Abstract:
Disclosed are a method of fabricating a light emitting device includes the steps of: forming a plurality of compound semiconductor layers on a substrate, the substrate including a plurality of chip regions and isolation region; selectively etching the compound semiconductor layers to form a light emitting structure on each chip region and form a buffer structure on the isolation region; forming a conductive support member on the light emitting structure and the buffer structure; removing the substrate by using a laser lift off process; and dividing the conductive support member into the a plurality of chips of the chip regions, wherein the buffer structure is spaced apart from the light emitting structure.

Description:
[0001]    The present application claims priority of Korean Patent Application No. 10-2010-0020485 filed on Mar. 8, 2010, which is hereby incorporated by reference in its entirety. 
       BACKGROUND 
       [0002]    The embodiment relates to a light emitting device and a light emitting device package. 
         [0003]    Light emitting diodes (LEDs) are a kind of semiconductor devices that convert electric energy into light. The LED is advantageous as compared with conventional light sources, such as a fluorescent lamp or a glow lamp, in terms of power consumption, life span, response speed, safety and environmental-friendly requirement. In this regard, various studies have been performed to replace the conventional light sources with the LEDs. The LEDs are increasingly used as light sources for lighting devices such as various lamps, liquid crystal displays, electric signboards, and street lamps. 
       SUMMARY 
       [0004]    The embodiment provides a light emitting device and a light emitting device package capable of improving reliability. 
         [0005]    The embodiment provides a light emitting device and a light emitting device package capable of preventing damages, such as cracks, of the light emitting structure. 
         [0006]    The embodiment provides a light emitting device and a light emitting device package capable of improving light emission efficiency. 
         [0007]    According to the embodiment, a light emitting device includes: a conductive support member; a plurality of chip regions defining light emitting structures on the conductive support member; an isolation region between the chip regions on the conductive support member; and at least one buffer structure at the isolation region, wherein the light emitting structure and the buffer structure include a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer. 
         [0008]    According to the embodiment, a light emitting device includes: a conductive support member; a plurality of chip regions defining light emitting structures on the conductive support member; an isolation region between the chip regions on the conductive support member; and at least one buffer structure at the isolation region, wherein the light emitting structure and the buffer structure include a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer, and wherein the buffer structure includes a zener device. 
         [0009]    According to the embodiment, a light emitting device package includes: a body; first and second electrodes on the body; a light emitting device electrically connected to the first and second lead electrodes on the body; and a molding member surrounding the light emitting device on the body, wherein the light emitting device includes: a conductive support member; a plurality of chip regions defining light emitting structures on the conductive support member; an isolation region between the chip regions on the conductive support member; and at least one buffer structure at the isolation region, and wherein the light emitting structure and the buffer structure include a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a sectional view showing a light emitting device according to a first embodiment; 
           [0011]      FIGS. 2A to 2C  are plan views showing the light emitting device of  FIG. 1 ; 
           [0012]      FIGS. 3 to 10  are sectional views showing the manufacturing process of the light emitting device according to the first embodiment; 
           [0013]      FIG. 11  is a sectional view showing a light emitting device according to a second embodiment; 
           [0014]      FIG. 12  is a sectional view showing a light emitting device package including a light emitting device according to the embodiment; 
           [0015]      FIG. 13  is an exploded perspective view showing a display apparatus according to the embodiment; 
           [0016]      FIG. 14  is a view showing the display apparatus according to the embodiment; and 
           [0017]      FIG. 15  is a perspective view showing a lighting unit according to the embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0018]    In the description of the embodiments, it will be understood that, when a layer (or film), a region, a pattern, or a structure is referred to as being “on” or “under” another substrate, another layer (or film), another region, another pad, or another pattern, it can be “directly” or “indirectly” over the other substrate, layer (or film), region, pad, or pattern, or one or more intervening layers may also be present. Such a position of the layer has been described with reference to the drawings. 
         [0019]    The thickness and size of each layer shown in the drawings may be exaggerated, omitted or schematically drawn for the purpose of convenience or clarity. In addition, the size of elements does not utterly reflect an actual size. 
         [0020]      FIG. 1  is a sectional view showing a light emitting device  100  according to a first embodiment, and  FIGS. 2A to 2C  are plan views showing the light emitting device  100  of  FIG. 1 . 
         [0021]    Referring to  FIGS. 1 and 2 , the light emitting device  100  according to the first embodiment includes a conductive support member  160 , a light emitting structure  120  formed on the conductive support member  160  to generate light, and at least one buffer structure  180  formed on the conductive support member  160  such that the buffer structure  180  is spaced apart from the light emitting structure  120  at a predetermined distance d, and prevents the light emitting device  120  from being damaged in the manufacturing process of the light emitting device  100 . 
         [0022]    The light emitting structure  120  includes a first adhesive layer  158 , a reflective layer  157  on the first adhesive layer  158 , a diffusion barrier layer  159  at lateral surfaces of the first adhesive layer  158  and the reflective layer  157 , a plurality of compound semiconductor layers  145  formed on the reflective layer  157  to emit light, and an electrode  170  formed on the compound semiconductor layers  145  to supply power to the light emitting structure  120  together with the conductive support member  160 . The electrode  170  may include at least one electrode pad. In addition, the electrode  170  may have an arm electrode structure. The buffer structure  180  and the light emitting structure  120  may nave a stack structure of the same layers or the same height. 
         [0023]    At least one buffer structure  180  may be spaced apart from the lateral surfaces of the light emitting structure  120  at a predetermined distance d. 
         [0024]    For example, the distance d may be in the range of about 5 μm to about 50 μm. In addition, a width of the buffer structure  180  may be the range of about 5 μm to about 30 μm. However, the distance d and the width w 1  may vary according to the design of the light emitting device  100 , but the embodiment is not limited thereto. 
         [0025]    The buffer structure  180  may not generate light, but absorbs the impact that may occur in the manufacturing process of the light emitting device  100  according to the embodiment, so that the damage of the light emitting structure  120  can be prevented. In other words, the buffer structure  180  is formed, so that the reliability for the light emitting device  100  according to the embodiment and the method of manufacturing the light emitting device  100  can be improved, and the details thereof will be described below. 
         [0026]    Hereinafter, the light emitting device  100  according to the embodiment will be described in detail while focusing on the components and the operation of the light emitting device  100 . 
         [0027]    The conductive support member  160  supports the light emitting structure  120  and the buffer structure  180  while supplying power to the light emitting structure  120  together with the electrode  170 . 
         [0028]    For example, the conductive support member  160  may include at least one selected from the group consisting of titan (Ti), chromium (Cr), nickel (Ni), aluminum (Al), platinum (Pt), gold (Au), tungsten (W), copper (Cu), molybdenum (Mo) and a carrier wafer (including Si, Ge, GaAs, ZnO, SiC, SiGe, or GaN). 
         [0029]    A second adhesive layer  161  may be formed on a top surface of the conductive support member  160 . The second adhesive layer  161  may include AuSn, AuIn, or NiSn representing superior adhesive strength to firmly bond the light emitting structure  120  and the buffer structure  180  to the conductive support member  160 . 
         [0030]    The light emitting structure  120  and the buffer structure  180  may be formed on the conductive support member  160 . The buffer structure  180  may be spaced apart from the lateral surfaces of the light emitting structure  120  at the distance d. The buffer structure  180  and the light emitting structure  120  may have a stack structure of the same layers or the same height. 
         [0031]    As shown in  FIG. 2A , the buffer structure  180  may be spaced apart from edge regions of the light emitting structure  120  at the distance d. 
         [0032]    As shown in  FIGS. 2B and 2C , a plurality of buffer structures  180  may be provided separately from each other or may be integral with each other while being spaced apart from the edge regions of the light emitting structure  120  and the lateral surfaces of the light emitting structure  120 . In other words, the integration means that the buffer structures  180  is not separated from each other, but continuously liked with each other along each lateral surface of the light emitting structure  120 . 
         [0033]    The distance d may vary according to the positions of the buffer structure  180 . In other words, the distance d 1  between the buffer structure  180  and the edge regions of the light emitting structure  120  may be greater than a distance d 2  between the lateral surfaces of the light emitting structure  120  and the buffer structure  180 . 
         [0034]    For example, the distance d may be in the range of about 5 μm to about 50 μm. The distance d may be determined according to the width of an isolation region formed to divide a plurality of chips in the unit of an individual chip in the manufacturing process of the light emitting device  100  according to the embodiment, and the details thereof will be described in detail below. 
         [0035]    For example, the width w 1  of the buffer structure  180  may be in the range of about 5 μm to about 30 μm. The width w 1  of the buffer structure  180  may vary according to the design or the manufacturing process of the light emitting device  100 , but the embodiment is not limited thereto. 
         [0036]    In addition, a top surface of the buffer structure  180  may have a cross shape, a circular shape, a diamond shape, a sector shape, a semicircular shape, a polygonal shape, or a ring shape, but the embodiment is not limited thereto. 
         [0037]    The buffer structure  180  may not generate light, but absorbs the impact that may occur in the manufacturing process of the light emitting device  100  according to the embodiment, so that the damage of the light emitting structure  120  can be prevented. 
         [0038]    In detail, in place of the light emitting structure  120 , the buffer structure  180  absorbs the impact caused by the energy of a laser used in an LLO (Laser Lift Off) process to remove a substrate. 
         [0039]    In other words, in a typical LLO process, which does not employ the buffer structure  180 , damages such as cracks may occur in the lateral surfaces or the edge regions of the light emitting structure  120  due to the impact caused by the energy of a laser used in the LLO process. In contrast, the light emitting device  100  according to the embodiment includes the buffer structure  180  to absorb the impact caused by the laser energy, thereby preventing damages such as cracks from occurring in the light emitting structure  120 . 
         [0040]    The light emitting structure  120  and the buffer structure  180  may be simultaneously formed in the same manufacturing process. In this case, at least parts of the stack structures of the above structures may have the same layers as each other. 
         [0041]    Hereinafter, the embodiment will be described while focusing on a case in which at least parts of the stack structures of the above structures have the same layers as each other. However, the light emitting structure  120  and the buffer structure  180  may be formed through different manufacturing processes and may include different materials, but the embodiment is not limited thereto. 
         [0042]    The light emitting structure  120  and the buffer structure  180  may include the first adhesive layer  158 , the reflective layer  157  on the first adhesive layer  158 , the diffusion barrier layer  150  on the lateral surfaces of the first adhesive layer  158  and the reflective layer  157 , and the compound semiconductor layers  145  on the reflective layer  157 . 
         [0043]    The first adhesive layer  158  may have the same material as that of the second adhesive layer  161 . For example, the first adhesive layer  158  may include AuSn, AuIn, or NiSn representing superior adhesive strength. The first adhesive layer  158  is bonded to the second adhesive layer  161  to firmly bond the light emitting structure  120  and the conductive support member  160  to the buffer structure  180 . 
         [0044]    The reflective layer  157  is interposed between the compound semiconductor layers  145  and the conductive support member  160  to reflect light generated from the compound semiconductor layers  145  of the light emitting structure  120 . Accordingly, the light emission efficiency of the light emitting device  100  can be improved. 
         [0045]    For example, the reflective layer  157  may include one of silver (Ag), the alloy thereof, aluminum (Al), and the alloy thereof, but the embodiment is not limited thereto. 
         [0046]    When the reflective layer  157  does not make ohmic contact with the compound semiconductor layer  145 , an ohmic layer (not shown) may be additionally interposed between the reflective layer  157  and the compound semiconductor layer  145 . 
         [0047]    The diffusion barrier layer  159  may be formed on the lateral surfaces of the first adhesive layer  158  and the reflective layer  157 . 
         [0048]    The diffusion barrier layer  159  can prevent the first adhesive layer  158 , the reflective layer  157 , the second adhesive layer  161 , and the conductive support member  160  from being degraded due to inter-diffusion. The diffusion barrier layer  159  may have a single layer structure or a multiple layer structure including at least one selected from the group consisting of Ti, Ni, W and Pt, but the embodiment is not limited thereto. 
         [0049]    The compound semiconductor layers  145  may be formed on the reflective layer  157 . The compound semiconductor layers  145  may include group III to V compound semiconductors, and may include a semiconductor material having a compositional formula of In x Al y Ga 1-x-y N (0≦x≦1, 0≦y≦1, 0≦x+y≦1), but the embodiment is not limited thereto. 
         [0050]    The electrode  170  may be formed on the top surface of the compound semiconductor layers  145  formed in the light emitting structure  120 . Power is supplied by the electrode  170  and the conductive support member  160 , so that light can be generated from the compound semiconductor layers  145 . 
         [0051]    For example, the compound semiconductor layers  145  may include a second conductive semiconductor layer  150 , an active layer  140  on the second conductive semiconductor layer  150 , and a first semiconductor layer  130  on the active layer  140 . 
         [0052]    For example, the second conductive semiconductor layer  150  may include a P type semiconductor layer having P type dopants. The p type semiconductor layer may include semiconductor materials having the compositional formula of In x Al y Ga 1-x-y N (0≦x≦1, 0≦y≦1, 0≦x+y≦1), such as InAlGaN, GaN, AlGaN, InGaN, AlInN, AlN, or InN. In addition, the P type semiconductor layer may be doped with P type dopant such as Mg, Zn, Ca, Sr, or Ba. 
         [0053]    The active layer  140  may be formed on the second conductive semiconductor layer  150 . Electrons (or holes) injected through the first conductive semiconductor layer  130  may be recombined with holes (or electrons) injected through the second conductive semiconductor layer  150  at the active layer  140 , so that the active layer  140  emits the light of the wavelength based on the band gap difference of the energy band according to the intrinsic material of the active layer  140 . 
         [0054]    The active layer  140  may have a single quantum well structure, a multiple quantum well (MQW) structure, a quantum wire structure or a quantum dot structure, but the embodiment is not limited thereto. 
         [0055]    The active layer  140  may include a semiconductor material having a compositional formula of In x Al y Ga 1-x-y N (0≦x≦1, 0≦y≦1, 0≦x+y≦1). If the active layer  140  has the MQW, the active layer  140  may have the stack structure of a plurality of well layers and a plurality of barrier layers. For example, the active layer  140  may have the stack structure of InGaN well/GaN barrier layers. 
         [0056]    A clad layer (not shown) doped with the N type or P type dopants can be formed on and/or under the active layer  140 . The clad layer may include an AlGaN layer or an InAlGaN layer. 
         [0057]    The first semiconductor layer  130  may be formed on the active layer  140 . The first semiconductor layer  130  includes only a first conductive semiconductor layer, or an undoped semiconductor layer formed on the first conductive semiconductor layer, but the embodiment is not limited thereto. 
         [0058]    For instance, the first conductive semiconductor layer may include an N type semiconductor layer including N type dopants. The N type semiconductor layer may include semiconductor materials having the compositional formula of In x Al y Ga 1-x-y N (0≦x≦1, 0≦y≦1, 0≦x+y≦1), such as InAlGaN, GaN, AlGaN, AlInN, InGaN, AlN, or InN. In addition, the N type semiconductor layer may be doped with N type dopant such as Si, Ge or Sn. 
         [0059]    Since the undoped semiconductor layer is not doped with conductive dopants, the undoped semiconductor layer may have remarkably low electrical conductivity as compared with that of the second conductive semiconductor layer  150 , and may be formed to improve the crystalline of the first conductive semiconductor layer. 
         [0060]    Differently from the previous embodiments, the first conductive layer  130  may include a P type semiconductor layer including P type dopants, and the second conductive semiconductor layer  150  may include an N type semiconductor layer including N type dopants. In addition, a third conductive semiconductor layer (not shown) including N type dopants or P type dopants may be formed on the first semiconductor layer  130 . Accordingly, the light emitting device  100  may have at least one of 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. The doping concentration of conductive dopants of the first conductive semiconductor layer and the second conductive semiconductor layer  150  may be irregular or uniform. In other words, the compound semiconductor layers  145  may have various structures, but the embodiment is not limited thereto. 
         [0061]    A first protective layer  155  may be formed at a lateral surface of the compound semiconductor layers  145 . The first protective layer  155  may include at least one selected from the group consisting of Si x O y , Si 3 N 4 , Si x N y , SiO x N y , Al 2 O 3 , TiO 2  and MgF 2 . Accordingly, the compound semiconductor layers  145  can be prevented from being electrically shorted with the conductive support member  160 . 
         [0062]    Meanwhile, as shown in  FIG. 1 , the first protective layer  155  may be not formed at the lateral surface of the compound semiconductor layers  145  of the buffer structure  180  that does not generate light. 
         [0063]    A second protective layer  165  may be formed at the lateral surfaces of the light emitting structure  120  and the buffer structure  180  and on the conductive support member  160 . In detail, the second protective layer  165  may be formed on the lateral surface of the first protective layer  155 , the lateral surface of the diffusion barrier layer  159 , and the top surface of the second adhesive layer  161 . 
         [0064]    The second protective layer  165  may be formed to prepare for the damage of the first protective layer  155  in the manufacturing process of the light emitting device  100 . In other words, the second protective layer  165  can prevent the light emitting structure  120  from being electrically shorted with the conductive support member  160  or the buffer structure  180  due to the crack of the first protective layer  155 . 
         [0065]    The second protective layer  165  may include material the same as that of the first protective layer  155 . For example, the second protective layer  165  may be formed by using at least one selected from the group consisting of SiO 2 , Si x O y , Si 3 N 4 , Si x N y , SiO x N y , Al 2 O 3 , TiO 2 , and MgF 2  through a deposition scheme, but the embodiment is not limited thereto. 
         [0066]    Hereinafter, the manufacturing process of the light emitting device  100  according to the embodiment will be described in detail, and the structures and components the same as those of the previous embodiments will be not further described or will be briefly described. 
         [0067]      FIGS. 3 to 10  are views showing the manufacturing process of the light emitting device  100  according to the first embodiment. 
         [0068]    Referring to  FIG. 3 , the compound semiconductor layers  145  may be grown from a substrate  110 . For example, the compound semiconductor layers  145  may include the first semiconductor layer  130 , the active layer  140  on the first semiconductor layer  130 , and the second conductive semiconductor layer  150  on the active layer  140 . 
         [0069]    The compound semiconductor layers  145  may be formed using a MOCVD (Metal Organic Chemical Vapor Deposition), CVD (Chemical Vapor Deposition), PECVD (Plasma-Enhanced Chemical Vapor Deposition), MBE (Molecular Beam Epitaxy), or HVPE (Hydride Vapor Phase Epitaxy) scheme, but the embodiment is not limited thereto. 
         [0070]    Referring to  FIG. 4  and  FIGS. 5A to 5C , the compound semiconductor layers  145  is selectively removed, so that a plurality of first structures  120   a  and a plurality of second structures  180   a  may be formed. For example, the compound semiconductor layers  145  may be selectively removed through an etching process, but the embodiment is not limited thereto. 
         [0071]    The first and second structures  120   a  and  180   a  are formed to the light emitting structure  120  and the buffer structure  180 , respectively, through the manufacturing process. 
         [0072]    The width between the first structures  120   a , that is, a width x of an isolation region M to divide a plurality of chip regions which each chip region has one chip, in the unit of an individual chip (1 CHIP), may be in the range of about 5 μm to about 100 μm. The width x of the isolation region M may be defined by the distance between adjacent chips. In addition, the second structures  180   a  may be formed at the middle portion of the isolation region M, that is, a region corresponding to ½ of the width x of the isolation region M. 
         [0073]    Therefore, the light emitting structure  120  and the buffer structure  180 , which are formed in the following process, may be spaced apart from each other at the distance d corresponding to about ½ of the width x of the isolation region M. 
         [0074]    Meanwhile, the top surface of the second structures  180   a  may have a circular shape or a polygonal shape as shown in  FIGS. 5A and 5B , or may have a lattice shape formed along the lateral surface of the first structures  120   a  as shown in  FIG. 5   c . However, according to the embodiment, the shape of the second structures  180   a  IS not limited thereto. 
         [0075]    Referring to  FIG. 6 , the reflective layer  157 , the first adhesive layer  158 , and the diffusion barrier layer  159  are formed on the first structures  120   a  and the second structures  180   a , so that the light emitting structure  120  and the buffer structure  180  according to the embodiment can be provided. 
         [0076]    Before the reflective layer  157  is formed, the first protective layer  155  may be additionally formed on the lateral surface of the light emitting structure  120  and the buffer structure  180 . 
         [0077]    Referring to  FIG. 7 , the conductive support member  160  may be formed on the light emitting structure  120  and the buffer structure  180 . 
         [0078]    For example, the conductive support member  160  may be prepared in the form of a sheet plate and bonded onto the light emitting structure  120  and the buffer structure  180 . 
         [0079]    In this case, the second adhesive layer  161  may be formed on the bottom surface of the conductive support member  160 . The second adhesive layer  161  may be bonded to the first adhesive layer  158  on the top surface of the light emitting structure  120  and the buffer structure  180 . 
         [0080]    Referring to  FIG. 8 , the substrate  110  may be removed through an LLO (Laser Lift Off) process. 
         [0081]    The LLO process is to separate the compound semiconductor layers  145  from the substrate  110  by laser energy applied to the bottom surface of the substrate  110 . 
         [0082]    According to the conventional LLO process, damages such as cracks may occur at the lateral surface or the edge of the light emitting structure due to the impact caused by the laser energy. 
         [0083]    However, in the light emitting device  100  according to the embodiment, since the buffer structure  180  is formed to absorb the impact caused by the laser energy, the impact to be applied to the lateral surfaces and the edge regions of the light emitting structure  120  is absorbed by the buffer structure  180 , thereby preventing damages such as cracks from occurring in the light emitting structure  120 . 
         [0084]    Since the buffer structure  180  absorbs laser energy, the buffer structure  180  can prevent damages such as cracks. 
         [0085]    Referring to  FIG. 9 , the second protective layer  165  may be formed on the lateral surfaces of the light emitting structure  120  and the buffer structure  180  and on the conductive support member  160 . 
         [0086]    For example, the second protective layer  165  may be formed using a deposition process along a surface exposed when the substrate  110  is removed. 
         [0087]    The second protective layer  165  may complement the first protective layer  155  that may be damaged in the LLO process. 
         [0088]    The electrode  170  may be formed on the bottom surface of the light emitting structure  120 . The electrode  170  may have a single layer structure or a multiple layer structure including at least one selected from the group consisting of aluminum (Al), titanium (Ti), chrome (Cr), nickel (Ni), copper (Cu), and gold (Au). 
         [0089]    Referring to  FIG. 10 , the chip separation process is performed to divide the chips in the unit of an individual chip (1 chip), so that the light emitting device  100  according to the embodiment can be provided. 
         [0090]    The chip separate process may include at least one of a breaking process using a cutter, an etching process including a dry etching process or a wet etching process, and a laser scribing process using a laser, but the embodiment is not limited thereto. 
         [0091]    The buffer structure  180  may be separated or removed along the chip boundary through the chip separation process. 
         [0092]      FIG. 11  is a sectional view showing a light emitting device according to the second embodiment. 
         [0093]    The second embodiment has the same structure as that of the first embodiment except that the buffer structure  180  according to the second embodiment includes a zener device. Accordingly, in the second embodiment, the same reference numbers will be assigned to those of the first embodiment, and the details thereof will be omitted. 
         [0094]    Referring to  FIG. 11 , the light emitting device  200  according to the second to the embodiment includes the conductive support member  160 , the light emitting structure  120  formed on the conductive support member  160  to generate light, and at least one buffer structure  180  spaced apart from the light emitting structure  120  at the distance d on the conductive support member  160  to prevent the light emitting structure  120  from being damaged in the manufacturing process of the light emitting device  200 . 
         [0095]    The light emitting structure  120  may include the first adhesive layer  158 , the reflective layer  157  on the first adhesive layer  158 , the diffusion barrier layer  150  on the lateral surfaces of the first adhesive layer  158  and the reflective layer  157 , the compound semiconductor layers  145  on the reflective layer  157  to emit light, and the electrode  170  formed on the compound semiconductor layers  145  to supply power to the light emitting structure  120  together with the conductive support member  160 . 
         [0096]    The buffer structure  180  and the light emitting structure  120  may have a stack structure of the same layers or may have the same height. 
         [0097]    For example, the buffer structure  180  may include the first adhesive layer  158  and the compound semiconductor layers  145 . 
         [0098]    At least one buffer structure  180  may be spaced apart from the lateral surface of the light emitting structure  120  at the distance d. 
         [0099]    The buffer structure  180  may not generate light. Instead, the buffer structure  180  absorbs the impact that may occur in the manufacturing process of the light emitting device  100  according to the embodiment to prevent the light emitting structure  120  from being damaged. In other words, the buffer structure  180  is formed, so that the reliability of the light emitting device  200  according to the embodiment and the method of manufacturing the same can be improved. 
         [0100]    The conductive support member  160  supports the light emitting structure  120  and the buffer structure  180  while supplying power to the light emitting structure  120  together with the electrode  170 . 
         [0101]    The light emitting structure  120  and the buffer structure  180  may be simultaneously formed in the same manufacturing process. In this case, at least parts of the stack structures of the above structures  1210  and  180  may be the same layers as each other. 
         [0102]    The second protective layer  165  may be formed on the lateral surfaces of the light emitting structure  120  and the buffer structure  180  and on the conductive support member  160 . In detail, the second protective layer  165  may be formed on the lateral surfaces of the first protective layer  155  and the diffusion barrier layer and on the second adhesive layer  161 . 
         [0103]    An insulating layer  210  may be formed on the second adhesive layer  161  between the light emitting structure  120  and the buffer structure  180 , or on the conductive support member  160 . The insulating layer  210  may be formed on the lateral surfaces of the second protective layer  165  of the light emitting structure  120 , a top surface of the second adhesive layer  161  or the conductive support member  160 , and lateral surfaces of the first adhesive layer  158  and the reflective layer  157  of the buffer structure  180 . 
         [0104]    The insulating layer  210  may include at least one selected from the group consisting of SiO 2 , Si x O y , Si 3 N 4 , Si x N y , SiO x N y , Al 2 O 3 , TiO 2  and MgF 2 . 
         [0105]    The buffer structure  180  may include a zener device. To this end, the first and second zener electrodes  220  and  230  may be electrically connected to the buffer structure  180 . 
         [0106]    The first zener electrode  220  may be electrically connected to the second conductive semiconductor layer  150  of the buffer structure  180 . The first zener electrode  220  may make contact with the lateral surface of the second conductive semiconductor layer  150  of the buffer structure  180 . The first zener electrode  220  connected to the second conductive semiconductor layer  150  may be electrically connected to the first conductive semiconductor layer  130  of the light emitting structure  120 . 
         [0107]    The first zener electrode  220  may be formed on the second protective layer  165  and the insulating layer  210  between the first conductive semiconductor layer  130  of the light emitting structure  120  and the second conductive semiconductor layer  150  of the buffer structure  180 . 
         [0108]    The insulating layer  210  may have the same material as that of the second protective layer  165 , but the embodiment is not limited thereto. 
         [0109]    The second zener electrode  230  may be electrically connected to the first conductive semiconductor layer  130  of the buffer structure  180 . 
         [0110]    The second zener electrode  230  may be electrically connected to the first conductive semiconductor layer  130  of the buffer structure  180  and the conductive support member  160 . 
         [0111]    The second zener electrode  230  is formed on the second protective layer  165 , and may be electrically connected to the conductive support member  160  through the second adhesive layer  161 . 
         [0112]    The second protective layer  165  can prevent the first conductive semiconductor layer  130  from being electrically shorted with the second conductive semiconductor layer  150  by the second zener electrode  230 . 
         [0113]    The first and second zener electrodes  220  and  230  may include the same material as that of the light emitting structure  120 , or may include material different from that of the light emitting structure  120 . For example, the first and second zener electrodes  220  and  230  may have a single layer structure or a multiple layer structure including at least one selected from the group consisting of Al, Ti, Cr, Ni, Cu, and Au 
         [0114]    As described above, since the buffer structure  180  includes a zener device, if great reverse voltage is applied, current flows to the zener device of the buffer structure  180 . Accordingly, the current does not flow to the light emitting structure  120 , thereby preventing the light emitting structure  120  from being damaged. 
         [0115]      FIG. 12  is a light emitting device package  30  including the light emitting device according to the embodiment. 
         [0116]    Referring to  FIG. 12 , the light emitting device package  30  includes a body  20 , first and second lead electrodes  31  and  32  installed in the body  20 , the light emitting device  100  provided on the body  20  and electrically connected to the first and second lead electrodes  31  and  32 , and a molding member  40  that surrounds the light emitting device  100  on the body  20 . 
         [0117]    The body  20  may include silicon, synthetic resin or metallic material. When viewed from the top, the body  20  has a cavity having an open upper portion and formed with an inclined inner wall. 
         [0118]    The first and second electrode layers  31  and  32  are electrically isolated from each other and pass through the body  20 . 
         [0119]    In detail, one ends of the first and second lead electrodes  31  and  32  are disposed in the cavity  50  and the other ends of the first and second lead electrodes  31  and  32  are attached to an outer surface of the body  20  and exposed to the outside. 
         [0120]    The first and second electrode layers  31  and  32  supply power to the light emitting device  100  and improve the light efficiency by reflecting the light emitted from the light emitting device  100 . Further, the first and second lead electrodes  31  and  32  dissipate heat generated from the light emitting device  100  to the outside. 
         [0121]    The light emitting device  100  can be installed on the body  20  or the first or second lead electrode  31  or  32 . 
         [0122]    The molding member  40  surrounds the light emitting device  100  to protect the light emitting device  100 . In addition, the molding member  40  may include luminescence material to change the wavelength of the light emitted from the light emitting device  100  by the luminescence material. 
         [0123]    The light emitting device or the light emitting device package according to the embodiment may be applied to the light unit. The light unit has an array structure of a plurality of light emitting devices or a plurality of light emitting device packages. The light unit may include the display device as shown in  FIGS. 13 and 14  and the lighting device as shown in  FIG. 15 . In addition, the light unit may include a lighting lamp, a signal lamp, a headlight of a vehicle, and an electric signboard. 
         [0124]      FIG. 13  is an exploded perspective view showing the display device according to the embodiment. 
         [0125]    Referring to  FIG. 13 , the display device  1000  includes a light guide plate  1041 , a light emitting module  1031  for supplying the light to the light guide plate  1041 , a reflective member  1022  provided below the light guide plate  1041 , an optical sheet  1051  provided above the light guide plate  1041 , a display panel  1061  provided above the optical sheet  1051 , and a bottom cover  1011  for receiving the light guide plate  1041 , the light emitting module  1031 , and the reflective member  1022 . However, the embodiment is not limited to the above structure. 
         [0126]    The bottom cover  1011 , the reflective sheet  1022 , the light guide plate  1041  and the optical sheet  1051  may constitute a light unit  1050 . 
         [0127]    The light guide plate  1041  diffuses the light supplied from the light emitting module  1031  to provide surface light. The light guide plate  1041  may include transparent material. For instance, the light guide plate  1041  may include one of acryl-based resin, such as PMMA (polymethyl methacrylate), PET (polyethylene terephthalate), PC (polycarbonate), COC (cyclic olefin copolymer) and PEN (polyethylene naphthalate) resin. 
         [0128]    The light emitting module  1031  is disposed at one side of the light guide plate  1041  to supply the light to at least one side of the light guide plate  1041 . The light emitting module  1031  serves as the light source of the display device. 
         [0129]    At least one light emitting module  1031  is provided to directly or indirectly supply the light from one side of the light guide plate  1041 . The light emitting module  1031  may include a substrate  1033  and light emitting device packages  30  according to the embodiments. The light emitting device packages  30  are arranged on the substrate  1033  while being spaced apart from each other at the predetermined interval. The substrate  1033  may include a printed circuit board (PCB), but the embodiment is not limited thereto. In addition, the substrate  1033  may also include a metal core PCB (MCPCB) or a flexible PCB (FPCB), but the embodiment is not limited thereto. If the light emitting device packages  30  are installed on the side of the bottom cover  1011  or on a heat dissipation plate, the substrate  1033  may be omitted. The heat dissipation plate partially makes contact with the top surface of the bottom cover  1011 . Thus, the heat generated from the light emitting device packages  30  can be emitted to the bottom cover  1011  through the heat dissipation plate. 
         [0130]    In addition, the light emitting device packages  30  are arranged such that light exit surfaces of the light emitting device packages  30  are spaced apart from the guide plate  1041  by a predetermined distance, but the embodiment is not limited thereto. The light emitting device packages  30  may directly or indirectly supply the light to a light incident surface, which is one side of the light guide plate  1041 , but the embodiment is not limited thereto. 
         [0131]    The reflective member  1022  is disposed below the light guide plate  1041 . The reflective member  1022  reflects the light, which travels downward through the bottom surface of the light guide plate  1041 , toward the display panel  1061 , thereby improving the brightness of the display panel  1061 . For instance, the reflective member  1022  may include PET, PC or PVC resin, but the embodiment is not limited thereto. The reflective member  1022  may serve as the top surface of the bottom cover  1011 , but the embodiment is not limited thereto. 
         [0132]    The bottom cover  1011  may receive the light guide plate  1041 , the light emitting module  1031 , and the reflective member  1022  therein. To this end, the bottom cover  1011  has a receiving section  1012  having a box shape with an opened top surface, but the embodiment is not limited thereto. The bottom cover  1011  can be coupled with the top cover (not shown), but the embodiment is not limited thereto. 
         [0133]    The bottom cover  1011  can be manufactured through a press process or an extrusion process by using metallic material or resin material. In addition, the bottom cover  1011  may include metal or non-metallic material having superior thermal conductivity, but the embodiment is not limited thereto. 
         [0134]    The display panel  1061 , for instance, is an LCD panel including first and second transparent substrates, which are opposite to each other, and a liquid crystal layer interposed between the first and second substrates. A polarizing plate can be attached to at least one surface of the display panel  1061 , but the embodiment is not limited thereto. The display panel  1061  displays information by blocking the light generated from the light emitting module  1031  or allowing the light to pass therethrough. The display device  1000  can be applied to various portable terminals, monitors of notebook computers, monitors or laptop computers, and televisions. 
         [0135]    The optical sheet  1051  is disposed between the display panel  1061  and the light guide plate  1041  and includes at least one transmittive sheet. For instance, the optical sheet  1051  includes at least one of a diffusion sheet, a horizontal and vertical prism sheet, and a brightness enhanced sheet. The diffusion sheet diffuses the incident light, the horizontal and vertical prism sheet concentrates the incident light onto the display panel  1061 , and the brightness enhanced sheet improves the brightness by reusing the lost light. In addition, a protective sheet can be provided on the display panel  1061 , but the embodiment is not limited thereto. 
         [0136]    The light guide plate  1041  and the optical sheet  1051  can be provided in the light path of the light emitting module  1031  as optical members, but the embodiment is not limited thereto. 
         [0137]      FIG. 14  is a sectional view showing a display device according to the embodiment. 
         [0138]    Referring to  FIG. 14 , the display device  1100  includes a bottom cover  1152 , a substrate  1120  on which the light emitting device packages  30  are arranged, an optical member  1154 , and a display panel  1155 . 
         [0139]    The substrate  1120  and the light emitting device packages  30  may constitute the light emitting module  1060 . In addition, the bottom cover  1152 , at least one light emitting module  1060 , and the optical member  1154  may constitute the light unit (not shown). 
         [0140]    The bottom cover  1151  can be provided with a receiving section  1153 , but the embodiment is not limited thereto. 
         [0141]    The optical member  1154  may include at least one of a lens, a light guide plate, a diffusion sheet, a horizontal and vertical prism sheet, and a brightness enhanced sheet. The light guide plate may include PC or PMMA (Poly methyl methacrylate). The light guide plate can be omitted. The diffusion sheet diffuses the incident light, the horizontal and vertical prism sheet concentrates the incident light onto the display panel  1155 , and the brightness enhanced sheet improves the brightness by reusing the lost light. 
         [0142]    The optical member  1154  is disposed above the light emitting module  1060  in order to convert the light emitted from the light emitting module  1060  into the surface light. In addition, the optical member  1154  may diffuse or collect the light. 
         [0143]      FIG. 15  is a perspective view showing a lighting device according to the embodiment. 
         [0144]    Referring to  FIG. 15 , the lighting device  1500  includes a case  1510 , a light emitting module  1530  installed in the case  1510 , and a connection terminal  1520  installed in the case  1510  to receive power from an external power source. 
         [0145]    Preferably, the case  1510  includes material having superior heat dissipation property. For instance, the case  1510  includes metallic material or resin material. 
         [0146]    The light emitting module  1530  may include a substrate  1532  and light emitting device packages  30  installed on the substrate  1532 . The light emitting device packages  30  are spaced apart from each other or arranged in the form of a matrix. 
         [0147]    The substrate  1532  includes an insulating member printed with a circuit pattern. For instance, the substrate  1532  includes a PCB, an MCPCB, an FPCB, a ceramic PCB, and an FR-4 substrate. 
         [0148]    In addition, the substrate  1532  may include material that effectively reflects the light. A coating layer can be formed on the surface of the substrate  1532 . At this time, the coating layer has a white color or a silver color to effectively reflect the light. 
         [0149]    At least one light emitting device package  30  is installed on the substrate  1532 . Each light emitting device package  30  may include at least one LED (light emitting diode) chip. The LED chip may include an LED that emits the light of visible ray band having red, green, blue or white color and a UV (ultraviolet) LED that emits UV light. 
         [0150]    The light emitting device packages  30  of the light emitting module  1530  can be variously arranged to provide various colors and brightness. For instance, the white LED, the red LED and the green LED can be arranged to achieve the high color rendering index (CRI). 
         [0151]    The connection terminal  1520  is electrically connected to the light emitting module  1530  to supply power to the light emitting module  1530 . The connection terminal  1520  has a shape of a socket screw-coupled with the external power source, but the embodiment is not limited thereto. For instance, the connection terminal  1520  can be prepared in the form of a pin inserted into the external power source or connected to the external power source through a wire. 
         [0152]    According to the embodiment, the light emitting device includes at least one buffer structure spaced apart from the light emitting structure, thereby preventing the light emitting structure from being damaged (e.g., cracked) due to the impact applied in the LLO process. 
         [0153]    According to the embodiment, the buffer structures may be separated from each other or integrated with each other while being spaced apart from each edge region or each lateral surface of the light emitting structure. The integration has been described above. As described above, the buffer structures are sufficiently ensured, so that the cracks of the light emitting structure can be prevented. Accordingly, the reliability for the light emitting structure can be improved. 
         [0154]    According to the embodiment, the buffer structure and the light emitting structure have a stack structure of the same layers, so that the manufacturing process can be easily performed. 
         [0155]    According to the embodiment, the first protective layer is provided on a lateral surface of the compound semiconductor layer, so that the compound semiconductor layers can be prevented from electrically shorted with the conductive support member. 
         [0156]    According to the embodiment, the first and second adhesive layers are formed between the conductive support member and the compound semiconductor layers, so that adhesive performance between the compound semiconductor layer and the conductive support member can be maximized. 
         [0157]    According to the embodiment, the reflective layer is provided on the first and second adhesive layers, so that light emitted from the compound semiconductor layers is reflected upward, thereby improving light emission efficiency. 
         [0158]    According to the embodiment, the light emitting device is provided at a region corresponding to about ½ of the width of the isolation region, thereby preventing the light emitting structure from being damaged (e.g., cracked) due to the impact applied in the LLO process. 
         [0159]    Any reference in this specification to “one embodiment,” “an embodiment,” “example embodiment,” etc., means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with any embodiment, it is submitted that it is within the purview of one skilled in the art to effect such feature, structure, or characteristic in connection with other ones of the embodiments. 
         [0160]    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.