the ultraviolet (UV) range can be improved, for example.
  • a p-type electrode layer is formed on the reflective layer (S130).
  • the p-type electrode layer may be formed as a single layer structure made of a single material, but any one of chromium (Cr), nickel (Ni), gold (Au), aluminum (Al) It is preferable to form a plurality of layers.
  • a conductive filament electrically connecting the transparent electrode layer and the p-type electrode layer is formed in the reflective layer (S140).
  • the conductive filament of the reflective layer may be formed by an electric field applied through the transparent electrode layer and the p-type electrode layer after the transparent electrode layer, the reflective layer, and the p-type electrode layer are sequentially laminated.
  • the conductive filament of the reflective layer enables electrical connection between the p-type electrode layer and the transparent electrode layer.
  • the present invention can be used for producing a reflective electrode for a micro light emitting device.

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Abstract

The present invention relates to a reflective electrode for a micro light emitting element, a micro light emitting element having the same, and a method for manufacturing a reflective electrode for a micro light emitting element. Further, the present invention comprises: a transparent electrode layer formed on a p-type semiconductor layer of a micro light emitting element; a reflective layer formed on the transparent electrode layer, wherein the reflective layer is an insulator reflecting light that is emitted from an active layer of the micro light emitting element and introduced through the transparent electrode layer, and includes a conductive filament connecting the transparent electrode layer and a p-type electrode layer therein; and the p-type electrode layer formed on the reflective layer and electrically connected to the transparent electrode layer through the conductive filament of the reflection layer. Due to these features, the present invention can provide a reflective electrode which has good conductivity and enhanced reflection efficiency compared to conventional general metal electrodes and in particular, has enhanced reflection efficiency in the ultraviolet (UV) region.

Description

마이크로 발광소자용 반사전극, 이를 구비한 마이크로 발광소자 및 마이크로 발광소자용 반사전극의 제조방법A reflective electrode for a micro light emitting device, a micro light emitting device having the same, and a method for manufacturing a reflective electrode for a micro light emitting device
본 발명은 마이크로 발광소자용 반사전극, 이를 구비한 마이크로 발광소자 및 마이크로 발광소자용 반사전극의 제조방법에 관한 것이다.The present invention relates to a reflective electrode for a micro light emitting device, a micro light emitting device having the same, and a method of manufacturing a reflective electrode for a micro light emitting device.
일반적으로, 질화물 기반의 발광소자에서는 주입된 전류밀도가 높아질수록 효율 저하(Efficiency droop)가 발생하여 외부양자효율(EQE)이 감소하는 문제점이 있으므로, 이러한 외부양자효율의 감소를 줄이고자 하는 다양한 연구와 개발이 이루어지고 있다.Generally, in a nitride-based light emitting device, there is a problem that an efficiency droplet is generated as the injected current density is increased, thereby reducing the external quantum efficiency (EQE). Therefore, various studies And development.
이에 관련하여, 전류분산효과와 전류주입효율이 우수한 100μm 이하의 픽셀(pixel) 사이즈를 갖는 마이크로 발광소자에 대한 연구가 활발하게 진행되고 있는데, 이 경우, 픽셀 사이즈가 작기 때문에 p-전극 면적에 의해 반사 효율이 감소되는 문제점이 있다.In this connection, studies have been actively made on a micro light emitting device having a pixel size of 100 m or less, which is excellent in current dispersion effect and current injection efficiency. In this case, since the pixel size is small, There is a problem that the reflection efficiency is reduced.
즉, 마이크로 발광소자에서 전류주입을 위해 사용되는 p-전극이 픽셀 내부의 활성층으로부터 발광되는 빛을 흡수하거나 차단하므로, 마이크로 발광소자에서 외부로 발광되어야 할 빛이 감소하게 된다.That is, since the p-electrode used for current injection in the micro light emitting device absorbs or blocks the light emitted from the active layer in the pixel, light to be emitted from the micro light emitting device to the outside is reduced.
따라서, p-전극에 의한 반사 효율 감소를 최소화하고자, 금(Au) 또는 알루미늄(Al)으로 구성된 금속 전극이 대부분 사용되고 있으나, 이러한 금속 전극의 경우에도 전류 군집현상(Current crowding)에 의한 효율 감소가 크고, 특히, 자외선(UV) 영역의 파장에 대한 반사도가 현저하게 낮은 문제점이 있다.Therefore, metal electrodes composed of gold (Au) or aluminum (Al) are mostly used in order to minimize the reduction of the reflection efficiency by the p-electrode. However, even in the case of such a metal electrode, efficiency reduction by current crowding There is a problem that the reflectance with respect to the wavelength of the ultraviolet (UV) region is remarkably low.
본 발명은 상기와 같은 문제점을 감안하여 안출된 것으로, 자외선(UV) 영역에 대한 높은 반사도를 갖는 동시에, 마이크로 발광소자 자체의 효율을 향상시킬 수 있는 마이크로 발광소자용 반사전극, 이를 구비한 마이크로 발광소자 및 마이크로 발광소자용 반사전극의 제조방법을 제공하는데 그 목적이 있다.SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is an object of the present invention to provide a reflective electrode for a micro light emitting device having a high reflectivity to an ultraviolet (UV) And a method of manufacturing a reflective electrode for a micro light emitting device.
본 발명의 목적들은 이상에서 언급한 목적으로 제한되지 않으며, 언급되지 않은 또 다른 목적들은 아래의 기재로부터 당업자에게 명확하게 이해될 수 있을 것이다.The objects of the present invention are not limited to the above-mentioned objects, and other objects not mentioned can be clearly understood by those skilled in the art from the following description.
상기와 같은 목적을 달성하기 위한 본 발명은 기판, n형 반도체층, 활성층 및 p형 반도체층이 순차적으로 적층된 마이크로 발광소자에 구비되는 반사전극으로서, 상기 p형 반도체층의 위에 형성되는 투명 전극층; 상기 투명 전극층의 위에, 상기 활성층으로부터 발광되어 상기 투명 전극층을 통해 유입되는 빛을 반사하는 절연체로 형성되고, 그 내부에는 상기 투명 전극층과 p형 전극층을 연결하는 전도성 필라멘트가 포함된 반사층; 및 상기 반사층의 위에 형성되고, 상기 반사층의 전도성 필라멘트를 통해 상기 투명 전극층에 전기적으로 연결되는 p형 전극층;을 포함하는 마이크로 발광소자용 반사전극을 제공한다.According to an aspect of the present invention, there is provided a reflective electrode provided in a micro light emitting device in which a substrate, an n-type semiconductor layer, an active layer, and a p-type semiconductor layer are sequentially stacked, ; A reflective layer formed on the transparent electrode layer, the reflective layer including a conductive filament connecting the transparent electrode layer and the p-type electrode layer in an insulator that reflects light emitted from the active layer through the transparent electrode layer; And a p-type electrode layer formed on the reflective layer and electrically connected to the transparent electrode layer through the conductive filament of the reflective layer.
바람직한 실시예에 있어서, 상기 반사층의 전도성 필라멘트는, 상기 투명 전극층, 상기 반사층 및 상기 p형 전극층이 순차적으로 적층된 이후에, 상기 투명 전극층과 상기 p형 전극층을 통해 인가되는 전계에 의해 형성된다.In a preferred embodiment, the conductive filament of the reflective layer is formed by an electric field applied through the transparent electrode layer and the p-type electrode layer after the transparent electrode layer, the reflective layer, and the p-type electrode layer are sequentially laminated.
바람직한 실시예에 있어서, 상기 반사층은, 서로 다른 저항 변화 물질을 교대로 반복하여 적층시킨 분산 브래그 반사기(Distributed Bragg Reflector, DBR)이다.In a preferred embodiment, the reflective layer is a distributed Bragg reflector (DBR) in which different resistance change materials are alternately repeatedly laminated.
바람직한 실시예에 있어서, 상기 반사층을 형성하는 저항 변화 물질은, 산화알루미늄(Al2O3), 이산화규소(SiO2), 산화하프늄(HfO2), 이산화 타이타늄(TiO2), 산화아연(ZnO), 삼산화텅스텐(WO3), 산화몰리브덴(MoO3), 산화니켈(NiO), Mn-doped tin oxide(MTO), Zn doped tin oxide(ZTO), Ga doped ZnO(GZO), SnxOy, ZrxOy, CoxOy, CrxOy, VxOy, NbxOy ZnMgBeO, MgxOy, MgxNy, TixNy, InxNy, GaxNy, GaxOy, boron nitride(BN), NixNy, SixNy, Al doped ZnO(AZO), MgxZnyOx 및 CuxOy 중에서 선택된다.In a preferred embodiment, the resistance-changing material forming the reflective layer is selected from the group consisting of Al 2 O 3 , SiO 2 , HfO 2 , TiO 2 , ZnO, ), trioxide, tungsten (WO 3), molybdenum oxide (MoO 3), nickel oxide (NiO), Mn-doped tin oxide (MTO), Zn doped tin oxide (ZTO), Ga doped ZnO (GZO), Sn x O y , Zr x O y, Co x O y, Cr x O y, V x O y, Nb x O y ZnMgBeO, Mg x O y, Mg x N y, Ti x N y, In x N y, Ga x N y , Ga x O y , boron nitride (BN), Ni x N y , Si x N y , Al doped ZnO (AZO), Mg x Zn y O x, and Cu x O y .
바람직한 실시예에 있어서, 상기 p형 전극층은, 크롬(Cr), 니켈(Ni), 금(Au), 알루미늄(Al) 및 은(Ag) 중에서 적어도 두 개 이상의 물질이 순차적으로 적층된 복수의 층으로 형성된다.In a preferred embodiment, the p-type electrode layer includes a plurality of layers in which at least two materials among chromium (Cr), nickel (Ni), gold (Au), aluminum (Al) .
또한, 본 발명은 기판 위에 적층되는 n형 반도체층; 상기 n형 반도체층의 위에 적층되는 활성층; 상기 활성층의 위에 적층되는 p형 반도체층; 상기 p형 반도체층의 위에 형성되는 투명 전극층; 상기 투명 전극층의 위에, 상기 활성층으로부터 발광되어 상기 투명 전극층을 통해 유입되는 빛을 반사하는 절연체로 형성되고, 그 내부에는 상기 투명 전극층과 p형 전극층을 연결하는 전도성 필라멘트가 포함된 반사층; 및 상기 반사층의 위에 형성되고, 상기 반사층의 전도성 필라멘트를 통해 상기 투명 전극층에 전기적으로 연결되는 p형 전극층;을 포함하는 마이크로 발광소자를 제공한다.Further, the present invention provides a semiconductor device comprising: an n-type semiconductor layer laminated on a substrate; An active layer stacked on the n-type semiconductor layer; A p-type semiconductor layer laminated on the active layer; A transparent electrode layer formed on the p-type semiconductor layer; A reflective layer formed on the transparent electrode layer, the reflective layer including a conductive filament connecting the transparent electrode layer and the p-type electrode layer in an insulator that reflects light emitted from the active layer through the transparent electrode layer; And a p-type electrode layer formed on the reflective layer and electrically connected to the transparent electrode layer through the conductive filament of the reflective layer.
바람직한 실시예에 있어서, 상기 반사층의 전도성 필라멘트는, 상기 투명 전극층, 상기 반사층 및 상기 p형 전극층이 순차적으로 적층된 이후에, 상기 투명 전극층과 상기 p형 전극층을 통해 인가되는 전계에 의해 형성된다.In a preferred embodiment, the conductive filament of the reflective layer is formed by an electric field applied through the transparent electrode layer and the p-type electrode layer after the transparent electrode layer, the reflective layer, and the p-type electrode layer are sequentially laminated.
바람직한 실시예에 있어서, 상기 반사층은, 서로 다른 저항 변화 물질을 교대로 반복하여 적층시킨 분산 브래그 반사기(Distributed Bragg Reflector, DBR)이다.In a preferred embodiment, the reflective layer is a distributed Bragg reflector (DBR) in which different resistance change materials are alternately repeatedly laminated.
바람직한 실시예에 있어서, 상기 반사층을 형성하는 저항 변화 물질은, 산화알루미늄(Al2O3), 이산화규소(SiO2), 산화하프늄(HfO2), 이산화 타이타늄(TiO2), 산화아연(ZnO), 삼산화텅스텐(WO3), 산화몰리브덴(MoO3), 산화니켈(NiO), Mn-doped tin oxide(MTO), Zn doped tin oxide(ZTO), Ga doped ZnO(GZO), SnxOy, ZrxOy, CoxOy, CrxOy, VxOy, NbxOy ZnMgBeO, MgxOy, MgxNy, TixNy, InxNy, GaxNy, GaxOy, boron nitride(BN), NixNy, SixNy, Al doped ZnO(AZO), MgxZnyOx 및 CuxOy 중에서 선택된다.In a preferred embodiment, the resistance-changing material forming the reflective layer is selected from the group consisting of Al 2 O 3 , SiO 2 , HfO 2 , TiO 2 , ZnO, ), trioxide, tungsten (WO 3), molybdenum oxide (MoO 3), nickel oxide (NiO), Mn-doped tin oxide (MTO), Zn doped tin oxide (ZTO), Ga doped ZnO (GZO), Sn x O y , Zr x O y, Co x O y, Cr x O y, V x O y, Nb x O y ZnMgBeO, Mg x O y, Mg x N y, Ti x N y, In x N y, Ga x N y , Ga x O y , boron nitride (BN), Ni x N y , Si x N y , Al doped ZnO (AZO), Mg x Zn y O x, and Cu x O y .
바람직한 실시예에 있어서, 상기 p형 전극층은, 크롬(Cr), 니켈(Ni), 금(Au), 알루미늄(Al) 및 은(Ag) 중에서 적어도 두 개 이상의 물질이 순차적으로 적층된 복수의 층으로 형성된다.In a preferred embodiment, the p-type electrode layer includes a plurality of layers in which at least two materials among chromium (Cr), nickel (Ni), gold (Au), aluminum (Al) .
또한, 본 발명은 기판, n형 반도체층, 활성층 및 p형 반도체층이 순차적으로 적층된 마이크로 발광소자에 구비되는 반사전극의 제조방법으로서, (1) 상기 p형 반도체층의 위에 투명 전극층을 형성하는 단계; (2) 상기 활성층으로부터 발광되어 상기 투명 전극층을 통해 유입되는 빛을 반사하는 반사층을 상기 투명 전극층의 위에 형성하는 단계; (3) 상기 반사층을 통해 상기 투명 전극층에 전기적으로 연결되는 p형 전극층을 상기 반사층의 위에 형성하는 단계; 및 (4) 상기 반사층의 내부에 상기 투명 전극층과 상기 p형 전극층을 전기적으로 연결하는 전도성 필라멘트를 형성하는 단계;를 포함하는 마이크로 발광소자용 반사전극의 제조방법을 제공한다.The present invention also provides a method of manufacturing a reflective electrode provided in a micro light emitting device in which a substrate, an n-type semiconductor layer, an active layer and a p-type semiconductor layer are sequentially laminated, comprising the steps of: (1) forming a transparent electrode layer on the p- ; (2) forming a reflective layer on the transparent electrode layer to reflect light emitted from the active layer and flowing through the transparent electrode layer; (3) forming a p-type electrode layer electrically connected to the transparent electrode layer through the reflective layer on the reflective layer; And (4) forming a conductive filament in the reflective layer to electrically connect the transparent electrode layer and the p-type electrode layer to each other.
바람직한 실시예에 있어서, 상기 제 (4)단계에서 형성되는 상기 반사층의 전도성 필라멘트는, 상기 투명 전극층, 상기 반사층 및 상기 p형 전극층이 순차적으로 적층된 이후에, 상기 투명 전극층과 상기 p형 전극층을 통해 인가되는 전계에 의해 형성된다.In a preferred embodiment, the conductive filament of the reflective layer formed in the step (4) is formed by sequentially laminating the transparent electrode layer, the reflective layer and the p-type electrode layer, and then the transparent electrode layer and the p- Lt; / RTI >
바람직한 실시예에 있어서, 상기 제 (2)단계에서 형성되는 상기 반사층은, 서로 다른 저항 변화 물질을 교대로 반복하여 적층시킨 분산 브래그 반사기(Distributed Bragg Reflector, DBR)이다.In a preferred embodiment, the reflective layer formed in step (2) is a distributed Bragg reflector (DBR) in which different resistance change materials are alternately repeatedly laminated.
바람직한 실시예에 있어서, 상기 제 (2)단계에서 상기 반사층을 형성하는 저항 변화 물질은, 산화알루미늄(Al2O3), 이산화규소(SiO2), 산화하프늄(HfO2), 이산화 타이타늄(TiO2), 산화아연(ZnO), 삼산화텅스텐(WO3), 산화몰리브덴(MoO3), 산화니켈(NiO), Mn-doped tin oxide(MTO), Zn doped tin oxide(ZTO), Ga doped ZnO(GZO), SnxOy, ZrxOy, CoxOy, CrxOy, VxOy, NbxOy ZnMgBeO, MgxOy, MgxNy, TixNy, InxNy, GaxNy, GaxOy, boron nitride(BN), NixNy, SixNy, Al doped ZnO(AZO), MgxZnyOx 및 CuxOy 중에서 선택된다.In a preferred embodiment, the resistance change material forming the reflective layer in the step (2) is at least one selected from the group consisting of aluminum oxide (Al 2 O 3 ), silicon dioxide (SiO 2 ), hafnium oxide (HfO 2 ) 2), zinc oxide (ZnO), antimony trioxide of tungsten (WO 3), molybdenum (MoO 3), nickel oxide (NiO), Mn-doped tin oxide (MTO), Zn doped tin oxide (ZTO) oxide, Ga doped ZnO ( GZO), Sn x O y, Zr x O y, Co x O y, Cr x O y, V x O y, Nb x O y ZnMgBeO, Mg x O y, Mg x N y, Ti x N y, In selected from x N y, Ga x N y , Ga x O y, boron nitride (BN), Ni x N y, Si x N y, Al doped ZnO (AZO), Mg x Zn y O x , and Cu x O y do.
바람직한 실시예에 있어서, 상기 제 (3)단계에서 형성되는 상기 p형 전극층은, 크롬(Cr), 니켈(Ni), 금(Au), 알루미늄(Al) 및 은(Ag) 중에서 적어도 두 개 이상의 물질이 순차적으로 적층된 복수의 층으로 형성된다.In a preferred embodiment, the p-type electrode layer formed in step (3) is at least two of chromium (Cr), nickel (Ni), gold (Au), aluminum (Al) The material is formed of a plurality of layers which are sequentially stacked.
전술한 과제해결 수단에 의해 본 발명은 마이크로 발광소자의 p형 반도체층의 위에 형성되는 투명 전극층과, 투명 전극층의 위에 형성되고 마이크로 발광소자의 활성층으로부터 발광되어 투명 전극층을 통해 유입되는 빛을 반사하는 절연체이며 그 내부에는 상기 투명 전극층과 p형 전극층을 연결하는 전도성 필라멘트가 포함된 반사층 및 반사층의 위에 형성되고 반사층의 전도성 필라멘트를 통해 투명 전극층에 전기적으로 연결되는 p형 전극층을 구비함으로써, 종래의 일반적인 금속 전극에 비해 향상된 반사 효율을 가지면서 전도성도 우수한 반사 전극을 제공할 수 있고, 특히, 자외선(UV) 영역에서의 반사 효율을 향상시킬 수 있는 효과가 있다.According to an embodiment of the present invention, there is provided a light emitting device comprising: a transparent electrode layer formed on a p-type semiconductor layer of a micro light emitting device; a light emitting layer formed on the transparent electrode layer and emitting light from the active layer of the micro light emitting device, And a p-type electrode layer formed on the reflective layer and including a conductive filament connecting the transparent electrode layer and the p-type electrode layer and electrically connected to the transparent electrode layer through the conductive filament of the reflective layer, It is possible to provide a reflective electrode having an improved reflection efficiency and an excellent conductivity as compared with the metal electrode, and in particular, the reflection efficiency in the ultraviolet (UV) region can be improved.
아울러, 본 발명은 반사 전극에 의한 반사 효율을 향상시킴으로써, 마이크로 발광소자 자체의 효율을 향상시킬 수 있는 효과가 있다.In addition, the present invention has the effect of improving the efficiency of reflection by the reflective electrode, thereby improving the efficiency of the micro-light emitting device itself.
도 1은 본 발명의 일실시예에 따른 마이크로 발광소자를 설명하기 위한 도면.1 is a view for explaining a micro light emitting device according to an embodiment of the present invention.
도 2는 본 발명의 일실시예에 따른 마이크로 발광소자용 반사전극의 세부 구성을 설명하기 위한 도면.2 is a view for explaining a detailed configuration of a reflective electrode for a micro light emitting device according to an embodiment of the present invention.
도 3은 마이크로 발광소자용 반사전극의 반사층을 설명하기 위한 도면.3 is a view for explaining a reflection layer of a reflection electrode for a micro light-emitting device;
도 4 및 도 5는 마이크로 발광소자용 반사전극의 반사도를 설명하기 위한 도면.FIGS. 4 and 5 are diagrams for explaining the reflectivity of a reflective electrode for a micro light-emitting device. FIG.
도 6은 마이크로 발광소자용 반사전극의 p형 전극층을 설명하기 위한 도면.6 is a view for explaining a p-type electrode layer of a reflective electrode for a micro light-emitting element;
도 7은 본 발명의 일실시예에 따른 마이크로 발광소자용 반사전극의 제조방법을 설명하기 위한 도면.7 is a view for explaining a method of manufacturing a reflective electrode for a micro light emitting device according to an embodiment of the present invention.
하기의 설명에서 본 발명의 특정 상세들이 본 발명의 전반적인 이해를 제공하기 위해 나타나 있는데, 이들 특정 상세들 없이 또한 이들의 변형에 의해서도 본 발명이 용이하게 실시될 수 있다는 것은 이 기술분야에서 통상의 지식을 가진 자에게 자명할 것이다.It will be understood by those skilled in the art that the specific details of the invention are set forth in order to provide a thorough understanding of the present invention and that the present invention may be readily practiced without these specific details, It will be clear to those who have.
이하, 본 발명에 따른 바람직한 실시예를 첨부된 도 1 내지 도 7을 참조하여 상세히 설명하되, 본 발명에 따른 동작 및 작용을 이해하는데 필요한 부분을 중심으로 설명한다.DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to FIGS. 1 to 7, but the present invention will be described with reference to the portions necessary for understanding the operation and operation according to the present invention.
도 1은 본 발명의 일실시예에 따른 마이크로 발광소자를 설명하기 위한 도면이다.1 is a view for explaining a micro light emitting device according to an embodiment of the present invention.
도 1을 참조하면, 본 발명의 일실시예에 따른 마이크로 발광소자는 마이크로 발광소자용 반사전극(100), n형 질화물 반도체층(200), 활성층(300), p형 질화물 반도체층(400) 및 리플렉터층(500)을 포함하여 구성될 수 있다.1, a micro light emitting device according to an embodiment of the present invention includes a reflective electrode 100 for a micro light emitting device, an n-type nitride semiconductor layer 200, an active layer 300, a p-type nitride semiconductor layer 400, And a reflector layer 500.
여기서, 본 발명의 일실시예에 따른 마이크로 발광소자용 반사전극(100)은 기판(10)에 형성된 마이크로 발광소자의 상부면에 형성될 수 있으며, 전술한 마이크로 발광소자는 n형 질화물 반도체층(200), 활성층(300) 및 p형 질화물 반도체층(400)이 순차적으로 적층되어 형성된 것일 수 있다.Here, the reflective electrode 100 for a micro light-emitting device according to an embodiment of the present invention may be formed on a top surface of a micro light-emitting device formed on a substrate 10, and the micro light-emitting device may include an n-type nitride semiconductor layer 200, an active layer 300, and a p-type nitride semiconductor layer 400 sequentially stacked.
상기 n형 질화물 반도체층(200)은 기판(10)의 위에 적층된다. 아울러, n형 질화물 반도체층(200)은 갈륨 나이트라이드(GaN) 또는 N형 갈륨 나이트라이드(N-GaN)로 구비될 수 있으며, 그 n형 질화물 반도체층(200)에는 후술할 활성층(300)으로의 전류 주입을 위한 N형 전극이 연결될 수 있다.The n-type nitride semiconductor layer 200 is deposited on the substrate 10. The n-type nitride semiconductor layer 200 may be formed of gallium nitride (GaN) or n-type gallium nitride (N-GaN). The n-type nitride semiconductor layer 200 may include an active layer 300, Lt; RTI ID = 0.0 > N-type < / RTI >
상기 활성층(300)은 n형 질화물 반도체층(200)의 위에 적층된다. 또한, 활성층(300)은 다중양자 우물(Multi Quantum Well, MQW) 구조로 형성되며, GaN계 화합물을 성장시켜서 형성될 수 있다. 아울러, 활성층(300)은 빛을 발광하는 발광층으로서 기능하게 된다.The active layer 300 is deposited on the n-type nitride semiconductor layer 200. In addition, the active layer 300 may be formed of a multi quantum well (MQW) structure, and may be formed by growing a GaN-based compound. In addition, the active layer 300 functions as a light emitting layer for emitting light.
상기 p형 질화물 반도체층(400)은 활성층(300)의 위에 적층된다. 또한, p형 질화물 반도체층(400)은 P형 갈륨 나이트라이드(P-GaN)로 구비될 수 있다.The p-type nitride semiconductor layer 400 is stacked on the active layer 300. In addition, the p-type nitride semiconductor layer 400 may be formed of p-type gallium nitride (P-GaN).
상기 마이크로 발광소자용 반사전극(100)은 p형 질화물 반도체층(400) 위에 형성될 수 있다. 또한, 마이크로 발광소자용 반사전극(100)은 외부에서 인가되는 전류를 p형 질화물 반도체층(400)에 공급하는 동시에, 전술한 활성층(300)으로부터 발광된 빛을 반사시켜 마이크로 발광소자 자체의 효율을 개선할 수 있다.The reflective electrode 100 for the micro light emitting device may be formed on the p-type nitride semiconductor layer 400. In addition, the reflective electrode 100 for a micro light-emitting device may supply an externally applied current to the p-type nitride semiconductor layer 400, reflect the light emitted from the active layer 300, Can be improved.
상기 리플렉터층(500)은 상기 기판(10)의 하부면에 형성될 수 있다. 또한, 리플렉터층(500)은 기판(10)을 통해 유입되는 빛을 반사하는 기능을 수행하게 되는데, 이에 의해, 마이크로 발광소자의 효율을 더 향상시킬 수 있다.The reflector layer 500 may be formed on the lower surface of the substrate 10. In addition, the reflector layer 500 functions to reflect light entering through the substrate 10, thereby further improving the efficiency of the micro light emitting device.
이하에서는, 본 발명의 일실시예에 따른 마이크로 발광소자용 반사전극(100)에 대해 구체적으로 설명하고자 한다.Hereinafter, the reflective electrode 100 for a micro light emitting device according to an embodiment of the present invention will be described in detail.
도 2는 본 발명의 일실시예에 따른 마이크로 발광소자용 반사전극의 세부 구성을 설명하기 위한 도면이고, 도 3은 마이크로 발광소자용 반사전극의 반사층을 설명하기 위한 도면이며, 도 4 및 도 5는 마이크로 발광소자용 반사전극의 반사도를 설명하기 위한 도면이고, 도 6은 마이크로 발광소자용 반사전극의 p형 전극층을 설명하기 위한 도면이다.FIG. 2 is a view for explaining a detailed configuration of a reflective electrode for a micro light emitting device according to an embodiment of the present invention, FIG. 3 is a view for explaining a reflective layer of a reflective electrode for a micro light emitting device, 6 is a view for explaining a p-type electrode layer of a reflective electrode for a micro light-emitting element. Fig.
도 2 내지 도 6을 참조하면, 본 발명의 일실시예에 따른 마이크로 발광소자용 반사전극(100)은 투명 전극층(110), 반사층(120) 및 p형 전극층(130)을 포함하여 구성된다.2 to 6, the reflective electrode 100 for a micro light emitting device according to an embodiment of the present invention includes a transparent electrode layer 110, a reflective layer 120, and a p-type electrode layer 130.
상기 투명 전극층(110)은 전술한 p형 질화물 반도체층(400) 위에 형성되는 것으로, 투명 전도성 산화물(transparent conductive oxide, TCO)을 증착시켜 형성될 수 있다.The transparent electrode layer 110 is formed on the p-type nitride semiconductor layer 400. The transparent electrode layer 110 may be formed by depositing a transparent conductive oxide (TCO).
이때, 투명 전극층(110)의 증착 공정은, 화학기상 증착(chemical vapor deposition, CVD), 전자빔 증착(electron beam evaporation), 펄스 레이저 증착(pulsed laser deposition) 또는 스퍼터링(sputtering)을 통해 수행될 수 있다.At this time, the deposition process of the transparent electrode layer 110 can be performed by chemical vapor deposition (CVD), electron beam evaporation, pulsed laser deposition, or sputtering .
아울러, 투명 전극층(110)은 인듐 주석 산화물(indium tin oxide, ITO)을 증착시켜 형성된 ITO 단일막으로 구비될 수도 있으나, 전도성 산화물층의 사이에 금속층이 게재된 다층 박막 구조의 투명합성전극(transparent composite electrode, TCE)으로 구비함이 바람직하다.In addition, the transparent electrode layer 110 may be formed of an ITO single layer formed by depositing indium tin oxide (ITO), but a transparent synthetic electrode having a multilayer thin film structure in which a metal layer is disposed between the conductive oxide layers composite electrode, TCE).
상기 반사층(120)은 투명 전극층(110)의 위에 적층되는 것으로, 전술한 활성층(300)으로부터 발광되어 투명 전극층(110)을 통해 유입되는 빛을 반사하는 기능을 수행하게 된다. 또한, 반사층(120)은 투명 전극층(110)과 후술할 p형 전극층(130)을 전기적으로 연결하는 전도성 필라멘트(125)가 내부에 포함된 절연체로 형성될 수 있다.The reflective layer 120 is stacked on the transparent electrode layer 110 and reflects light emitted from the active layer 300 through the transparent electrode layer 110. The reflective layer 120 may be formed of an insulator including a conductive filament 125 electrically connecting the transparent electrode layer 110 and a p-type electrode layer 130, which will be described later.
여기서, 반사층(120)의 전도성 필라멘트(125)는 반사층(120)의 전체 또는 일부에 형성될 수 있는데, 투명 전극층(110), 반사층(120) 및 p형 전극층(130)이 순차적으로 적층된 이후에, 투명 전극층(110)과 p형 전극층(130)을 통해 반사층(120)으로 전계를 인가하는 과정을 수행하여 형성될 수 있다.Here, the conductive filament 125 of the reflective layer 120 may be formed on the entire or part of the reflective layer 120. Since the transparent electrode layer 110, the reflective layer 120, and the p-type electrode layer 130 are sequentially stacked And then applying an electric field to the reflective layer 120 through the transparent electrode layer 110 and the p-type electrode layer 130.
이를 위해, 반사층(120)은 절연체 중에서도, 고유한 임계치 이상의 전압을 물질에 인가하면, electrical break down 현상이 발생하면서 electro-forming이 수행되어, 최초에는 절연체인 물질의 저항 상태가 고저항 상태에서 저저항 상태로 변화되어 전도성을 나타내는 저항 변화 물질로 형성됨이 바람직하다.For this, when a voltage higher than a specific threshold value is applied to a material in the insulating layer 120, an electrical breakdown phenomenon occurs and electro-forming is performed. At first, the resistance state of the insulator is changed from a high resistance state to a low resistance state. It is preferable to be formed of a resistance change material which changes in a resistance state and exhibits conductivity.
즉, 투명 전극층(110)과 p형 전극층(130)을 통해 반사층(120)으로 임계치 이상의 전압을 인가하면, 저항 변화 물질로 형성된 반사층(120) 내부에 전도성 필라멘트(125)(conducting filaments)가 형성되며, 상기 형성된 전도성 필라멘트(125)를 통해서 전류가 흐르게 되어, 반사층(120)의 저항 상태가 저저항 상태로 유지될 수 있다.That is, when a voltage higher than a threshold value is applied to the reflective layer 120 through the transparent electrode layer 110 and the p-type electrode layer 130, conducting filaments 125 are formed in the reflective layer 120 formed of the resistance- And a current flows through the conductive filament 125, so that the resistance state of the reflection layer 120 can be maintained in a low resistance state.
또한, 상기 반사층을 형성하는 저항 변화 물질은, 산화알루미늄(Al2O3), 이산화규소(SiO2), 산화하프늄(HfO2), 이산화 타이타늄(TiO2), 산화아연(ZnO), 삼산화텅스텐(WO3), 산화몰리브덴(MoO3), 산화니켈(NiO), Mn-doped tin oxide(MTO), Zn doped tin oxide(ZTO), Ga doped ZnO(GZO), SnxOy, ZrxOy, CoxOy, CrxOy, VxOy, NbxOy ZnMgBeO, MgxOy, MgxNy, TixNy, InxNy, GaxNy, GaxOy, boron nitride(BN), NixNy, SixNy, Al doped ZnO(AZO), MgxZnyOx 및 CuxOy 중에서 선택될 수 있으나, 상술한 물질 이외에도 투명하고 상술한 저항 변화 특성을 나타내는 물질이라면, 본 발명의 반사층(120)을 형성하는데 이용될 수 있음은 물론이다.The resistance change material forming the reflective layer may be at least one selected from the group consisting of aluminum oxide (Al 2 O 3 ), silicon dioxide (SiO 2 ), hafnium oxide (HfO 2 ), titanium dioxide (TiO 2 ), zinc oxide (ZnO), tungsten trioxide (WO 3), molybdenum oxide (MoO 3), nickel oxide (NiO), Mn-doped tin oxide (MTO), Zn doped tin oxide (ZTO), Ga doped ZnO (GZO), Sn x O y, Zr x O y, Co x O y, Cr x O y, V x O y, Nb x O y ZnMgBeO, Mg x O y, Mg x N y, Ti x N y, In x N y, Ga x N y, Ga x O y , boron nitride (BN), Ni x N y , Si x N y , Al doped ZnO (AZO), Mg x Zn y O x and Cu x O y , It is needless to say that the material may be used to form the reflective layer 120 of the present invention if it exhibits a resistance change characteristic.
한편, 반사층(120)은 빛의 반사를 위해, 적어도 두 개의 저항 변화 물질을 교대로 반복하여 적층시킨 다층 구조를 갖는 분산 브래그 반사기(Distributed Bragg Reflector, DBR)로 형성될 수 있다. 이때, 반사층(120)을 형성하는 두 개의 저항 변화 물질은 서로 다른 굴절률을 갖도록 구비함이 바람직하다. Meanwhile, the reflection layer 120 may be formed of a distributed Bragg reflector (DBR) having a multilayer structure in which at least two resistance change materials are alternately repeatedly stacked for reflection of light. At this time, it is preferable that the two resistance change materials forming the reflective layer 120 have different refractive indexes.
이러한, 분산 브래그 반사기는 특정 파장 영역의 빛에 대한 반사도를 크게 향상시킬 수 있는데, 특히, 적층된 저항 변화 물질의 두께와 수에 따라 자외선(UV) 영역의 빛에 대한 반사도를 향상시킬 수 있다.Such a distributed Bragg reflector can greatly improve the reflectivity of light in a specific wavelength range, and in particular, reflectivity of light in the ultraviolet (UV) range can be improved depending on the thickness and number of the laminated resistance change material.
예컨대, 도 3에 도시된 바와 같이, 반사층(120)은 전술한 저항 변화 물질 중 어느 하나의 저항 변화 물질로 이루어진 제 1반사층(121a)이 투명 전극층(110)의 위에 형성되고, 그 위에 제 1반사층(121a)과 다른 저항 변화 물질로 이루어진 제 2반사층(121b)이 형성된다. 이와 동일한 구조로, 제 2반사층(121b)의 위에 제 3반사층(122a)과 제 4반사층(122b)이 순차적으로 적층되어 형성되고, 그 위에는 제 5반사층(123a)과 제 6반사층(123b)이 적층되는 구조로 형성될 수 있다.For example, as shown in FIG. 3, the reflective layer 120 is formed by forming a first reflective layer 121a made of any one of the above-described resistance changing materials on the transparent electrode layer 110, A second reflective layer 121b made of a resistance-change material different from the reflective layer 121a is formed. A third reflective layer 122a and a fourth reflective layer 122b are sequentially stacked on the second reflective layer 121b and a fifth reflective layer 123a and a sixth reflective layer 123b are formed thereon, May be formed as a laminated structure.
즉, 전술한 제 1반사층(121a)과 제 2반사층(121b)이 한 쌍(pair)을 이루고, 제 3반사층(122a)과 제 4반사층(122b)이 다른 한 쌍을 이루며, 제 5반사층(123a)과 제 6반사층(123b)이 또 다른 한 쌍을 이루며 적층되는 구조를 형성하게 된다.That is, the first reflection layer 121a and the second reflection layer 121b form a pair, the third reflection layer 122a and the fourth reflection layer 122b form another pair, and the fifth reflection layer 123a and the sixth reflective layer 123b form another pair.
여기서, 제 1반사층(121a), 제 3반사층(122a) 및 제 5반사층(123a)이 서로 동일한 저항 변화 물질로 구비되고, 제 2반사층(121b)과 제 4반사층(122b) 및 제 6반사층(123b)이 서로 동일한 저항 변화 물질로 구비될 수 있다.Here, the first reflective layer 121a, the third reflective layer 122a, and the fifth reflective layer 123a are formed of the same resistance change material, and the second reflective layer 121b, the fourth reflective layer 122b, 123b may be provided with the same resistance change material.
이러한, 반사층(120)은 종래의 일반적인 금속 전극에 비해 향상된 반사 효율을 가지면서, 특히, 자외선(UV) 영역에서의 반사 효율을 향상시킬 수 있다.The reflective layer 120 can improve the reflection efficiency in the ultraviolet (UV) region while having an improved reflection efficiency as compared with the conventional metal electrode.
예컨대, 도 4에는 일반적인 은(Ag)으로 형성된 반사전극의 반사도와, 이산화 타이타늄(TiO2)과 산화알루미늄(Al2O3)을 한 쌍으로 하는 3층 구조의 반사층(DBR)의 반사도가 도시되어 있는데, 일반적인 은(Ag)을 이용하여 반사전극을 형성한 경우에는 330㎚ 이하의 파장에 대한 반사도가 거의 없는 반면에, 본 발명에 따른 반사층(DBR)의 경우에는 400㎚ 이하의 자외선 영역에서의 반사도가 현저하게 높게 측정된다는 것을 확인할 수 있다.For example, FIG. 4 shows reflectivity of a reflective electrode formed of silver (Ag) and reflectivity of a reflective layer (DBR) of a three-layer structure in which titanium dioxide (TiO 2 ) and aluminum oxide (Al 2 O 3 ) When the reflective electrode is formed using silver (Ag), there is little reflectance with respect to a wavelength of 330 nm or less. On the other hand, in the case of the reflective layer (DBR) according to the present invention, It can be confirmed that the reflectivity of the light-emitting layer is measured to be remarkably high.
아울러, 도 5에는 일반적인 은(Ag)으로 형성된 반사전극의 반사도와, 이산화 타이타늄(TiO2)과 산화알루미늄(Al2O3)을 한 쌍으로 하는 3층 구조의 반사층(DBR)에 후술할 p형 전극층을 형성한 상태에서의 반사도가 도시되어 있다.5 shows the relationship between the reflectance of a reflective electrode formed of general silver (Ag) and the reflective layer (DBR) of a three-layered structure in which titanium dioxide (TiO 2 ) and aluminum oxide (Al 2 O 3 ) -Type electrode layer is shown in the figure.
이때, 도 5에 도시된 바와 같이, 일반적인 은(Ag)을 이용하여 반사전극을 형성한 경우에는 330㎚ 이하의 파장에 대한 반사도가 거의 없지만, 본 발명에 따른 반사층(DBR)에 p형 전극층이 형성된 경우에는 330㎚ 이하의 자외선 영역에서의 반사도가 거의 100%에 가깝게 측정된다는 것을 확인할 수 있다.In this case, as shown in FIG. 5, when the reflective electrode is formed using general silver (Ag), there is little reflectance for a wavelength of 330 nm or less. However, in the reflective layer DBR according to the present invention, It can be confirmed that the reflectance in the ultraviolet region of 330 nm or less is measured to be close to 100%.
상기 p형 전극층(130)은 반사층(120)의 위에 적층되는 것으로, 반사층(120)의 전도성 필라멘트(125)를 통해서 투명 전극층(110)으로 전류를 인가하고, 궁극적으로는, 투명 전극층(110)을 통해 전술한 p형 질화물 반도체층(400)에 전류를 인가하는 기능을 수행한다. 또한, p형 전극층(130)은 전술한 반사층(120)과 동일한 폭을 갖도록 증착되거나 패터닝될 수 있다.The p-type electrode layer 130 is laminated on the reflective layer 120 to apply a current to the transparent electrode layer 110 through the conductive filament 125 of the reflective layer 120 and ultimately to form the transparent electrode layer 110, Type nitride semiconductor layer 400. The p-type nitride semiconductor layer 400 is formed of a nitride semiconductor. The p-type electrode layer 130 may be deposited or patterned to have the same width as the reflective layer 120 described above.
아울러, p형 전극층(130)은 전기 전도성을 갖는 금속 재질로 형성될 수 있으며, 예컨대, 크롬(Cr), 니켈(Ni), 금(Au), 알루미늄(Al) 및 은(Ag) 중에서 어느 하나의 물질로 형성될 수 있다.The p-type electrode layer 130 may be formed of a metal having electrical conductivity and may be formed of any one of chromium (Cr), nickel (Ni), gold (Au), aluminum (Al) Lt; / RTI >
다만, 도 6에 도시된 바와 같이, p형 전극층(130)은 단일 물질로 이루어질 수도 있으나, 서로 다른 물질들이 순차적으로 적층되어 복수의 층을 이루는 구조로 형성함이 바람직하다. 즉, p형 전극층(130)의 형성 시, 타 기판 또는 타 금속과의 접착력이 우수한 성질을 갖는 금속 물질을 먼저 형성하고, 그 위에 p형 질화물 반도체층(400)과 유사한 일함수를 갖는 금속 물질을 형성하여 옴 접촉(ohmic contact)이 이루어지게 하면 전류 주입 효율을 향상시킬 수 있다.However, as shown in FIG. 6, the p-type electrode layer 130 may be formed of a single material, but it is preferable that different materials are sequentially stacked to form a plurality of layers. That is, when forming the p-type electrode layer 130, a metal material having properties excellent in adhesion to other substrates or other metals is formed first, and a metal material having a work function similar to the p-type nitride semiconductor layer 400 is formed thereon. And an ohmic contact is made to improve the current injection efficiency.
예컨대, p형 전극층(130)은 크롬(Cr)으로 이루어진 제 1전극층(131)이 반사층(120)의 위에 형성되고, 그 위에 니켈(Ni)로 이루어진 제 2전극층(132)이 형성되며, 다시 그 위에는 금(Au)으로 이루어진 제 3전극층(133)이 형성된 구조로 형성될 수 있다. 여기서, 니켈(Ni)의 경우에는 5.15eV의 일함수를 가지며 금(Au)의 경우에는 5.10eV의 일함수를 가지므로, 전술한 p형 질화물 반도체층(400)과의 옴 접촉이 보다 용이하게 이루어질 수 있다.For example, in the p-type electrode layer 130, a first electrode layer 131 made of chromium (Cr) is formed on the reflective layer 120, a second electrode layer 132 made of nickel (Ni) And a third electrode layer 133 made of gold (Au) is formed thereon. Since the work function of nickel (Ni) has a work function of 5.15 eV and the work function of gold (Au) is 5.10 eV, ohmic contact with the p-type nitride semiconductor layer 400 described above is easier Lt; / RTI >
따라서, 본 발명의 일실시예에 따른 마이크로 발광소자용 반사전극(100)은 자외선(UV) 영역에서의 반사도를 향상시킬 수 있고 마이크로 발광소자의 반사 효율 감소를 방지함으로써, 마이크로 발광소자 자체의 효율도 향상시킬 수 있다.Therefore, the reflective electrode 100 for a micro light emitting device according to an embodiment of the present invention can improve the reflectivity in the ultraviolet (UV) region and prevent the reduction in the reflection efficiency of the micro light emitting device, Can also be improved.
도 7은 본 발명의 일실시예에 따른 마이크로 발광소자용 반사전극의 제조방법을 설명하기 위한 도면이다.7 is a view for explaining a method of manufacturing a reflective electrode for a micro light emitting device according to an embodiment of the present invention.
도 7을 참조하여, 본 발명의 일실시예에 따른 마이크로 발광소자용 반사전극을 제조하기 위해 수행되는 마이크로 발광소자용 반사전극의 제조방법을 설명한다.Referring to FIG. 7, a method of fabricating a reflective electrode for a micro light emitting device, which is performed to fabricate a reflective electrode for a micro light emitting device according to an embodiment of the present invention, will be described.
먼저, 마이크로 발광소자의 위에 투명 전극층을 형성한다(S110).First, a transparent electrode layer is formed on the micro light-emitting device (S110).
이때, 전술한 마이크로 발광소자는 기판에 n형 질화물 반도체층과 활성층 및 p형 질화물 반도체층이 순차적으로 적층된 구조로 형성된 것일 수 있고, 전술한 p형 질화물 반도체층의 위에 투명 전극층을 증착시켜 형성할 수 있다.At this time, the above-mentioned micro light emitting device may be formed in a structure in which an n-type nitride semiconductor layer, an active layer and a p-type nitride semiconductor layer are sequentially laminated on a substrate, and a transparent electrode layer is deposited on the above- can do.
아울러, 투명 전극층의 증착 공정은, 화학기상 증착(chemical vapor deposition, CVD), 전자빔 증착(electron beam evaporation), 펄스 레이저 증착(pulsed laser deposition) 또는 스퍼터링(sputtering)을 통해 수행될 수 있으며, 전술한 투명 전극층은 전도성 산화물층의 사이에 금속층이 게재된 다층 박막 구조의 투명합성전극(transparent composite electrode, TCE) 구조로 형성될 수 있다.In addition, the process of depositing the transparent electrode layer may be performed by chemical vapor deposition (CVD), electron beam evaporation, pulsed laser deposition, or sputtering, The transparent electrode layer may be formed of a transparent composite electrode (TCE) structure having a multilayer thin film structure in which a metal layer is disposed between the conductive oxide layers.
다음, 투명 전극층의 위에 반사층을 형성한다(S120).Next, a reflective layer is formed on the transparent electrode layer (S120).
이때, 반사층은 절연체로 이루어진 분산 브래그 반사기(Distributed Bragg Reflector, DBR)로 구비되고, 전술한 활성층으로부터 발광되어 상기 투명 전극층을 통해 유입되는 빛을 반사하는 기능을 수행하게 된다.At this time, the reflective layer is a distributed Bragg reflector (DBR) made of an insulator, and reflects light emitted from the active layer and introduced through the transparent electrode layer.
아울러, 반사층은 절연체 중에서도, 고유한 임계치 이상의 전압을 물질에 인가하면, electrical break down 현상이 발생하면서 electro-forming이 수행되어, 최초에는 절연체인 물질의 저항 상태가 고저항 상태에서 저저항 상태로 변화되어 전도성을 나타내는 저항 변화 물질로 형성됨이 바람직하다.In addition, when a voltage higher than a specific threshold value is applied to a material in an insulator, an electro-forming process is performed while an electrical breakdown phenomenon occurs, so that the resistance state of a material which is an insulator initially changes from a high resistance state to a low resistance state And is formed of a resistance change material that exhibits conductivity.
또한, 상기 반사층을 형성하는 저항 변화 물질은, 산화알루미늄(Al2O3), 이산화규소(SiO2), 산화하프늄(HfO2), 이산화 타이타늄(TiO2), 산화아연(ZnO), 삼산화텅스텐(WO3), 산화몰리브덴(MoO3), 산화니켈(NiO), Mn-doped tin oxide(MTO), Zn doped tin oxide(ZTO), Ga doped ZnO(GZO), SnxOy, ZrxOy, CoxOy, CrxOy, VxOy, NbxOy ZnMgBeO, MgxOy, MgxNy, TixNy, InxNy, GaxNy, GaxOy, boron nitride(BN), NixNy, SixNy, Al doped ZnO(AZO), MgxZnyOx 및 CuxOy 중에서 선택될 수 있으나, 상술한 물질 이외에도 투명하고 상술한 저항 변화 특성을 나타내는 물질이라면, 본 발명의 반사층(120)을 형성하는데 이용될 수 있음은 물론이다.The resistance change material forming the reflective layer may be at least one selected from the group consisting of aluminum oxide (Al 2 O 3 ), silicon dioxide (SiO 2 ), hafnium oxide (HfO 2 ), titanium dioxide (TiO 2 ), zinc oxide (ZnO), tungsten trioxide (WO 3), molybdenum oxide (MoO 3), nickel oxide (NiO), Mn-doped tin oxide (MTO), Zn doped tin oxide (ZTO), Ga doped ZnO (GZO), Sn x O y, Zr x O y, Co x O y, Cr x O y, V x O y, Nb x O y ZnMgBeO, Mg x O y, Mg x N y, Ti x N y, In x N y, Ga x N y, Ga x O y , boron nitride (BN), Ni x N y , Si x N y , Al doped ZnO (AZO), Mg x Zn y O x and Cu x O y , It is needless to say that the material may be used to form the reflective layer 120 of the present invention if it exhibits a resistance change characteristic.
한편, 반사층을 형성하는 두 개의 저항 변화 물질은 서로 다른 굴절률을 갖도록 구비함이 바람직하다. 이러한, 반사층을 분산 브래그 반사기로 형성함으로써, 특정 파장 영역의 빛에 대한 반사도를 크게 향상시킬 수 있으며, 예컨대, 자외선(UV) 영역의 빛에 대한 반사도를 향상시킬 수 있다.On the other hand, it is preferable that the two resistance change materials forming the reflective layer have different refractive indexes. By forming the reflective layer with the dispersive Bragg reflector, the reflectance of light in a specific wavelength range can be greatly improved, and the reflectivity of light in the ultraviolet (UV) range can be improved, for example.
그 다음, 반사층의 위에 p형 전극층을 형성한다(S130).Then, a p-type electrode layer is formed on the reflective layer (S130).
이때, p형 전극층은 단일 물질로 이루어진 단일 층 구조로 형성될 수도 있으나, 크롬(Cr), 니켈(Ni), 금(Au), 알루미늄(Al) 및 은(Ag) 중에서 어느 하나의 물질이 순차적으로 적층된 복수의 층으로 형성함이 바람직하다.At this time, the p-type electrode layer may be formed as a single layer structure made of a single material, but any one of chromium (Cr), nickel (Ni), gold (Au), aluminum (Al) It is preferable to form a plurality of layers.
그 다음에는, 반사층의 내부에 상기 투명 전극층과 상기 p형 전극층을 전기적으로 연결하는 전도성 필라멘트를 형성한다(S140).Next, a conductive filament electrically connecting the transparent electrode layer and the p-type electrode layer is formed in the reflective layer (S140).
이때, 반사층의 전도성 필라멘트는, 투명 전극층, 반사층 및 p형 전극층이 순차적으로 적층된 이후에, 그 투명 전극층과 p형 전극층을 통해 인가되는 전계에 의해 형성될 수 있다.At this time, the conductive filament of the reflective layer may be formed by an electric field applied through the transparent electrode layer and the p-type electrode layer after the transparent electrode layer, the reflective layer, and the p-type electrode layer are sequentially laminated.
즉, 투명 전극층과 p형 전극층을 통해 반사층으로 임계치 이상의 전압을 인가하면, 전술한 저항 변화 물질로 형성된 반사층의 내부에 electrical break down 현상이 발생하면서 electro-forming이 수행되어 전도성 필라멘트(conducting filaments)가 형성되며, 상기 형성된 전도성 필라멘트를 통해서 전류가 흐르게 되어 반사층의 저항 상태가 저저항 상태로 유지될 수 있다.That is, when a voltage equal to or higher than the threshold value is applied to the reflective layer through the transparent electrode layer and the p-type electrode layer, electro-forming is performed while electrical breakdown phenomenon occurs in the reflective layer formed of the above- And a current flows through the conductive filament thus formed, so that the resistance state of the reflection layer can be maintained in a low resistance state.
이러한, 반사층의 전도성 필라멘트를 통해 p형 전극층과 투명 전극층 간의 전기적으로 연결이 가능하게 된다.The conductive filament of the reflective layer enables electrical connection between the p-type electrode layer and the transparent electrode layer.
이상에서는 본 발명의 바람직한 실시예를 예시적으로 설명하였으나, 본 발명의 범위는 이와 같은 특정 실시예에만 한정되는 것은 아니며, 특허청구범위에 기재된 범주 내에서 적절하게 변경 가능한 것이다.While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention.
본 발명은 마이크로 발광소자용 반사전극을 제조하는 용도로 사용될 수 있다.The present invention can be used for producing a reflective electrode for a micro light emitting device.

Claims (15)

  1. 기판, n형 반도체층, 활성층 및 p형 반도체층이 순차적으로 적층된 마이크로 발광소자에 구비되는 반사전극으로서,A reflective electrode provided in a micro light emitting device in which a substrate, an n-type semiconductor layer, an active layer and a p-type semiconductor layer are sequentially stacked,
    상기 p형 반도체층의 위에 형성되는 투명 전극층;A transparent electrode layer formed on the p-type semiconductor layer;
    상기 투명 전극층의 위에, 상기 활성층으로부터 발광되어 상기 투명 전극층을 통해 유입되는 빛을 반사하는 절연체로 형성되고, 그 내부에는 상기 투명 전극층과 p형 전극층을 연결하는 전도성 필라멘트가 포함된 반사층; 및A reflective layer formed on the transparent electrode layer, the reflective layer including a conductive filament connecting the transparent electrode layer and the p-type electrode layer in an insulator that reflects light emitted from the active layer through the transparent electrode layer; And
    상기 반사층의 위에 형성되고, 상기 반사층의 전도성 필라멘트를 통해 상기 투명 전극층에 전기적으로 연결되는 p형 전극층;을 포함하는 마이크로 발광소자용 반사전극.And a p-type electrode layer formed on the reflective layer and electrically connected to the transparent electrode layer through the conductive filament of the reflective layer.
  2. 제 1항에 있어서,The method according to claim 1,
    상기 반사층의 전도성 필라멘트는,Wherein the conductive filament of the reflective layer
    상기 투명 전극층, 상기 반사층 및 상기 p형 전극층이 순차적으로 적층된 이후에, 상기 투명 전극층과 상기 p형 전극층을 통해 인가되는 전계에 의해 형성되는 것을 특징으로 하는 마이크로 발광소자용 반사전극.Wherein the transparent electrode layer, the reflective layer, and the p-type electrode layer are sequentially stacked and then formed by an electric field applied through the transparent electrode layer and the p-type electrode layer.
  3. 제 1항에 있어서,The method according to claim 1,
    상기 반사층은,Wherein,
    서로 다른 저항 변화 물질을 교대로 반복하여 적층시킨 분산 브래그 반사기(Distributed Bragg Reflector, DBR)인 것을 특징으로 하는 마이크로 발광소자용 반사전극.Wherein the DBR is a distributed Bragg reflector (DBR) in which different resistance change materials are alternately repeatedly laminated.
  4. 제 3항에 있어서,The method of claim 3,
    상기 반사층을 형성하는 저항 변화 물질은,The resistance-changing material for forming the reflective layer may be,
    산화알루미늄(Al2O3), 이산화규소(SiO2), 산화하프늄(HfO2), 이산화 타이타늄(TiO2), 산화아연(ZnO), 삼산화텅스텐(WO3), 산화몰리브덴(MoO3), 산화니켈(NiO), Mn-doped tin oxide(MTO), Zn doped tin oxide(ZTO), Ga doped ZnO(GZO), SnxOy, ZrxOy, CoxOy, CrxOy, VxOy, NbxOy ZnMgBeO, MgxOy, MgxNy, TixNy, InxNy, GaxNy, GaxOy, boron nitride(BN), NixNy, SixNy, Al doped ZnO(AZO), MgxZnyOx 및 CuxOy 중에서 선택되는 것을 특징으로 하는 마이크로 발광소자용 반사전극.Aluminum oxide (Al 2 O 3), silicon dioxide (SiO 2), hafnium oxide (HfO 2), titanium dioxide (TiO 2), zinc oxide (ZnO), antimony trioxide of tungsten (WO 3), molybdenum oxide (MoO 3), (ZnO), Sn x O y , Zr x O y , Co x O y , Cr x O y , and Zn x O y , which are doped with ZnO, Mn-doped tin oxide (MTO) V x O y, Nb x O y ZnMgBeO, Mg x O y, Mg x N y, Ti x N y, In x N y, Ga x N y, Ga x O y, boron nitride (BN), Ni x N y , Si x N y , Al doped ZnO (AZO), Mg x Zn y O x, and Cu x O y .
  5. 제 1항에 있어서,The method according to claim 1,
    상기 p형 전극층은,The p-
    크롬(Cr), 니켈(Ni), 금(Au), 알루미늄(Al) 및 은(Ag) 중에서 적어도 두 개 이상의 물질이 순차적으로 적층된 복수의 층으로 형성되는 것을 특징으로 하는 마이크로 발광소자용 반사전극.Wherein the reflective layer is formed of a plurality of layers in which at least two or more materials selected from the group consisting of chromium (Cr), nickel (Ni), gold (Au), aluminum (Al) electrode.
  6. 기판 위에 적층되는 n형 반도체층;An n-type semiconductor layer laminated on a substrate;
    상기 n형 반도체층의 위에 적층되는 활성층;An active layer stacked on the n-type semiconductor layer;
    상기 활성층의 위에 적층되는 p형 반도체층;A p-type semiconductor layer laminated on the active layer;
    상기 p형 반도체층의 위에 형성되는 투명 전극층;A transparent electrode layer formed on the p-type semiconductor layer;
    상기 투명 전극층의 위에, 상기 활성층으로부터 발광되어 상기 투명 전극층을 통해 유입되는 빛을 반사하는 절연체로 형성되고, 그 내부에는 상기 투명 전극층과 p형 전극층을 연결하는 전도성 필라멘트가 포함된 반사층; 및A reflective layer formed on the transparent electrode layer, the reflective layer including a conductive filament connecting the transparent electrode layer and the p-type electrode layer in an insulator that reflects light emitted from the active layer through the transparent electrode layer; And
    상기 반사층의 위에 형성되고, 상기 반사층의 전도성 필라멘트를 통해 상기 투명 전극층에 전기적으로 연결되는 p형 전극층;을 포함하는 마이크로 발광소자.And a p-type electrode layer formed on the reflective layer and electrically connected to the transparent electrode layer through the conductive filament of the reflective layer.
  7. 제 6항에 있어서,The method according to claim 6,
    상기 반사층의 전도성 필라멘트는,Wherein the conductive filament of the reflective layer
    상기 투명 전극층, 상기 반사층 및 상기 p형 전극층이 순차적으로 적층된 이후에, 상기 투명 전극층과 상기 p형 전극층을 통해 인가되는 전계에 의해 형성되는 것을 특징으로 하는 마이크로 발광소자.Wherein the transparent electrode layer, the reflective layer, and the p-type electrode layer are sequentially stacked and then formed by an electric field applied through the transparent electrode layer and the p-type electrode layer.
  8. 제 7항에 있어서,8. The method of claim 7,
    상기 반사층은,Wherein,
    서로 다른 저항 변화 물질을 교대로 반복하여 적층시킨 분산 브래그 반사기(Distributed Bragg Reflector, DBR)인 것을 특징으로 하는 마이크로 발광소자.Wherein the DBR is a distributed Bragg reflector (DBR) in which different resistance change materials are alternately repeatedly laminated.
  9. 제 6항에 있어서,The method according to claim 6,
    상기 반사층을 형성하는 저항 변화 물질은,The resistance-changing material for forming the reflective layer may be,
    산화알루미늄(Al2O3), 이산화규소(SiO2), 산화하프늄(HfO2), 이산화 타이타늄(TiO2), 산화아연(ZnO), 삼산화텅스텐(WO3), 산화몰리브덴(MoO3), 산화니켈(NiO), Mn-doped tin oxide(MTO), Zn doped tin oxide(ZTO), Ga doped ZnO(GZO), SnxOy, ZrxOy, CoxOy, CrxOy, VxOy, NbxOy ZnMgBeO, MgxOy, MgxNy, TixNy, InxNy, GaxNy, GaxOy, boron nitride(BN), NixNy, SixNy, Al doped ZnO(AZO), MgxZnyOx 및 CuxOy 중에서 선택되는 것을 특징으로 하는 마이크로 발광소자.Aluminum oxide (Al 2 O 3), silicon dioxide (SiO 2), hafnium oxide (HfO 2), titanium dioxide (TiO 2), zinc oxide (ZnO), antimony trioxide of tungsten (WO 3), molybdenum oxide (MoO 3), (ZnO), Sn x O y , Zr x O y , Co x O y , Cr x O y , and Zn x O y , which are doped with ZnO, Mn-doped tin oxide (MTO) V x O y, Nb x O y ZnMgBeO, Mg x O y, Mg x N y, Ti x N y, In x N y, Ga x N y, Ga x O y, boron nitride (BN), Ni x N y , Si x N y , Al doped ZnO (AZO), Mg x Zn y O x, and Cu x O y .
  10. 제 6항에 있어서,The method according to claim 6,
    상기 p형 전극층은,The p-
    크롬(Cr), 니켈(Ni), 금(Au), 알루미늄(Al) 및 은(Ag) 중에서 적어도 두 개 이상의 물질이 순차적으로 적층된 복수의 층으로 형성되는 것을 특징으로 하는 마이크로 발광소자.Wherein at least two materials among chromium (Cr), nickel (Ni), gold (Au), aluminum (Al) and silver (Ag) are sequentially laminated.
  11. 기판, n형 반도체층, 활성층 및 p형 반도체층이 순차적으로 적층된 마이크로 발광소자에 구비되는 반사전극의 제조방법으로서,A manufacturing method of a reflective electrode provided in a micro light emitting device in which a substrate, an n-type semiconductor layer, an active layer and a p-type semiconductor layer are sequentially laminated,
    (1) 상기 p형 반도체층의 위에 투명 전극층을 형성하는 단계;(1) forming a transparent electrode layer on the p-type semiconductor layer;
    (2) 상기 활성층으로부터 발광되어 상기 투명 전극층을 통해 유입되는 빛을 반사하는 반사층을 상기 투명 전극층의 위에 형성하는 단계;(2) forming a reflective layer on the transparent electrode layer to reflect light emitted from the active layer and flowing through the transparent electrode layer;
    (3) 상기 반사층을 통해 상기 투명 전극층에 전기적으로 연결되는 p형 전극층을 상기 반사층의 위에 형성하는 단계; 및(3) forming a p-type electrode layer electrically connected to the transparent electrode layer through the reflective layer on the reflective layer; And
    (4) 상기 반사층의 내부에 상기 투명 전극층과 상기 p형 전극층을 전기적으로 연결하는 전도성 필라멘트를 형성하는 단계;를 포함하는 마이크로 발광소자용 반사전극의 제조방법.(4) forming a conductive filament inside the reflective layer to electrically connect the transparent electrode layer and the p-type electrode layer.
  12. 제 11항에 있어서,12. The method of claim 11,
    상기 제 (4)단계에서 형성되는 상기 반사층의 전도성 필라멘트는,The conductive filament of the reflective layer formed in the step (4)
    상기 투명 전극층, 상기 반사층 및 상기 p형 전극층이 순차적으로 적층된 이후에, 상기 투명 전극층과 상기 p형 전극층을 통해 인가되는 전계에 의해 형성되는 것을 특징으로 하는 마이크로 발광소자용 반사전극의 제조방법.Wherein the transparent electrode layer, the reflective layer, and the p-type electrode layer are sequentially stacked and then formed by an electric field applied through the transparent electrode layer and the p-type electrode layer.
  13. 제 11항에 있어서,12. The method of claim 11,
    상기 제 (2)단계에서 형성되는 상기 반사층은,The reflective layer formed in the step (2)
    서로 다른 저항 변화 물질을 교대로 반복하여 적층시킨 분산 브래그 반사기(Distributed Bragg Reflector, DBR)인 것을 특징으로 하는 마이크로 발광소자용 반사전극의 제조방법.Wherein the DBR is a distributed Bragg reflector (DBR) in which different resistance changing materials are alternately repeatedly laminated.
  14. 제 13항에 있어서,14. The method of claim 13,
    상기 제 (2)단계에서 상기 반사층을 형성하는 저항 변화 물질은,In the step (2), the resistance-changing material for forming the reflective layer may be formed of,
    산화알루미늄(Al2O3), 이산화규소(SiO2), 산화하프늄(HfO2), 이산화 타이타늄(TiO2), 산화아연(ZnO), 삼산화텅스텐(WO3), 산화몰리브덴(MoO3), 산화니켈(NiO), Mn-doped tin oxide(MTO), Zn doped tin oxide(ZTO), Ga doped ZnO(GZO), SnxOy, ZrxOy, CoxOy, CrxOy, VxOy, NbxOy ZnMgBeO, MgxOy, MgxNy, TixNy, InxNy, GaxNy, GaxOy, boron nitride(BN), NixNy, SixNy, Al doped ZnO(AZO), MgxZnyOx 및 CuxOy 중에서 선택되는 것을 특징으로 하는 마이크로 발광소자용 반사전극의 제조방법.Aluminum oxide (Al 2 O 3), silicon dioxide (SiO 2), hafnium oxide (HfO 2), titanium dioxide (TiO 2), zinc oxide (ZnO), antimony trioxide of tungsten (WO 3), molybdenum oxide (MoO 3), (ZnO), Sn x O y , Zr x O y , Co x O y , Cr x O y , and Zn x O y , which are doped with ZnO, Mn-doped tin oxide (MTO) V x O y, Nb x O y ZnMgBeO, Mg x O y, Mg x N y, Ti x N y, In x N y, Ga x N y, Ga x O y, boron nitride (BN), Ni x N y , Si x N y , Al doped ZnO (AZO), Mg x Zn y O x, and Cu x O y .
  15. 제 11항에 있어서,12. The method of claim 11,
    상기 제 (3)단계에서 형성되는 상기 p형 전극층은,The p-type electrode layer formed in the step (3)
    크롬(Cr), 니켈(Ni), 금(Au), 알루미늄(Al) 및 은(Ag) 중에서 적어도 두 개 이상의 물질이 순차적으로 적층된 복수의 층으로 형성되는 것을 특징으로 하는 마이크로 발광소자용 반사전극의 제조방법.Wherein the reflective layer is formed of a plurality of layers in which at least two or more materials selected from the group consisting of chromium (Cr), nickel (Ni), gold (Au), aluminum (Al) Gt;
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