Abstract:
A semiconductor light emitting device, including a reflective electrode layer; a second conductive semiconductor layer formed on a portion of a top surface of the reflective electrode layer; an active layer formed on the second conductive semiconductor layer; a first conductive semiconductor layer formed on the active layer; a first electrode formed under one portion of the first conductive semiconductor layer; and an insulating layer having a lower portion, a first upwardly directed side wall portion at a first side of the first electrode and a second upwardly directed side wall portion at a second side of the first electrode that is opposite to the first side. At least one portion of the lower portion is between the second conductive semiconductor layer and the reflective electrode layer.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a Continuation of co-pending U.S. patent application Ser. No. 12/428,622 filed on Apr. 23, 2009, which claims priority to Korean Patent Application No. 10-2008-0038117(filed on Apr. 24, 2008), which is hereby incorporated by reference in its entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of Invention 
         [0003]    The present disclosure relates to a semiconductor light emitting device. 
         [0004]    2. Discussion of the Related Art 
         [0005]    Group III-V nitride semiconductors have been variously applied to an optical device such as blue and green Light Emitting Diodes (LED), a high speed switching device such as a Metal Oxide Semiconductor Field Effect Transistor (MOSFET) and a High Electron Mobility Transistor (HEMT), and a light source of a lighting device or a display device. Particularly, light emitting device using a group III nitride semiconductor has a direct transition bandgap corresponding to a region from visible rays to ultraviolet and can realize high-efficiency light radiation. 
         [0006]    The nitride semiconductor is mainly used for an LED or a Laser Diode (LD), and studies have been continuously conducted to improve the manufacturing process or light efficiency of the nitride semiconductor. 
       SUMMARY OF THE INVENTION 
       [0007]    Embodiments provide a semiconductor light emitting device which comprises a second electrode layer under a plurality of compound semiconductor layers and a first electrode in the outer side thereof. 
         [0008]    Embodiments provide a semiconductor light emitting device which comprises a second electrode layer disposed under a light emitting structure, an insulator disposed on the one side of the second electrode layer and a first electrode disposed on the insulator. 
         [0009]    An embodiment provides a semiconductor light emitting device comprising: a first conductive semiconductor layer; an active layer under the first conductive semiconductor layer; a second conductive semiconductor layer under the active layer; a second electrode layer under the second conductive semiconductor layer; an insulator on one side of the second electrode layer; and a first electrode electrically connected to a one end of the first conductive semiconductor layer, on the insulator. 
         [0010]    An embodiment provides a semiconductor light emitting device comprising: a light emitting structure comprising a first conductive semiconductor layer, an active layer under the first conductive semiconductor layer, and a second conductive semiconductor layer under the active layer; a second electrode layer under the light emitting structure; a first electrode electrically connected to the first conductive semiconductor layer, in an outer side of the light emitting structure; and an insulator between the first electrode and the second electrode layer. 
         [0011]    An embodiment provides a semiconductor light emitting device comprising: a light emitting structure comprising a first conductive semiconductor layer, an active layer under the first conductive semiconductor layer, and a second conductive semiconductor layer under the active layer; a second electrode layer under the second conductive semiconductor layer; an insulator on the second electrode layer and in a one side of the light emitting structure; and a first electrode between the insulator and a one end of the first conductive semiconductor layer. 
         [0012]    The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features will be apparent from the description and drawings, and from the claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  is a side-sectional view of a semiconductor light emitting device according to one embodiment. 
           [0014]      FIG. 2  is a diagram illustrating an example where a wire is bonded with the first electrode of  FIG. 1 . 
           [0015]      FIGS. 3 to 8  are diagrams illustrating a process of manufacturing the semiconductor light emitting device according to one embodiment. 
           [0016]      FIG. 9  is a side-sectional view of a semiconductor light emitting device according to another embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0017]    Reference will now be made in detail to the embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. 
         [0018]    In the following description, it will be understood that when a layer (or film) is referred to as being ‘on’ another layer or substrate, it can be directly on the another layer or substrate, or intervening layers may also be present. Further, it will be understood that when a layer is referred to as being ‘under’ another layer, it can be directly under the another layer, and one or more intervening layers may also be present. In addition, it will also be understood that when a layer is referred to as being ‘between’ two layers, it can be the only layer between the two layers, or one or more intervening layers may also be present. 
         [0019]      FIG. 1  is a side-sectional view of a semiconductor light emitting device according to one embodiment.  FIG. 2  is a diagram illustrating an example where a wire is bonded with the first electrode of  FIG. 1 . 
         [0020]    Referring to  FIG. 1 , a semiconductor light emitting device  100  comprises a first conductive semiconductor layer  110 , an active layer  120 , a second conductive semiconductor layer  130 , a second electrode layer  140 , a conductive support member  150 , an insulator  160 , and a first electrode  170 . 
         [0021]    The semiconductor light emitting device  100  comprises a Light Emitting Diodes (LED) using a group III-V compound semiconductor. The LED may be a chromatic LED emitting chromatic light such as blue light, red light or green light, or may be an ultraviolet (UV) LED. The emission light of the LED may be variously implemented in the spirit and scope of embodiments. 
         [0022]    The first conductive semiconductor layer  110  may be selected from the compound semiconductors of group III-V elements (on which a first conductive dopant is doped), for example, GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs and GaAsP. 
         [0023]    When the first conductive semiconductor layer  110  is an N-type semiconductor layer, the first conductive dopant comprises an N-type dopant such as Si, Ge, Sn, Se and Te. The first conductive semiconductor layer  110  may serve as an electrode contact layer and may be formed in a single layer or multi layers, but is not limited thereto. 
         [0024]    The first electrode  170  is electrically connected to the one end  115  of the first conductive semiconductor layer  110 . The first electrode  170  may be disposed under the one end  115  of the first conductive semiconductor layer  110 , or may be disposed in a line at an outer side. A power supply source having a first polarity is applied to the first electrode  170 . Herein, a roughness (not shown) of a certain shape may be formed on the entire surface of the first conductive semiconductor layer  110 , and may be added or modified in the spirit and scope of embodiments. 
         [0025]    Moreover, a translucent electrode layer (not shown) may be formed on the first conductive semiconductor layer  110 , and diffuses the power supply source having the first polarity applied by the first electrode  170  to an entire region. The translucent electrode layer may comprise at least one of indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium aluminum zinc oxide (IAZO), indium gallium zinc oxide (IGZO), indium gallium tin oxide (IGTO), aluminum zinc oxide (AZO), antimony tin oxide (ATO), gallium zinc oxide (GZO), IrOx, RuOx, RuOx/ITO, Ni/IrOx/Au and Ni/IrOx/Au/ITO. 
         [0026]    The active layer  120  is formed under the first conductive semiconductor layer  110 , and the active layer  120  may be formed in a single quantum well structure or a multiple quantum well structure. The active layer  120  may form the period of a well layer and a barrier layer, for example, the period of an InGaN well layer/GaN barrier layer or the period of an AlGaN well layer/GaN barrier layer by using the compound semiconductor materials of group III-V elements. 
         [0027]    The active layer  120  may be formed of a material having a bandgap energy according to the wavelength of an emitting light. The active layer  120  may comprise a material that emits a chromatic light such as a light having a blue wavelength, a light having a red wavelength and a light having a green wavelength, but is not limited thereto. A conductive clad layer may be formed on and/or under the active layer  120 , and may be formed in an AlGaN layer. 
         [0028]    The second conductive semiconductor layer  130  is formed under the active layer  120 , and may be formed of at least one of the compound semiconductors of group III-V elements (on which a second conductive dopant is doped), for example, GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs and GaAsP. When the second conductive semiconductor layer  130  is a P-type semiconductor layer, the second conductive dopant may comprise a P-type dopant such as Mg and Ze. The second conductive semiconductor layer  130  may serve as an electrode contact layer and may be formed in a single layer or multi layers, but is not limited thereto. 
         [0029]    Herein, the first conductive semiconductor layer  110 , the active layer  120  and the second conductive semiconductor layer  130  may be defined as a light emitting structure  135 . Moreover, the first conductive semiconductor layer  110  may be formed of a P-type semiconductor, and the second conductive semiconductor layer  130  may be formed of an N-type semiconductor. A third conductive semiconductor layer, for example, an N-type semiconductor layer or a P-type semiconductor layer, may be formed under the second conductive semiconductor layer  130 . Accordingly, the light emitting structure  135  may comprise at least one of an N-P junction structure, a P-N junction structure, an N-P-N junction structure and a P-N-P junction structure. 
         [0030]    The second electrode layer  140  is formed under the second conductive semiconductor layer  130 . The second electrode layer  140  may be formed of a reflection electrode material, or may be formed of at least one of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, Hf and a material consisting of their selective combination. Herein, the reflection electrode material may be composed of a material having characteristic where a reflection rate is equal to or higher than 50%. 
         [0031]    An ohmic contact layer (not shown), in which a plurality of patterns are formed in a matrix shape or/and a layer type, may be formed in the second electrode layer  140 . The ohmic contact layer comprises at least one of materials such as ITO, IZO, AZO, IZTO, IAZO, IGZO, IGTO and ATO. 
         [0032]    Herein, the second electrode layer  140  may be schottky/ohmic contacted to the second conductive semiconductor layer  130 . When the ohmic contact layer exists, the second electrode layer  140  is schottky contacted to the second conductive semiconductor layer  130 , and the ohmic contact layer is ohmic contacted to the second conductive semiconductor layer  130 . Accordingly, the second electrode layer  140  and the ohmic contact layer may divide a current applied to the second conductive semiconductor layer  130  because they have different electrical characteristics. 
         [0033]    The second electrode layer  140  serves as an electrode which stably provides a power supply source having a second polarity to the light emitting structure  135 , and reflects light incident though the second conductive semiconductor layer  130 . 
         [0034]    The conductive support member  150  is formed under the second electrode layer  140 . The conductive support member  150  may be formed of at least one of copper (Cu), gold (Au), nickel (Ni), molybdenum (Mo), copper-tungsten (Cu—W) and carrier wafer (for example, Si, Ge, GaAs, ZnO, SiC and the like). The conductive support member  150  may be formed in an electro plating process, but is not limited thereto. 
         [0035]    The second electrode layer  140  and the conductive support member  150  may be used as a second electrode member which provides the power supply source having the second polarity to the light emitting structure  135 , and the second electrode member may be formed in a single layer or multi layers. Herein, the second electrode member having the single layer may be attached under the second conductive semiconductor layer  130  with adhesives. 
         [0036]    An etched region A 1  exists in the outer side of the light emitting structure  135 , which may be disposed more inward than the edge of the second electrode layer  140 . 
         [0037]    The first electrode  170  is insulated from the layers  120 ,  130  and  140  by the insulator  160 , and is electrically connected to the first conductive semiconductor layer  110 . The first electrode  170  may be formed of at least one of Ti, Al, In, Ta, Pd, Co, Ni, Si, Ge, Ag and Au, but is not limited thereto. 
         [0038]    The insulator  160  comprises side wall portions  161  and  162 , a base portion  163 , and a support portion  164 . The insulator  160  may be formed of at least one of SiO 2 , Si 3 N 4 , Al 2 O 3  and TiO 2 . The side wall portions  161  and  162  of the insulator  160  are formed in the outer surface of the first electrode  170 , and may be formed in a circle or polygon shape. In this case, the first electrode  170  may be formed in a circle or polygon shape. 
         [0039]    The inner side wall portion  161  of the side wall portions  161  and  162  is disposed between the first electrode  170  and the outer side of the second conductive semiconductor layer  130  and the active layer  120 , and insulates the inner side surface of the first electrode  170  from the layers  120  and  130 . Moreover, the inner side wall portion  161  is extended to the bottom of the one end  115  of the first conductive semiconductor layer  110 , and can electrically disconnect the first electrode  170  and the active layer  120 . The one end  115  of the first conductive semiconductor layer  110  is formed to partially overlap on the first electrode  170 . 
         [0040]    The outer side wall portion  162  of the side wall portions  161  and  162  insulates other side surface of the first electrode  170  in the channel region of a chip, and prevents the outer side of the first electrode  170  from being exposed. 
         [0041]    The base portion  163  is formed between the first electrode  170  and the second electrode layer  140 , and is disposed under the side wall portions  161  and  162 . The base portion  163  is formed on the one side of the second electrode layer  140 , and electrically insulates the first electrode  170  and the second electrode layer  140 . 
         [0042]    The support portion  164  extended to the inner side of the base portion  163  is disposed between the second conductive semiconductor layer  130  and the second electrode layer  140 , and prevents the insulator  160  from being separated from a chip. 
         [0043]    A passivation portion  165  may be formed around the top of the second electrode layer  140 . The passivation portion  165  has a ring shape or a belt shape, and may be connected to the base portion  163  of the insulator  160 . The material of the passivation portion  165  may be the same as that of the insulator  160 . That is, the insulator  160  may further comprise the passivation portion  165 . 
         [0044]    Moreover, the passivation portion  165  may be formed in a material different from the insulator  160 , for example, a conductive material. For example, the passivation portion  165  may comprise at least one of ITO, IZO, AZO, IZTO, IAZO, IGZO, IGTO and ATO. The passivation portion  165  may not be formed. 
         [0045]    The passivation portion  165  separates the light emitting structure  135  from the second electrode layer  140 , and thus, can prevent influences that are transferred from the second electrode layer  140  to the side wall of the light emitting structure  135 . 
         [0046]    The first electrode  170  is disposed on the outer side of the light emitting structure  135  and the one side of the second electrode layer  140  by the insulator  160 , is electrically connected to the first conductive semiconductor layer  110 , and is electrically opened from the layers  120 ,  130  and  140 . 
         [0047]    Referring to  FIG. 2 , a wire  180  is bonded on the first electrode  170 . In this case, the wire  180  is connected to the first electrode  170  which is disposed in the outer side of the semiconductor light emitting device  100 , and thus, may be disposed outward the semiconductor light emitting device  100 . 
         [0048]    The power supply source having the first polarity is provided to the first conductive semiconductor layer  110  through the first electrode  170 , and the power supply source having the second polarity is provided through the conductive support member  150  and the second electrode layer  140 . Light radiated from the active layer  120  of the semiconductor light emitting device  100  is irradiated in a forward direction. 
         [0049]    At this point, there is no obstacle in the top of the first conductive semiconductor layer  110 , thereby decreasing obstacles that obstructs the traveling of light L 1 . 
         [0050]    For example, if the first electrode is disposed in the top of the first conductive semiconductor layer and a wire is bonded, the following limitations may occur. The first electrode and the wire may serve as obstacles that obstruct a light path extracted to the top of the first conductive semiconductor layer. That is, there may occur limitations that the wire and the first electrode disposed in the upper side of the first conductive semiconductor layer absorb light. 
         [0051]    The first electrode  170  is disposed in the side of the semiconductor light emitting device  100 , and thus, the wire  180  does not pass though the upper portion of the semiconductor light emitting device  100 . Accordingly, light extraction efficiency can be improved. 
         [0052]      FIGS. 3 to 8  are diagrams illustrating a process of manufacturing the semiconductor light emitting device according to one embodiment. 
         [0053]    Referring to  FIG. 3 , the light emitting structure  135  on which a plurality of compound semiconductor layers are stacked is formed on a substrate  101 . The light emitting structure  135  may comprise the first conductive semiconductor layer  110 , the active layer  120  and the second conductive semiconductor layer  130  which are sequentially stacked. 
         [0054]    The substrate  101  may be selected from the group consisting of sapphire substrate (Al 2 O 3 ), GaN, SiC, ZnO, Si, GaP, InP and GaAs. A concave-convex pattern may be formed on the substrate  101 , but is not limited thereto. 
         [0055]    A group III-V compound semiconductor may grow on the substrate  101 . Herein, the growth equipment of the compound semiconductor may be implemented with electron beam evaporator, Physical Vapor Deposition (PVD), Chemical Vapor Deposition (CVD), Plasma Laser Deposition (PLD), dual-type thermal evaporator, sputtering and Metal Organic Chemical Vapor Deposition (MOCVD), but is not limited thereto. 
         [0056]    A buffer layer (not shown) or/and an undoped semiconductor layer (not shown) may be formed on the substrate  101 . The buffer layer may be formed of a single crystal buffer layer or a group III-V compound semiconductor, and decreases a lattice constant difference with the substrate  110 . The undoped semiconductor layer may be formed of a GaN-based semiconductor. The substrate  101 , the buffer layer and the undoped semiconductor layer may be separated or removed after the growth of a thin film. Herein, a separate patterned metal material (not shown) may be formed between the substrate  101  and the first conductive semiconductor layer  110  for protecting the active layer  120 . 
         [0057]    The first conductive semiconductor layer  110  is formed on the substrate  101 . The first conductive semiconductor layer  110  may be selected from the compound semiconductors of group III-V elements (on which a first conductive dopant is doped), for example, GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs and GaAsP. When the first conductive semiconductor layer  110  is an N-type dopant, the first conductive dopant comprises an N-type dopant such as Si, Ge, Sn, Se and Te. 
         [0058]    The active layer  120  is formed of a group III-V compound semiconductor on the first conductive semiconductor layer  110 , and has a single quantum well structure or a multiple quantum well structure. The active layer  120  may comprise a material that emits a chromatic light such as a light having a blue wavelength, a light having a red wavelength and a light having a green wavelength. A conductive clad layer may be formed on and/or under the active layer  120  and may be formed in an AlGaN layer, but is not limited thereto. 
         [0059]    The second conductive semiconductor layer  130  is formed on the active layer  120 , and may be formed of at least one of the compound semiconductors of group III-V elements (on which a second conductive dopant is doped), for example, GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs and GaAsP. When the second conductive semiconductor layer  130  is a P-type semiconductor layer, the second conductive dopant may comprise a P-type dopant such as Mg and Ze. 
         [0060]    A third conductive semiconductor layer, for example, an N-type semiconductor layer or a P-type semiconductor layer, may be formed on the second conductive semiconductor layer  130 . Accordingly, the light emitting structure  135  may comprise at least one of an N-P junction structure, a P-N junction structure, an N-P-N junction structure and a P-N-P junction structure. 
         [0061]    Referring to  FIG. 4 , the one-side region  167  of the second conductive semiconductor layer  110  is exposed in a first mesa etching process. Herein, the first mesa etching process is performed in a portion of the second conductive semiconductor layer  130  until the first conductive semiconductor layer  110  is exposed in a dry or/and wet etching process. The etching process may be changed in the spirit and scope of embodiments. 
         [0062]    The first electrode  170  is formed in the one-side region  167  of the first conductive semiconductor layer  110 . The first electrode  170  may be formed of at least one of Ti, Al, In, Ta, Pd, Co, Ni, Si, Ge, Ag and Au, but is not limited thereto. The one side of the first conductive semiconductor layer  110  contacts the bottom of the first electrode  170 , and the size of the contacted region may be changed according to an etching region by the first mesa etching process. 
         [0063]    Herein, the bottom of the first electrode  170  may be electrically connected to the first conductive semiconductor layer  110 . 
         [0064]    The thickness H 1  of the first electrode  170  heightens or lowers the top of the second conductive semiconductor layer  130 . 
         [0065]    The first electrode  170  is separated from the second conductive semiconductor layer  130  and the side surface of the active layer  120  at a certain interval, and may be formed in a circle shape, a polygon shape or a line shape. 
         [0066]    Referring to  FIG. 5 , the insulator  160  is formed in the outer surface and top of the first electrode  170 . The insulator  160  comprises the side wall portions  161  and  162 , the base portion  163  and the support portion  164 , and covers the exposed region of the first electrode  170 . The insulator  160  may be formed of at least one of SiO 2 , Si 3 N 4 , Al 2 O 3  and TiO 2 . 
         [0067]    The side wall portions  161  and  162  are formed in the outer surface of the first electrode  170 . The inner side wall portion  161  insulates the inner side surface of the first electrode  170  and the first conductive semiconductor layer  110 , and insulates the active layer  120  and the one side of the second conductive semiconductor layer  130 . The outer side wall portion  162  insulates other side surface of the first electrode  170  in the channel region of the chip. Accordingly, the side wall portions  161  and  162  prevent the outer side of the first electrode  170  from being exposed. 
         [0068]    The base portion  163  is formed in the top of the first electrode  170 , and insulates the top of the first electrode  170 . The support portion  164  extended to the inner side of the base portion  163  supports the entirety of the insulator  160 . 
         [0069]    The passivation portion  165  may be formed along the outer side of the top of the second conductive semiconductor layer  130 . The passivation portion  165  has a ring shape or a belt shape, and may be connected to the base portion  163  of the insulator  160 . The material of the passivation portion  165  may be the same as that of the insulator  160 . That is, the insulator  160  may further comprise the passivation portion  165 . 
         [0070]    Moreover, the passivation portion  165  may be formed in a material different from the insulator  160 , for example, a conductive material. For example, the passivation portion  165  may comprise at least one of ITO, IZO, AZO, IZTO, IAZO, IGZO, IGTO and ATO. The passivation portion  165  may not be formed. 
         [0071]    Referring to  FIG. 6 , the second electrode layer  140  is formed on the second conductive semiconductor layer  130  and the insulator  160 , the conductive support member  150  is formed on the second electrode layer  140 . 
         [0072]    The passivation portion  165 , which is disposed around the top of the second conductive semiconductor layer  130 , separates the light emitting structure  135  from the second electrode layer  140 , and thus, can prevent influences that are transferred from the second electrode layer  140  to the side wall of the light emitting structure  135 . 
         [0073]    The second electrode layer  140  may be formed of at least one of reflection electrode materials, for example, Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, Hf and a material consisting of their selective combination. An ohmic contact layer (not shown), in which a plurality of patterns are formed in a matrix shape or/and a layer type, may be formed between the second electrode layer  140  and the second conductive semiconductor layer  130 . The ohmic contact layer comprises at least one of materials such as ITO, IZO, AZO, IZTO, IAZO, IGZO, IGTO and ATO. 
         [0074]    The second electrode layer  140  serves as an electrode which stably provides the power supply source having the second polarity to the light emitting structure  135 . Herein, the second electrode layer  140  may be schottky/ohmic contacted to the second conductive semiconductor layer  130 . When the ohmic contact layer exists, the ohmic contact layer and the second electrode layer  140  may divide a current applied to the second conductive semiconductor layer  130  because they have different electrical resistances. 
         [0075]    The conductive support member  150  may be formed of at least one of Cu, Au, Ni, Mo, Cu—W and carrier wafer (for example, Si, Ge, GaAs, ZnO, SiC and the like). Herein, the second electrode layer  140 , for example, may be formed in a sputtering process. The conductive support member  150 , for example, may be formed in a plating process. The formation processes may be changed in the spirit and scope of embodiments. 
         [0076]    Referring to  FIGS. 6 and 7 , the substrate  101  is removed. In this case, the substrate  101  is disposed upward and is removed. 
         [0077]    The substrate  101  that is disposed under the first conductive semiconductor layer  110  is removed in a physical/chemical process. For example, when laser ray having a wavelength of a certain region is irradiated to the substrate  101 , a heating energy is concentrated on a boundary surface between the substrate  101  and the first conductive semiconductor layer  110 , and thus the substrate  101  is separated. Furthermore, a polishing process using an Inductively coupled Plasma/Reactive Ion Etching (ICP/RCE) process may be performed on the surface of the first conductive semiconductor layer  110  from which the substrate  101  has been removed. 
         [0078]    When a non-conductive semiconductor layer, for example, a buffer layer or/and an undoped semiconductor layer exists between the substrate  101  and the first conductive semiconductor layer  110 , it may be removed in an etching process or a polishing process, but is not limited thereto. 
         [0079]    Referring to  FIGS. 7 and 8 , the one side of the first conductive semiconductor layer  110  is disposed on the first electrode  170  and the insulator  160 . 
         [0080]    A roughness (not shown) of a certain shape may be formed on the top of the first conductive semiconductor layer  110 . Moreover, a translucent electrode layer (not shown) may be formed on the first conductive semiconductor layer  110 , and may diffuse a current. The translucent electrode layer may comprise at least one of ITO, IZO, IZTO, IAZO, IGZO, IGTO, AZO, ATO, gallium zinc oxide (GZO), IrOx, RuOx, RuOx/ITO, Ni/IrOx/Au and Ni/IrOx/Au/ITO. 
         [0081]    A second mesa etching process is performed on the light emitting structure  135 . In this case, an etched region A 1  exists in the outer perimeter of the light emitting structure  135 , which is disposed more inward than the edge of the second electrode layer  140 . Herein, the region A 1  may not exist. 
         [0082]    The second mesa etching process may use a wet or/and dry etching process, and may be changed in the spirit and scope of embodiments. 
         [0083]    When the second mesa etching process is performed in a portion of the one-side region D 1  of the first conductive semiconductor layer  110 , the top of the first electrode  170  is exposed in the one side of the first conductive semiconductor layer  110 . 
         [0084]    Since the certain region D 2  of the first conductive semiconductor layer  110  is disposed to overlap on the first electrode  170 , the first electrode  170  is electrically connected to the one end  115  of the first conductive semiconductor layer  110 . 
         [0085]    In the semiconductor light emitting device  100 , the first electrode  170  is disposed in the side direction of the first conductive semiconductor layer  110 , and a wire bonded to the first electrode  170  may be disposed in the outer side of the semiconductor light emitting device  100 . Accordingly, the light extraction efficiency of the semiconductor light emitting device  100  can be improved. 
         [0086]      FIG. 9  is a side-sectional view of a semiconductor light emitting device according to another embodiment. In description of another embodiment, repetitive description on the same elements as those of one embodiment will be omitted and refers to that of one embodiment. 
         [0087]    Referring to  FIG. 9 , a semiconductor light emitting device  100 A according to another embodiment comprises the first conductive semiconductor layer  110 , the active layer  120 , the second conductive semiconductor layer  130 , the second electrode layer  140 , the conductive support member  150 , a plurality of insulators  160  and  160 A, and a plurality of first electrodes  170  and  170 A. 
         [0088]    The plurality of insulators  160  and  160 A are disposed in the both sides of the light emitting structure  135  respectively, and electrically insulate the first electrodes  170  and  170 A and the layers  120 ,  130  and  140 . A detailed description on the insulators  160  and  160 A refers to one embodiment. 
         [0089]    In the plurality of first electrodes  170  and  170 A, regions D 2  and D 3  where the one side  115  and other side  117  of the first conductive semiconductor layer  110  overlap may be identical to or different from each other. 
         [0090]    The plurality of first electrodes  170  and  170 A may be electrically connected by an electrode pattern formed on the first conductive semiconductor each other. 
         [0091]    In the semiconductor light emitting device  100 A, the first electrodes  170  and  170 A are disposed in the both-side directions of the first conductive semiconductor layer  110  respectively, and a plurality of wires bonded to the first electrodes  170  and  170 A may be disposed in the outer side of the semiconductor light emitting device  100 A. Accordingly, the light extraction efficiency of the semiconductor light emitting device  100 A can be improved. 
         [0092]    Embodiments dispose the first electrode in the outer side of the plurality of compound semiconductor layers, thereby solving light absorption limitations due to the first electrode and the wire. 
         [0093]    Embodiments can improve light efficiency. 
         [0094]    Embodiments can improve the reliability of the semiconductor light emitting device. 
         [0095]    Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.