Patent Publication Number: US-2015060925-A1

Title: Light emitting device and method of manufacturing the same

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the priority of Korean Patent Application Nos. 10-2010-0066927 filed on Jul. 12, 2010 and 10-2010-0066928 filed on Jul. 12, 2010, in the Korean Intellectual Property Office, the disclosures of which are incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a light emitting device and a method of manufacturing the same. 
     2. Description of the Related Art 
     A light emitting diode (LED) is a semiconductor device that can emit light of various colors due to electron-hole recombination occurring at a p-n junction between p-type and n-type semiconductors when a current is supplied thereto. Such an LED is advantageous over a filament-based light emitting device in that it has a long lifespan, low power usage, superior initial-operation characteristics, and high vibration resistance. These factors have continually boosted the demand for LEDs. Notably of late, a great deal of attention has been drawn to group III nitride semiconductors that can emit light in a blue/short wavelength region. 
     In order to manufacture LEDs, a wafer is processed and subsequently diced into individual chip units. Thereafter, the individual chip units are provided with phosphorus layers, lenses or the like and then subjected to a packaging process. However, the packaging process, performed upon each of the chips, complicates the manufacturing process, increases costs, and interferes with reducing the size of a final package structure. Therefore, there is a demand in this technical field for an appropriate wafer-level packaging technique to simplify the process and achieve a reduction in the size of a device. 
     SUMMARY OF THE INVENTION 
     An aspect of the present invention provides a light emitting device capable of achieving a reduction in size and ensuring improved light extraction efficiency by using a chip-sized lens. 
     An aspect of the present invention also provides a method of manufacturing a light emitting device, capable of simplifying manufacturing processes and reducing manufacturing costs in manufacturing the aforementioned light emitting device. 
     According to an aspect of the present invention, there is provided a light emitting device including: a substrate; a light emitting structure disposed on the substrate and having a stack structure in which a first conductivity type semiconductor layer, an active layer and a second conductivity type semiconductor layer are stacked; a lens disposed on the light emitting structure; and a first terminal portion and a second terminal portion electrically connected to the first conductivity type semiconductor layer and the second conductivity type semiconductor layer, respectively, wherein at least one of the first and second terminal portions extends from a top surface of the light emitting structure along respective side surfaces of the light emitting structure and the substrate. 
     The substrate may be an electrically conductive substrate. 
     The first terminal portion may be disposed on a bottom surface of the substrate, and the second terminal portion may extend from the top surface of the light emitting structure along the respective side surfaces of the light emitting structure and the substrate. 
     The light emitting device may further include an insulator disposed between the second terminal portion and each of the respective side surfaces of the light emitting structure and the substrate. 
     The lens may not cover side surfaces of the light emitting structure. 
     The light emitting device may further include a transparent polymer layer disposed between the lens and the light emitting structure. 
     The light emitting device may further include a light conversion layer disposed between the lens and the light emitting structure and converting a wavelength of light emitted from the light emitting structure. 
     The lens may include a micro-lens array formed on a surface thereof. 
     The substrate may be an electrically insulating substrate. 
     The first terminal portion may be disposed on a bottom surface of the substrate and electrically connected to the light emitting structure by a conductive via penetrating the substrate, and the second terminal portion may extend from the top surface of the light emitting structure along the respective side surfaces of the light emitting structure and the substrate. 
     The first and second terminal portions may each extend from the top surface of the light emitting structure along the respective side surfaces of the light emitting structure and the substrate. 
     According to another aspect of the present invention, there is provided a method of manufacturing a light emitting device, the method including: forming a light emitting structure by growing a first conductivity type semiconductor layer, an active layer and a second conductivity type semiconductor layer on a growth substrate; attaching a support substrate to the light emitting structure and separating the growth substrate from the light emitting structure; forming at least one through hole in the light emitting structure and the support substrate; and forming a terminal portion occupying at least part of the through hole so as to be connected to a top surface of the light emitting structure. 
     The method may further include forming a lens on the light emitting structure. 
     The lens may be formed on individual chip units. 
     The method may further include dicing the light emitting structure and the support substrate into individual chip units. 
     At least one of portions cut in the dicing of the light emitting structure and the support substrate may include the terminal portion. 
     The method may further include forming a transparent polymer layer on the light emitting structure. 
     The method may further include forming a light conversion layer on the light emitting structure, the light conversion layer converting a wavelength of light emitted from the light emitting structure. 
     The method may further include forming an insulator on an inner wall of the through hole before the forming of the terminal portion. 
     According to another aspect of the present invention, there is provided a light emitting device including: a substrate; a light emitting structure disposed on the substrate and having a stack structure in which a first conductivity type semiconductor layer, an active layer and a second conductivity type semiconductor layer are stacked; a lens disposed on the light emitting structure; a first terminal portion electrically connected to the first conductivity type semiconductor layer, penetrating the substrate and exposed to the outside; and a second terminal portion electrically connected to the second conductivity type semiconductor layer, penetrating the substrate and exposed to the outside, wherein the second terminal portion has a conductive via penetrating the first conductivity type semiconductor layer and the active layer and connected to the second conductivity type semiconductor layer. 
     The light emitting device may further include a bonding layer disposed between the light emitting structure and the substrate. 
     The bonding layer may have an electrically insulating property. In detail, the bonding layer maybe formed of silicon resin or epoxy resin. 
     The bonding layer may have electrical conductivity. In this case, the light emitting device may further include an insulator disposed between the bonding layer and each of the first and second terminal portions. 
     The substrate may be an electrically insulating substrate. 
     The substrate may be formed of a material selected from the group consisting of AlN and un-doped silicon. 
     The substrate may be an electrically conductive substrate. 
     The light emitting device may further include an insulator disposed between the substrate and each of the first and second terminal portions. 
     A part of the first terminal portion penetrating the substrate may be formed of the same material as the substrate and may be integrated with the substrate. 
     The light emitting device may further include an insulator disposed between the conductive via and each of the first conductivity type semiconductor layer and the active layer. 
     The lens may be formed so as not to cover side surfaces of the light emitting structure. 
     The light emitting device may further include a transparent polymer layer disposed between the lens and the light emitting structure. 
     The light emitting device may further include a light conversion layer disposed between the lens and the light emitting structure and converting a wavelength of light emitted from the light emitting structure. 
     The lens may include a micro-lens array formed on a surface thereof. 
     According to another aspect of the present invention, there is provided a method of manufacturing a light emitting device, the method including: forming a light emitting structure by growing a first conductivity type semiconductor layer, an active layer and a second conductivity type semiconductor layer on a growth substrate; attaching a support substrate to the light emitting structure and separating the growth substrate from the light emitting structure; forming a first terminal portion electrically connected to the first conductivity type semiconductor layer, penetrating the substrate and exposed to the outside; forming a recess in the light emitting structure and the support substrate to thereby expose the second conductivity type semiconductor layer; and forming a second terminal portion occupying at least part of the recess so as to be connected to the second conductivity type semiconductor layer. 
     The method may further include forming a lens on the light emitting structure. 
     The lens may be formed on individual chip units. 
     The method may further include dicing the light emitting structure and the support substrate into individual chip units. 
     The method may further include forming a transparent polymer layer on the light emitting structure. 
     The method may further include forming a light conversion layer on the light emitting structure and converting a wavelength of light emitted from the light emitting structure. 
     The method may further include forming an insulator on an inner wall of the recess before the forming of the terminal portion. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other aspects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a schematic cross-sectional view illustrating a light emitting device according to an embodiment of the present invention; 
         FIG. 2  is a schematic cross-sectional view illustrating a light emitting structure in the light emitting device depicted in  FIG. 1 ; 
         FIG. 3  is an enlarged cross-sectional view illustrating a region between a substrate and the light emitting structure of the light emitting device depicted in  FIG. 1 ; 
         FIG. 4  is an enlarged cross-sectional view illustrating a lens region of the light emitting device depicted in  FIG. 1 ; 
         FIGS. 5 through 10  are schematic cross-sectional views illustrating a method of manufacturing a light emitting device according to an embodiment of the present invention; 
         FIG. 11  is a schematic cross-sectional view illustrating an alternative to the light emitting device of the embodiment depicted in  FIG. 1 ; 
         FIG. 12  is a schematic cross-sectional view illustrating a light emitting device according to another embodiment of the present invention; and 
         FIGS. 13 through 15  are schematic cross-sectional views illustrating alternatives to the light emitting device of the embodiment depicted in  FIG. 12 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. 
     The invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the shapes and sizes of elements may be exaggerated for clarity. Like reference numerals in the drawings denote like elements. 
       FIG. 1  is a schematic cross-sectional view illustrating a light emitting device according to an embodiment of the present invention.  FIG. 2  is a schematic cross-sectional view illustrating a light emitting structure in the light emitting device depicted in  FIG. 1 .  FIG. 3  is an enlarged cross-sectional view illustrating a region between a substrate and the light emitting structure of the light emitting device depicted in  FIG. 1 .  FIG. 4  is an enlarged cross-sectional view illustrating a lens region of the light emitting device depicted in  FIG. 1 . 
     Referring to  FIG. 1 , a light emitting device  100 , according to this embodiment, includes a substrate  102 , a light emitting structure  101  placed on the substrate  102 , first and second terminal portions  103   a  and  103   b,  a transparent polymer layer  105 , a light conversion layer  106  and a lens  107 . According to this embodiment, the substrate  102  may utilize an electrically conductive substrate. For example, the substrate  102  may be made of a variety of materials such as Au, Ni, Al, Cu, W, Si, Se, GaAs, GaN, SiC, a mixture thereof or the like. The first terminal portion  103   a  may be placed on the bottom surface of the substrate  102  and connected to a first conductivity type semiconductor layer  203  of the light emitting structure  101 . 
     Furthermore, the second terminal portion  103   b  extends along the respective side surfaces of the light emitting structure  101  and the substrate  102  from the top surface of the light emitting structure  101 . Thus, the second terminal portion  103   b  may be connected to a second conductivity type semiconductor layer  201  of the light emitting structure  101 . In this case, an insulator  104  may be placed between the second terminal potion  103   b  and each of the respective side surfaces of the light emitting structure  101  and the substrate  102 . The insulator  104  may utilize a silicon oxide, a silicon nitride or the like. Furthermore, the second terminal portion  103   b  may be bent and extend along the bottom surface of the substrate  102 . Since the first and second terminal portions  103   a  and  103   b  are placed at the lower portion of the light emitting device  100 , the light emitting device  100  can be easily mounted on a printed circuit board (PCB) or the like by using a surface mounting technique (SMT). The first and second terminal portions  103   a  and  103   b  may be formed by using a metal having high electrical conductivity. 
     As shown in  FIG. 2 , the light emitting structure  100  has a stack structure including the first and second conductivity type semiconductor layers  203  and  201  and an active layer  202  placed therebetween. According to this embodiment, the first and second conductivity type semiconductor layers  203  and  201  may be p-type and n-type semiconductor layers, respectively, and may be formed of a nitride semiconductor, for example, Al x In y Ga (1-x-y) N, wherein 0≦x≦1, 0≦y≦1 and 0≦x+y≦1. However, GaAs-based semiconductors or GaP-based semiconductors, other than the nitride semiconductor, may be utilized for the first and second conductivity type semiconductor layers  203  and  201 . The active layer  202  provided between the first and second conductivity type semiconductor layers  203  and  201  emits light having a predetermined level of energy through electron-hole recombination. The active layer  202  may have a multi-quantum well (MQW) structure in which quantum well and quantum barrier layers are alternately stacked. The multi-quantum well structure may employ an InGaN/GaN structure, for example. The first and second conductivity type semiconductor layers  203  and  201  and the active layer  202  may be formed by using a known semiconductor-layer growth technique such as MOCVD, MBE, HVPE or the like. 
     As shown in  FIG. 3 , a bonding layer  108  may be placed between the light emitting structure  101  and the substrate  102 . The bonding layer  108  may be made of a eutectic metal such as AuSn or a conductive polymer such as conductive epoxy. The bonding layer  108  is not necessarily made of a conductive material, and a non-conductive bonding material may be used. However, in this case, the first terminal portion  103   a  may be connected to the first conductivity type semiconductor layer  203  through a via structure penetrating the bonding layer  108  (see  FIG. 11 ). However, a reflective metal layer (not shown) may be further provided between the light emitting structure  101  and the substrate  102 . The reflective metal layer may serve to reflect light, emitted from the light emitting structure  101 , in an upward direction of the light emitting device  100 , that is, a direction toward the lens  107  and to form an ohmic-contact with the first conductivity type semiconductor layer  203 . In due consideration of such a function, the reflective metal layer may contain Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au or the like. 
     As shown in  FIG. 1 , the transparent polymer layer  105  is placed on the top surface of the light emitting structure  101 . The transparent polymer layer  105  may be formed of a silicon resin, an epoxy resin or the like to thereby provide stable bonding with the light conversion layer  106  placed thereon. Also, the transparent polymer layer  105  may cover the upper portion of the second terminal portion  103   b  to thereby provide a flat surface before the formation of the light conversion layer  106 . However, the transparent polymer layer  105  is not an essential element in the present invention, and the light conversion layer  106  or the lens  107  may be directly formed without the transparent polymer layer  105 . Although not shown, the transparent polymer layer  105  may have a reflective wall structure in the edge thereof to thereby adjust the orientation angle of light emitted toward the outside. 
     The light conversion layer  106  serves to convert a wavelength of light emitted from the light emitting structure  101 , and may contain a wavelength conversion material such as phosphors or quantum dots. In this case, the wavelength conversion material may be solely formed as a plate (e.g., a ceramic converting body), or may be provided as a film structure by being distributed in a silicon resin or the like. In this case, if the wavelength conversion material is phosphors and blue light is emitted from the light emitting structure  101 , red phosphors may include nitride-based phosphors of MAlSiNx:Re (1≦x≦5), sulfide-based phosphors of MD:Re, and the like. Here, M denotes at least one selected from the group consisting of Ba, Sr, Ca and Mg, D denotes at least one selected from the group consisting of S, Se and Te, and Re denotes at least one selected from the group consisting of Eu, Y, La, Ce, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, F, Cl, Br and I. Furthermore, green phosphors may include silicate-based phosphors of M 2 SiO 4 :Re, sulfide-based phosphors of MA 2 D 4 :Re, phosphors of β-SiAlON:Re, oxide-based phosphors of MA′ 2 O 4 :Re′. Here, M denotes at least one selected from the group consisting of Ba, Sr, Ca and Mg, A denotes at least one selected from the group consisting of Ga, Al and In, D denotes at least one selected from the group consisting of S, Se and Te, A′ denotes at least one selected from the group consisting of Sc, Y, Gd, La, Lu, Al and In, Re denotes at least one selected from the group consisting of Eu, Y, La, Ce, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, F, Cl, Br and I, and Re′ may be at least one selected from the group consisting of Ce, Nd, Pm, Sm, Tb, Dy, Ho, Er, Tm, Yb, F, Cl, Br and I. 
     Furthermore, the quantum dots are nano crystal particles, each consisting of a core and a shell. The core sizes of the quantum dots may range from about 2 nm to 100 nm. By controlling the core sizes, the quantum dots may act as phosphors that emit light of various colors such as blue (B), yellowy (Y), green (G) and red (R). The core-shell structure of each of the quantum dots may be obtained by a hetero-junction between at least two kinds of semiconductors among group II-VI compound semiconductors such as ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe, HgS, HgSe, HgTe, MgTe and the like, group III-V compound semiconductors such as GaN, GaP, GaAs, GaSb, InN, InP, InAs, InSb, AlAs, AlP, AlSb, AlS and the like, or group IV semiconductors such as Ge, Si, Pb and the like. In this case, an organic ligand using a material such as an oleic acid may be provided on the outer surface of the shell of the quantum dot in order to terminate a molecular bond on the outer surface of the shell, suppress agglomeration between the quantum dots, improve the dispersibility thereof within a resin such as a silicon resin or an epoxy resin, or enhance its function as a phosphor. 
     The lens  107  is placed over the top surface of the light emitting structure  101  to thereby control the orientation angle of light. As will be described below, the lens  107  is not separately provided as a manufactured package but is fabricated at a wafer-level and is then subjected to a dicing process together with the light emitting structure  101  and the substrate  102 . In this case, as shown in  FIG. 1 , the lens  107  placed over the top surface of the light emitting structure  10  does not cover the side surfaces of the light emitting structure  101 . This contributes to reducing the size of the light emitting device  100  and allows more chips to be obtained from the same-sized wafer at a manufacturing stage. Alternatively, as shown in  FIG. 4 , a lens  107 ′ may include a micro-lens array a on the surface thereof. The micro-lens array a, formed on the surface of the lens  107 ′, may contribute to further enhancing light extraction efficiency. 
     Hereinafter, one example of the process of manufacturing a light emitting device having the above-described structure will be described.  FIGS. 5 through 10  are schematic cross-sectional views illustrating a method of manufacturing a light emitting device according to an embodiment of the present invention. 
     First, as shown in  FIG. 5 , the light emitting structure  101  is formed on a growth substrate  109 . The growth substrate  109  is used as abase substrate for growing semiconductor single crystals, for example, a sapphire substrate. Sapphire is a crystal having Hexa-Rhombo R3C symmetry and has a lattice constant of 13.001 along a C-axis and a lattice constant of 4.758 along an A-axis. Orientation planes of the sapphire include a C (0001) plane, an A (1120) plane, an R (1102) plane, and the like. Particularly, the C plane is mainly used as a substrate for nitride growth because it relatively facilitates the growth of a nitride film and is stable at a high temperature. Of course, as for the growth substrate  109 , a substrate formed of SiC, GaN, ZnO, MgAl 2 O 4 , MgO, LiAlO 2  or LiGaO 2  may be used. 
     As shown in  FIG. 2 , the light emitting structure  101  includes the first and second conductivity type semiconductor layers  203  and  201  and the active layer  202 , and the first conductivity type semiconductor layer  203  is disposed adjacent to the substrate  102 . Therefore, the second conductivity type semiconductor layer  201  is grown first on the growth substrate  109 . In this case, the first and second conductivity type semiconductor layers  203  and  201  and the active layer  202  may be grown by using a process such as MOCVD, MBE, HVPE or the like. 
     As shown in  FIG. 6 , the substrate  102  is attached to the light emitting structure  101  as a support. Thereafter, the growth substrate  109  is separated from the light emitting structure  101 . The substrate  102  serves as a support that supports the light emitting structure  101  when a process such as a laser lift-off process is carried out in order to remove the growth substrate  102 . The substrate  102 , when formed of a conductive material, may serve to transfer an electrical signal to the light emitting structure  101 . In this case, the substrate  102  may be formed by a method such as plating or bonding. However, as will be described below, the substrate  102  is not necessarily formed of a conductive material, and may be formed of a non-conductive material, such as alumina, AlN, un-doped silicon or the like. The separation of the growth substrate  109  may be performed by a laser lift-off process of emitting laser beams to a region between the growth substrate  109  and the light emitting structure  101 . However, the present invention is not limited thereto. For example, a chemical lift-off process or the like may be used for the separation of the growth substrate  109 . 
     Thereafter, as shown in  FIG. 7 , a through hole H is formed in the light emitting structure  101  and the substrate  102 . In  FIG. 7 , a single through hole H is illustrated as an example. However, two or more through holes H may be formed according to the number of devices to be manufactured. In this embodiment, the through hole H is formed after the light emitting structure  101  and the substrate  102  are bonded together. However, the light emitting structure  101  and the substrate  102  may be bonded after through holes H are individually formed therein. Thereafter, the insulator  104  is formed on the inner wall of the through hole H by using a process such as deposition. As described above, the insulator  104  serves to prevent the terminal portion from directly contacting the light emitting structure  101  and the substrate  102  having electrical conductivity. In this case, the insulator  104  may extend appropriately to a portion other than the inner wall of the through hole H, depending on the formation of the second terminal portion  103   b.  For example, as shown in  FIG. 7 , the insulator  104  may be formed along the bottom surface of the substrate  102 . 
     Thereafter, as shown in  FIG. 8 , the first and second terminal portions  103   a  and  103   b  are formed. At this time, a known method such as deposition or plating may be appropriately used. According to this embodiment, the first terminal portion  103   a  is formed on the bottom surface of the substrate  102  and connected to the light emitting structure  101 , and the second terminal portion  103   b  extends from the top surface of the light emitting structure  101 , fills the through hole H and covers a portion of the bottom surface of the substrate  102 . 
     Subsequently, as shown in  FIG. 9 , the transparent polymer layer  105  and the light conversion layer  106  are formed on the light emitting structure  101 , and the lens  107  is then formed thereon as shown in  FIG. 10 . Here, the lens  107  is provided in the form of a wafer level lens having a structure in which a plurality of lenses are integrated, rather than being separated into individual chip units in advance. This wafer level lens may be separately produced and then attached over the light emitting structure. Alternatively, the wafer level lens may be molded into individual lenses after being attached thereto. Thereafter, the resultant structure including the attached lens  107  is cut into individual light emitting devices in a direction of arrows as indicated in  FIG. 10 . In such a manner, in the embodiment illustrated in  FIG. 10 , three light emitting devices can be obtained. 
       FIG. 11  is a schematic cross-sectional view illustrating an alternative to the light emitting device of the embodiment depicted in  FIG. 1 . According to this embodiment, a light emitting device  200  employs an electrically insulating substrate  102 ′ unlike the previous embodiment. For example, the electrically insulating substrate  102 ′ may be formed of, for example, alumina, AlN, un-doped silicon or the like. Due to the use of the electrically insulating substrate  102 ′, the first terminal portion  103   a  may be connected to the light emitting structure  101  through a conductive via V, and the insulator  104  may not be placed between the substrate  102 ′ and the second terminal portion  103   b.    
     While the previous embodiment is associated with a structure in which an external electrical signal is supplied through the top and bottom surfaces of the light emitting structure  101 , a pair of electrodes of the light emitting structure  101  may be arranged to face in the same direction. In detail, if the pair of electrodes are arranged toward the lens  107 , the first terminal portion  103   a  may have the same structure as the second terminal portion  103   b,  that is, a structure which extends from the top surface of the light emitting structure  101  toward the side surfaces of the light emitting structure  101  and the substrate  102  (or  102 ′). Furthermore, if the pair of electrodes are arranged toward the substrate  102  (or  102 ′), that is, if they are provided in a flip-chip structure, the first and second terminal portions  103   a  and  103   b  may be electrically connected to the light emitting structure  101  through a conductive via V penetrating the substrate  102  (or  102 ′). 
       FIG. 12  is a schematic cross-sectional view illustrating a light emitting device according to another embodiment of the present invention. Referring to  FIG. 12 , a light emitting device  300 , according to this embodiment of the present invention, includes a substrate  302 , a light emitting structure  301  disposed over the substrate  302 , first and second terminal portions  303   a  and  303   b,  a light conversion layer  306 , and a lens  307 . Although not shown in  FIG. 12 , a transparent polymer layer may be disposed between the light emitting structure  301  and the light conversion layer  306 . As for the difference of this embodiment to the previous embodiment, the substrate  302  employs an electrically insulating substrate, and the first terminal portion  303   a,  while having a bottom surface exposed to the outside, maybe connected to a first conductivity type semiconductor layer  403  through a conductive via penetrating the substrate  302 . In this case, apart of the first terminal portion  303   a  positioned between the first conductivity type semiconductor layer  403  and the substrate  302  may be provided as a reflective metal layer forming an ohmic-contact with the first conductivity type semiconductor layer  403  and having a light reflection function. 
     Like the first terminal portion  303   a,  the second terminal portion  303   b  includes a conductive via penetrating the substrate  302  and has a bottom surface exposed to the outside. Furthermore, the second terminal portion  303   b  may be provided with a conductive via penetrating the first conductivity type semiconductor layer  403  and an active layer  402  and connected to the second conductivity type semiconductor layer  401 . An insulator  304  is placed between the conductive via, connected to the second conductivity type semiconductor layer  401 , and each of the active layer  402  and the first conductivity type semiconductor layer  403 , thereby preventing the occurrence of a short-circuit. Due to the second terminal portion  303   b  having the aforementioned structure, a part that may cause interference with the passage of light does not exist on the top surface of the light emitting structure  301 , thereby enhancing light extraction efficiency. Also, since a contact area is positioned inside the second conductivity type semiconductor layer  401 , it may be favorable to current distribution. To be even more favorable for current distribution, the second terminal portion  303   b  may be provided with two or more conductive vias contacting the second conductivity type semiconductor layer  401 . In the embodiment shown in  FIG. 12 , the conductive vias are illustrated as being integrated, that is, the conductive via in the substrate  302  and the conductive via in the light emitting structure  301  are illustrated as forming a single conductive via. However, the present invention is not limited thereto, and the two conductive vias may be spatially separated, provided that they are electrically connected with each other. 
     A bonding layer  308  may be disposed between the light emitting structure  301  and the substrate  302  or between the reflective metal layer of the first terminal portion  303   a  and the substrate  302  as in this embodiment. The bonding layer  308  may be formed of an electrically insulating material. As the electrically insulating material for the bonding layer  308 , silicon resin, epoxy resin or the like may be used. This may contribute to achieving lower processing costs than a case in which a conductive bonding material such as AuSn is used. 
       FIGS. 13 through 15  are schematic cross-sectional views illustrating alternatives to the light emitting device of the embodiment depicted in  FIG. 12 . According to the alternative embodiment shown in  FIG. 13 , unlike the embodiment depicted in  FIG. 12 , an electrically conductive substrate  302 ′ is used, which is made of a variety of materials such as Au, Ni, Al, Cu, W, Si, Se, GaAs, GaN, SiC, a mixture thereof or the like. Accordingly, the insulator  304  is further provided between the substrate  302 ′ and each of the first and second terminal portions  303   a  and  303   b.    
     According to the alternative embodiment shown in FIG.  14 , a light emitting device  500  employs the electrically conductive substrate  302 ′ and has the first terminal portion  303   a  which is not directly exposed to the outside. The first terminal portion  303   a  is connected to the first conductivity type semiconductor layer  403  and also connected to the substrate  302 ′ by penetrating the bonding layer  308  having an electrically insulating property. In this case, the substrate  302 ′ may be considered to act as a terminal portion even if the first terminal portion  303   a  is not directly exposed to the outside. 
     According to the alternative embodiment shown in  FIG. 15 , a light emitting device  600  employs a bonding layer  308 ′ having electrical conductivity, unlike the previous embodiment in which the electrically insulating bonding layer  308  is used. As the electrically conductive bonding layer  308 ′, a eutectic metal layer, such as AuSn, or a conductive epoxy may be used. Due to the bonding layer  308 ′ having electrical conductivity, the insulator  304  extends between the bonding layer  308 ′ and each of the first and second terminal portions  303   a  and  303   b.    
     As described above, the light emitting device proposed by the present invention employs both an electrically insulating material and an electrically conductive material for a substrate and a bonding layer. Therefore, internal electrical connections and insulating structures may be varied in various manners. 
     Meanwhile, the light emitting devices according to the embodiments shown in  FIGS. 12 through 15  can be fabricated by appropriately modifying the manufacturing method described above with reference to  FIGS. 5 through 10 . As for modifications made in the process, a recess that does not penetrate the light emitting structure  301  is formed instead of the through hole to thereby form a conductive via connected to the second conductivity type semiconductor layer  401 . As for another modification, according to the embodiments shown in  FIGS. 12 through 15 , the conductive vias of the first and second terminal portions  303   a  and  303   b  are not provided as a portion to be diced, while the second terminal portion  103   b  according to the embodiments depicted in  FIGS. 5 through 10  is formed along the side surfaces of the light emitting structure  101  and the substrate  102  and thus is provided as a portion to be diced. 
     As set forth above, according to embodiments of the invention, a light emitting device can achieve a reduction in size and ensure enhanced light extraction efficiency by using a chip-sized lens. Furthermore, a process of manufacturing such a light emitting device can be simplified, and manufacturing costs can be reduced. 
     While the present invention has been shown and described in connection with the embodiments, it will be apparent to those skilled in the art that modifications and variations can be made without departing from the spirit and scope of the invention as defined by the appended claims.