In describing an embodiment according to the invention, in the case of being described as being formed "above" or "below" each element, the upper (upper) or lower (lower) Directly contacted or formed such that one or more other components are disposed between the two components. In addition, when expressed as "up (up) or down (down)" may include the meaning of the down direction as well as the up direction based on one component.
1 is a side sectional view showing a light emitting device according to the first embodiment.
Referring to FIG. 1, the light emitting device 1 according to the first embodiment may include a first electrode 11, an adhesive layer 13, a barrier layer 15, a reflective layer 17, an ohmic contact layer 19, and a current cutoff. The layer 21, the protective layer 23, the first light emitting structure 30, the conductive layer 60, the second light emitting structure 50, and the second electrode 67 may be included.
The first electrode 11 may not only support a plurality of layers formed thereon but also have a function as an electrode. In other words, the first electrode 11 may include a support member having conductivity. The first electrode 11 may supply power to the first and second light emitting structures 30 and 50 together with the second electrode 67.
For example, the first electrode 11 may include titanium (Ti), chromium (Cr), nickel (Ni), aluminum (Al), platinum (Pt), gold (Au), tungsten (W), and copper (Cu). ), Molybdenum (Mo), and copper-tungsten (Cu-W).
The first electrode 11 may be plated and / or deposited under the first light emitting structure 30, or may be attached in the form of a sheet, but is not limited thereto.
The adhesive layer 13 may be formed on the first electrode 11. The adhesive layer 13 may be formed as a bonding layer between the barrier layer 15 and the first electrode 11. The adhesive layer 13 serves as a medium for strengthening the adhesive force between the barrier layer 15 and the first electrode 11. When the barrier layer 15 has a function of an adhesive layer, the adhesive layer 13 Can be omitted.
The adhesive layer 13 may include a barrier metal or a bonding metal. The adhesive layer 13 may include, for example, at least one selected from the group consisting of Ti, Au, Sn, Ni, Nb, Cr, Ga, In, Bi, Cu, Ag, and Ta.
The barrier layer 15 may be formed on the adhesive layer 13. The barrier layer 15 may be formed to cover at least the entire area of the lower surface of the protective layer 23. The barrier layer 15 may prevent the adhesive layer 13 and the first electrode 11 from being diffused into the reflective layer 17 or the first light emitting structure 30.
The barrier layer 15 may be formed to contact the bottom surface of the protective layer 23 and the bottom surface of the reflective layer 17.
If the barrier layer 15 is not formed, the adhesive layer 13 may be formed to contact the bottom surface of the protective layer 23 and the bottom surface of the reflective layer 17.
The barrier layer 15 may include at least one selected from the group consisting of Ni, Pt, Ti, W, V, Fe, and Mo.
The reflective layer 17 may be formed on the barrier layer 15. The reflective layer 17 may reflect light incident from the first light emitting structure 30, thereby improving light extraction efficiency.
The reflective layer 17 comprises, for example, at least one or two or more alloys selected from the group consisting of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au and Hf. It is not limited. In addition, the reflective layer 17 together with the metal, IZO (In-ZnO), GZO (Ga-ZnO), AZO (Al-ZnO), AGZO (Al-Ga-ZnO), IGZO (In-Ga-ZnO), Multi-layer using a transparent conductive material including one selected from the group consisting of indium zinc tin oxide (IZTO), indium aluminum zinc oxide (IAZO), indium gallium tin oxide (IGTO), and aluminum tin oxide (ATO) ) Can be formed. That is, the reflective layer 17 may be formed of, for example, a multilayer including any one of IZO / Ni, AZO / Ag, IZO / Ag / Ni, and AZO / Ag / Ni.
Although not shown, the reflective layer 17 may be formed to overlap the lower surface of the ohmic contact layer 19 and a portion of the lower surface of the protective layer 23. In order to reflect all of the light from the first light emitting structure 30, the reflective layer 17 may have an area larger than that of the first light emitting structure 30.
The ohmic contact layer 19 may be formed on the reflective layer 17. The ohmic contact layer 19 may be in ohmic contact with the first light emitting structure 30, specifically, the first conductive semiconductor layer 25, so that power may be smoothly supplied to the first light emitting structure 30.
The ohmic contact layer 19 may selectively use a transparent conductive material and a metal material, and may include indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), and indium aluminum zinc oxide (IAZO). , IGZO (indium gallium zinc oxide), IGTO (indium gallium tin oxide), AZO (aluminum zinc oxide), ATO (antimony tin oxide), GZO (gallium zinc oxide), IrOx, RuOx, RuOx / ITO, Ni, Ag, It can be implemented in a single layer or multiple layers containing at least one selected from the group consisting of Ni / IrOx / Au, and Ni / IrOx / Au / ITO.
The ohmic contact layer 19 may have the same area as the reflective layer 17. The entire area of the ohmic contact layer 19 may be formed to contact the first conductive semiconductor layer 25 of the first light emitting structure 30. As described above, the ohmic contact layer 19 is formed to be in contact with the first conductivity type semiconductor layer 25 in the widest possible area, whereby the first conductivity type semiconductor layer is in contact with the ohmic contact layer 19 ( Since the current is evenly supplied to the active layer 27 through the entire region of 25), the luminous efficiency can be remarkably improved.
The current blocking layer 21 may be formed in the ohmic contact layer 19 to be in contact with the first conductive semiconductor layer 25. The current blocking layer 21 may be formed to overlap at least a portion of the current blocking layer 21 in the vertical direction. The current blocking layer 21 may serve to block a current supplied to the first conductive semiconductor layer 25 through the ohmic contact layer 19. Therefore, the supply of current to the first conductive semiconductor layer 25 may be cut off at the current blocking layer 21 and the surroundings thereof.
That is, current flows intensively along the shortest path between the first electrode 11 and the second electrode 67. In order to prevent such current concentration, the current blocking layer 21 overlapping the second electrode 67 may be formed. Accordingly, current does not flow through the current blocking layer 21 to the first conductive semiconductor layer 25, but only through the ohmic contact layer 19 to the first conductive semiconductor layer 25. As the current flows uniformly over the entire area of the first conductivity type semiconductor layer 25, the luminous efficiency may be remarkably improved.
The current blocking layer 21 has a smaller electrical conductivity than the ohmic contact layer 19, has a larger electrical insulation than the ohmic contact layer 19, or is shorted with the first conductive semiconductor layer 25. It may be formed using a material forming a key contact. In addition, the current blocking layer 21 may be formed of a transparent material.
The current blocking layer 21 is, for example, ITO, IZO, IZTO, IAZO, IGZO, IGTO, AZO, ATO, ZnO, SiO 2 , SiO x , SiO x N y , Si 3 N 4 , Al 2 O 3 , TiO x , Ti, Al, and Cr may include at least one selected from the group consisting of. Here, the SiO 2 , SiO x , SiO x N y , Si 3 N 4 , Al 2 O 3 may be an insulating material.
The current blocking layer 21 may be formed between the ohmic contact layer 19 and the first conductive semiconductor layer 25 or may be formed between the reflective layer 17 and the ohmic contact layer 19. It may be, but is not limited thereto.
In addition, the current blocking layer 21 may be formed in a groove formed in the ohmic contact layer 19, protruded on the ohmic contact layer 19, or may be formed on the top and bottom surfaces of the ohmic contact layer 19. It is formed in the hole passing through, but is not limited thereto.
The protective layer 23 may be formed in a circumferential region of the upper surface of the barrier layer 15. That is, the protective layer 23 may be formed in the peripheral region between the first light emitting structure 30 and the barrier layer 15. In detail, the protective layer 23 may be formed to be surrounded by the barrier layer 15, the reflective layer 17, the ohmic contact layer 19, and the first light emitting structure 30.
The protective layer 23 may be formed to be surrounded by the first conductive semiconductor layer 25, the ohmic contact layer 19, and the barrier layer 15 of the first light emitting structure 30.
Some regions of the inner surface and the lower surface of the protective layer 23 contact the ohmic contact layer 19, and other regions of the lower surface of the protective layer 23 contact the upper surface of the barrier layer 15, A portion of the upper surface of the protective layer 23 may contact a peripheral area of the lower surface of the first conductive semiconductor layer 25 of the first light emitting structure 30.
An area in which the protective layer 23 contacts the first light emitting structure 30 may be secured to effectively prevent the first light emitting structure 30 from being separated from the barrier layer 15.
The protective layer 23 is a protective layer 23 during a laser scribing process for separating a plurality of chips into individual chip units and a laser lift-off process for removing a substrate in a chip separation process. Since cracking or debris does not occur, the reliability of the light emitting device 1 can be improved.
In addition, the protective layer 23 may be formed of an insulating material or a transparent material. The protective layer 23 may include, for example, at least one selected from the group consisting of SiO 2 , SiO x , SiO x N y , Si 3 N 4 , and Al 2 O 3 .
The protective layer 23 may be formed of the same material as the current blocking layer 21 or may be formed of another material. That is, the protective layer 23 and the current blocking layer 21 may be formed of the insulating material.
The first light emitting structure 30 may be formed on the ohmic contact layer 19, the current blocking layer 21, and the protective layer 23.
Side surfaces of the first light emitting structure 30 may be vertically or inclined by an isolation etching for dividing the plurality of chips into individual chip units.
The first light emitting structure 30 may include a compound semiconductor material of a plurality of Group 3 to 5 elements.
The first light emitting structure 30 may include a first conductive semiconductor layer 25, an active layer 27 on the first conductive semiconductor layer 25, and a second conductive semiconductor layer on the active layer 27 ( 29).
The first conductive semiconductor layer 25 may be formed on the protective layer 23, the ohmic contact layer 19, and the current blocking layer 21. The first conductive semiconductor layer 25 may be a p-type semiconductor layer including a p-type dopant. The p-type semiconductor layer may include one selected from the group consisting of compound semiconductor materials of Group 3 to 5 elements, such as GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsP, and AlGaInP. Can be. The P-type dopant may be Mg, Zn, Ga, Sr, Ba, or the like. The first conductivity type semiconductor layer 25 may be formed as a single layer or a multilayer, but is not limited thereto.
The first conductive semiconductor layer 25 serves to supply a plurality of carriers, for example, holes, to the active layer 27.
The active layer 27 is formed on the first conductivity type semiconductor layer 25 and may include any one of a single quantum well structure, a multi-quantum well structure (MQW), a quantum dot structure, or a quantum line structure. It does not limit about.
The active layer 27 may be formed in a cycle of a well layer and a barrier layer using a compound semiconductor material of Group 3 to Group 5 elements. Compound semiconductor materials for use as the active layer 27 may be GaN, InGaN, AlGaN. Accordingly, the active layer 27 may include, for example, a period of an InGaN well layer / GaN barrier layer, a period of an InGaN well layer / AlGaN barrier layer, a period of an InGaN well layer / InGaN barrier layer, and the like, but is not limited thereto. I never do that.
The active layer 27 recombines the holes supplied from the first conductivity type semiconductor layer 25 and the electrons supplied from the second conductivity type semiconductor layer 29 to recombine the semiconductor of the active layer 27. It is possible to produce light of a wavelength corresponding to the band cap determined by the material.
Although not shown, a conductive clad layer may be formed on or below the active layer 27, and the conductive clad layer may be formed of an AlGaN-based semiconductor. For example, a p-type cladding layer including a p-type dopant is formed between the first conductive semiconductor layer 25 and the active layer 27, and the active layer 27 and the second conductive semiconductor layer ( 29) an n-type cladding layer including an n-type dopant may be formed.
The conductive cladding layer serves as a guide for preventing the plurality of holes and the electrons supplied to the active layer 27 from being transferred to the first conductive semiconductor layer 25 and the second conductive semiconductor layer 29. do. Therefore, more holes and electrons supplied to the active layer 27 are recombined by the conductive cladding layer, thereby improving luminous efficiency of the light emitting device 1.
The second conductivity type semiconductor layer 29 may be formed on the active layer 27. The second conductive semiconductor layer 29 may be an n-type semiconductor layer including an n-type dopant. The second conductive semiconductor layer 29 is made of a compound semiconductor material of Group 3 to Group 5 elements, for example, GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsP, and AlGaInP. It may include one selected from the group. The n-type dopant may be Si, Ge, Sn, Se, Te, or the like. The second conductive semiconductor layer 29 may be formed as a single layer or a multilayer, but is not limited thereto.
First roughness or irregularities 33 may be formed on the top surface of the second conductivity-type semiconductor layer 29 for light extraction efficiency. The first roughness or irregularities 33 may be formed in a random pattern formed by wet etching, or may be formed in a periodic pattern such as a photonic crystal structure formed by a patterning process, but is not limited thereto. Do not.
The first roughness or unevenness 33 may have a concave shape and a convex shape periodically. Both the concave shape and the convex shape may have round faces or both inclined surfaces that meet at vertices.
The conductive layer 60 may be formed on the first light emitting structure 30. Specifically, the conductive layer 60 may be formed on the second conductive semiconductor layer 29 of the first light emitting structure 30.
The conductive layer 60 may simultaneously and in common serve as an electrode of the first light emitting structure 30 and an electrode of the second light emitting structure 50. In other words, the conductive layer 60 includes the first light emitting structure 30, specifically, the second conductive semiconductor layer 29 and the second light emitting structure 50, and specifically, the first conductive semiconductor layer 47. ) May be a common electrode.
The conductive layer 60 may electrically connect the first light emitting structure 30 and the second light emitting structure 50.
The conductive layer 60 is formed in direct contact with the second conductive semiconductor layer 29 of the first light emitting structure 30 and the first conductive semiconductor layer 47 of the second light emitting structure 50. Can be.
In addition, the conductive layer 60 contributes to an increase in the height of the light emitting device 1 so that the area of the side surface of the light emitting device 1 is closer to the area of the upper surface of the light emitting device 1, so that the light quantity is uniform. One volume emitting can be obtained.
To this end, the conductive layer 60 may have a thickness of 0.05 ㎛ to 500 ㎛ relatively thick.
When the thickness of the conductive layer 60 is 0.05 μm or less, there is a problem in that it does not contribute to the height of the light emitting device 1. In addition, when the thickness of the conductive layer 60 is 500 μm or more, transparency decreases, so that light movement between the first light emitting structure and the second light emitting structure is not smooth, thereby reducing light extraction efficiency.
Therefore, the conductive layer 60 may have a thickness of 0.05 μm to 500 μm in order to contribute to the height of the light emitting device 1 while ensuring light extraction efficiency.
The conductive layer 60 may include a material having transparency and conductivity. For example, the conductive layer 60 includes ITO, IZO (In-ZnO), GZO (Ga-ZnO), AZO (Al-ZnO), AGZO (Al-Ga ZnO), and IGZO (In-Ga ZnO). It may include at least one.
The transmittance may be 80% or more.
The second light emitting structure 50 may be formed on the conductive layer 60.
The side surface of the second light emitting structure 50 may have a vertical surface. This is in contrast to the side of the first light emitting structure 30 described above has an inclined surface.
By forming the side of the first light emitting structure 30 adjacent to the first electrode 11 to be inclined, light generated in the first light emitting structure 30 may be emitted in a diagonal direction between the lateral direction and the upper direction.
In addition, by forming the side surface of the second light emitting structure 50 relatively spaced apart from the first electrode 11 to have a vertical surface, the light generated in the second light emitting structure 50 can be emitted laterally. . Accordingly, light is diagonally emitted from the side of the first light emitting structure 30, light is emitted laterally from the side of the second light emitting structure 50, and light is emitted from an upper surface of the second light emitting structure 50. By being emitted in this upward direction, light can be evenly emitted in all directions except the downward direction.
The second light emitting structure 50 may include a compound semiconductor material of a plurality of Group 3 to 5 elements.
The second light emitting structure 50 may include a first conductive semiconductor layer 47, an active layer 45 on the first conductive semiconductor layer 47, and a second conductive semiconductor layer on the active layer 45 ( 43).
The first conductivity type semiconductor layer 47 may be formed on the conductive layer 60. The first conductive semiconductor layer 47 may be a p-type semiconductor layer including a p-type dopant. The p-type semiconductor layer may include one selected from the group consisting of compound semiconductor materials of Group 3 to 5 elements, such as GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsP, and AlGaInP. Can be. The P-type dopant may be Mg, Zn, Ga, Sr, Ba, or the like. The first conductivity type semiconductor layer 47 may be formed as a single layer or a multilayer, but is not limited thereto.
The first conductivity type semiconductor layer 47 supplies a plurality of carriers, for example, holes, to the active layer 45.
The active layer 45 is formed on the first conductivity type semiconductor layer 47 and may include any one of a single quantum well structure, a multi quantum well structure (MQW), a quantum dot structure, or a quantum line structure. It does not limit about.
The active layer 45 may have the same area as the first conductivity-type semiconductor layer 47.
The active layer 45 may be formed in a cycle of a well layer and a barrier layer using a compound semiconductor material of Group 3 to Group 5 elements. Compound semiconductor materials for use as the active layer 45 may be GaN, InGaN, AlGaN. Accordingly, the active layer 45 may include, for example, a period of an InGaN well layer / GaN barrier layer, a period of an InGaN well layer / AlGaN barrier layer, a period of an InGaN well layer / InGaN barrier layer, and the like. I never do that.
The active layer 45 recombines the holes supplied from the first conductivity type semiconductor layer 47 and the electrons supplied from the second conductivity type semiconductor layer 43, thereby resolving the semiconductor of the active layer 45. It is possible to produce light of a wavelength corresponding to the band cap determined by the material.
The second conductivity type semiconductor layer 43 may be formed on the active layer 45. The second conductive semiconductor layer 43 may be an n-type semiconductor layer including an n-type dopant. The second conductive semiconductor layer 43 is formed of a compound semiconductor material of Group 3 to Group 5 elements, for example, GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsP, and AlGaInP. It may include one selected from the group. The n-type dopant may be Si, Ge, Sn, Se, Te, or the like. The second conductivity-type semiconductor layer 43 may be formed as a single layer or a multilayer, but is not limited thereto.
The first light emitting structure 30 and the second light emitting structure 50 may have an electrically series structure.
That is, the first conductive semiconductor layer 25 of the first light emitting structure 30 and the first conductive semiconductor layer 47 of the second light emitting structure 50 may have the same polarity, for example, p-type. . The second conductive semiconductor layer 29 of the first light emitting structure 30 and the second conductive semiconductor layer 43 of the second light emitting structure 50 may have the same polarity, for example, n-type.
Therefore, since the first and second light emitting structures 30 and 50 are connected in the order of the p-type semiconductor layer, the n-type semiconductor layer, the p-type semiconductor layer, and the n-type semiconductor layer, they may have a series structure.
When the voltage of positive polarity (+) is applied to the first electrode 11 and the voltage of negative polarity (−) is applied to the second electrode 67, the first light emitting structure 30 and the second light emitting structure 50 are applied. Light may be emitted from both).
A second roughness or unevenness 69 may be formed on the top surface of the second conductive semiconductor layer 43 for light extraction efficiency. The second roughness or irregularities 69 may be formed in a random pattern formed by wet etching, or may be formed in a periodic pattern such as a photonic crystal structure formed by a patterning process, but is not limited thereto. Do not.
The second roughness or unevenness 69 may have a concave shape and a convex shape periodically. Both the concave shape and the convex shape may have round faces or both inclined surfaces that meet at vertices.
A second electrode 67 may be formed on an upper surface of the second light emitting structure 50. The second electrode 67 may have a locally formed pattern shape without covering the entire area of the second light emitting structure 50.
The second electrode 67 branches at least one or more electrode pads 63 to which wires are bonded, and at least one side of the electrode pads 63 to uniformly current the entire area of the second light emitting structure 50. It may include a plurality of electrode lines 65 for supplying.
The electrode pad 63 may have a quadrangular, circular, elliptical, or polygonal shape when viewed from above, but is not limited thereto.
The plurality of electrode lines 65 may be formed to cross each other.
The second electrode 67 may be formed in a single layer or a multilayer structure including at least one selected from the group consisting of V, W, Au, Ti, Ni, Pd, Ru, Cu, Al, Cr, Ag, and Pt. .
The second electrode 67 may have a multilayer structure including, for example, first to sixth layers.
The first layer, which is the lowest layer, includes at least one metal material selected from the group consisting of Cr, V, W, and Ti for forming ohmic contact with the second conductivity-type semiconductor layer 43 of the second light emitting structure 50. It may include an ohmic layer.
The second layer on the first layer may be a reflective layer including a metal material such as Al and Ag having high reflective properties.
The third layer on the second layer includes at least one metal material selected from the group consisting of Ni, Pt, Pd, Ru, V, Ti, Al, Cu, and W to prevent interlayer diffusion. 1 may be a diffusion barrier layer.
The fourth layer on the third layer may be a conductive layer including at least one metal material selected from the group consisting of Ni, Pt, Pd, Ru, V, Ti, Al, Cu, and W having high electrical conductivity. have.
The fifth layer on the fourth layer may be a second diffusion barrier layer including at least one metal material selected from the group consisting of Ni, Pt, Pd, Ru, V, Ti, Al, Cu, and W.
The sixth layer on the fifth layer may be an adhesive layer including a metal material having high adhesive strength such that Au and Ti can be easily bonded.
All of the first to sixth layers do not need to be used, and may be selectively used as necessary.
The electrode pads 63 may have the same stacked structure as the electrode lines 65 or may have different stacked structures. For example, since the electrode layer 65 does not require an adhesive layer for wire bonding, the adhesive layer may not be formed. In addition, the electrode line 65 may be formed of at least one of, for example, ITO, IZO, IZTO, IAZO, IGZO, IGTO, AZO, ATO, and ZnO.
With the above configuration, the first embodiment includes a first light emitting part including the first light emitting structure 30 and a second light emitting structure 50 between the first and second electrodes 11 and 67. The second light emitting units may be connected in series. Specifically, the first conductive semiconductor layer 25 including the p-type dopant of the first light emitting structure 30 is connected to the first electrode 11, and the first light emitting structure is connected to the conductive layer 60. The second conductive semiconductor layer 29 including the n-type dopant of 30 may be connected. In addition, the first conductive semiconductor layer 47 including the p-type dopant of the second light emitting structure 50 is connected to the conductive layer 60, and the second light emitting structure 50 is connected to the second electrode 67. The second conductive semiconductor layer 43 including n-type dopant may be connected. Thus, a current may flow from the first electrode 11 to the conductive layer 60 via the first light emitting structure 30 and then to the second electrode 67 via the second light emitting structure 50. have.
A positive voltage may be applied to the first electrode 11 and a negative voltage may be applied to the second electrode 67. In this case, a current flows from the first electrode 11 to the conductive layer 60, and light may be emitted from the active layer 27 of the first light emitting structure by the current. In addition, a current flows from the conductive layer 60 to the second electrode 67, and light may be emitted from the active layer 45 of the second light emitting structure 50 by the current.
According to the first embodiment, by increasing the thickness of the conductive layer 60 between the first light emitting structure 30 and the second light emitting structure 50, the area of the side surface of the light emitting device 1 is increased to Uniform volume emitting can be obtained.
According to the first embodiment, the total light amount may be increased by connecting the first light emitting structure 30 and the second light emitting structure 50 in series.
According to the first exemplary embodiment, light extraction efficiency may be improved by forming first and second unevennesses 33 and 69 on upper surfaces of each of the first light emitting structure 30 and the second light emitting structure 50. .
In the above embodiment, only the first and second light emitting structures 30 and 50 have been described, but the present invention is not limited thereto.
That is, the light emitting device according to the embodiment may include a plurality of light emitting structures electrically connected to each other, and a transparent conductive layer disposed between the light emitting structures.
2 to 9 are views illustrating a manufacturing process of the light emitting device according to the first embodiment. In the following description, description overlapping with the structure of the light emitting device of the first embodiment will be omitted.
In the first embodiment, only the first and second light emitting structures 30 and 50 are described, but the first embodiment is not limited thereto. That is, in the first embodiment, a plurality of light emitting structures may be formed between the first and second electrodes 11 and 67, and a conductive layer may be formed between the light emitting structures.
Referring to FIG. 2, a first light emitting structure 30 may be formed on the first growth substrate 70.
The first light emitting structure 30 may include a second conductive semiconductor layer 29, an active layer 27, and a first conductive semiconductor layer 25.
The second conductive semiconductor layer 29 is formed on the first growth substrate 70, and the active layer 27 is formed on the second conductive semiconductor layer 29. The semiconductor layer 25 may be formed on the active layer 27.
The first conductivity type semiconductor layer 25, the active layer 27, and the second conductivity type semiconductor layer 29 may include a plurality of compound semiconductor materials of Group 3 to Group 5 elements.
For example, the first conductive semiconductor layer 25 may include a p-type dopant, and the second conductive semiconductor layer 29 may include an n-type dopant.
The current blocking layer 21 and the protective layer 23 may be formed on the first conductive semiconductor layer 25.
The current blocking layer 21 is, for example, ITO, IZO, IZTO, IAZO, IGZO, IGTO, AZO, ATO, ZnO, SiO 2 , SiO x , SiO x N y , Si 3 N 4 , Al 2 O 3 , TiO x , Ti, Al, and Cr may include at least one selected from the group consisting of. Here, the SiO 2 , SiO x , SiO x N y , Si 3 N 4 , Al 2 O 3 may be an insulating material.
The protective layer 23 may include at least one selected from the group consisting of an insulating material, for example, SiO 2 , SiO x , SiO x N y , Si 3 N 4 , Al 2 O 3 .
The current blocking layer 21 may be formed of the same material as the protective layer 23 or may be formed of a different material.
Referring to FIG. 3, an ohmic contact layer 19 may be formed on the first conductive semiconductor layer 25, the current blocking layer 21, and the protective layer 23.
An end of the ohmic contact layer 19 may be formed on a portion of the upper surface of the protective layer 23. The current blocking layer 21 may be surrounded by the ohmic contact layer 19.
Although not shown, the current blocking layer 21 may be formed on the ohmic contact layer 19.
The ohmic contact layer 19 may selectively use a transparent conductive material and a metal material, and may include indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), and indium aluminum zinc oxide (IAZO). , IGZO (indium gallium zinc oxide), IGTO (indium gallium tin oxide), AZO (aluminum zinc oxide), ATO (antimony tin oxide), GZO (gallium zinc oxide), IrOx, RuOx, RuOx / ITO, Ni, Ag, It can be implemented in a single layer or multiple layers containing at least one selected from the group consisting of Ni / IrOx / Au, and Ni / IrOx / Au / ITO.
The reflective layer 17 may be formed on the ohmic contact layer 19. The reflective layer 17 may have the same area as the ohmic contact layer 19.
Although not shown, the reflective layer 17 may be formed on the ohmic contact layer 19 and the protective layer 23.
The reflective layer 17 comprises, for example, at least one or two or more alloys selected from the group consisting of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au and Hf. It is not limited. In addition, the reflective layer 17 together with the metal, IZO (In-ZnO), GZO (Ga-ZnO), AZO (Al-ZnO), AGZO (Al-Ga-ZnO), IGZO (In-Ga-ZnO), Multi-layer using a transparent conductive material including one selected from the group consisting of indium zinc tin oxide (IZTO), indium aluminum zinc oxide (IAZO), indium gallium tin oxide (IGTO), and aluminum tin oxide (ATO) ) Can be formed. That is, the reflective layer 17 may be formed of, for example, a multilayer including any one of IZO / Ni, AZO / Ag, IZO / Ag / Ni, and AZO / Ag / Ni.
Referring to FIG. 4, a barrier layer 15 is formed on the reflective layer 17 and the protective layer 23, an adhesive layer 13 is formed on the barrier layer 15, and the adhesive layer 13 is formed. The first electrode 11 may be formed on the first electrode 11.
The barrier layer 15 may include at least one selected from the group consisting of Ni, Pt, Ti, W, V, Fe, and Mo.
The adhesive layer 13 may include, for example, at least one selected from the group consisting of Ti, Au, Sn, Ni, Nb, Cr, Ga, In, Bi, Cu, Ag, and Ta.
The first electrode 11 may not only support a plurality of layers formed thereon but also have a function as an electrode. In other words, the first electrode 11 may include a support member having conductivity.
For example, the first electrode 11 may include titanium (Ti), chromium (Cr), nickel (Ni), aluminum (Al), platinum (Pt), gold (Au), tungsten (W), and copper (Cu). ), Molybdenum (Mo), copper-tungsten (Cu-W), and a carrier wafer. The carrier wafer may comprise at least one selected from the group consisting of Si, Ge, GaAs, ZnO, SiC and SiGe, for example.
Referring to FIG. 5, after inverting the first growth substrate 70 by 180 °, the first growth substrate 70 may be removed.
The first growth substrate 70 may be removed by at least one of laser lift off (LLO), chemical etching (CLO), or physical polishing.
The laser lift-off LLO intensively irradiates a laser to an interface between the first growth substrate 70 and the second conductivity-type semiconductor layer 29 so that the first growth substrate 70 is electrically conductive. The semiconductor layer 29 is separated from the semiconductor layer 29.
The chemical etching removes the first growth substrate 70 to expose the second conductivity type semiconductor layer 29 using wet etching.
Physically polishing the substrate using the physical polishing machine to sequentially remove the upper surface of the first growth substrate 70 so that the second conductivity-type semiconductor layer 29 is exposed.
Subsequently, the first light emitting structure 30 may be mesa-etched to expose the protective layer 23. That is, the second conductive semiconductor layer 29, the active layer 27, and the first conductive semiconductor layer 25 of the first light emitting structure 30 are sequentially etched until the protective layer 23 is exposed. Can be. By the mesa etching, the second conductive semiconductor layer 29, the active layer 27, and the first conductive semiconductor layer 25 may have inclined side surfaces.
Subsequently, an etching process may be performed on the upper surface of the second conductive semiconductor layer 29 to form first roughness or irregularities 33 on the upper surface of the second conductive semiconductor layer 29.
Referring to FIG. 6, a first conductive layer 35 may be formed on the second conductive semiconductor layer 29.
The first conductive layer 35 may be formed of a material having transparency and conductivity. For example, the first conductive layer 35 may include at least one of Zn, In, Ga, and Al.
By the above process, the first light emitting part including the first light emitting structure 30 may be manufactured.
Referring to FIG. 7, a second light emitting part including the second light emitting structure 50 is provided.
That is, the second light emitting structure 50 may be formed on the second growth substrate 41.
The second light emitting structure 50 may include a second conductive semiconductor layer 43, an active layer 45, and a first conductive semiconductor layer 47.
The second conductive semiconductor layer 43 is formed on the second growth substrate 41, the active layer 45 is formed on the second conductive semiconductor layer 43, and the first conductivity type. The semiconductor layer 47 may be formed on the active layer 45.
The first conductivity type semiconductor layer 47, the active layer 45, and the second conductivity type semiconductor layer 43 may include a plurality of compound semiconductor materials of Group 3 to Group 5 elements.
For example, the first conductivity type semiconductor layer 47 may include a p-type dopant, and the second conductivity type semiconductor layer 43 may include an n-type dopant.
A second conductive layer 53 may be formed on the first conductive semiconductor layer 47 of the second light emitting structure 50.
The second conductive layer 53 may be formed of a material having transparency and conductivity. For example, the second conductive layer 53 may include at least one of Zn, In, Ga, and Al.
Referring to FIG. 8, the first conductive film 35 of the first light emitting part and the second conductive film 53 of the second light emitting part are disposed to face each other, and then heat of 600 ° C. to 700 ° C. is applied to the first conductive film 35. And a conductive layer 60 to which the second conductive layers 35 and 53 are bonded. Therefore, the conductive layer 60 may include at least one of Zn and In.
The conductive layer 60 may have a thickness of 0.05 μm to 500 μm, which is relatively thick. By forming the conductive layer 60 thick in this manner, the area of the side surface of the light emitting element can be expanded to increase the amount of light in the lateral direction by the amount of light in the upper direction, thereby obtaining uniform volume emission.
Referring to FIG. 9, the second growth substrate 41 of the second light emitting part may be removed. The second growth substrate 41 may be removed by at least one of laser lift off (LLO), chemical etching (CLO), or physical polishing.
Subsequently, a second electrode 67 may be formed on the second conductive semiconductor layer 43 of the second light emitting structure 50.
The second electrode 67 may have a locally formed pattern shape without covering the entire area of the second light emitting structure 50.
The second electrode 67 branches at least one or more electrode pads 63 to which wires are bonded, and at least one side of the electrode pads 63 to uniformly current the entire area of the second light emitting structure 50. It may include a plurality of electrode lines 65 for supplying.
The electrode pad 63 may have a quadrangular, circular, elliptical, or polygonal shape when viewed from above, but is not limited thereto.
The plurality of electrode lines 65 may be formed to cross each other.
The current blocking layer 21 may be formed to overlap the electrode line 65 in a vertical direction, thereby preventing current from flowing in the shortest path from the electrode line 65, thereby preventing concentration of current.
The second electrode 67 may be formed in a single layer or a multilayer structure including at least one selected from the group consisting of V, W, Au, Ti, Ni, Pd, Ru, Cu, Al, Cr, Ag, and Pt. .
An etching process is performed on the upper surface of the second conductive semiconductor layer 43 of the second light emitting structure 50 by using the second electrode 67 as an etching mask, so that the second conductive semiconductor layer 43 The second roughness or unevenness 69 may be formed on the upper surface of the substrate.
As described above, the light extraction efficiency can be further improved by forming the first and second unevennesses 33 and 69.
As described above, a high temperature, for example, 600 ° C. to 700 ° C., is applied to the first conductive film 35 of the first light emitting part and the second conductive film 53 of the second light emitting part to apply the heat to the first and second conductive films 35. By forming the conductive layer 60 to which the 53 is bonded, the light emitting device 1 including the first and second light emitting structures 30 and 50 connected in series simply and simply can be manufactured.
10 is a side sectional view showing a light emitting device according to the second embodiment.
The second embodiment is almost the same as the first embodiment except for another ohmic contact layer 80 formed between the conductive type 60 and the second conductive semiconductor layer 29 of the first light emitting structure 30. Do.
In the second embodiment, detailed descriptions of components having the same functions as those of the first embodiment will be omitted.
According to the second embodiment, the first light emitting structure 30 may include a first conductive semiconductor layer 25, an active layer 27, and a second conductive semiconductor layer 29.
Another ohmic contact layer may be formed on the first light emitting structure 30, specifically, on the second conductive semiconductor layer 29.
If the ohmic contact layer 19 is called a first ohmic contact layer, the another ohmic contact layer 80 may be called a second ohmic contact layer.
The second ohmic contact layer 80 may selectively use a transparent conductive material and a metal material, and may include indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), and indium aluminum zinc oxide (AZO). ), 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, Ag , Ni / IrOx / Au, and Ni / IrOx / Au / ITO, which may be implemented as a single layer or multiple layers.
The second ohmic contact layer 80 may include the same material as or different from the first ohmic contact layer 19.
The second ohmic contact layer 80 causes the contact resistance between the conductive layer 60 and the second conductive semiconductor layer 29 to be lowered, so that the second conductive semiconductor in the conductive layer 6 is reduced. The current can be more smoothly supplied to the layer 29.
11 is a side sectional view showing a light emitting device according to the third embodiment.
The third embodiment is almost the same as the first embodiment except for another ohmic contact layer 85 formed between the conductive type 60 and the first conductive semiconductor layer 47 of the second light emitting structure 50. Do.
In the third embodiment, detailed descriptions of the components having the same functions as the first embodiment will be omitted.
According to the third embodiment, the second light emitting structure 50 may include a first conductive semiconductor layer 47, an active layer 45, and a second conductive semiconductor layer 43.
The second conductive semiconductor layer 43, the active layer 45, and the first conductive semiconductor layer 47 may be sequentially formed on a substrate (not shown).
Another ohmic contact layer 85 is formed on the second light emitting structure 50, specifically, the first conductive semiconductor layer 47, and the conductive layer 60 is formed on the another ohmic contact layer 85. ) May be formed.
If the ohmic contact layer 19 is called a first ohmic contact layer, the another ohmic contact layer 85 may be called a second ohmic contact layer.
The second ohmic contact layer 85 may selectively use a transparent conductive material and a metal material, and may include indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), and indium aluminum zinc oxide (AZO). ), 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, Ag , Ni / IrOx / Au, and Ni / IrOx / Au / ITO, which may be implemented as a single layer or multiple layers.
The second ohmic contact layer 85 may include the same material as or different from the first ohmic contact layer 19.
The second ohmic contact layer 85 causes the contact resistance between the conductive layer 60 and the first conductive semiconductor layer 47 to be lowered, so that the first conductive semiconductor in the conductive layer 6 The current can be more smoothly supplied to layer 47.
12 is a cross-sectional view of a light emitting device package including a light emitting device according to embodiments.
12, the light emitting device package 200 according to the embodiment includes a body 330, a first lead frame 310 and a second lead frame 320 installed on the body 330, and the body ( The light emitting device 1 according to the first to third embodiments installed in the 330 and supplied with power from the first lead frame 310 and the second lead frame 320, and the light emitting device (1) It includes a molding member 340 surrounding the).
The body 330 may include a silicon material, a synthetic resin material, or a metal material, and an inclined surface may be formed around the light emitting device 1.
The first lead frame 310 and the second lead frame 320 are electrically separated from each other, and provide power to the light emitting device 1.
In addition, the first and second lead frames 310 and 320 may increase light efficiency by reflecting light generated from the light emitting device 1, and discharge heat generated from the light emitting device 1 to the outside. You can also do
The light emitting device 1 may be installed on any one of the first lead frame 310, the second lead frame 320, and the body 330. The light emitting device 1 may be formed by a wire method, a die bonding method, or the like. 2 may be electrically connected to the lead frames 310 and 320, but is not limited thereto.
In the embodiment, the light emitting device 1 according to the first embodiment is illustrated, and the first and second lead frames 310 and 320 are electrically connected to each other through two wires 350. In the case of the light emitting device 1 according to the present invention, the first and second lead frames 310 and 320 may be electrically connected without the wire 350. In the light emitting device 1 according to the third embodiment, one wire 350 may be used. ) May be electrically connected to the first and second lead frames 310 and 320.
The molding member 340 may surround the light emitting device 1 to protect the light emitting device 1. In addition, the molding member 340 may include a phosphor to change the wavelength of light emitted from the light emitting device 1.
In addition, the light emitting device package 200 may include a Chip On Board (COB) type, and an upper surface of the body 330 may be flat, and a plurality of light emitting devices 1 may be installed on the body 330. .
A plurality of light emitting device packages 200 according to an embodiment are arranged on a substrate, and a light guide plate, a prism sheet, a diffusion sheet, a fluorescent sheet, or the like, which is an optical member, is disposed on a path of light emitted from the light emitting device package 200. Can be. The light emitting device package 200, the substrate, and the optical member may function as a backlight unit. Another embodiment may be implemented as a lighting unit including the light emitting device 1 or the light emitting device package 200 described in the above-described embodiments, for example, the lighting unit may be a display device, an indicator device, a lamp, It may include a street lamp.
FIG. 13 illustrates a backlight unit including a light emitting device or a light emitting device package according to an embodiment. However, the backlight unit of FIG. 13 is an example of a lighting system, but is not limited thereto.
Referring to FIG. 13, the backlight unit 1100 may include a bottom cover 1140, an optical guide member 1120 disposed in the bottom cover 1140, and at least one side surface or a bottom surface of the optical guide member 1120. It may include a light emitting module 1110 disposed in. In addition, a reflective sheet 1130 may be disposed under the light guide member 1120.
The bottom cover 1140 may be formed by forming a box having an upper surface open to accommodate the light guide member 1120, the light emitting module 1110, and the reflective sheet 1130. Or it may be formed of a resin material but is not limited thereto.
The light emitting module 1110 may include a substrate 300 and a light emitting device 100 or a light emitting device package 200 according to a plurality of embodiments mounted on the substrate 300. The light emitting device 100 or the light emitting device package 200 according to the plurality of embodiments may provide light to the light guide member 1120. However, in the drawing, it is illustrated that the light emitting device package 200 is installed on the substrate 300.
As shown, the light emitting module 1110 may be disposed on at least one of the inner side surfaces of the bottom cover 1140, thereby providing light toward at least one side of the light guide member 1120. have.
However, the light emitting module 1110 may be disposed under the bottom cover 1140 to provide light toward the bottom surface of the light guide member 1120, which may vary depending on the design of the backlight unit 1100. The present invention is not limited thereto because it can be modified.
The light guide member 1120 may be disposed in the bottom cover 1140. The light guide member 1120 may guide the light provided from the light emitting module 1110 to a display panel by surface light source.
The light guide member 1120 may be, for example, a light guide panel (LGP). The light guide plate may be formed of, for example, one of an acrylic resin series such as polymethyl metaacrylate (PMMA), polyethylene terephthlate (PET), polycarbonate (PC), COC, or polyethylene naphthalate (PEN) resin.
The optical sheet 1150 may be disposed above the light guide member 1120.
The optical sheet 1150 may include at least one of, for example, a diffusion sheet, a light collecting sheet, a luminance rising sheet, or a fluorescent sheet. For example, the optical sheet 1150 may be formed by stacking the diffusion sheet, the light collecting sheet, the luminance increasing sheet, and the fluorescent sheet. In this case, the diffusion sheet 1150 may evenly diffuse the light emitted from the light emitting module 1110, and the diffused light may be focused onto a display panel (not shown) by the light collecting sheet. In this case, the light emitted from the light collecting sheet is randomly polarized light, and the luminance increasing sheet may increase the degree of polarization of the light emitted from the light collecting sheet. The light collecting sheet may be, for example, a horizontal or / and vertical prism sheet. In addition, the luminance increase sheet may be, for example, a roughness enhancement film. In addition, the fluorescent sheet may be a translucent plate or film containing a phosphor.
The reflective sheet 1130 may be disposed under the light guide member 1120. The reflective sheet 1130 may reflect light emitted through the bottom surface of the light guide member 1120 toward the exit surface of the light guide member 1120.
The reflective sheet 1130 may be formed of a resin material having good reflectance, for example, PET, PC, PVC resin, etc., but is not limited thereto.
14 is a perspective view of an illumination unit 1200 including a light emitting device 100 or a light emitting device package 200 according to an embodiment. However, the lighting unit 1200 of FIG. 13 is an example of a lighting system, but is not limited thereto.
Referring to FIG. 14, the lighting unit 1200 is installed in the case body 1210, the light emitting module unit 1230 installed in the case body 1210, and the case body 1210, and supplies power from an external power source. It may include a connection terminal 1220 provided.
The case body 1210 is preferably formed of a material having good heat dissipation characteristics, for example, may be formed of a metal material or a resin material.
The light emitting module unit 1230 may include a substrate 300 and a light emitting device 100 or a light emitting device package 200 according to at least one embodiment mounted on the substrate 300. However, in the embodiment, the light emitting device package 200 is illustrated on the substrate 300.
The substrate 300 may be a circuit pattern printed on an insulator. For example, a printed circuit board (PCB), a metal core PCB, a flexible PCB, a ceramic PCB, or the like may be used. It may include.
In addition, the substrate 300 may be formed of a material that reflects light efficiently, or the surface may be formed of a color that reflects light efficiently, for example, white, silver, or the like.
The light emitting device package 200 according to the at least one embodiment may be mounted on the substrate 300. Each of the light emitting device packages 200 may include at least one light emitting diode (LED). The light emitting diodes may include colored light emitting diodes emitting red, green, blue, or white colored light, and UV light emitting diodes emitting ultraviolet (UV) light.
The light emitting module unit 1230 may be arranged to have a combination of various light emitting devices to obtain color and luminance. For example, a white light emitting diode, a red light emitting diode, and a green light emitting diode may be combined to secure high color rendering (CRI). In addition, a fluorescent sheet may be further disposed on a traveling path of the light emitted from the light emitting module unit 1230, and the fluorescent sheet changes the wavelength of light emitted from the light emitting module unit 1230. For example, when the light emitted from the light emitting module unit 1230 has a blue wavelength band, the fluorescent sheet may include a yellow phosphor, and the light emitted from the light emitting module unit 1230 is finally passed through the fluorescent sheet. It is shown as white light.
The connection terminal 1220 may be electrically connected to the light emitting module unit 1230 to supply power. According to FIG. 15, the connection terminal 1220 is inserted into and coupled to an external power source in a socket manner, but is not limited thereto. For example, the connection terminal 1220 may be formed in a pin shape and inserted into an external power source, or may be connected to the external power source by a wire.
