KR102404655B1 - Light emitting device and light emitting device package having thereof - Google Patents

Abstract

The light emitting device disclosed in the embodiment includes a light emitting structure including a first semiconductor layer, an active layer under the first semiconductor layer, and a second semiconductor layer under the active layer; a plurality of contact electrodes in contact with different regions of the first semiconductor layer within the first semiconductor layer; a first electrode layer disposed under the light emitting structure, connected to the second semiconductor layer, and having a plurality of conductive layers; a second electrode layer disposed under the first electrode layer and connected to the plurality of contact electrodes; a pad connected to at least one of the plurality of conductive layers of the first electrode layer and disposed outside the light emitting structure; and a conductive support member disposed under the second electrode layer, wherein the light emitting structure has a greater thickness as the distance from the pad increases.

Description

A light emitting device and a light emitting device package having the same

The embodiment relates to a light emitting device, a light emitting device package, and a light unit.

A light emitting diode (LED: Light Emitting Diode) is widely used as one of the light emitting devices. Light emitting diodes use the properties of compound semiconductors to convert electrical signals into light forms such as infrared, visible, and ultraviolet.

As the light efficiency of the light emitting device increases, the light emitting device is applied to various fields including display devices, vehicle lamps, and various lighting devices.

The embodiment provides a light emitting device having a thickness of a semiconductor layer that is proportional to a distance from a pad.

The embodiment provides a light emitting device having a thicker thickness as the distance from the pad increases as the distance from the semiconductor layer increases.

Provided is a light emitting device in which the thickness of the first semiconductor layer is increased in proportion to the distance from the pad when the distance between the second electrode layer and the second semiconductor layer is the same according to the embodiment.

The embodiment provides a light emitting device package and a light unit having a light emitting device.

A light emitting device according to an embodiment includes: a light emitting structure including a first semiconductor layer, an active layer under the first semiconductor layer, and a second semiconductor layer under the active layer; a plurality of contact electrodes in contact with different regions of the first semiconductor layer within the first semiconductor layer; a first electrode layer disposed between the second semiconductor layer and the second electrode layer, connected to the second semiconductor layer, and having a plurality of conductive layers; the second electrode layer disposed under the light emitting structure, connected to the plurality of contact electrodes, and having a plurality of conductive layers; a pad connected to at least one of the plurality of conductive layers of the first electrode layer and disposed outside the light emitting structure; and a conductive support member under the second electrode layer, wherein the light emitting structure has a greater thickness in a region where the distance between the light emitting structure and the pad is greater than that in a region where the distance between the light emitting structure and the pad is close. including thickness.

It is possible to improve the current concentration problem in the light emitting structure in the light emitting device according to the embodiment.

According to the embodiment, the thickness of the semiconductor layer in contact with the contact electrodes is proportional to the distance according to the distance between the contact electrode and the pad in the light emitting structure, thereby reducing the resistance difference in the semiconductor layer in contact with the contact electrodes. can give

The embodiment improves the current diffusion of the light emitting device, thereby preventing a decrease in light output.

The embodiment may improve heat generation characteristics in the light emitting device and improve chip lifespan and reliability.

It is possible to improve the reliability of the light emitting device package and the light unit having the light emitting device according to the embodiment.

1 is a plan view showing a light emitting device according to a first embodiment.
FIG. 2 is a cross-sectional view on the AA side of the light emitting device of FIG. 1 .
3 is a view illustrating a current flow in a light emitting structure of the light emitting device of FIG. 2 .
4 to 6 are views illustrating variations of the thickness of the light emitting structure according to the pad position of FIG. 1 .
7 is another example of the light emitting device of FIG.
8 is a plan view of a light emitting device according to a second embodiment.
9 is a side cross-sectional view of the light emitting device of FIG. 8 .
10 is an example of a light emitting device according to the third embodiment.
11 is a view showing a light emitting device package having a light emitting device according to an embodiment.
12 is an image showing the operating characteristics according to the amount of current supplied to the light emitting device according to the embodiment.
13A and 13B are images comparing light emission characteristics according to current magnitudes in Comparative Examples and Examples.
14 is an image illustrating thermal characteristics according to a current magnitude in a light emitting device according to an embodiment.
15 is a graph illustrating a relationship between a distance to a pad and resistance in a semiconductor layer according to an embodiment.
16 is a graph illustrating a relationship between resistance according to a thickness of a semiconductor layer according to an embodiment.

In the description of an embodiment, each layer (film), region, pattern or structure is “on” or “under” the substrate, each layer (film), region, pad or pattern. In the case of being described as being formed in, "on" and "under/under" include both "directly" or "indirectly" formed through another layer. do. In addition, the criteria for the upper / upper or lower / lower of each layer will be described with reference to the drawings.

Hereinafter, a light emitting device and a light emitting device package according to embodiments will be described in detail with reference to the accompanying drawings.

1 is a plan view showing a light emitting device according to a first embodiment, FIG. 2 is a cross-sectional view taken along the A-A side of the light emitting device of FIG. 1 , and FIG. 3 is a view comparing the current flow of the light emitting device of FIG. 2 .

1 to 3 , the light emitting device 100 includes a light emitting structure 10 having a plurality of semiconductor layers 11 , 12 , 13 having different thicknesses for each region 10A, 10B, and 10C, the light emitting structure ( A plurality of contact electrodes 33 in 10), a first electrode layer 81 having a reflective layer 17 under the light emitting structure 10, is disposed under the first electrode layer 81 and is disposed on the contact electrode 33 A second electrode layer 83 connected thereto, an insulating layer 41 between the first and second electrode layers 81 and 83 , and a pad 92 may be included.

The light emitting structure 10 may include a first semiconductor layer 11 , an active layer 12 , and a second semiconductor layer 13 . The active layer 12 may be disposed between the first semiconductor layer 11 and the second semiconductor layer 13 . The active layer 12 may be disposed under the first semiconductor layer 11 , and the second semiconductor layer 13 may be disposed under the active layer 12 .

The side surface of the light emitting structure 10 may be formed in a vertical, inclined, or stepped structure with respect to the lower surface of the light emitting structure 10, but is not limited thereto.

For example, the first semiconductor layer 11 includes an n-type semiconductor layer to which a first conductivity-type dopant, for example, an n-type dopant is added, and the second semiconductor layer 13 includes a second conductivity-type dopant, for example, p It may include a p-type semiconductor layer to which a type dopant is added. As another example, the first semiconductor layer 11 may be formed of a p-type semiconductor layer, and the second semiconductor layer 13 may be formed of an n-type semiconductor layer.

The first semiconductor layer 11 may be implemented as a compound semiconductor. The first semiconductor layer 11 may be embodied as, for example, at least one of a group II-VI compound semiconductor and a group III-V compound semiconductor. For example, the first semiconductor layer 11 is a single layer or a semiconductor material having a composition formula of In _x Al _y Ga _1-xy N (0≤x≤1, 0≤y≤1, 0≤x+y≤1) It can be implemented in multiple layers. The first semiconductor layer 11 may be selected from, for example, GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsP, AlGaInP, etc., Si, Ge, Sn, Se, An n-type dopant such as Te may be doped.

The upper surface of the first semiconductor layer 11 may be formed of rough uneven portions 11A, and the uneven portions 11A may improve light extraction efficiency. A side cross-section of the concave-convex portion 11A may have a polygonal shape or a hemispherical shape.

The active layer 12 may be disposed under the first semiconductor layer 11 . In the active layer 12, electrons (or holes) injected through the first semiconductor layer 11 and holes (or electrons) injected through the second semiconductor layer 13 meet each other to form the active layer 12 . It is a layer that emits light due to the difference in the band gap of the energy band according to the material forming of it. The active layer 12 may be formed of any one of a single well structure, a multi-well structure, a quantum dot structure, or a quantum wire structure, but is not limited thereto.

The active layer 12 may be implemented with a compound semiconductor. The active layer 12 may be implemented, for example, by at least one of a group II-VI compound semiconductor and a group III-V compound semiconductor. The active layer 12 may be implemented as, for example, a semiconductor material having a composition formula of In _x Al _y Ga _1-xy N (0≤x≤1, 0≤y≤1, 0≤x+y≤1). When the active layer 12 is implemented in the multi-well structure, the active layer 12 may be implemented by stacking a plurality of well layers and a plurality of barrier layers, for example, an InGaN well layer/GaN barrier layer; It can be implemented with a cycle of InGaN well layer/AlGaN barrier layer, InAlGaN well layer/InAlGaN barrier layer, AlGaN well layer/AlGaN barrier layer, or GaN well layer/AlGaN barrier layer.

The second semiconductor layer 13 may be disposed under the active layer 12 . The second semiconductor layer 13 may be implemented as, for example, a p-type semiconductor layer. The second semiconductor layer 13 may be implemented as a compound semiconductor. The second semiconductor layer 13 may be implemented as, for example, at least one of a group II-VI compound semiconductor and a group III-V compound semiconductor, and may be formed as a single layer or multiple layers.

For example, the second semiconductor layer 13 may be implemented with a semiconductor material having a composition formula of In _x Al _y Ga _1-xy N (0≤x≤1, 0≤y≤1, 0≤x+y≤1). can The second semiconductor layer 13 may be selected from, for example, GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsP, AlGaInP, etc., Mg, Zn, Ca, Sr, A p-type dopant such as Ba may be doped.

As another example, an n-type semiconductor layer having a conductivity type different from that of the second semiconductor layer 13 may be further formed under the second semiconductor layer 13 . Accordingly, the light emitting structure 10 may have at least one of np, pn, npn, and pnp junction structures. In addition, doping concentrations of impurities in the first semiconductor layer 11 and the second semiconductor layer 13 may be uniformly or non-uniformly formed. That is, the structure of the light emitting structure 10 may be formed in various ways, but is not limited thereto.

In addition, different semiconductor layers are alternately disposed between the first semiconductor layer 11 and the active layer 12 or between the second semiconductor layer 13 and the active layer 12, for example, AlGaN/GaN, InGaN. A /GaN or InGaN/InGaN superlattice structure may be formed. In addition, an electron blocking layer to which a second conductivity type dopant is added may be included between the second semiconductor layer 13 and the active layer 12 . For example, the electron blocking layer may include an AlGaN layer. , but not limited thereto.

The first electrode layer 81 may be electrically connected to the second semiconductor layer 13 , and the second electrode layer 83 may be electrically connected to the first semiconductor layer 11 . At least one or both of the first and second electrode layers 81 and 83 may be disposed under the light emitting structure 10 . The second electrode layer 83 may have a contact electrode 33 in the first semiconductor layer 11 and be disposed under the light emitting structure 10 . Any one of the first and second electrode layers 81 and 83 may include a support member 70 supporting the light emitting device 100, and the support member 70 may be an electrically conductive support member. have. The support member 70 may be included in any one of the electrode layers 81 and 83 or may be configured separately, but is not limited thereto.

The first electrode layer 81 is, for example, disposed between the light emitting structure 10 and the second electrode layer 83, is electrically connected to the second semiconductor layer 13 of the light emitting structure 10, and It is electrically insulated from the second electrode layer 83 . The first electrode layer 81 may include a first contact layer 15 , a reflective layer 17 , and a capping layer 35 . The first electrode layer 81 may include a barrier layer 21 . The first contact layer 15 is disposed between the reflective layer 17 and the second semiconductor layer 13 , and the reflective layer 17 is disposed between the first contact layer 15 and the capping layer 35 . are placed The first contact layer 15 , the reflective layer 17 , and the capping layer 35 may be formed of different conductive materials, but are not limited thereto.

The first contact layer 15 may be in contact with the second semiconductor layer 13 , and for example, an ohmic contact may be formed with the second semiconductor layer 13 . The first contact layer 15 may be formed of, for example, a conductive oxide film, a conductive nitride, or a metal. The first contact layer 15 is, for example, ITO (Indium Tin Oxide), ITON (ITO Nitride), IZO (Indium Zinc Oxide), IZON (IZO Nitride), AZO (Aluminum Zinc Oxide), AGZO (Aluminum Gallium Zinc Oxide) ), IZTO(Indium Zinc Tin Oxide), IAZO(Indium Aluminum Zinc Oxide), IGZO(Indium Gallium Zinc Oxide), IGTO(Indium Gallium Tin Oxide), ATO(Antimony Tin Oxide), GZO(Gallium Zinc Oxide), GZO(Gallium Zinc Oxide) IZO Nitride), ZnO, IrOx, RuOx, NiO, In, Au, W, Al, Pt, Ag, may be formed to include at least one of Ti.

The reflective layer 17 may be electrically connected to the first contact layer 15 and the capping layer 35 . The reflective layer 17 may reflect the light incident from the light emitting structure 10 to increase the amount of light extracted to the outside.

The reflective layer 17 may be formed of a metal having a light reflectance of 70% or more. For example, the reflective layer 17 may be formed of a metal or alloy including at least one of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Cu, Au, and Hf. In addition, the reflective layer 17 and the metal or alloy and ITO (Indium-Tin-Oxide), IZO (Indium-Zinc-Oxide), IZTO (Indium-Zinc-Tin-Oxide), IAZO (Indium-Aluminum-Zinc-) Oxide), IGZO (Indium-Gallium-Zinc-Oxide), IGTO (Indium-Gallium-Tin-Oxide), AZO (Aluminum-Zinc-Oxide), ATO (Antimony-Tin-Oxide), etc. It may be formed in a single layer or in multiple layers. For example, in an embodiment, the reflective layer 17 may include at least one of Ag, Al, an Ag-Pd-Cu alloy, or an Ag-Cu alloy. For example, the reflective layer 17 may be formed of an Ag layer and a Ni layer alternately, and may include Ni/Ag/Ni, a Ti layer, or a Pt layer. As another example, the first contact layer 15 may be formed under the reflective layer 17 , and at least a portion may pass through the reflective layer 17 to contact the second semiconductor layer 13 . As another example, the reflective layer 17 may be disposed under the first contact layer 15 , and a portion may pass through the first contact layer 15 to contact the second semiconductor layer 13 . .

The light emitting device according to the embodiment may include a capping layer 35 under the reflective layer 17 . The capping layer 35 may be in contact with a lower surface of the reflective layer 17 . The capping layer 35 may include a contact portion 34 in which a pad 92 is disposed on a portion of the outer portion. The capping layer 35 may be a wiring layer that transmits power supplied from the pad 92 , but is not limited thereto. The capping layer 35 may be formed of a metal, for example, may include at least one of Au, Cu, Ni, Ti, Ti-W, Cr, W, Pt, V, Fe, and Mo materials, and may include a single layer or It may be formed in multiple layers.

The contact portion 34 of the capping layer 35 may be disposed in an area that does not overlap the light emitting structure 10 in the vertical direction, and may overlap the pad 92 in the vertical direction. The contact portion 34 of the capping layer 35 is disposed in a region that does not vertically overlap the first contact layer 15 and the reflective layer 17 . The contact portion 34 of the capping layer 35 may be disposed at a lower position than the light emitting structure 10 and may be in direct contact with the pad 92 .

The outer portion of the capping layer 35 may be disposed more outside than the side surface of the light emitting structure 10 . An outer portion of the capping layer 35 may be disposed to overlap in a vertical direction with respect to an outer portion of the passivation layer 95 and an outer portion of the passivation layer 95 .

The pad 92 may be formed as a single layer or a multilayer, and may include at least one of Ti, Ag, Cu, and Au. For example, the single layer may be Au, and in the case of a multilayer, it may be a Ti/Ag/Cu/Au stack structure or a Ti/Cu/Au stack structure, but is not limited thereto.

At least one of the reflective layer 17 and the first contact layer 15 may be in direct contact with the pad 92 , but is not limited thereto.

At least one or a plurality of the pads 92 may be disposed outside the light emitting structure 10 , for example, in a corner region of either side S1 or S2 . The pad 92 may be disposed in the area A1 between the outer sidewall of the first electrode layer 81 and the light emitting structure 10 . The pad 92 may be in contact with the protective layer 30 and the passivation layer 95 on the lower periphery, but is not limited thereto.

The protective layer 30 is disposed on the lower surface of the light emitting structure 10 , and may be in contact with the lower surface of the second semiconductor layer 13 and the first contact layer 15 , and the reflective layer 17 and can be contacted.

An inner portion of the protective layer 30 that vertically overlaps with the light emitting structure 10 may be disposed around the first contact layer 15 . The outer portion of the protective layer 30 extends above the contact portion 34 of the capping layer 35 and is disposed to vertically overlap with the contact portion 34 and the outer portion of the capping layer 35 . The outer portion of the protective layer 30 may extend to the outer region A1 than the sidewall of the light emitting structure 10 , thereby preventing moisture from penetrating and protecting it from impact transmitted to the chip during the etching process. . In addition, the protective layer 30 may function as an etching stopper during the isolation process for the individual light emitting structure 10 , and may also prevent deterioration of electrical characteristics of the light emitting device by the isolation process.

The protective layer 30 may be defined as a channel layer, a low refractive material, or an isolation layer. The protective layer 30 may be implemented with an insulating material, for example, it may be implemented with an oxide or nitride. For example, the protective layer 30 is at least one from the group consisting of SiO ₂ , Si _x O _y , Si ₃ N ₄ , Si _x N _y , SiO _x N _y , Al ₂ O ₃ , TiO ₂ , AlN, and the like. may be selected and formed. The protective layer 30 may be formed of a transparent material.

The light emitting device 100 according to the embodiment may include an insulating layer 41 under the first electrode layer 81 and on the second electrode layer 83 . The insulating layer 41 is disposed between the first electrode layer 81 and the second electrode layer 83 to electrically insulate the first electrode layer 81 and the second electrode layer 83 . The insulating layer 41 is in contact with the lower surface of the first electrode layer 81 and the upper surface of the second electrode layer 83 , and the protective layer 30 , the capping layer 35 , and the first contact layer 15 . , may be formed to be thicker than each of the reflective layers 17 . An upper portion of the insulating layer 41 may protrude into the first electrode layer 81 and contact the protective layer 30 .

The insulating layer 41 may be formed of, for example, oxide or nitride. For example, the insulating layer 41 is at least one from the group consisting of SiO ₂ , Si _x O _y , Si ₃ N ₄ , Si _x N _y , SiO _x N _y , Al ₂ O ₃ , TiO ₂ , AlN, and the like. may be selected and formed.

The second electrode layer 83 includes a diffusion barrier layer 50 disposed under the insulating layer 41 , a bonding layer 60 disposed under the diffusion barrier layer 50 , and a bonding layer 60 disposed under the diffusion barrier layer 50 . It may include a support member 70 made of a conductive material. The second electrode layer 83 may be electrically connected to the first semiconductor layer 11 . The second electrode layer 83 may selectively include one or two of the diffusion barrier layer 50 , the bonding layer 60 , and the support member 70 , and the diffusion barrier layer 50 or the bonding layer At least one of (60) may not be formed. The support member 70 may be formed separately from the second electrode layer 83 , but is not limited thereto.

The diffusion barrier layer 50 may include at least one of Cu, Ni, Ti, Ti-W, Cr, W, Pt, V, Fe, and Mo materials, and may be formed as a single layer or multiple layers. The diffusion barrier layer 50 may function as a diffusion barrier layer between the insulating layer 41 and the bonding layer 60 . The diffusion barrier layer 50 may be electrically connected to the bonding layer 60 and the conductive support member 70 , and may be electrically connected to the first semiconductor layer 11 .

The diffusion barrier layer 50 may function to prevent the material included in the bonding layer 60 from being diffused in the direction of the reflective layer 17 in the process in which the bonding layer 60 is provided. For example, the diffusion barrier layer 50 may prevent a material such as tin (Sn) included in the bonding layer 60 from affecting the reflective layer 17 .

The bonding layer 60 includes a barrier metal or a bonding metal, for example, at least one of Ti, Au, Sn, Ni, Cr, Ga, In, Bi, Cu, Ag, Nb, Pd, or Ta. may be included and may be formed in a single layer or in multiple layers. The support member 70 may support the light emitting structure 10 according to an embodiment and perform a heat dissipation function. The bonding layer 60 may include a seed layer.

The support member 70 is a metal or carrier substrate, for example, Ti, Cr, Ni, Al, Pt, Au, W, Cu, Mo, Cu-W or a semiconductor substrate implanted with impurities (eg, Si, Ge, GaN, GaAs, ZnO, SiC, SiGe, etc.) may be formed of at least one, and may be formed as a single layer or a multilayer.

Meanwhile, a plurality of contact electrodes 33 are disposed inside the first semiconductor layer 11 and are in contact with the first semiconductor layer 11 . The upper surface of the contact electrode 33 may be disposed above the lower surface of the first semiconductor layer 11, is electrically connected to the first semiconductor layer 11, and the active layer 12 and the second semiconductor layer ( 13) and insulated. As shown in FIG. 2 , the thickness T0 of the plurality of contact electrodes 33 or the depth of the recesses 2 may be the same. A thickness T0 of the plurality of contact electrodes 33 is a depth at which a portion of the first semiconductor layer 11 is exposed by the recess 2 .

The contact electrode 33 may be electrically connected to the second electrode layer 83 . The contact electrode 33 may be disposed through the active layer 12 and the second semiconductor layer 13 . The contact electrode 33 is disposed in a recess 2 disposed in the light emitting structure 10 , and is insulated by the active layer 12 , the second semiconductor layer 13 , and the protective layer 30 . do. A plurality of the contact electrodes 33 may be disposed to be spaced apart from each other to spread a current in the first semiconductor layer 11 .

The contact electrode 33 may be connected to the protrusion 51 of the second electrode layer 83 , and the protrusion 51 may protrude from the diffusion barrier layer 50 or be formed separately. The protrusion 51 penetrates through the hole 41A disposed in the insulating layer 41 and the protective layer 30 , and may be insulated from the first electrode layer 81 , and may be formed in a single layer or in multiple layers.

The contact electrode 33 may include, for example, at least one of Cr, V, W, Ti, Zn, Ni, Cu, Al, Au, and Mo, and may be formed as a single layer or multiple layers. The protrusion 51 may include at least one of a material constituting the diffusion barrier layer 50 and the bonding layer 60 , but is not limited thereto. For example, the protrusion 51 may include, for example, at least one of Ti, Au, Sn, Ni, Cr, Ga, In, Bi, Cu, Ag, Nb, Pd, or Ta. The second electrode layer 83 may include the contact electrode 33 and the protrusion 51 connected thereto, but is not limited thereto.

The pad 92 may be electrically connected to the first electrode layer 81 and may be exposed in the area A1 outside the sidewall of the light emitting structure 10 . The pad 92 may include, for example, at least one of Cu, Ni, Ti, Ti-W, Cr, W, Pt, V, Fe, and Mo materials, and may be formed as a single layer or multiple layers.

The passivation layer 95 may protect the surface of the light emitting structure 10 , and may insulate between the pad 92 and the light emitting structure 10 , and may come into contact with the peripheral portion of the protective layer 30 . can The passivation layer 95 may have a lower refractive index than a material of the semiconductor layer constituting the light emitting structure 10 , and may improve light extraction efficiency. The passivation layer 95 may be formed of, for example, oxide or nitride. For example, the passivation layer 95 is at least from the group consisting of SiO ₂ , Si _x O _y , Si ₃ N ₄ , Si _x N _y , SiO _x N _y , Al ₂ O ₃ , TiO ₂ , AlN, and the like. One can be selected and formed. Meanwhile, the passivation layer 95 may be omitted according to design.

According to an embodiment, the light emitting structure 10 may be driven by the first electrode layer 81 and the second electrode layer 83 . That is, the light emitting device according to the embodiment may include a plurality of light emitting structures that can be individually driven in one device. Although the embodiment has been described with reference to a case in which two light emitting structures are disposed in one light emitting device, three or four or more light emitting structures may be disposed in one light emitting device, and may be implemented to be individually driven. A light emitting device having such a structure may be usefully applied to a vehicle lighting device, for example, a headlamp or a tail lamp, as an example.

In addition, in the light emitting device according to the embodiment, a phosphor layer (not shown) may be provided on the light emitting structure 10, and the phosphor layer may be formed to a uniform thickness through, for example, conformal coating. , but not limited thereto.

In addition, the light emitting device according to the embodiment may include an optical lens, but is not limited thereto.

1 and 2 , the light emitting structure 10 includes a plurality of regions 10A, 10B, and 10C having different thicknesses T4, T5, and T6. In the plurality of regions 10A, 10B, and 10C, the thicknesses T4, T5, and T6 of the light emitting structure 10 may become thicker as the regions 10A, 10B, and 10C are farther from the pad 92, for example. It may be gradually thickened or may be thickened in proportion to the distance from the pad 92 . The plurality of regions 10A, 10B, and 10C may be disposed on the first semiconductor layer 11 , and the plurality of regions 10A, 10B, and 10C may include at least two, three or more, or four or more. These can have different thicknesses. The regions 10A, 10B, and 10C of the first semiconductor layer 11 may be thickened non-linearly, stepwise, or linearly, but is not limited thereto.

The light emitting structure 10 may become thicker as the thicknesses T7 , T8 , and T9 of the first semiconductor layer 11 increase in regions 10A, 10B, and 10C that are farther from the pad 92 . Here, the second electrode layer 81 disposed under the second semiconductor layer 13 has the same electrical characteristics and the contact electrode 33 and the second electrode layer 81 in contact with the first semiconductor layer 11 are the same. ), the respective regions 10A, 10B, and 10C of the first semiconductor layer 11 are the straight-line distances D2, D3, and D4 between the pad 92 and the contact electrode 33. ), the thickness (T4, T5, T6) may vary.

The difference between the thicknesses T7 , T8 , and T9 of the first semiconductor layer 11 may vary depending on the contact electrode 33 , but may be 0.2 μm or more, for example, 0.3 μm to 1 μm. When the difference between the thicknesses T7, T8, and T9 is less than the above range, an extraction structure such as an uneven portion 11A is formed on the surface of the first semiconductor layer 11 or a recess depth for the contact electrode 33 is formed. There may be difficulties in securing, and the difference in resistance may be insignificant due to a reduced cross-sectional area difference, and if the thickness exceeds the thickness range, it may be difficult to increase the thickness of the first semiconductor layer 11, so that the size of the light emitting structure 10 is increased have difficulty doing

In the embodiment, the thickness of the first semiconductor layer 11 (T7, T8, T9) because the resistance of the first semiconductor layer 11 increases as the regions 10A, 10B, and 10C are farther from the pad 92. It is possible to prevent an increase in resistance by gradually increasing the The thicknesses T7, T8, and T9 of the first semiconductor layer 11 are increased as the regions 10A, 10B, and 10C are farther from the pad 92, for example, on a straight line with the pad 92. It increases at the boundary line E1 between the placed contact electrodes 33 , increases every time the contact electrodes 33 increase by one or two, increases periodically, or increases according to the position of the contact electrodes 33 . can do it

The boundary line E1 between the plurality of regions 10A, 10B, and 10C is the contact electrode 33 placed on the straight line when a straight line passing through the center of the contact electrode 33 is drawn with respect to the pad 92 . It may be an intermediate part between them. As shown in FIG. 1 , the middle portion is a point 1/2 of the distance D1 between two contact electrodes 33 adjacent in the horizontal and vertical directions, or 1/2 of the distance X3 between two contact electrodes 33 in the diagonal direction. It may contain branches.

When 1/2 of the interval D1 is X1 and 1/2 of the interval X3 is X2, the size of each region 10A, 10B, 10C of the light emitting structure 10 is The interval D1 may be greater than or equal to twice X1, greater than or equal to two times D1, or less than or equal to twice X3. The sizes of the regions 10A, 10B, and 10C may be gradually increased based on the pad 92 or may be increased from positions spaced apart from each other.

As shown in FIG. 1 , the first to third regions 10A, 10B, and 10C of the light emitting structure 10 are described as including one contact electrode 33 on a straight line with respect to the pad 92 , It may include two contact electrodes 33 , or each region 10A, 10B, and 10C may include one or two contact electrodes 33 .

2, in the pad 92, the linear distance between the contact electrodes 33 in the first region 10A is D2, and the linear distance between the contact electrodes 33 in the second region 10B is D3, When the linear distance between the contact electrodes 33 in the third region 10C is D4, if the linear distance is D2<D3<D4, the thickness (T4, T5) of the first to third regions 10A, 10B, and 10C , T6) satisfies the first area < the second area < the third area.

The contact electrodes 33 in the first to third regions 10A, 10B, and 10C may have linear distances D2, D3, and D4 from the pad 92 to satisfy the first region > the second region > the third region. can The thickness ( T7 , T8 , T9 ) of the first semiconductor layer 11 satisfies a first region < a second region < a third region.

When the distance T0 between the contact electrode 33 and the lower surface of the second semiconductor layer 13 in each region 10A, 10B, and 10C of the light emitting structure 10 is the same, the contact electrode 33 Based on , the distance to the top surface of the first semiconductor layer 11 may satisfy the first region < the second region < the third region (D2<D3<D4).

When the ratio of the distance between the pad 92 to the contact electrode 33 and the distance from the contact electrode 33 to the surface of each region 10A, 10B, and 10C of the first semiconductor layer 11 is seen, , D2/T1, D3/T2, and D4/T3 may have the same value or a difference within an error range. The error range may be an error value according to a semiconductor material, an amount of dopant in the first semiconductor layer, or a current size.

Looking at the ratio between the distance between the contact electrode 33 from the pad 92 and the thickness (T7, T8, T9) of the first semiconductor layer 11, D2/T7, D3/D8, D4/D9 At least two of them may have the same value or a difference within an error range. The error range may be an error value according to a semiconductor material, an amount of dopant in the first semiconductor layer, or a current size.

The top area of the first to third regions 10A, 10B, and 10C may satisfy the third region > second region > first region, or first region > third region > second region. That is, the first area 10B adjacent to the pad 92 may have the smallest area among the areas 10A, 10B, and 10C of the light emitting structure 10 , and the area of the top surface of the light emitting structure 10 may be the smallest. The furthest region 10C may have the largest area.

In the embodiment, the thicknesses T7, T8, and T9 of the first semiconductor layer 11 are increased as the distance from the pad 92 is increased, and the surface of the contact electrode 33 and the first semiconductor layer 11 is increased. By increasing the distances T1 , T2 , and T3 , the resistance in the first semiconductor layer 11 can be suppressed from increasing as the distance from the pad 92 increases. That is, referring to FIGS. 2 and 15 , in the comparative example, the resistance R1 in the light emitting structure 10 increases linearly as the distance from the pad 92 increases, but in the embodiment, the pad 92 As the distance between the and the contact electrode 33 increases, the resistance may be set to be constant or may be set to come within a certain range. As shown in FIG. 16 , when the resistance in the light emitting structure increases, for example, the thickness of the first semiconductor layer increases, the resistance gradually decreases. In the embodiment, the resistance R2 in the light emitting structure of FIG. 15 may be provided so that the resistance R2 in the light emitting structure of FIG. 15 has a constant value by gradually increasing the thickness of the first semiconductor layer in the region further away from the pad.

Here, the resistance (R) applied to the semiconductor layer may be obtained by the following Equation (1).

ρ may be resistivity, L may be distance, and S may be cross-sectional area.

And, referring to FIG. 3 , any one or two of the contact electrodes 33 disposed under each of the plurality of areas 10A, 10B, and 10C is in each area 10A with respect to the contact electrode 33 . , 10B, and 10C may be disposed closer to the boundary line E1 than to the center. That is, at least one or two of the plurality of contact electrodes 33 are located in the area opposite to the pad 92 or on the outer side with respect to the contact electrode 33 in the respective areas 10A, 10B, and 10C. It may be arranged more closely to improve the current spread to the outer region.

As shown in FIG. 3 , looking at the current diffusion distributions I1 , I2 , and I3 in the first semiconductor layer 11 of the light emitting structure 10 , the region 10C far from the pad 92 , for example, the thickest region. The current diffusion distribution I3 at 10C is the largest, and becomes smaller as it approaches the pad 92 .

The embodiment prevents the current concentration problem in the region 10C far from the pad 92 among the regions 10A, 10B, and 10C of the first semiconductor layer 11 to spread the current and increase the light extraction efficiency. It can improve and improve heat dissipation efficiency. Also, the reliability of the pad 92 and the active layer 12 may be improved.

12 is a diagram illustrating operating characteristics according to a current magnitude in a light emitting device according to an embodiment.

Referring to FIG. 12 , as the current supplied to the light emitting device increases to 1 mA, 350 mA, or 1000 mA, it can be seen that the operating characteristics on the entire surface of the light emitting structure are uniformly displayed.

13(A) is a light emitting characteristic of the light emitting device of the Example, and (B) is a view showing the light emission characteristic of the light emitting device of the comparative example. Here, in the comparative example, the thickness of the light emitting structure is the same regardless of the distance of the pad.

As shown in (A) of FIG. 13 , the light emitting structure exhibits a uniform distribution of light emission characteristics in the entire area of the light emitting structure as the amount of current increases. It can be seen that the light emission characteristic is lowered in the region of the light emitting structure far from the luminescent structure.

14 (A) is a diagram comparing the thermal characteristics of the light emitting device at 350 mA, (B) is a diagram showing the thermal characteristics of the light emitting device at 1000 mA. 14A , the light emitting device of the embodiment has a uniform distribution of thermal characteristics over the entire region, but in the comparative example, it can be seen that the heat distribution is different as the region is farther from the pad.

4 is another example of the light emitting device of FIG.

Referring to FIG. 4 , in the light emitting device, when the straight distance between the pad 92 and the contact electrode 33 is viewed, the first region 10A having the two contact electrodes 33 on a straight line is the second region ( 10B), and the second region 10B may be thinner than the third region 10C. Each of the second and third regions 10B and 10C may have one, two, or more contact electrodes 33 disposed at a straight distance from the pad 92 , but the present invention is not limited thereto. In the embodiment, the size of the region 10A adjacent to the pad 92 among the regions 10A, 10B, and 10C in the light emitting device is large because the difference in resistance is not large, and the regions 10A, 10B, and 10C having a difference in thickness. can be minimized.

Referring to FIG. 5 , the light emitting structure 10 may be arranged in an oblique shape with respect to the pad 92 between the regions 10A, 10B-1, 10B-2, ..., 10C. In each of the regions 10A, 10B-1, 10B-2, ..., 10C, zero, one, or two contact electrodes 33 may be disposed on a straight line extending from the pad 92 . not limited to

At least some of the boundary lines E1 of each of the regions 10A, 10B-1, 10B-2, ..., 10C may be parallel to each other. Comparing the area of the top surface among the regions 10A, 10B-1, 10B-2, ..., 10C, the center region 10B-3 is the widest, and the center region 10B-3 becomes narrower as it moves away from the center region 10B-3. can

In the embodiment, the thickness increases as the distance from the center region 10B-3 in the light emitting device increases, but by reducing the area of the light emitting structure, current aggregation or luminous efficiency in the distant region 10C or an area adjacent thereto decreases. problems can be suppressed.

Referring to FIG. 6 , in the light emitting device, a pad 92 may be disposed adjacent to the center of any one side S1 of the light emitting structure 10 . As the distance from the pad 92 increases, the regions 10A, 10B-1, 10B-2, and 10C of the light emitting structure 10 may gradually thicken. The boundary lines E1 of the regions 10A, 10B-1, 10B-2, and 10C may or may not be parallel to each other. For example, at least one of the boundary lines E1 between the regions 10A, 10B-1, 10B-2, and 10C may have an arc shape or an angular shape, but is not limited thereto.

Such a light emitting device can provide all regions 10A, 10B-1, 10B-2, and 10C of the light emitting structure 10 in a uniform size, thereby improving the effect of current diffusion in the light emitting device.

7 is another example of the light emitting device of FIG.

Referring to FIG. 7 , the light emitting structure 10 of the light emitting device may include a plurality of regions 10A, 10B, and 10C whose thickness is gradually increased as the distance from the pad 92 increases. The plurality of regions 10A, 10B, and 10C may be surfaces C1, C2, and C3 in which a surface corresponding to the pad 92 is inclined. The inclined surfaces C1 , C2 , and C3 may be formed on the first semiconductor layer 11 . The inclined surfaces C1, C2, and C3 may improve light extraction efficiency.

The contact electrodes 33 , 33A and 33B disposed inside each of the plurality of regions 10A, 10B, and 10C may have the same or different thicknesses Ta, Tb, and Tc or the depth of the recess 2 . .

8 is a plan view showing a light emitting device according to a second embodiment, and FIG. 9 is a cross-sectional view taken along the B-B side of the light emitting device of FIG. 8 .

8 and 9 , the light emitting device 100 includes a light emitting structure 10 having a plurality of semiconductor layers 11 , 12 , and 13 , a plurality of contact electrodes 33 in the light emitting structure 10 , and the A first electrode layer 81 having a reflective layer 17 under the light emitting structure 10 , a second electrode layer 83 disposed under the first electrode layer 81 and connected to the contact electrode 33 , and the first and an insulating layer 41 between the second electrode layers 81 and 83 , and a plurality of pads 92 and 92A.

The plurality of pads 92 and 92A may be spaced apart from each other on the outside of the light emitting structure 10 , and may be connected to the second electrode layer 83 disposed under the light emitting structure 10 .

The plurality of pads 92 and 92A are respectively disposed in both edge areas A1 and A2 of either side S2 of the light emitting structure 10 , or opposite corner areas or opposite sides of the light emitting structure 10 . Each may be disposed at the center of the side.

The light emitting structure 10 may include a plurality of regions 10A, 10B, 10C, and 10D that are gradually thickened as the distance from the plurality of pads 92 and 92A increases. The plurality of regions 10A, 10B, 10C, and 10D includes a first region 10A adjacent to each of the pads 92 and 92A, and the first region 10A with respect to each of the pads 92 and 92A. ) may include a second region 10B, and third and fourth regions 10C and 10D disposed outside. The thickness of the first to fourth regions 10A, 10B, 10C, and 10D may satisfy the condition of first region < second region < third region < fourth region. The resistance difference between the first to fourth regions 10A, 10B, 10C, and 10D is prevented from being proportionally increased by the thickness difference, thereby preventing current aggregation in a distant region.

10 is a view showing a light emitting device according to a third embodiment.

Referring to FIG. 10 , the light emitting device 100 includes a light emitting structure 10 having a plurality of semiconductor layers 11 , 12 , 13 , a plurality of contact electrodes 33 in the light emitting structure 10 , and the light emitting structure ( 10) a first electrode layer 81 having a reflective layer 17 underneath, a second electrode layer 83 disposed under the first electrode layer 81 and connected to the contact electrode 33, and the first and second An insulating layer 41 between the electrode layers 81 and 83 , a phosphor layer 150 on the light emitting structure 10 , and a pad 92 may be included.

The light emitting structure 10 includes a plurality of regions 10A, 10B, and 10C having different thicknesses. The plurality of regions 10A, 10B, and 10C may have a thickness T4 < T5 < T6 that becomes thicker as the regions 10A, 10B, and 10C are farther from the pad 92 . ) and may be thickened in proportion to the distance (D2<D3<D4).

The phosphor layer 150 may be disposed on the regions 10A, 10B, and 10C having different thicknesses T4 , T5 , and T6 of the light emitting structure 10 . In the phosphor layer 150 , individual films for each region 10A, 10B, and 10C may be disposed, or a single film may be disposed on all regions 10A, 10B, and 10C.

The phosphor layer 150 includes at least one or a plurality of blue, green, yellow, and red phosphors, and may be disposed in a single layer or in multiple layers. In the phosphor layer 150, a phosphor is added in a light-transmitting resin material. The light-transmitting resin material may include a material such as silicone or epoxy, and the phosphor may be selectively formed from among YAG, TAG, Silicate, Nitride, and Oxy-nitride-based materials.

The phosphor layer 150 may be disposed in each region 10A, 10B, and 10C of the light emitting structure 10 , or may extend on a side surface of the light emitting structure 10 . The phosphor layer 150 may be disposed on the surface of the light emitting structure 10 to convert a wavelength of light.

The phosphor layer 150 may include a single layer or different phosphor layers. In the different phosphor layers, a first layer may have at least one type of red, yellow, or green phosphor, and the second layer may include a single phosphor layer. It is formed on the first layer and may have a phosphor different from that of the first layer among red, yellow, and green phosphors. As another example, the different phosphor layers may include three or more phosphor layers, but is not limited thereto.

As another example, the phosphor layer 150 may include a film type. Since the film-type phosphor layer provides a uniform thickness, color distribution according to wavelength conversion may be uniform.

The light emitting device according to the embodiment may include a plurality of light emitting structures that can be individually driven in one device. Although the embodiment has been described based on a case in which one light emitting structure is disposed in one light emitting device, two or more light emitting structures may be disposed in one light emitting device, and may be implemented to be individually driven. In the light emitting device according to the embodiment, the support member is described as a conductive material, but may be an insulating support member, but is not limited thereto.

The light emitting device as described above may be mounted on a board or mounted on a board after being packaged. Hereinafter, a light emitting device package or a light emitting module having the light emitting device of the embodiment (s) disclosed above will be described.

11 is a cross-sectional view of a light emitting device package including a light emitting device according to an embodiment.

11 , the light emitting device package 500 includes a body 515, a plurality of lead frames 521 and 523 disposed on the body 515, and a plurality of lead frames 521 and 523 disposed on the body 515 ( The light emitting device 100 according to the embodiment is electrically connected to 521 and 523 , and a molding member 531 surrounding the light emitting device 100 is included.

The body 515 may include a conductive substrate such as silicon, a synthetic resin material such as polyphthalamide (PPA), a ceramic substrate, an insulating substrate, or a metal substrate (eg, MCPCB-Metal core PCB). The body 515 may have an inclined surface formed around the light emitting device 100 by the cavity 517 structure. Also, the outer surface of the body 515 may be formed while being vertical or inclined. The body 515 may include a reflective part 513 having a concave cavity 517 with an open top and a support part 511 for supporting the reflective part 513, but is not limited thereto.

Lead frames 521 and 523 and the light emitting device 100 are disposed in the cavity 517 of the body 515 . The plurality of lead frames 521 and 523 includes a first lead frame 521 and a second lead frame 523 spaced apart from each other at the bottom of the cavity 517 . The light emitting device 100 may be disposed on the second lead frame 523 and may be connected to the first lead frame 521 by a connecting member 503 . The first lead frame 521 and the second lead frame 523 are electrically isolated from each other and provide power to the light emitting device 100 . The connecting member 503 may include a wire. In addition, the first lead frame 521 and the second lead frame 523 may reflect the light generated by the light emitting device 100 to increase light efficiency. To this end, a separate reflective layer may be further formed on the first lead frame 521 and the second lead frame 523, but is not limited thereto. In addition, the first and second lead frames 521 and 523 may serve to discharge heat generated by the light emitting device 100 to the outside. The lead part 522 of the first lead frame 521 and the lead part 524 of the second lead frame 523 may be disposed on a lower surface of the body 515 .

The first and second lead frames 521 and 523 are made of a metal material, for example, titanium (Ti), copper (Cu), nickel (Ni), gold (Au), chromium (Cr), tantalum (Ta), It may include at least one of platinum (Pt), tin (Sn), silver (Ag), and phosphorus (P). In addition, the first and second lead frames 521 and 523 may be formed to have a single-layer or multi-layer structure, but are not limited thereto.

The molding member 531 may include a resin material such as silicone or epoxy, and may surround the light emitting device 100 to protect the light emitting device 100 . In addition, the molding member 531 may include a phosphor to change the wavelength of light emitted from the light emitting device 100 . The phosphor may be selectively formed from YAG, TAG, Silicate, Nitride, and Oxy-nitride-based materials. The phosphor includes at least one of a red phosphor, a yellow phosphor, and a green phosphor. The molding member 531 may have a flat upper surface, or a concave or convex shape.

A lens may be disposed on the molding member 531 , and the lens may be implemented in a form that is in contact with or not in contact with the molding member 531 . The lens may include a concave or convex shape. The molding member 531 may have a flat, convex, or concave upper surface, but is not limited thereto.

A plurality of light emitting devices or light emitting device packages according to the embodiment may be arrayed on a substrate, and optical members such as lenses, light guide plates, prism sheets, diffusion sheets, etc. may be disposed on a light path of the light emitting device package. Such a light emitting device package, a substrate, and an optical member may function as a light unit. The light unit may be implemented as a top view or side view type, and may be provided to display devices such as portable terminals and notebook computers, or may be variously applied to lighting devices and indicator devices. Another embodiment may be implemented as a lighting device including the light emitting device or the light emitting device package described in the above-described embodiments. For example, the lighting device may include a lamp, a street lamp, an electric billboard, and a headlamp.

Features, structures, effects, etc. described in the above embodiments are included in at least one embodiment of the present invention, and are not necessarily limited to only one embodiment. Furthermore, features, structures, effects, etc. illustrated in each embodiment can be combined or modified for other embodiments by a person skilled in the art to which the embodiments belong. Accordingly, the contents related to such combinations and modifications should be interpreted as being included in the scope of the present invention.

In addition, although the embodiment has been described above, it is merely an example and does not limit the present invention, and those of ordinary skill in the art to which the present invention pertains are exemplified above in a range that does not depart from the essential characteristics of the present embodiment. It can be seen that various modifications and applications that have not been made are possible. For example, each component specifically shown in the embodiment can be implemented by modification. And differences related to such modifications and applications should be construed as being included in the scope of the present invention defined in the appended claims.

10: light emitting structure 10A, 10B, 10C: region
11: first semiconductor layer 12: active layer
13: second semiconductor layer 15: first contact layer
17: reflective layer 30: protective layer
33: contact electrode 35: capping layer
41: insulating layer 50: diffusion barrier layer
60: bonding layer 70: support member
81: first electrode layer 83: second electrode layer
92: pad 95: passivation layer

Claims (14)

a light emitting structure including a first semiconductor layer, an active layer under the first semiconductor layer, and a second semiconductor layer under the active layer;
a plurality of contact electrodes in contact with different regions of the first semiconductor layer within the first semiconductor layer;
a first electrode layer disposed between the second semiconductor layer and the second electrode layer, connected to the second semiconductor layer, and having a plurality of conductive layers;
the second electrode layer disposed under the light emitting structure, connected to the plurality of contact electrodes, and having a plurality of conductive layers;
a pad connected to at least one of the plurality of conductive layers of the first electrode layer and disposed outside the light emitting structure; and
and a conductive support member under the second electrode layer,
In the light emitting structure, a thickness of a region having a far distance between the light emitting structure and the pad has a greater thickness than a thickness of a region having a close distance between the light emitting structure and the pad,
The thickness of the light emitting structure is a distance between the upper surface of the first semiconductor layer and the lower surface of the second semiconductor layer in each region of the light emitting structure. According to claim 1,
In the first semiconductor layer, a thickness of a region having a greater distance between the first semiconductor layer and the pad is greater than a thickness of a region having a short distance between the semiconductor layer and the pad, and
The thickness of the first semiconductor layer is the distance from the lower surface to the upper surface in each region of the first semiconductor layer,
A light emitting device in which the plurality of contact electrodes are in contact with regions having different thicknesses in the first semiconductor layer. According to claim 1,
In the first semiconductor layer, a height of a top surface of a region close to the pad is lower than a top surface height of a region far from the pad with respect to a bottom surface of the first semiconductor layer,
In the first semiconductor layer, there are at least three regions having different top surface heights,
A light emitting device in which the plurality of contact electrodes are in contact with regions having different top surface heights in the first semiconductor layer. 4. The method of claim 2 or 3,
The light emitting structure includes a plurality of recesses having the same depth from the lower surface of the light emitting structure,
each of the plurality of contact electrodes is disposed in each of the plurality of recesses. 4. The method of claim 2 or 3,
a passivation layer disposed on the surface of the light emitting structure; and an insulating layer disposed between the first and second electrode layers,
The first electrode layer includes a reflective layer,
The pad is a light emitting device disposed in the center of at least one side of the light emitting structure or at least one corner region of any one side.

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